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000
FXUS63 KDMX 312138
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
338 PM CST SAT JAN 31 2015

.SHORT TERM /TONIGHT/...
ISSUED AT 329 PM CST SAT JAN 31 2015

MAIN CONCERNS CONTINUE THE TIMING OF THE CHANGEOVER AND EVENTUAL
SNOWFALL RATES/AMOUNTS IN THE NEXT 12 TO 24 HOURS. WILL CONTINUE
WITH HEADLINES FOR LONG DURATION EVENT WITH SNOWFALL RATES OF NEAR
1/2 INCH OR SLIGHTLY HIGHER PER HOUR OVERNIGHT ONCE THE MIX CHANGES
OVER TO ALL SNOW. A SURFACE BOUNDARY CONTINUES OVER THE REGION FROM
CARROLL TO NEAR WATERLOO AT 20Z. TEMPERATURES NORTHWEST OF THE
BOUNDARY HAVE COOLED A FEW DEGREES AND THE PRECIPITATION HAS CHANGED
OVER TO SNOW THERE. THE BOUNDARY CONTINUES TO DRIFT SOUTH THIS
EVENING AS ISENTROPIC LIFT INCREASES AS THE H850 APPROACHES FROM THE
SOUTHWEST. BY 06Z THE LOW WILL BE OVER NORTHERN KS WITH MODEST LIFT
CONTINUING INTO THE BOUNDARY OVERNIGHT. INITIALLY THE BETTER LIFT IS
ABOVE THE DENDRITIC LAYER SOUTH OF INTERSTATE 80 BEFORE 03Z. AFTER
03Z A BROAD ZONE OF MODEST LIFT DEVELOPS IN THE DENDRITIC LAYER AND
CONTINUES THROUGH SUNDAY. LOOKING AT A XSECT FROM CARROLL...ACROSS
THE WEST AND NORTHWEST THERE IS ALREADY SOME LIFT IN THE DENDRITIC
LAYER WHICH GENERALLY REMAINS MODEST DURING THE EVENING AND
OVERNIGHT HOURS. AS THE LOW DEEPENS SATURDAY MORNING THERE IS ALSO A
HINT AT A DEFORMATION AXIS AND WEAK TROWAL DEVELOPING OVER SOUTH
CENTRAL TOWARD EAST CENTRAL AREAS. THIS MAY HELP TO ENHANCE SNOWFALL
AMOUNTS ALONG INTERSTATE 80 JUST TO THE EAST OF DES MOINES AFT 06Z
THROUGH SUNDAY MORNING. OVERALL...SNOWFALL AMOUNTS SHOULD BE HIGHER
ACROSS THIS AREA FOR THE STORM TOTAL. MODEL QPF HAS BEEN GENERALLY
CONSISTENT WITH A RANGE OF .35 NORTHWEST TO NEAR 0.70 SOUTH/EAST
OVERNIGHT. WITH SNOWFALL RATIOS OF 12 TO 14 OVERNIGHT...ABOUT 4 TO
NEARLY 7 INCHES OF SNOW IS LIKELY BY 12Z SUNDAY GIVEN SOME OF THE
PRECIP WILL FALL FIRST AS RAIN...SOME MELTING AND COMPACTION ISSUES
AS WELL. WINDS OVERNIGHT REMAIN MODEST INITIALLY BETWEEN 10 TO 15
MPH THROUGH 12Z SOUTHEAST BUT INCREASE OVER NORTHERN AND
NORTHEASTERN SECTIONS TO 15 TO 20 MPH TOWARD 12Z. GIVEN THE WET
NATURE OF THE SNOW SOME BLOWING AND SETTLING WILL OCCUR...BUT NOT
EXPECTING MORE THAN PATCHY BLOWING SNOW UNTIL 12Z NORTHWEST
SECTIONS. ELSEWHERE ACROSS THE SOUTH THIS SHOULDN`T POSE ANY
ADDITIONAL ISSUES. WITH TEMPERATURES BEGINNING ABOVE FREEZING IN THE
SOUTHEAST/SOUTH AND DROPPING THIS EVENING...ROADS MAY BECOME
SLUSHY/SLICK PRIOR TO SNOWFALL ACCUMULATING TO A GREAT DEGREE. THUS
TRAVEL MAY BECOME HAZARDOUS EARLY DUE TO THIS RATHER THAN COMPLETELY
SNOW COVERED ROADS INITIALLY.

.LONG TERM /SUNDAY THROUGH SATURDAY/...
ISSUED AT 329 PM CST SAT JAN 31 2015

SNOW WILL BE ONGOING SUNDAY AS THE SURFACE LOW SLOWLY DRIFTS EASTERN
MISSOURI.  THE SNOW WILL GRADUALLY END FROM NORTHWEST TO SOUTHEAST
THROUGH THE DAY BUT SHOULD LINGER IN THE SOUTHEAST FOR A FAIR
PORTION OF THE AFTERNOON.  THE UPPER LEVEL WAVE WILL TAKE ITS TIME
PUSHING EAST AND BY 18Z IT WILL BARELY BE ACROSS THE MID SECTION OF
THE STATE.  THE BRUNT OF THE FORCING WILL BE EXITING THE EAST
SHORTLY AFTER 18Z SO THE HEAVIEST SNOW WILL FALL BY THEN BUT WE WILL
STILL SEE LIGHT ACCUMULATIONS IN THE SOUTHEAST THROUGH THE MID-
AFTERNOON.  BETWEEN 6AM AND 6 PM WE WILL GET ANOTHER 2 TO 4 INCHES
ACROSS THE SOUTHEAST.  I HAVE LINGERED SNOW IN THE FAR SOUTHEAST
THROUGH EARLY EVENING.  ALTHOUGH WE LOSE MOST OF THE FORCING...THE
GFS HANGS ON TO SOME OF IT ACROSS OUR AREA IN THE 700-500 MB LAYER
AND THE AXIS OF THE UPPER LEVEL WAVE WILL STILL BE IN THE FAR
SOUTHEAST PORTION OF THE FORECAST AREA.

WINDS CONTINUE FOR SUNDAY NIGHT AND MONDAY WITH WIND CHILLS SOLIDLY
IN THE -10 TO -20 RANGE THROUGH MONDAY MORNING.  WHILE THIS IS NOT
QUITE ADVISORY CRITERIA IT WILL BE COLD.

THE PATTERN REMAINS ACTIVE THROUGH MUCH OF THE LONG TERM PERIOD.
ALL THE MODELS ARE DEPICTING ANOTHER SHORTWAVE DROPPING DOWN THE NW
FLOW OVER THE REGION.  THIS ONE IS NOT ANY WHERE NEAR THE STRENGTH
OF THE WEEKEND SYSTEM BUT THERE IS SOME FORCING WITH IT AND WHILE
MOISTURE IS LACKING THERE SHOULD BE ENOUGH FORCING TO SQUEAK OUT
SOME LIGHT SNOW MONDAY AFTERNOON THROUGH MONDAY EVENING.

AFTER THAT PASSES A LOW DEVELOPING IN THE PLAINS AND A WARM FRONT
WILL TRY TO ESTABLISH ITSELF ACROSS MISSOURI.  WHILE WE WILL NOT SEE
THE REAL WARM AIR WE WILL BE CONSIDERABLY WARMER TUESDAY THAN WE WILL
BE ON MONDAY.  HOWEVER...I THINK MODELS ARE A BIT OPTIMISTIC WITH
ALL THE FRESH SNOW COVER. ANOTHER SHORTWAVE DROPS DOWN INTO THE
STATE ON TUESDAY AND WITH THE WARM ADVECTION WILL COME A LITTLE
BETTER MOISTURE SO WE WILL BE SEEING SOME MEASURABLE SNOW AGAIN
TUESDAY AFTERNOON INTO THE EVENING.

CANADIAN HIGH PRESSURE WILL THEN SETTLE INTO THE STATE FOR WEDNESDAY
INTO THURSDAY AND MORE COLD AIR WILL BE IN PLACE.  TEMPS GO INTO THE
COOLER AGAIN WITH HIGHS IN THE TEENS AND 20S AND LOWS IN THE SINGLE
DIGITS ABOVE AND BELOW ZERO.

ANOTHER SHORT WAVE WAS SUGGESTED BY SOME OF THE MEDIUM RANGE MODELS
FOR THURSDAY/FRIDAY BUT THERE WAS NO CONSENSUS ON PRECIP AND SINCE
FORECAST SOUNDINGS WERE VERY DRY I LEFT PRECIP OUT OF THIS PERIOD.

FOR THE START OF THE WEEKEND ANOTHER SURFACE LOW AND WARM FRONT
DEVELOPS OVER THE PLAINS AND THIS TIME THE BOUNDARY SHIFTS INTO
IOWA.  TEMPS WILL BE WARMER ONCE AGAIN...BUT TEMPERED BY GROUND
COVER OF THE PREVIOUS SNOWS.

&&

.AVIATION...31/18Z
ISSUED AT 1155 AM CST SAT JAN 31 2015

RAIN SHIELD MOVING NORTHEAST WITH STORM THIS AFTERNOON. EXPECTING
CIGS TO LOWER QUICKLY TO MVFR/IFR BY 00Z MOST AREAS AND REMAIN IFR
FOR THE BALANCE OF THE FORECAST. VSBY BEGINS TO DROP WITH SNOW
ESPECIALLY AFT 10Z WEST AND LOWERING EAST AS LOW BEGINS TO PULL
INTO EASTERN IOWA AFT 12Z SUNDAY. SNOW AND BLOWING SNOW WILL
INCREASE WITH NNE WINDS OF 17 GUST 28KTS BY LATE MORNING. EXPECT
VSBY TO LOWER TO 1SM AT TIMES THROUGH 18Z SUNDAY. /REV


&&

.DMX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING FROM 7 PM THIS EVENING TO 9 PM CST SUNDAY
FOR ADAIR-ADAMS-APPANOOSE-AUDUBON-BLACK HAWK-BOONE-BREMER-BUTLER-
CALHOUN-CARROLL-CASS-CLARKE-CRAWFORD-DALLAS-DAVIS-DECATUR-
FRANKLIN-GREENE-GRUNDY-GUTHRIE-HAMILTON-HARDIN-HUMBOLDT-JASPER-
LUCAS-MADISON-MAHASKA-MARION-MARSHALL-MONROE-POCAHONTAS-POLK-
POWESHIEK-RINGGOLD-SAC-STORY-TAMA-TAYLOR-UNION-WAPELLO-WARREN-
WAYNE-WEBSTER-WRIGHT.

WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 9 PM CST
SUNDAY FOR CERRO GORDO-EMMET-HANCOCK-KOSSUTH-PALO ALTO-WINNEBAGO-
WORTH.

&&

$$

SHORT TERM...REV
LONG TERM...FAB
AVIATION...REV




000
FXUS63 KDMX 312138
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
338 PM CST SAT JAN 31 2015

.SHORT TERM /TONIGHT/...
ISSUED AT 329 PM CST SAT JAN 31 2015

MAIN CONCERNS CONTINUE THE TIMING OF THE CHANGEOVER AND EVENTUAL
SNOWFALL RATES/AMOUNTS IN THE NEXT 12 TO 24 HOURS. WILL CONTINUE
WITH HEADLINES FOR LONG DURATION EVENT WITH SNOWFALL RATES OF NEAR
1/2 INCH OR SLIGHTLY HIGHER PER HOUR OVERNIGHT ONCE THE MIX CHANGES
OVER TO ALL SNOW. A SURFACE BOUNDARY CONTINUES OVER THE REGION FROM
CARROLL TO NEAR WATERLOO AT 20Z. TEMPERATURES NORTHWEST OF THE
BOUNDARY HAVE COOLED A FEW DEGREES AND THE PRECIPITATION HAS CHANGED
OVER TO SNOW THERE. THE BOUNDARY CONTINUES TO DRIFT SOUTH THIS
EVENING AS ISENTROPIC LIFT INCREASES AS THE H850 APPROACHES FROM THE
SOUTHWEST. BY 06Z THE LOW WILL BE OVER NORTHERN KS WITH MODEST LIFT
CONTINUING INTO THE BOUNDARY OVERNIGHT. INITIALLY THE BETTER LIFT IS
ABOVE THE DENDRITIC LAYER SOUTH OF INTERSTATE 80 BEFORE 03Z. AFTER
03Z A BROAD ZONE OF MODEST LIFT DEVELOPS IN THE DENDRITIC LAYER AND
CONTINUES THROUGH SUNDAY. LOOKING AT A XSECT FROM CARROLL...ACROSS
THE WEST AND NORTHWEST THERE IS ALREADY SOME LIFT IN THE DENDRITIC
LAYER WHICH GENERALLY REMAINS MODEST DURING THE EVENING AND
OVERNIGHT HOURS. AS THE LOW DEEPENS SATURDAY MORNING THERE IS ALSO A
HINT AT A DEFORMATION AXIS AND WEAK TROWAL DEVELOPING OVER SOUTH
CENTRAL TOWARD EAST CENTRAL AREAS. THIS MAY HELP TO ENHANCE SNOWFALL
AMOUNTS ALONG INTERSTATE 80 JUST TO THE EAST OF DES MOINES AFT 06Z
THROUGH SUNDAY MORNING. OVERALL...SNOWFALL AMOUNTS SHOULD BE HIGHER
ACROSS THIS AREA FOR THE STORM TOTAL. MODEL QPF HAS BEEN GENERALLY
CONSISTENT WITH A RANGE OF .35 NORTHWEST TO NEAR 0.70 SOUTH/EAST
OVERNIGHT. WITH SNOWFALL RATIOS OF 12 TO 14 OVERNIGHT...ABOUT 4 TO
NEARLY 7 INCHES OF SNOW IS LIKELY BY 12Z SUNDAY GIVEN SOME OF THE
PRECIP WILL FALL FIRST AS RAIN...SOME MELTING AND COMPACTION ISSUES
AS WELL. WINDS OVERNIGHT REMAIN MODEST INITIALLY BETWEEN 10 TO 15
MPH THROUGH 12Z SOUTHEAST BUT INCREASE OVER NORTHERN AND
NORTHEASTERN SECTIONS TO 15 TO 20 MPH TOWARD 12Z. GIVEN THE WET
NATURE OF THE SNOW SOME BLOWING AND SETTLING WILL OCCUR...BUT NOT
EXPECTING MORE THAN PATCHY BLOWING SNOW UNTIL 12Z NORTHWEST
SECTIONS. ELSEWHERE ACROSS THE SOUTH THIS SHOULDN`T POSE ANY
ADDITIONAL ISSUES. WITH TEMPERATURES BEGINNING ABOVE FREEZING IN THE
SOUTHEAST/SOUTH AND DROPPING THIS EVENING...ROADS MAY BECOME
SLUSHY/SLICK PRIOR TO SNOWFALL ACCUMULATING TO A GREAT DEGREE. THUS
TRAVEL MAY BECOME HAZARDOUS EARLY DUE TO THIS RATHER THAN COMPLETELY
SNOW COVERED ROADS INITIALLY.

.LONG TERM /SUNDAY THROUGH SATURDAY/...
ISSUED AT 329 PM CST SAT JAN 31 2015

SNOW WILL BE ONGOING SUNDAY AS THE SURFACE LOW SLOWLY DRIFTS EASTERN
MISSOURI.  THE SNOW WILL GRADUALLY END FROM NORTHWEST TO SOUTHEAST
THROUGH THE DAY BUT SHOULD LINGER IN THE SOUTHEAST FOR A FAIR
PORTION OF THE AFTERNOON.  THE UPPER LEVEL WAVE WILL TAKE ITS TIME
PUSHING EAST AND BY 18Z IT WILL BARELY BE ACROSS THE MID SECTION OF
THE STATE.  THE BRUNT OF THE FORCING WILL BE EXITING THE EAST
SHORTLY AFTER 18Z SO THE HEAVIEST SNOW WILL FALL BY THEN BUT WE WILL
STILL SEE LIGHT ACCUMULATIONS IN THE SOUTHEAST THROUGH THE MID-
AFTERNOON.  BETWEEN 6AM AND 6 PM WE WILL GET ANOTHER 2 TO 4 INCHES
ACROSS THE SOUTHEAST.  I HAVE LINGERED SNOW IN THE FAR SOUTHEAST
THROUGH EARLY EVENING.  ALTHOUGH WE LOSE MOST OF THE FORCING...THE
GFS HANGS ON TO SOME OF IT ACROSS OUR AREA IN THE 700-500 MB LAYER
AND THE AXIS OF THE UPPER LEVEL WAVE WILL STILL BE IN THE FAR
SOUTHEAST PORTION OF THE FORECAST AREA.

WINDS CONTINUE FOR SUNDAY NIGHT AND MONDAY WITH WIND CHILLS SOLIDLY
IN THE -10 TO -20 RANGE THROUGH MONDAY MORNING.  WHILE THIS IS NOT
QUITE ADVISORY CRITERIA IT WILL BE COLD.

THE PATTERN REMAINS ACTIVE THROUGH MUCH OF THE LONG TERM PERIOD.
ALL THE MODELS ARE DEPICTING ANOTHER SHORTWAVE DROPPING DOWN THE NW
FLOW OVER THE REGION.  THIS ONE IS NOT ANY WHERE NEAR THE STRENGTH
OF THE WEEKEND SYSTEM BUT THERE IS SOME FORCING WITH IT AND WHILE
MOISTURE IS LACKING THERE SHOULD BE ENOUGH FORCING TO SQUEAK OUT
SOME LIGHT SNOW MONDAY AFTERNOON THROUGH MONDAY EVENING.

AFTER THAT PASSES A LOW DEVELOPING IN THE PLAINS AND A WARM FRONT
WILL TRY TO ESTABLISH ITSELF ACROSS MISSOURI.  WHILE WE WILL NOT SEE
THE REAL WARM AIR WE WILL BE CONSIDERABLY WARMER TUESDAY THAN WE WILL
BE ON MONDAY.  HOWEVER...I THINK MODELS ARE A BIT OPTIMISTIC WITH
ALL THE FRESH SNOW COVER. ANOTHER SHORTWAVE DROPS DOWN INTO THE
STATE ON TUESDAY AND WITH THE WARM ADVECTION WILL COME A LITTLE
BETTER MOISTURE SO WE WILL BE SEEING SOME MEASURABLE SNOW AGAIN
TUESDAY AFTERNOON INTO THE EVENING.

CANADIAN HIGH PRESSURE WILL THEN SETTLE INTO THE STATE FOR WEDNESDAY
INTO THURSDAY AND MORE COLD AIR WILL BE IN PLACE.  TEMPS GO INTO THE
COOLER AGAIN WITH HIGHS IN THE TEENS AND 20S AND LOWS IN THE SINGLE
DIGITS ABOVE AND BELOW ZERO.

ANOTHER SHORT WAVE WAS SUGGESTED BY SOME OF THE MEDIUM RANGE MODELS
FOR THURSDAY/FRIDAY BUT THERE WAS NO CONSENSUS ON PRECIP AND SINCE
FORECAST SOUNDINGS WERE VERY DRY I LEFT PRECIP OUT OF THIS PERIOD.

FOR THE START OF THE WEEKEND ANOTHER SURFACE LOW AND WARM FRONT
DEVELOPS OVER THE PLAINS AND THIS TIME THE BOUNDARY SHIFTS INTO
IOWA.  TEMPS WILL BE WARMER ONCE AGAIN...BUT TEMPERED BY GROUND
COVER OF THE PREVIOUS SNOWS.

&&

.AVIATION...31/18Z
ISSUED AT 1155 AM CST SAT JAN 31 2015

RAIN SHIELD MOVING NORTHEAST WITH STORM THIS AFTERNOON. EXPECTING
CIGS TO LOWER QUICKLY TO MVFR/IFR BY 00Z MOST AREAS AND REMAIN IFR
FOR THE BALANCE OF THE FORECAST. VSBY BEGINS TO DROP WITH SNOW
ESPECIALLY AFT 10Z WEST AND LOWERING EAST AS LOW BEGINS TO PULL
INTO EASTERN IOWA AFT 12Z SUNDAY. SNOW AND BLOWING SNOW WILL
INCREASE WITH NNE WINDS OF 17 GUST 28KTS BY LATE MORNING. EXPECT
VSBY TO LOWER TO 1SM AT TIMES THROUGH 18Z SUNDAY. /REV


&&

.DMX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING FROM 7 PM THIS EVENING TO 9 PM CST SUNDAY
FOR ADAIR-ADAMS-APPANOOSE-AUDUBON-BLACK HAWK-BOONE-BREMER-BUTLER-
CALHOUN-CARROLL-CASS-CLARKE-CRAWFORD-DALLAS-DAVIS-DECATUR-
FRANKLIN-GREENE-GRUNDY-GUTHRIE-HAMILTON-HARDIN-HUMBOLDT-JASPER-
LUCAS-MADISON-MAHASKA-MARION-MARSHALL-MONROE-POCAHONTAS-POLK-
POWESHIEK-RINGGOLD-SAC-STORY-TAMA-TAYLOR-UNION-WAPELLO-WARREN-
WAYNE-WEBSTER-WRIGHT.

WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 9 PM CST
SUNDAY FOR CERRO GORDO-EMMET-HANCOCK-KOSSUTH-PALO ALTO-WINNEBAGO-
WORTH.

&&

$$

SHORT TERM...REV
LONG TERM...FAB
AVIATION...REV





000
FXUS63 KDMX 312138
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
338 PM CST SAT JAN 31 2015

.SHORT TERM /TONIGHT/...
ISSUED AT 329 PM CST SAT JAN 31 2015

MAIN CONCERNS CONTINUE THE TIMING OF THE CHANGEOVER AND EVENTUAL
SNOWFALL RATES/AMOUNTS IN THE NEXT 12 TO 24 HOURS. WILL CONTINUE
WITH HEADLINES FOR LONG DURATION EVENT WITH SNOWFALL RATES OF NEAR
1/2 INCH OR SLIGHTLY HIGHER PER HOUR OVERNIGHT ONCE THE MIX CHANGES
OVER TO ALL SNOW. A SURFACE BOUNDARY CONTINUES OVER THE REGION FROM
CARROLL TO NEAR WATERLOO AT 20Z. TEMPERATURES NORTHWEST OF THE
BOUNDARY HAVE COOLED A FEW DEGREES AND THE PRECIPITATION HAS CHANGED
OVER TO SNOW THERE. THE BOUNDARY CONTINUES TO DRIFT SOUTH THIS
EVENING AS ISENTROPIC LIFT INCREASES AS THE H850 APPROACHES FROM THE
SOUTHWEST. BY 06Z THE LOW WILL BE OVER NORTHERN KS WITH MODEST LIFT
CONTINUING INTO THE BOUNDARY OVERNIGHT. INITIALLY THE BETTER LIFT IS
ABOVE THE DENDRITIC LAYER SOUTH OF INTERSTATE 80 BEFORE 03Z. AFTER
03Z A BROAD ZONE OF MODEST LIFT DEVELOPS IN THE DENDRITIC LAYER AND
CONTINUES THROUGH SUNDAY. LOOKING AT A XSECT FROM CARROLL...ACROSS
THE WEST AND NORTHWEST THERE IS ALREADY SOME LIFT IN THE DENDRITIC
LAYER WHICH GENERALLY REMAINS MODEST DURING THE EVENING AND
OVERNIGHT HOURS. AS THE LOW DEEPENS SATURDAY MORNING THERE IS ALSO A
HINT AT A DEFORMATION AXIS AND WEAK TROWAL DEVELOPING OVER SOUTH
CENTRAL TOWARD EAST CENTRAL AREAS. THIS MAY HELP TO ENHANCE SNOWFALL
AMOUNTS ALONG INTERSTATE 80 JUST TO THE EAST OF DES MOINES AFT 06Z
THROUGH SUNDAY MORNING. OVERALL...SNOWFALL AMOUNTS SHOULD BE HIGHER
ACROSS THIS AREA FOR THE STORM TOTAL. MODEL QPF HAS BEEN GENERALLY
CONSISTENT WITH A RANGE OF .35 NORTHWEST TO NEAR 0.70 SOUTH/EAST
OVERNIGHT. WITH SNOWFALL RATIOS OF 12 TO 14 OVERNIGHT...ABOUT 4 TO
NEARLY 7 INCHES OF SNOW IS LIKELY BY 12Z SUNDAY GIVEN SOME OF THE
PRECIP WILL FALL FIRST AS RAIN...SOME MELTING AND COMPACTION ISSUES
AS WELL. WINDS OVERNIGHT REMAIN MODEST INITIALLY BETWEEN 10 TO 15
MPH THROUGH 12Z SOUTHEAST BUT INCREASE OVER NORTHERN AND
NORTHEASTERN SECTIONS TO 15 TO 20 MPH TOWARD 12Z. GIVEN THE WET
NATURE OF THE SNOW SOME BLOWING AND SETTLING WILL OCCUR...BUT NOT
EXPECTING MORE THAN PATCHY BLOWING SNOW UNTIL 12Z NORTHWEST
SECTIONS. ELSEWHERE ACROSS THE SOUTH THIS SHOULDN`T POSE ANY
ADDITIONAL ISSUES. WITH TEMPERATURES BEGINNING ABOVE FREEZING IN THE
SOUTHEAST/SOUTH AND DROPPING THIS EVENING...ROADS MAY BECOME
SLUSHY/SLICK PRIOR TO SNOWFALL ACCUMULATING TO A GREAT DEGREE. THUS
TRAVEL MAY BECOME HAZARDOUS EARLY DUE TO THIS RATHER THAN COMPLETELY
SNOW COVERED ROADS INITIALLY.

.LONG TERM /SUNDAY THROUGH SATURDAY/...
ISSUED AT 329 PM CST SAT JAN 31 2015

SNOW WILL BE ONGOING SUNDAY AS THE SURFACE LOW SLOWLY DRIFTS EASTERN
MISSOURI.  THE SNOW WILL GRADUALLY END FROM NORTHWEST TO SOUTHEAST
THROUGH THE DAY BUT SHOULD LINGER IN THE SOUTHEAST FOR A FAIR
PORTION OF THE AFTERNOON.  THE UPPER LEVEL WAVE WILL TAKE ITS TIME
PUSHING EAST AND BY 18Z IT WILL BARELY BE ACROSS THE MID SECTION OF
THE STATE.  THE BRUNT OF THE FORCING WILL BE EXITING THE EAST
SHORTLY AFTER 18Z SO THE HEAVIEST SNOW WILL FALL BY THEN BUT WE WILL
STILL SEE LIGHT ACCUMULATIONS IN THE SOUTHEAST THROUGH THE MID-
AFTERNOON.  BETWEEN 6AM AND 6 PM WE WILL GET ANOTHER 2 TO 4 INCHES
ACROSS THE SOUTHEAST.  I HAVE LINGERED SNOW IN THE FAR SOUTHEAST
THROUGH EARLY EVENING.  ALTHOUGH WE LOSE MOST OF THE FORCING...THE
GFS HANGS ON TO SOME OF IT ACROSS OUR AREA IN THE 700-500 MB LAYER
AND THE AXIS OF THE UPPER LEVEL WAVE WILL STILL BE IN THE FAR
SOUTHEAST PORTION OF THE FORECAST AREA.

WINDS CONTINUE FOR SUNDAY NIGHT AND MONDAY WITH WIND CHILLS SOLIDLY
IN THE -10 TO -20 RANGE THROUGH MONDAY MORNING.  WHILE THIS IS NOT
QUITE ADVISORY CRITERIA IT WILL BE COLD.

THE PATTERN REMAINS ACTIVE THROUGH MUCH OF THE LONG TERM PERIOD.
ALL THE MODELS ARE DEPICTING ANOTHER SHORTWAVE DROPPING DOWN THE NW
FLOW OVER THE REGION.  THIS ONE IS NOT ANY WHERE NEAR THE STRENGTH
OF THE WEEKEND SYSTEM BUT THERE IS SOME FORCING WITH IT AND WHILE
MOISTURE IS LACKING THERE SHOULD BE ENOUGH FORCING TO SQUEAK OUT
SOME LIGHT SNOW MONDAY AFTERNOON THROUGH MONDAY EVENING.

AFTER THAT PASSES A LOW DEVELOPING IN THE PLAINS AND A WARM FRONT
WILL TRY TO ESTABLISH ITSELF ACROSS MISSOURI.  WHILE WE WILL NOT SEE
THE REAL WARM AIR WE WILL BE CONSIDERABLY WARMER TUESDAY THAN WE WILL
BE ON MONDAY.  HOWEVER...I THINK MODELS ARE A BIT OPTIMISTIC WITH
ALL THE FRESH SNOW COVER. ANOTHER SHORTWAVE DROPS DOWN INTO THE
STATE ON TUESDAY AND WITH THE WARM ADVECTION WILL COME A LITTLE
BETTER MOISTURE SO WE WILL BE SEEING SOME MEASURABLE SNOW AGAIN
TUESDAY AFTERNOON INTO THE EVENING.

CANADIAN HIGH PRESSURE WILL THEN SETTLE INTO THE STATE FOR WEDNESDAY
INTO THURSDAY AND MORE COLD AIR WILL BE IN PLACE.  TEMPS GO INTO THE
COOLER AGAIN WITH HIGHS IN THE TEENS AND 20S AND LOWS IN THE SINGLE
DIGITS ABOVE AND BELOW ZERO.

ANOTHER SHORT WAVE WAS SUGGESTED BY SOME OF THE MEDIUM RANGE MODELS
FOR THURSDAY/FRIDAY BUT THERE WAS NO CONSENSUS ON PRECIP AND SINCE
FORECAST SOUNDINGS WERE VERY DRY I LEFT PRECIP OUT OF THIS PERIOD.

FOR THE START OF THE WEEKEND ANOTHER SURFACE LOW AND WARM FRONT
DEVELOPS OVER THE PLAINS AND THIS TIME THE BOUNDARY SHIFTS INTO
IOWA.  TEMPS WILL BE WARMER ONCE AGAIN...BUT TEMPERED BY GROUND
COVER OF THE PREVIOUS SNOWS.

&&

.AVIATION...31/18Z
ISSUED AT 1155 AM CST SAT JAN 31 2015

RAIN SHIELD MOVING NORTHEAST WITH STORM THIS AFTERNOON. EXPECTING
CIGS TO LOWER QUICKLY TO MVFR/IFR BY 00Z MOST AREAS AND REMAIN IFR
FOR THE BALANCE OF THE FORECAST. VSBY BEGINS TO DROP WITH SNOW
ESPECIALLY AFT 10Z WEST AND LOWERING EAST AS LOW BEGINS TO PULL
INTO EASTERN IOWA AFT 12Z SUNDAY. SNOW AND BLOWING SNOW WILL
INCREASE WITH NNE WINDS OF 17 GUST 28KTS BY LATE MORNING. EXPECT
VSBY TO LOWER TO 1SM AT TIMES THROUGH 18Z SUNDAY. /REV


&&

.DMX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING FROM 7 PM THIS EVENING TO 9 PM CST SUNDAY
FOR ADAIR-ADAMS-APPANOOSE-AUDUBON-BLACK HAWK-BOONE-BREMER-BUTLER-
CALHOUN-CARROLL-CASS-CLARKE-CRAWFORD-DALLAS-DAVIS-DECATUR-
FRANKLIN-GREENE-GRUNDY-GUTHRIE-HAMILTON-HARDIN-HUMBOLDT-JASPER-
LUCAS-MADISON-MAHASKA-MARION-MARSHALL-MONROE-POCAHONTAS-POLK-
POWESHIEK-RINGGOLD-SAC-STORY-TAMA-TAYLOR-UNION-WAPELLO-WARREN-
WAYNE-WEBSTER-WRIGHT.

WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 9 PM CST
SUNDAY FOR CERRO GORDO-EMMET-HANCOCK-KOSSUTH-PALO ALTO-WINNEBAGO-
WORTH.

&&

$$

SHORT TERM...REV
LONG TERM...FAB
AVIATION...REV





000
FXUS63 KDMX 312138
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
338 PM CST SAT JAN 31 2015

.SHORT TERM /TONIGHT/...
ISSUED AT 329 PM CST SAT JAN 31 2015

MAIN CONCERNS CONTINUE THE TIMING OF THE CHANGEOVER AND EVENTUAL
SNOWFALL RATES/AMOUNTS IN THE NEXT 12 TO 24 HOURS. WILL CONTINUE
WITH HEADLINES FOR LONG DURATION EVENT WITH SNOWFALL RATES OF NEAR
1/2 INCH OR SLIGHTLY HIGHER PER HOUR OVERNIGHT ONCE THE MIX CHANGES
OVER TO ALL SNOW. A SURFACE BOUNDARY CONTINUES OVER THE REGION FROM
CARROLL TO NEAR WATERLOO AT 20Z. TEMPERATURES NORTHWEST OF THE
BOUNDARY HAVE COOLED A FEW DEGREES AND THE PRECIPITATION HAS CHANGED
OVER TO SNOW THERE. THE BOUNDARY CONTINUES TO DRIFT SOUTH THIS
EVENING AS ISENTROPIC LIFT INCREASES AS THE H850 APPROACHES FROM THE
SOUTHWEST. BY 06Z THE LOW WILL BE OVER NORTHERN KS WITH MODEST LIFT
CONTINUING INTO THE BOUNDARY OVERNIGHT. INITIALLY THE BETTER LIFT IS
ABOVE THE DENDRITIC LAYER SOUTH OF INTERSTATE 80 BEFORE 03Z. AFTER
03Z A BROAD ZONE OF MODEST LIFT DEVELOPS IN THE DENDRITIC LAYER AND
CONTINUES THROUGH SUNDAY. LOOKING AT A XSECT FROM CARROLL...ACROSS
THE WEST AND NORTHWEST THERE IS ALREADY SOME LIFT IN THE DENDRITIC
LAYER WHICH GENERALLY REMAINS MODEST DURING THE EVENING AND
OVERNIGHT HOURS. AS THE LOW DEEPENS SATURDAY MORNING THERE IS ALSO A
HINT AT A DEFORMATION AXIS AND WEAK TROWAL DEVELOPING OVER SOUTH
CENTRAL TOWARD EAST CENTRAL AREAS. THIS MAY HELP TO ENHANCE SNOWFALL
AMOUNTS ALONG INTERSTATE 80 JUST TO THE EAST OF DES MOINES AFT 06Z
THROUGH SUNDAY MORNING. OVERALL...SNOWFALL AMOUNTS SHOULD BE HIGHER
ACROSS THIS AREA FOR THE STORM TOTAL. MODEL QPF HAS BEEN GENERALLY
CONSISTENT WITH A RANGE OF .35 NORTHWEST TO NEAR 0.70 SOUTH/EAST
OVERNIGHT. WITH SNOWFALL RATIOS OF 12 TO 14 OVERNIGHT...ABOUT 4 TO
NEARLY 7 INCHES OF SNOW IS LIKELY BY 12Z SUNDAY GIVEN SOME OF THE
PRECIP WILL FALL FIRST AS RAIN...SOME MELTING AND COMPACTION ISSUES
AS WELL. WINDS OVERNIGHT REMAIN MODEST INITIALLY BETWEEN 10 TO 15
MPH THROUGH 12Z SOUTHEAST BUT INCREASE OVER NORTHERN AND
NORTHEASTERN SECTIONS TO 15 TO 20 MPH TOWARD 12Z. GIVEN THE WET
NATURE OF THE SNOW SOME BLOWING AND SETTLING WILL OCCUR...BUT NOT
EXPECTING MORE THAN PATCHY BLOWING SNOW UNTIL 12Z NORTHWEST
SECTIONS. ELSEWHERE ACROSS THE SOUTH THIS SHOULDN`T POSE ANY
ADDITIONAL ISSUES. WITH TEMPERATURES BEGINNING ABOVE FREEZING IN THE
SOUTHEAST/SOUTH AND DROPPING THIS EVENING...ROADS MAY BECOME
SLUSHY/SLICK PRIOR TO SNOWFALL ACCUMULATING TO A GREAT DEGREE. THUS
TRAVEL MAY BECOME HAZARDOUS EARLY DUE TO THIS RATHER THAN COMPLETELY
SNOW COVERED ROADS INITIALLY.

.LONG TERM /SUNDAY THROUGH SATURDAY/...
ISSUED AT 329 PM CST SAT JAN 31 2015

SNOW WILL BE ONGOING SUNDAY AS THE SURFACE LOW SLOWLY DRIFTS EASTERN
MISSOURI.  THE SNOW WILL GRADUALLY END FROM NORTHWEST TO SOUTHEAST
THROUGH THE DAY BUT SHOULD LINGER IN THE SOUTHEAST FOR A FAIR
PORTION OF THE AFTERNOON.  THE UPPER LEVEL WAVE WILL TAKE ITS TIME
PUSHING EAST AND BY 18Z IT WILL BARELY BE ACROSS THE MID SECTION OF
THE STATE.  THE BRUNT OF THE FORCING WILL BE EXITING THE EAST
SHORTLY AFTER 18Z SO THE HEAVIEST SNOW WILL FALL BY THEN BUT WE WILL
STILL SEE LIGHT ACCUMULATIONS IN THE SOUTHEAST THROUGH THE MID-
AFTERNOON.  BETWEEN 6AM AND 6 PM WE WILL GET ANOTHER 2 TO 4 INCHES
ACROSS THE SOUTHEAST.  I HAVE LINGERED SNOW IN THE FAR SOUTHEAST
THROUGH EARLY EVENING.  ALTHOUGH WE LOSE MOST OF THE FORCING...THE
GFS HANGS ON TO SOME OF IT ACROSS OUR AREA IN THE 700-500 MB LAYER
AND THE AXIS OF THE UPPER LEVEL WAVE WILL STILL BE IN THE FAR
SOUTHEAST PORTION OF THE FORECAST AREA.

WINDS CONTINUE FOR SUNDAY NIGHT AND MONDAY WITH WIND CHILLS SOLIDLY
IN THE -10 TO -20 RANGE THROUGH MONDAY MORNING.  WHILE THIS IS NOT
QUITE ADVISORY CRITERIA IT WILL BE COLD.

THE PATTERN REMAINS ACTIVE THROUGH MUCH OF THE LONG TERM PERIOD.
ALL THE MODELS ARE DEPICTING ANOTHER SHORTWAVE DROPPING DOWN THE NW
FLOW OVER THE REGION.  THIS ONE IS NOT ANY WHERE NEAR THE STRENGTH
OF THE WEEKEND SYSTEM BUT THERE IS SOME FORCING WITH IT AND WHILE
MOISTURE IS LACKING THERE SHOULD BE ENOUGH FORCING TO SQUEAK OUT
SOME LIGHT SNOW MONDAY AFTERNOON THROUGH MONDAY EVENING.

AFTER THAT PASSES A LOW DEVELOPING IN THE PLAINS AND A WARM FRONT
WILL TRY TO ESTABLISH ITSELF ACROSS MISSOURI.  WHILE WE WILL NOT SEE
THE REAL WARM AIR WE WILL BE CONSIDERABLY WARMER TUESDAY THAN WE WILL
BE ON MONDAY.  HOWEVER...I THINK MODELS ARE A BIT OPTIMISTIC WITH
ALL THE FRESH SNOW COVER. ANOTHER SHORTWAVE DROPS DOWN INTO THE
STATE ON TUESDAY AND WITH THE WARM ADVECTION WILL COME A LITTLE
BETTER MOISTURE SO WE WILL BE SEEING SOME MEASURABLE SNOW AGAIN
TUESDAY AFTERNOON INTO THE EVENING.

CANADIAN HIGH PRESSURE WILL THEN SETTLE INTO THE STATE FOR WEDNESDAY
INTO THURSDAY AND MORE COLD AIR WILL BE IN PLACE.  TEMPS GO INTO THE
COOLER AGAIN WITH HIGHS IN THE TEENS AND 20S AND LOWS IN THE SINGLE
DIGITS ABOVE AND BELOW ZERO.

ANOTHER SHORT WAVE WAS SUGGESTED BY SOME OF THE MEDIUM RANGE MODELS
FOR THURSDAY/FRIDAY BUT THERE WAS NO CONSENSUS ON PRECIP AND SINCE
FORECAST SOUNDINGS WERE VERY DRY I LEFT PRECIP OUT OF THIS PERIOD.

FOR THE START OF THE WEEKEND ANOTHER SURFACE LOW AND WARM FRONT
DEVELOPS OVER THE PLAINS AND THIS TIME THE BOUNDARY SHIFTS INTO
IOWA.  TEMPS WILL BE WARMER ONCE AGAIN...BUT TEMPERED BY GROUND
COVER OF THE PREVIOUS SNOWS.

&&

.AVIATION...31/18Z
ISSUED AT 1155 AM CST SAT JAN 31 2015

RAIN SHIELD MOVING NORTHEAST WITH STORM THIS AFTERNOON. EXPECTING
CIGS TO LOWER QUICKLY TO MVFR/IFR BY 00Z MOST AREAS AND REMAIN IFR
FOR THE BALANCE OF THE FORECAST. VSBY BEGINS TO DROP WITH SNOW
ESPECIALLY AFT 10Z WEST AND LOWERING EAST AS LOW BEGINS TO PULL
INTO EASTERN IOWA AFT 12Z SUNDAY. SNOW AND BLOWING SNOW WILL
INCREASE WITH NNE WINDS OF 17 GUST 28KTS BY LATE MORNING. EXPECT
VSBY TO LOWER TO 1SM AT TIMES THROUGH 18Z SUNDAY. /REV


&&

.DMX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING FROM 7 PM THIS EVENING TO 9 PM CST SUNDAY
FOR ADAIR-ADAMS-APPANOOSE-AUDUBON-BLACK HAWK-BOONE-BREMER-BUTLER-
CALHOUN-CARROLL-CASS-CLARKE-CRAWFORD-DALLAS-DAVIS-DECATUR-
FRANKLIN-GREENE-GRUNDY-GUTHRIE-HAMILTON-HARDIN-HUMBOLDT-JASPER-
LUCAS-MADISON-MAHASKA-MARION-MARSHALL-MONROE-POCAHONTAS-POLK-
POWESHIEK-RINGGOLD-SAC-STORY-TAMA-TAYLOR-UNION-WAPELLO-WARREN-
WAYNE-WEBSTER-WRIGHT.

WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 9 PM CST
SUNDAY FOR CERRO GORDO-EMMET-HANCOCK-KOSSUTH-PALO ALTO-WINNEBAGO-
WORTH.

&&

$$

SHORT TERM...REV
LONG TERM...FAB
AVIATION...REV




000
FXUS63 KDMX 311755
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1155 AM CST SAT JAN 31 2015

.SHORT TERM /TODAY/...
ISSUED AT 313 AM CST SAT JAN 31 2015

PRECIP TRENDS ARE THE OBVIOUS CONCERN IN THIS PERIOD. CONFIDENCE IS
HIGH IN PROGRESSION OF PRECIP AS A WHOLE...WHICH IS JUST TRYING TO
CROSS THE MO RIVER...BUT MAX TEMPS IN LOWEST 1KM ARE QUITE VARIABLE
IN TIME AND SPACE THROUGH THE RAIN/SNOW/MIX 1-3C THRESHOLD. USING A
GFS/NAM/RAP MODEL CONSENSUS FOR THESE TEMPS RESULTS IN A RAIN/SNOW
MIX ADVANCING INTO CENTRAL IA THIS MORNING AND INTO THE HIGHWAY 20
OR 30 CORRIDORS BY EARLY AFTERNOON WITH MAINLY RAIN SOUTH. TEMPS
BEGIN TO COOL LATE HOWEVER WITH LESS VARIABILITY CHANGING TO MAINLY
SNOW OUTSIDE OF A RAIN/SNOW MIX SE QUARTER TOWARD 00Z. ANY
ACCUMULATIONS SHOULD MAINLY BE UNDER AN INCH THROUGH 00Z DUE TO
EITHER LATE ARRIVAL NORTH OR MELTING AND MIX FARTHER SOUTH. ACCUMS
SHOULD REALLY PICK UP JUST AFTER THIS VALID PERIOD HOWEVER.

MODELS ARE IN GOOD AGREEMENT WITH DEEP WEAK/MODERATE KINEMATIC AND
THERMODYNAMIC FORCING ACCOMPANYING SLAB OF MOISTURE TO SIMILAR DEPTH
IN RIGHT ENTRANCE REGION OF GREAT LAKES TO EAST COAST JET SEGMENT.
HI RES REFLECTIVITY SIMULATIONS SHOW THIS NICELY AS WELL SO HAVE
CATEGORICAL WORDING SOUTH HALF BY AFTERNOON.  GENERALLY FOLLOWED A
BLEND OF NAM/GFS MOS FOR HIGHS WITH A SOMEWHAT HIGHER BLEND TOWARD
THE COOLER NAM NUMBERS DUE TO PRECIP.

.LONG TERM /TONIGHT THROUGH THURSDAY/...
ISSUED AT 313 AM CST SAT JAN 31 2015

A PROLONGED WINTER STORM IS SET TO AFFECT THE AREA FROM TONIGHT
THROUGH SUNDAY. AS APPROACHING NORTHERN AND SOUTHERN STREAM
SYSTEMS MERGE AND PHASE OVER THE MIDWEST WE WILL SEE AN INVERTED
TROUGH EXTEND FROM KANSAS AND NEBRASKA ACROSS CENTRAL IOWA BY THIS
AFTERNOON...WITH A LARGE PRECIP SHIELD MOVING NORTHEAST ACROSS
IOWA LATE TODAY IN ASSOCIATION WITH THE BROAD REGION OF ASCENT
AHEAD OF THE APPROACHING 500 MB TROUGH. TEMPERATURES WILL BE WARM
ENOUGH TO SUPPORT RAIN INITIALLY...ESPECIALLY ALONG AND SOUTH OF
THE SURFACE TROUGH...BUT AFTER DARK TONIGHT IT WILL TRANSITION
OVER TO SNOW PRETTY QUICKLY. SURFACE TEMPERATURES WILL LIKELY
REMAIN ABOVE FREEZING ACROSS ABOUT OUR SOUTHERN HALF OR SO THROUGH
THE LATE EVENING AND PERHAPS UNTIL CLOSE TO MIDNIGHT...HOWEVER
FORECAST SOUNDINGS INDICATE THAT TEMPERATURES WILL BE BELOW
FREEZING JUST ABOVE THE SURFACE AND DYNAMIC COOLING WITHIN THE
COLUMN SHOULD PRODUCE THE QUICK CHANGE TO SNOW. MEANWHILE...WITH
FRONTOGENETICAL FORCING OVERHEAD AND PWATS ABOVE THE 95TH
PERCENTILE FOR THE SEASON GIVEN THE SYSTEM PLENTY OF MOISTURE TO
WORK WITH...QPFS ARE UNSEASONABLY HIGH AND APPROACHING AN INCH IN
SOME AREAS WHICH IS NEAR THE CLIMATOLOGICAL AVERAGE FOR THE
ENTIRE MONTH OF JANUARY. COMBINED WITH A FAIRLY DEEP DENDRITIC
GROWTH ZONE...THIS SHOULD LEAD TO FAIRLY HEAVY SNOW WITH RAPID
ACCUMULATIONS OVERNIGHT ESPECIALLY AFTER ABOUT 8 OR 10 PM AS THE
SNOW REALLY STARTS TO STICK.

ON SUNDAY THE SURFACE LOW/TROUGH WILL SLIDE OFF TO OUR SOUTHEAST
BUT THE 500 MB TROUGH WILL JUST BE PASSING OVERHEAD...PROVIDING
AN ADDITIONAL SLUG OF FORCING AND COLD AIR SUPPORTING MORE SNOW
WITH AN EVEN DEEPER DENDRITIC GROWTH ZONE INDICATED BY ALL MODEL
SOUNDINGS. IN ADDITION...THE TIGHTENING PRESSURE GRADIENT BETWEEN
THE DEPARTING SURFACE LOW AND A LARGE RIDGE BUILDING IN FROM THE
NORTHWEST WILL LEAD TO STRONG NORTH WINDS OF AROUND 20 MPH WITH
HIGHER GUSTS DURING THE DAY SUNDAY. WITH MULTIPLE INCHES OF WETTER
SNOW ALREADY ON THE GROUND FROM SATURDAY NIGHT AND WINDS OF THIS
CALIBER BLOWING AROUND THE DRIER FALLING SNOW...BLOWING SNOW
ISSUES COULD BE SIGNIFICANT ON SUNDAY. THE WIND SPEEDS ARE TOO LOW
FOR BLIZZARD CONDITIONS TO BE REACHED...BUT TRAVEL COULD BE BADLY
AFFECTED ESPECIALLY WHILE THE SNOW IS FALLING. GIVEN THE
COMBINATION OF ALL OF THESE CONDITIONS AND IMPACTS...HAVE ISSUED A
WINTER STORM WARNING FOR MUCH OF THE FORECAST AREA FROM LATE THIS
EVENING THROUGH LATE SUNDAY EVENING.

THE SNOW WILL GRADUALLY END ON SUNDAY EVENING AS THE
AFOREMENTIONED HIGH PRESSURE RIDGE BUILDS INTO THE AREA BRINGING
MUCH COOLER WEATHER ESPECIALLY WITH THE FRESH SNOW PACK IN PLACE.
IOWA WILL THEN REMAIN BENEATH GENERALLY NORTHWESTERLY 500 MB FLOW
FOR THE BULK OF NEXT WEEK...PREVENTING ANY SIGNIFICANT WARMING AND
PREVENTING THE SNOW FROM MELTING MUCH. A SERIES OF MOSTLY WEAK
IMPULSES WILL MOVE THROUGH THIS NORTHWEST FLOW PRODUCING
ADDITIONAL LIGHT SNOW AT TIMES. THE STRONGEST SUCH WAVE MAY
PRODUCE ACCUMULATING SNOWFALL SOMEWHERE AROUND TUESDAY NIGHT...AND
WHILE AMOUNTS APPEAR LIGHT IT MAY STILL HAVE SOME TRAVEL IMPACTS
WITH DITCHES ALREADY FULL. THIS SYSTEM WILL ALSO PUSH THROUGH A
REINFORCING SHOT OF COOL AIR WHICH COULD MAKE WEDNESDAY NIGHT INTO
THURSDAY MORNING THE COLDEST PERIOD OF THE WEEK. TOWARD THURSDAY
AND FRIDAY THERE ARE SOME INDICATIONS OF WEAK RIDGING ALOFT AND
LOW LEVEL WARM AIR ADVECTION...BUT THESE EFFECTS WILL LIKELY BE
TEMPERED BY THE DEEP SNOW PACK EXPECTED TO BE IN PLACE.

&&

.AVIATION...31/18Z
ISSUED AT 1155 AM CST SAT JAN 31 2015

RAIN SHIELD MOVING NORTHEAST WITH STORM THIS AFTERNOON. EXPECTING
CIGS TO LOWER QUICKLY TO MVFR/IFR BY 00Z MOST AREAS AND REMAIN IFR
FOR THE BALANCE OF THE FORECAST. VSBY BEGINS TO DROP WITH SNOW
ESPECIALLY AFT 10Z WEST AND LOWERING EAST AS LOW BEGINS TO PULL
INTO EASTERN IOWA AFT 12Z SUNDAY. SNOW AND BLOWING SNOW WILL
INCREASE WITH NNE WINDS OF 17 GUST 28KTS BY LATE MORNING. EXPECT
VSBY TO LOWER TO 1SM AT TIMES THROUGH 18Z SUNDAY. /REV

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING FROM 7 PM THIS EVENING TO 9 PM CST SUNDAY
FOR ADAIR-ADAMS-APPANOOSE-AUDUBON-BLACK HAWK-BOONE-BREMER-BUTLER-
CALHOUN-CARROLL-CASS-CLARKE-CRAWFORD-DALLAS-DAVIS-DECATUR-
FRANKLIN-GREENE-GRUNDY-GUTHRIE-HAMILTON-HARDIN-HUMBOLDT-JASPER-
LUCAS-MADISON-MAHASKA-MARION-MARSHALL-MONROE-POCAHONTAS-POLK-
POWESHIEK-RINGGOLD-SAC-STORY-TAMA-TAYLOR-UNION-WAPELLO-WARREN-
WAYNE-WEBSTER-WRIGHT.

WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 9 PM CST
SUNDAY FOR CERRO GORDO-EMMET-HANCOCK-KOSSUTH-PALO ALTO-WINNEBAGO-
WORTH.

&&

$$

SHORT TERM...SMALL
LONG TERM...LEE
AVIATION...REV




000
FXUS63 KDMX 311755
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1155 AM CST SAT JAN 31 2015

.SHORT TERM /TODAY/...
ISSUED AT 313 AM CST SAT JAN 31 2015

PRECIP TRENDS ARE THE OBVIOUS CONCERN IN THIS PERIOD. CONFIDENCE IS
HIGH IN PROGRESSION OF PRECIP AS A WHOLE...WHICH IS JUST TRYING TO
CROSS THE MO RIVER...BUT MAX TEMPS IN LOWEST 1KM ARE QUITE VARIABLE
IN TIME AND SPACE THROUGH THE RAIN/SNOW/MIX 1-3C THRESHOLD. USING A
GFS/NAM/RAP MODEL CONSENSUS FOR THESE TEMPS RESULTS IN A RAIN/SNOW
MIX ADVANCING INTO CENTRAL IA THIS MORNING AND INTO THE HIGHWAY 20
OR 30 CORRIDORS BY EARLY AFTERNOON WITH MAINLY RAIN SOUTH. TEMPS
BEGIN TO COOL LATE HOWEVER WITH LESS VARIABILITY CHANGING TO MAINLY
SNOW OUTSIDE OF A RAIN/SNOW MIX SE QUARTER TOWARD 00Z. ANY
ACCUMULATIONS SHOULD MAINLY BE UNDER AN INCH THROUGH 00Z DUE TO
EITHER LATE ARRIVAL NORTH OR MELTING AND MIX FARTHER SOUTH. ACCUMS
SHOULD REALLY PICK UP JUST AFTER THIS VALID PERIOD HOWEVER.

MODELS ARE IN GOOD AGREEMENT WITH DEEP WEAK/MODERATE KINEMATIC AND
THERMODYNAMIC FORCING ACCOMPANYING SLAB OF MOISTURE TO SIMILAR DEPTH
IN RIGHT ENTRANCE REGION OF GREAT LAKES TO EAST COAST JET SEGMENT.
HI RES REFLECTIVITY SIMULATIONS SHOW THIS NICELY AS WELL SO HAVE
CATEGORICAL WORDING SOUTH HALF BY AFTERNOON.  GENERALLY FOLLOWED A
BLEND OF NAM/GFS MOS FOR HIGHS WITH A SOMEWHAT HIGHER BLEND TOWARD
THE COOLER NAM NUMBERS DUE TO PRECIP.

.LONG TERM /TONIGHT THROUGH THURSDAY/...
ISSUED AT 313 AM CST SAT JAN 31 2015

A PROLONGED WINTER STORM IS SET TO AFFECT THE AREA FROM TONIGHT
THROUGH SUNDAY. AS APPROACHING NORTHERN AND SOUTHERN STREAM
SYSTEMS MERGE AND PHASE OVER THE MIDWEST WE WILL SEE AN INVERTED
TROUGH EXTEND FROM KANSAS AND NEBRASKA ACROSS CENTRAL IOWA BY THIS
AFTERNOON...WITH A LARGE PRECIP SHIELD MOVING NORTHEAST ACROSS
IOWA LATE TODAY IN ASSOCIATION WITH THE BROAD REGION OF ASCENT
AHEAD OF THE APPROACHING 500 MB TROUGH. TEMPERATURES WILL BE WARM
ENOUGH TO SUPPORT RAIN INITIALLY...ESPECIALLY ALONG AND SOUTH OF
THE SURFACE TROUGH...BUT AFTER DARK TONIGHT IT WILL TRANSITION
OVER TO SNOW PRETTY QUICKLY. SURFACE TEMPERATURES WILL LIKELY
REMAIN ABOVE FREEZING ACROSS ABOUT OUR SOUTHERN HALF OR SO THROUGH
THE LATE EVENING AND PERHAPS UNTIL CLOSE TO MIDNIGHT...HOWEVER
FORECAST SOUNDINGS INDICATE THAT TEMPERATURES WILL BE BELOW
FREEZING JUST ABOVE THE SURFACE AND DYNAMIC COOLING WITHIN THE
COLUMN SHOULD PRODUCE THE QUICK CHANGE TO SNOW. MEANWHILE...WITH
FRONTOGENETICAL FORCING OVERHEAD AND PWATS ABOVE THE 95TH
PERCENTILE FOR THE SEASON GIVEN THE SYSTEM PLENTY OF MOISTURE TO
WORK WITH...QPFS ARE UNSEASONABLY HIGH AND APPROACHING AN INCH IN
SOME AREAS WHICH IS NEAR THE CLIMATOLOGICAL AVERAGE FOR THE
ENTIRE MONTH OF JANUARY. COMBINED WITH A FAIRLY DEEP DENDRITIC
GROWTH ZONE...THIS SHOULD LEAD TO FAIRLY HEAVY SNOW WITH RAPID
ACCUMULATIONS OVERNIGHT ESPECIALLY AFTER ABOUT 8 OR 10 PM AS THE
SNOW REALLY STARTS TO STICK.

ON SUNDAY THE SURFACE LOW/TROUGH WILL SLIDE OFF TO OUR SOUTHEAST
BUT THE 500 MB TROUGH WILL JUST BE PASSING OVERHEAD...PROVIDING
AN ADDITIONAL SLUG OF FORCING AND COLD AIR SUPPORTING MORE SNOW
WITH AN EVEN DEEPER DENDRITIC GROWTH ZONE INDICATED BY ALL MODEL
SOUNDINGS. IN ADDITION...THE TIGHTENING PRESSURE GRADIENT BETWEEN
THE DEPARTING SURFACE LOW AND A LARGE RIDGE BUILDING IN FROM THE
NORTHWEST WILL LEAD TO STRONG NORTH WINDS OF AROUND 20 MPH WITH
HIGHER GUSTS DURING THE DAY SUNDAY. WITH MULTIPLE INCHES OF WETTER
SNOW ALREADY ON THE GROUND FROM SATURDAY NIGHT AND WINDS OF THIS
CALIBER BLOWING AROUND THE DRIER FALLING SNOW...BLOWING SNOW
ISSUES COULD BE SIGNIFICANT ON SUNDAY. THE WIND SPEEDS ARE TOO LOW
FOR BLIZZARD CONDITIONS TO BE REACHED...BUT TRAVEL COULD BE BADLY
AFFECTED ESPECIALLY WHILE THE SNOW IS FALLING. GIVEN THE
COMBINATION OF ALL OF THESE CONDITIONS AND IMPACTS...HAVE ISSUED A
WINTER STORM WARNING FOR MUCH OF THE FORECAST AREA FROM LATE THIS
EVENING THROUGH LATE SUNDAY EVENING.

THE SNOW WILL GRADUALLY END ON SUNDAY EVENING AS THE
AFOREMENTIONED HIGH PRESSURE RIDGE BUILDS INTO THE AREA BRINGING
MUCH COOLER WEATHER ESPECIALLY WITH THE FRESH SNOW PACK IN PLACE.
IOWA WILL THEN REMAIN BENEATH GENERALLY NORTHWESTERLY 500 MB FLOW
FOR THE BULK OF NEXT WEEK...PREVENTING ANY SIGNIFICANT WARMING AND
PREVENTING THE SNOW FROM MELTING MUCH. A SERIES OF MOSTLY WEAK
IMPULSES WILL MOVE THROUGH THIS NORTHWEST FLOW PRODUCING
ADDITIONAL LIGHT SNOW AT TIMES. THE STRONGEST SUCH WAVE MAY
PRODUCE ACCUMULATING SNOWFALL SOMEWHERE AROUND TUESDAY NIGHT...AND
WHILE AMOUNTS APPEAR LIGHT IT MAY STILL HAVE SOME TRAVEL IMPACTS
WITH DITCHES ALREADY FULL. THIS SYSTEM WILL ALSO PUSH THROUGH A
REINFORCING SHOT OF COOL AIR WHICH COULD MAKE WEDNESDAY NIGHT INTO
THURSDAY MORNING THE COLDEST PERIOD OF THE WEEK. TOWARD THURSDAY
AND FRIDAY THERE ARE SOME INDICATIONS OF WEAK RIDGING ALOFT AND
LOW LEVEL WARM AIR ADVECTION...BUT THESE EFFECTS WILL LIKELY BE
TEMPERED BY THE DEEP SNOW PACK EXPECTED TO BE IN PLACE.

&&

.AVIATION...31/18Z
ISSUED AT 1155 AM CST SAT JAN 31 2015

RAIN SHIELD MOVING NORTHEAST WITH STORM THIS AFTERNOON. EXPECTING
CIGS TO LOWER QUICKLY TO MVFR/IFR BY 00Z MOST AREAS AND REMAIN IFR
FOR THE BALANCE OF THE FORECAST. VSBY BEGINS TO DROP WITH SNOW
ESPECIALLY AFT 10Z WEST AND LOWERING EAST AS LOW BEGINS TO PULL
INTO EASTERN IOWA AFT 12Z SUNDAY. SNOW AND BLOWING SNOW WILL
INCREASE WITH NNE WINDS OF 17 GUST 28KTS BY LATE MORNING. EXPECT
VSBY TO LOWER TO 1SM AT TIMES THROUGH 18Z SUNDAY. /REV

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING FROM 7 PM THIS EVENING TO 9 PM CST SUNDAY
FOR ADAIR-ADAMS-APPANOOSE-AUDUBON-BLACK HAWK-BOONE-BREMER-BUTLER-
CALHOUN-CARROLL-CASS-CLARKE-CRAWFORD-DALLAS-DAVIS-DECATUR-
FRANKLIN-GREENE-GRUNDY-GUTHRIE-HAMILTON-HARDIN-HUMBOLDT-JASPER-
LUCAS-MADISON-MAHASKA-MARION-MARSHALL-MONROE-POCAHONTAS-POLK-
POWESHIEK-RINGGOLD-SAC-STORY-TAMA-TAYLOR-UNION-WAPELLO-WARREN-
WAYNE-WEBSTER-WRIGHT.

WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 9 PM CST
SUNDAY FOR CERRO GORDO-EMMET-HANCOCK-KOSSUTH-PALO ALTO-WINNEBAGO-
WORTH.

&&

$$

SHORT TERM...SMALL
LONG TERM...LEE
AVIATION...REV





000
FXUS63 KDMX 311148
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
548 AM CST SAT JAN 31 2015

.SHORT TERM /TODAY/...
ISSUED AT 313 AM CST SAT JAN 31 2015

PRECIP TRENDS ARE THE OBVIOUS CONCERN IN THIS PERIOD. CONFIDENCE IS
HIGH IN PROGRESSION OF PRECIP AS A WHOLE...WHICH IS JUST TRYING TO
CROSS THE MO RIVER...BUT MAX TEMPS IN LOWEST 1KM ARE QUITE VARIABLE
IN TIME AND SPACE THROUGH THE RAIN/SNOW/MIX 1-3C THRESHOLD. USING A
GFS/NAM/RAP MODEL CONSENSUS FOR THESE TEMPS RESULTS IN A RAIN/SNOW
MIX ADVANCING INTO CENTRAL IA THIS MORNING AND INTO THE HIGHWAY 20
OR 30 CORRIDORS BY EARLY AFTERNOON WITH MAINLY RAIN SOUTH. TEMPS
BEGIN TO COOL LATE HOWEVER WITH LESS VARIABILITY CHANGING TO MAINLY
SNOW OUTSIDE OF A RAIN/SNOW MIX SE QUARTER TOWARD 00Z. ANY
ACCUMULATIONS SHOULD MAINLY BE UNDER AN INCH THROUGH 00Z DUE TO
EITHER LATE ARRIVAL NORTH OR MELTING AND MIX FARTHER SOUTH. ACCUMS
SHOULD REALLY PICK UP JUST AFTER THIS VALID PERIOD HOWEVER.

MODELS ARE IN GOOD AGREEMENT WITH DEEP WEAK/MODERATE KINEMATIC AND
THERMODYNAMIC FORCING ACCOMPANYING SLAB OF MOISTURE TO SIMILAR DEPTH
IN RIGHT ENTRANCE REGION OF GREAT LAKES TO EAST COAST JET SEGMENT.
HI RES REFLECTIVITY SIMULATIONS SHOW THIS NICELY AS WELL SO HAVE
CATEGORICAL WORDING SOUTH HALF BY AFTERNOON.  GENERALLY FOLLOWED A
BLEND OF NAM/GFS MOS FOR HIGHS WITH A SOMEWHAT HIGHER BLEND TOWARD
THE COOLER NAM NUMBERS DUE TO PRECIP.

.LONG TERM /TONIGHT THROUGH THURSDAY/...
ISSUED AT 313 AM CST SAT JAN 31 2015

A PROLONGED WINTER STORM IS SET TO AFFECT THE AREA FROM TONIGHT
THROUGH SUNDAY. AS APPROACHING NORTHERN AND SOUTHERN STREAM
SYSTEMS MERGE AND PHASE OVER THE MIDWEST WE WILL SEE AN INVERTED
TROUGH EXTEND FROM KANSAS AND NEBRASKA ACROSS CENTRAL IOWA BY THIS
AFTERNOON...WITH A LARGE PRECIP SHIELD MOVING NORTHEAST ACROSS
IOWA LATE TODAY IN ASSOCIATION WITH THE BROAD REGION OF ASCENT
AHEAD OF THE APPROACHING 500 MB TROUGH. TEMPERATURES WILL BE WARM
ENOUGH TO SUPPORT RAIN INITIALLY...ESPECIALLY ALONG AND SOUTH OF
THE SURFACE TROUGH...BUT AFTER DARK TONIGHT IT WILL TRANSITION
OVER TO SNOW PRETTY QUICKLY. SURFACE TEMPERATURES WILL LIKELY
REMAIN ABOVE FREEZING ACROSS ABOUT OUR SOUTHERN HALF OR SO THROUGH
THE LATE EVENING AND PERHAPS UNTIL CLOSE TO MIDNIGHT...HOWEVER
FORECAST SOUNDINGS INDICATE THAT TEMPERATURES WILL BE BELOW
FREEZING JUST ABOVE THE SURFACE AND DYNAMIC COOLING WITHIN THE
COLUMN SHOULD PRODUCE THE QUICK CHANGE TO SNOW. MEANWHILE...WITH
FRONTOGENETICAL FORCING OVERHEAD AND PWATS ABOVE THE 95TH
PERCENTILE FOR THE SEASON GIVEN THE SYSTEM PLENTY OF MOISTURE TO
WORK WITH...QPFS ARE UNSEASONABLY HIGH AND APPROACHING AN INCH IN
SOME AREAS WHICH IS NEAR THE CLIMATOLOGICAL AVERAGE FOR THE
ENTIRE MONTH OF JANUARY. COMBINED WITH A FAIRLY DEEP DENDRITIC
GROWTH ZONE...THIS SHOULD LEAD TO FAIRLY HEAVY SNOW WITH RAPID
ACCUMULATIONS OVERNIGHT ESPECIALLY AFTER ABOUT 8 OR 10 PM AS THE
SNOW REALLY STARTS TO STICK.

ON SUNDAY THE SURFACE LOW/TROUGH WILL SLIDE OFF TO OUR SOUTHEAST
BUT THE 500 MB TROUGH WILL JUST BE PASSING OVERHEAD...PROVIDING
AN ADDITIONAL SLUG OF FORCING AND COLD AIR SUPPORTING MORE SNOW
WITH AN EVEN DEEPER DENDRITIC GROWTH ZONE INDICATED BY ALL MODEL
SOUNDINGS. IN ADDITION...THE TIGHTENING PRESSURE GRADIENT BETWEEN
THE DEPARTING SURFACE LOW AND A LARGE RIDGE BUILDING IN FROM THE
NORTHWEST WILL LEAD TO STRONG NORTH WINDS OF AROUND 20 MPH WITH
HIGHER GUSTS DURING THE DAY SUNDAY. WITH MULTIPLE INCHES OF WETTER
SNOW ALREADY ON THE GROUND FROM SATURDAY NIGHT AND WINDS OF THIS
CALIBER BLOWING AROUND THE DRIER FALLING SNOW...BLOWING SNOW
ISSUES COULD BE SIGNIFICANT ON SUNDAY. THE WIND SPEEDS ARE TOO LOW
FOR BLIZZARD CONDITIONS TO BE REACHED...BUT TRAVEL COULD BE BADLY
AFFECTED ESPECIALLY WHILE THE SNOW IS FALLING. GIVEN THE
COMBINATION OF ALL OF THESE CONDITIONS AND IMPACTS...HAVE ISSUED A
WINTER STORM WARNING FOR MUCH OF THE FORECAST AREA FROM LATE THIS
EVENING THROUGH LATE SUNDAY EVENING.

THE SNOW WILL GRADUALLY END ON SUNDAY EVENING AS THE
AFOREMENTIONED HIGH PRESSURE RIDGE BUILDS INTO THE AREA BRINGING
MUCH COOLER WEATHER ESPECIALLY WITH THE FRESH SNOW PACK IN PLACE.
IOWA WILL THEN REMAIN BENEATH GENERALLY NORTHWESTERLY 500 MB FLOW
FOR THE BULK OF NEXT WEEK...PREVENTING ANY SIGNIFICANT WARMING AND
PREVENTING THE SNOW FROM MELTING MUCH. A SERIES OF MOSTLY WEAK
IMPULSES WILL MOVE THROUGH THIS NORTHWEST FLOW PRODUCING
ADDITIONAL LIGHT SNOW AT TIMES. THE STRONGEST SUCH WAVE MAY
PRODUCE ACCUMULATING SNOWFALL SOMEWHERE AROUND TUESDAY NIGHT...AND
WHILE AMOUNTS APPEAR LIGHT IT MAY STILL HAVE SOME TRAVEL IMPACTS
WITH DITCHES ALREADY FULL. THIS SYSTEM WILL ALSO PUSH THROUGH A
REINFORCING SHOT OF COOL AIR WHICH COULD MAKE WEDNESDAY NIGHT INTO
THURSDAY MORNING THE COLDEST PERIOD OF THE WEEK. TOWARD THURSDAY
AND FRIDAY THERE ARE SOME INDICATIONS OF WEAK RIDGING ALOFT AND
LOW LEVEL WARM AIR ADVECTION...BUT THESE EFFECTS WILL LIKELY BE
TEMPERED BY THE DEEP SNOW PACK EXPECTED TO BE IN PLACE.

&&

.AVIATION...31/12Z
ISSUED AT 548 AM CST SAT JAN 31 2015

CONDITIONS WILL CONTINUE TO DETERIORATE TODAY TRANSITIONING FROM
VFR THIS MORNING TO CERTAIN LOW END MVFR AND POSSIBLE IFR AT TIMES
TONIGHT AND INTO SUN MORNING. WIDESPREAD RAIN/SNOW MIX OR KS AND
WRN MO WILL ADVANCE INTO IA SOUTH TO NORTH TODAY AND TRANSITION TO
ALL SNOW BY THIS EVENING AND CONTINUING INTO SUN. WINDS WILL
INCREASE SOMEWHAT NORTH AND WEST /KFOD/KMCW/KALO/ 09-12Z LEADING
TO BLOWING SNOW AS WELL. THE SNOW AND BLOWING SNOW WITH IFR/MVFR
CONDITIONS WILL EXPAND STATE WIDE AND CONTINUE BEYOND THE VALID
PERIOD /12Z/ AS WELL.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING FROM 7 PM THIS EVENING TO 9 PM CST SUNDAY
FOR ADAIR-ADAMS-APPANOOSE-AUDUBON-BLACK HAWK-BOONE-BREMER-BUTLER-
CALHOUN-CARROLL-CASS-CLARKE-CRAWFORD-DALLAS-DAVIS-DECATUR-
FRANKLIN-GREENE-GRUNDY-GUTHRIE-HAMILTON-HARDIN-HUMBOLDT-JASPER-
LUCAS-MADISON-MAHASKA-MARION-MARSHALL-MONROE-POCAHONTAS-POLK-
POWESHIEK-RINGGOLD-SAC-STORY-TAMA-TAYLOR-UNION-WAPELLO-WARREN-
WAYNE-WEBSTER-WRIGHT.

WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 9 PM CST
SUNDAY FOR CERRO GORDO-EMMET-HANCOCK-KOSSUTH-PALO ALTO-WINNEBAGO-
WORTH.

&&

$$

SHORT TERM...SMALL
LONG TERM...LEE
AVIATION...SMALL





000
FXUS63 KDMX 311148
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
548 AM CST SAT JAN 31 2015

.SHORT TERM /TODAY/...
ISSUED AT 313 AM CST SAT JAN 31 2015

PRECIP TRENDS ARE THE OBVIOUS CONCERN IN THIS PERIOD. CONFIDENCE IS
HIGH IN PROGRESSION OF PRECIP AS A WHOLE...WHICH IS JUST TRYING TO
CROSS THE MO RIVER...BUT MAX TEMPS IN LOWEST 1KM ARE QUITE VARIABLE
IN TIME AND SPACE THROUGH THE RAIN/SNOW/MIX 1-3C THRESHOLD. USING A
GFS/NAM/RAP MODEL CONSENSUS FOR THESE TEMPS RESULTS IN A RAIN/SNOW
MIX ADVANCING INTO CENTRAL IA THIS MORNING AND INTO THE HIGHWAY 20
OR 30 CORRIDORS BY EARLY AFTERNOON WITH MAINLY RAIN SOUTH. TEMPS
BEGIN TO COOL LATE HOWEVER WITH LESS VARIABILITY CHANGING TO MAINLY
SNOW OUTSIDE OF A RAIN/SNOW MIX SE QUARTER TOWARD 00Z. ANY
ACCUMULATIONS SHOULD MAINLY BE UNDER AN INCH THROUGH 00Z DUE TO
EITHER LATE ARRIVAL NORTH OR MELTING AND MIX FARTHER SOUTH. ACCUMS
SHOULD REALLY PICK UP JUST AFTER THIS VALID PERIOD HOWEVER.

MODELS ARE IN GOOD AGREEMENT WITH DEEP WEAK/MODERATE KINEMATIC AND
THERMODYNAMIC FORCING ACCOMPANYING SLAB OF MOISTURE TO SIMILAR DEPTH
IN RIGHT ENTRANCE REGION OF GREAT LAKES TO EAST COAST JET SEGMENT.
HI RES REFLECTIVITY SIMULATIONS SHOW THIS NICELY AS WELL SO HAVE
CATEGORICAL WORDING SOUTH HALF BY AFTERNOON.  GENERALLY FOLLOWED A
BLEND OF NAM/GFS MOS FOR HIGHS WITH A SOMEWHAT HIGHER BLEND TOWARD
THE COOLER NAM NUMBERS DUE TO PRECIP.

.LONG TERM /TONIGHT THROUGH THURSDAY/...
ISSUED AT 313 AM CST SAT JAN 31 2015

A PROLONGED WINTER STORM IS SET TO AFFECT THE AREA FROM TONIGHT
THROUGH SUNDAY. AS APPROACHING NORTHERN AND SOUTHERN STREAM
SYSTEMS MERGE AND PHASE OVER THE MIDWEST WE WILL SEE AN INVERTED
TROUGH EXTEND FROM KANSAS AND NEBRASKA ACROSS CENTRAL IOWA BY THIS
AFTERNOON...WITH A LARGE PRECIP SHIELD MOVING NORTHEAST ACROSS
IOWA LATE TODAY IN ASSOCIATION WITH THE BROAD REGION OF ASCENT
AHEAD OF THE APPROACHING 500 MB TROUGH. TEMPERATURES WILL BE WARM
ENOUGH TO SUPPORT RAIN INITIALLY...ESPECIALLY ALONG AND SOUTH OF
THE SURFACE TROUGH...BUT AFTER DARK TONIGHT IT WILL TRANSITION
OVER TO SNOW PRETTY QUICKLY. SURFACE TEMPERATURES WILL LIKELY
REMAIN ABOVE FREEZING ACROSS ABOUT OUR SOUTHERN HALF OR SO THROUGH
THE LATE EVENING AND PERHAPS UNTIL CLOSE TO MIDNIGHT...HOWEVER
FORECAST SOUNDINGS INDICATE THAT TEMPERATURES WILL BE BELOW
FREEZING JUST ABOVE THE SURFACE AND DYNAMIC COOLING WITHIN THE
COLUMN SHOULD PRODUCE THE QUICK CHANGE TO SNOW. MEANWHILE...WITH
FRONTOGENETICAL FORCING OVERHEAD AND PWATS ABOVE THE 95TH
PERCENTILE FOR THE SEASON GIVEN THE SYSTEM PLENTY OF MOISTURE TO
WORK WITH...QPFS ARE UNSEASONABLY HIGH AND APPROACHING AN INCH IN
SOME AREAS WHICH IS NEAR THE CLIMATOLOGICAL AVERAGE FOR THE
ENTIRE MONTH OF JANUARY. COMBINED WITH A FAIRLY DEEP DENDRITIC
GROWTH ZONE...THIS SHOULD LEAD TO FAIRLY HEAVY SNOW WITH RAPID
ACCUMULATIONS OVERNIGHT ESPECIALLY AFTER ABOUT 8 OR 10 PM AS THE
SNOW REALLY STARTS TO STICK.

ON SUNDAY THE SURFACE LOW/TROUGH WILL SLIDE OFF TO OUR SOUTHEAST
BUT THE 500 MB TROUGH WILL JUST BE PASSING OVERHEAD...PROVIDING
AN ADDITIONAL SLUG OF FORCING AND COLD AIR SUPPORTING MORE SNOW
WITH AN EVEN DEEPER DENDRITIC GROWTH ZONE INDICATED BY ALL MODEL
SOUNDINGS. IN ADDITION...THE TIGHTENING PRESSURE GRADIENT BETWEEN
THE DEPARTING SURFACE LOW AND A LARGE RIDGE BUILDING IN FROM THE
NORTHWEST WILL LEAD TO STRONG NORTH WINDS OF AROUND 20 MPH WITH
HIGHER GUSTS DURING THE DAY SUNDAY. WITH MULTIPLE INCHES OF WETTER
SNOW ALREADY ON THE GROUND FROM SATURDAY NIGHT AND WINDS OF THIS
CALIBER BLOWING AROUND THE DRIER FALLING SNOW...BLOWING SNOW
ISSUES COULD BE SIGNIFICANT ON SUNDAY. THE WIND SPEEDS ARE TOO LOW
FOR BLIZZARD CONDITIONS TO BE REACHED...BUT TRAVEL COULD BE BADLY
AFFECTED ESPECIALLY WHILE THE SNOW IS FALLING. GIVEN THE
COMBINATION OF ALL OF THESE CONDITIONS AND IMPACTS...HAVE ISSUED A
WINTER STORM WARNING FOR MUCH OF THE FORECAST AREA FROM LATE THIS
EVENING THROUGH LATE SUNDAY EVENING.

THE SNOW WILL GRADUALLY END ON SUNDAY EVENING AS THE
AFOREMENTIONED HIGH PRESSURE RIDGE BUILDS INTO THE AREA BRINGING
MUCH COOLER WEATHER ESPECIALLY WITH THE FRESH SNOW PACK IN PLACE.
IOWA WILL THEN REMAIN BENEATH GENERALLY NORTHWESTERLY 500 MB FLOW
FOR THE BULK OF NEXT WEEK...PREVENTING ANY SIGNIFICANT WARMING AND
PREVENTING THE SNOW FROM MELTING MUCH. A SERIES OF MOSTLY WEAK
IMPULSES WILL MOVE THROUGH THIS NORTHWEST FLOW PRODUCING
ADDITIONAL LIGHT SNOW AT TIMES. THE STRONGEST SUCH WAVE MAY
PRODUCE ACCUMULATING SNOWFALL SOMEWHERE AROUND TUESDAY NIGHT...AND
WHILE AMOUNTS APPEAR LIGHT IT MAY STILL HAVE SOME TRAVEL IMPACTS
WITH DITCHES ALREADY FULL. THIS SYSTEM WILL ALSO PUSH THROUGH A
REINFORCING SHOT OF COOL AIR WHICH COULD MAKE WEDNESDAY NIGHT INTO
THURSDAY MORNING THE COLDEST PERIOD OF THE WEEK. TOWARD THURSDAY
AND FRIDAY THERE ARE SOME INDICATIONS OF WEAK RIDGING ALOFT AND
LOW LEVEL WARM AIR ADVECTION...BUT THESE EFFECTS WILL LIKELY BE
TEMPERED BY THE DEEP SNOW PACK EXPECTED TO BE IN PLACE.

&&

.AVIATION...31/12Z
ISSUED AT 548 AM CST SAT JAN 31 2015

CONDITIONS WILL CONTINUE TO DETERIORATE TODAY TRANSITIONING FROM
VFR THIS MORNING TO CERTAIN LOW END MVFR AND POSSIBLE IFR AT TIMES
TONIGHT AND INTO SUN MORNING. WIDESPREAD RAIN/SNOW MIX OR KS AND
WRN MO WILL ADVANCE INTO IA SOUTH TO NORTH TODAY AND TRANSITION TO
ALL SNOW BY THIS EVENING AND CONTINUING INTO SUN. WINDS WILL
INCREASE SOMEWHAT NORTH AND WEST /KFOD/KMCW/KALO/ 09-12Z LEADING
TO BLOWING SNOW AS WELL. THE SNOW AND BLOWING SNOW WITH IFR/MVFR
CONDITIONS WILL EXPAND STATE WIDE AND CONTINUE BEYOND THE VALID
PERIOD /12Z/ AS WELL.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING FROM 7 PM THIS EVENING TO 9 PM CST SUNDAY
FOR ADAIR-ADAMS-APPANOOSE-AUDUBON-BLACK HAWK-BOONE-BREMER-BUTLER-
CALHOUN-CARROLL-CASS-CLARKE-CRAWFORD-DALLAS-DAVIS-DECATUR-
FRANKLIN-GREENE-GRUNDY-GUTHRIE-HAMILTON-HARDIN-HUMBOLDT-JASPER-
LUCAS-MADISON-MAHASKA-MARION-MARSHALL-MONROE-POCAHONTAS-POLK-
POWESHIEK-RINGGOLD-SAC-STORY-TAMA-TAYLOR-UNION-WAPELLO-WARREN-
WAYNE-WEBSTER-WRIGHT.

WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 9 PM CST
SUNDAY FOR CERRO GORDO-EMMET-HANCOCK-KOSSUTH-PALO ALTO-WINNEBAGO-
WORTH.

&&

$$

SHORT TERM...SMALL
LONG TERM...LEE
AVIATION...SMALL




000
FXUS63 KDMX 310915
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
315 AM CST SAT JAN 31 2015

.SHORT TERM /TODAY/...
ISSUED AT 313 AM CST SAT JAN 31 2015

PRECIP TRENDS ARE THE OBVIOUS CONCERN IN THIS PERIOD. CONFIDENCE IS
HIGH IN PROGRESSION OF PRECIP AS A WHOLE...WHICH IS JUST TRYING TO
CROSS THE MO RIVER...BUT MAX TEMPS IN LOWEST 1KM ARE QUITE VARIABLE
IN TIME AND SPACE THROUGH THE RAIN/SNOW/MIX 1-3C THRESHOLD. USING A
GFS/NAM/RAP MODEL CONSENSUS FOR THESE TEMPS RESULTS IN A RAIN/SNOW
MIX ADVANCING INTO CENTRAL IA THIS MORNING AND INTO THE HIGHWAY 20
OR 30 CORRIDORS BY EARLY AFTERNOON WITH MAINLY RAIN SOUTH. TEMPS
BEGIN TO COOL LATE HOWEVER WITH LESS VARIABILITY CHANGING TO MAINLY
SNOW OUTSIDE OF A RAIN/SNOW MIX SE QUARTER TOWARD 00Z. ANY
ACCUMULATIONS SHOULD MAINLY BE UNDER AN INCH THROUGH 00Z DUE TO
EITHER LATE ARRIVAL NORTH OR MELTING AND MIX FARTHER SOUTH. ACCUMS
SHOULD REALLY PICK UP JUST AFTER THIS VALID PERIOD HOWEVER.

MODELS ARE IN GOOD AGREEMENT WITH DEEP WEAK/MODERATE KINEMATIC AND
THERMODYNAMIC FORCING ACCOMPANYING SLAB OF MOISTURE TO SIMILAR DEPTH
IN RIGHT ENTRANCE REGION OF GREAT LAKES TO EAST COAST JET SEGMENT.
HI RES REFLECTIVITY SIMULATIONS SHOW THIS NICELY AS WELL SO HAVE
CATEGORICAL WORDING SOUTH HALF BY AFTERNOON.  GENERALLY FOLLOWED A
BLEND OF NAM/GFS MOS FOR HIGHS WITH A SOMEWHAT HIGHER BLEND TOWARD
THE COOLER NAM NUMBERS DUE TO PRECIP.

.LONG TERM /TONIGHT THROUGH THURSDAY/...
ISSUED AT 313 AM CST SAT JAN 31 2015

A PROLONGED WINTER STORM IS SET TO AFFECT THE AREA FROM TONIGHT
THROUGH SUNDAY. AS APPROACHING NORTHERN AND SOUTHERN STREAM
SYSTEMS MERGE AND PHASE OVER THE MIDWEST WE WILL SEE AN INVERTED
TROUGH EXTEND FROM KANSAS AND NEBRASKA ACROSS CENTRAL IOWA BY THIS
AFTERNOON...WITH A LARGE PRECIP SHIELD MOVING NORTHEAST ACROSS
IOWA LATE TODAY IN ASSOCIATION WITH THE BROAD REGION OF ASCENT
AHEAD OF THE APPROACHING 500 MB TROUGH. TEMPERATURES WILL BE WARM
ENOUGH TO SUPPORT RAIN INITIALLY...ESPECIALLY ALONG AND SOUTH OF
THE SURFACE TROUGH...BUT AFTER DARK TONIGHT IT WILL TRANSITION
OVER TO SNOW PRETTY QUICKLY. SURFACE TEMPERATURES WILL LIKELY
REMAIN ABOVE FREEZING ACROSS ABOUT OUR SOUTHERN HALF OR SO THROUGH
THE LATE EVENING AND PERHAPS UNTIL CLOSE TO MIDNIGHT...HOWEVER
FORECAST SOUNDINGS INDICATE THAT TEMPERATURES WILL BE BELOW
FREEZING JUST ABOVE THE SURFACE AND DYNAMIC COOLING WITHIN THE
COLUMN SHOULD PRODUCE THE QUICK CHANGE TO SNOW. MEANWHILE...WITH
FRONTOGENETICAL FORCING OVERHEAD AND PWATS ABOVE THE 95TH
PERCENTILE FOR THE SEASON GIVEN THE SYSTEM PLENTY OF MOISTURE TO
WORK WITH...QPFS ARE UNSEASONABLY HIGH AND APPROACHING AN INCH IN
SOME AREAS WHICH IS NEAR THE CLIMATOLOGICAL AVERAGE FOR THE
ENTIRE MONTH OF JANUARY. COMBINED WITH A FAIRLY DEEP DENDRITIC
GROWTH ZONE...THIS SHOULD LEAD TO FAIRLY HEAVY SNOW WITH RAPID
ACCUMULATIONS OVERNIGHT ESPECIALLY AFTER ABOUT 8 OR 10 PM AS THE
SNOW REALLY STARTS TO STICK.

ON SUNDAY THE SURFACE LOW/TROUGH WILL SLIDE OFF TO OUR SOUTHEAST
BUT THE 500 MB TROUGH WILL JUST BE PASSING OVERHEAD...PROVIDING
AN ADDITIONAL SLUG OF FORCING AND COLD AIR SUPPORTING MORE SNOW
WITH AN EVEN DEEPER DENDRITIC GROWTH ZONE INDICATED BY ALL MODEL
SOUNDINGS. IN ADDITION...THE TIGHTENING PRESSURE GRADIENT BETWEEN
THE DEPARTING SURFACE LOW AND A LARGE RIDGE BUILDING IN FROM THE
NORTHWEST WILL LEAD TO STRONG NORTH WINDS OF AROUND 20 MPH WITH
HIGHER GUSTS DURING THE DAY SUNDAY. WITH MULTIPLE INCHES OF WETTER
SNOW ALREADY ON THE GROUND FROM SATURDAY NIGHT AND WINDS OF THIS
CALIBER BLOWING AROUND THE DRIER FALLING SNOW...BLOWING SNOW
ISSUES COULD BE SIGNIFICANT ON SUNDAY. THE WIND SPEEDS ARE TOO LOW
FOR BLIZZARD CONDITIONS TO BE REACHED...BUT TRAVEL COULD BE BADLY
AFFECTED ESPECIALLY WHILE THE SNOW IS FALLING. GIVEN THE
COMBINATION OF ALL OF THESE CONDITIONS AND IMPACTS...HAVE ISSUED A
WINTER STORM WARNING FOR MUCH OF THE FORECAST AREA FROM LATE THIS
EVENING THROUGH LATE SUNDAY EVENING.

THE SNOW WILL GRADUALLY END ON SUNDAY EVENING AS THE
AFOREMENTIONED HIGH PRESSURE RIDGE BUILDS INTO THE AREA BRINGING
MUCH COOLER WEATHER ESPECIALLY WITH THE FRESH SNOW PACK IN PLACE.
IOWA WILL THEN REMAIN BENEATH GENERALLY NORTHWESTERLY 500 MB FLOW
FOR THE BULK OF NEXT WEEK...PREVENTING ANY SIGNIFICANT WARMING AND
PREVENTING THE SNOW FROM MELTING MUCH. A SERIES OF MOSTLY WEAK
IMPULSES WILL MOVE THROUGH THIS NORTHWEST FLOW PRODUCING
ADDITIONAL LIGHT SNOW AT TIMES. THE STRONGEST SUCH WAVE MAY
PRODUCE ACCUMULATING SNOWFALL SOMEWHERE AROUND TUESDAY NIGHT...AND
WHILE AMOUNTS APPEAR LIGHT IT MAY STILL HAVE SOME TRAVEL IMPACTS
WITH DITCHES ALREADY FULL. THIS SYSTEM WILL ALSO PUSH THROUGH A
REINFORCING SHOT OF COOL AIR WHICH COULD MAKE WEDNESDAY NIGHT INTO
THURSDAY MORNING THE COLDEST PERIOD OF THE WEEK. TOWARD THURSDAY
AND FRIDAY THERE ARE SOME INDICATIONS OF WEAK RIDGING ALOFT AND
LOW LEVEL WARM AIR ADVECTION...BUT THESE EFFECTS WILL LIKELY BE
TEMPERED BY THE DEEP SNOW PACK EXPECTED TO BE IN PLACE.

&&

.AVIATION...31/06Z
ISSUED AT 1141 PM CST FRI JAN 30 2015

DEVELOPING LOW TO THE SOUTHWEST WILL AFFECT IA SAT INTO SUNDAY.
VFR CONDITIONS WILL DETERIORATE TO MVFR SAT WITH PRECIP AND CIGS.
MIXED PCPN IN THE SRN TAF SITES SATURDAY AFTERNOON AND
EVENING...SNOW IN THE NORTH. IFR TO LIFR STATEWIDE IN SNOW AND
STRATUS SATURDAY NIGHT.

OUTLOOK...CONDITIONS WILL IMPROVE SLOWLY SUNDAY WITH CLEARING
SUNDAY NIGHT INTO MON. NEXT WEATHER SYSTEM TO AFFECT THE AREA BY
MONDAY NIGHT.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...

WINTER STORM WARNING FROM HIGHWAY 3 SOUTH TO THE MISSOUR BORDER
FROM 7 PM THIS EVENING THROUGH 9 PM SUNDAY EVENING.

WINTER WEATHER ADVISORY NORTH OF HIGHWAY 3 FROM 7 PM THIS EVENING
THROUGH 9 PM SUNDAY EVENING.

&&

$$

SHORT TERM...SMALL
LONG TERM...LEE
AVIATION...MS JAN 15




000
FXUS63 KDMX 310915
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
315 AM CST SAT JAN 31 2015

.SHORT TERM /TODAY/...
ISSUED AT 313 AM CST SAT JAN 31 2015

PRECIP TRENDS ARE THE OBVIOUS CONCERN IN THIS PERIOD. CONFIDENCE IS
HIGH IN PROGRESSION OF PRECIP AS A WHOLE...WHICH IS JUST TRYING TO
CROSS THE MO RIVER...BUT MAX TEMPS IN LOWEST 1KM ARE QUITE VARIABLE
IN TIME AND SPACE THROUGH THE RAIN/SNOW/MIX 1-3C THRESHOLD. USING A
GFS/NAM/RAP MODEL CONSENSUS FOR THESE TEMPS RESULTS IN A RAIN/SNOW
MIX ADVANCING INTO CENTRAL IA THIS MORNING AND INTO THE HIGHWAY 20
OR 30 CORRIDORS BY EARLY AFTERNOON WITH MAINLY RAIN SOUTH. TEMPS
BEGIN TO COOL LATE HOWEVER WITH LESS VARIABILITY CHANGING TO MAINLY
SNOW OUTSIDE OF A RAIN/SNOW MIX SE QUARTER TOWARD 00Z. ANY
ACCUMULATIONS SHOULD MAINLY BE UNDER AN INCH THROUGH 00Z DUE TO
EITHER LATE ARRIVAL NORTH OR MELTING AND MIX FARTHER SOUTH. ACCUMS
SHOULD REALLY PICK UP JUST AFTER THIS VALID PERIOD HOWEVER.

MODELS ARE IN GOOD AGREEMENT WITH DEEP WEAK/MODERATE KINEMATIC AND
THERMODYNAMIC FORCING ACCOMPANYING SLAB OF MOISTURE TO SIMILAR DEPTH
IN RIGHT ENTRANCE REGION OF GREAT LAKES TO EAST COAST JET SEGMENT.
HI RES REFLECTIVITY SIMULATIONS SHOW THIS NICELY AS WELL SO HAVE
CATEGORICAL WORDING SOUTH HALF BY AFTERNOON.  GENERALLY FOLLOWED A
BLEND OF NAM/GFS MOS FOR HIGHS WITH A SOMEWHAT HIGHER BLEND TOWARD
THE COOLER NAM NUMBERS DUE TO PRECIP.

.LONG TERM /TONIGHT THROUGH THURSDAY/...
ISSUED AT 313 AM CST SAT JAN 31 2015

A PROLONGED WINTER STORM IS SET TO AFFECT THE AREA FROM TONIGHT
THROUGH SUNDAY. AS APPROACHING NORTHERN AND SOUTHERN STREAM
SYSTEMS MERGE AND PHASE OVER THE MIDWEST WE WILL SEE AN INVERTED
TROUGH EXTEND FROM KANSAS AND NEBRASKA ACROSS CENTRAL IOWA BY THIS
AFTERNOON...WITH A LARGE PRECIP SHIELD MOVING NORTHEAST ACROSS
IOWA LATE TODAY IN ASSOCIATION WITH THE BROAD REGION OF ASCENT
AHEAD OF THE APPROACHING 500 MB TROUGH. TEMPERATURES WILL BE WARM
ENOUGH TO SUPPORT RAIN INITIALLY...ESPECIALLY ALONG AND SOUTH OF
THE SURFACE TROUGH...BUT AFTER DARK TONIGHT IT WILL TRANSITION
OVER TO SNOW PRETTY QUICKLY. SURFACE TEMPERATURES WILL LIKELY
REMAIN ABOVE FREEZING ACROSS ABOUT OUR SOUTHERN HALF OR SO THROUGH
THE LATE EVENING AND PERHAPS UNTIL CLOSE TO MIDNIGHT...HOWEVER
FORECAST SOUNDINGS INDICATE THAT TEMPERATURES WILL BE BELOW
FREEZING JUST ABOVE THE SURFACE AND DYNAMIC COOLING WITHIN THE
COLUMN SHOULD PRODUCE THE QUICK CHANGE TO SNOW. MEANWHILE...WITH
FRONTOGENETICAL FORCING OVERHEAD AND PWATS ABOVE THE 95TH
PERCENTILE FOR THE SEASON GIVEN THE SYSTEM PLENTY OF MOISTURE TO
WORK WITH...QPFS ARE UNSEASONABLY HIGH AND APPROACHING AN INCH IN
SOME AREAS WHICH IS NEAR THE CLIMATOLOGICAL AVERAGE FOR THE
ENTIRE MONTH OF JANUARY. COMBINED WITH A FAIRLY DEEP DENDRITIC
GROWTH ZONE...THIS SHOULD LEAD TO FAIRLY HEAVY SNOW WITH RAPID
ACCUMULATIONS OVERNIGHT ESPECIALLY AFTER ABOUT 8 OR 10 PM AS THE
SNOW REALLY STARTS TO STICK.

ON SUNDAY THE SURFACE LOW/TROUGH WILL SLIDE OFF TO OUR SOUTHEAST
BUT THE 500 MB TROUGH WILL JUST BE PASSING OVERHEAD...PROVIDING
AN ADDITIONAL SLUG OF FORCING AND COLD AIR SUPPORTING MORE SNOW
WITH AN EVEN DEEPER DENDRITIC GROWTH ZONE INDICATED BY ALL MODEL
SOUNDINGS. IN ADDITION...THE TIGHTENING PRESSURE GRADIENT BETWEEN
THE DEPARTING SURFACE LOW AND A LARGE RIDGE BUILDING IN FROM THE
NORTHWEST WILL LEAD TO STRONG NORTH WINDS OF AROUND 20 MPH WITH
HIGHER GUSTS DURING THE DAY SUNDAY. WITH MULTIPLE INCHES OF WETTER
SNOW ALREADY ON THE GROUND FROM SATURDAY NIGHT AND WINDS OF THIS
CALIBER BLOWING AROUND THE DRIER FALLING SNOW...BLOWING SNOW
ISSUES COULD BE SIGNIFICANT ON SUNDAY. THE WIND SPEEDS ARE TOO LOW
FOR BLIZZARD CONDITIONS TO BE REACHED...BUT TRAVEL COULD BE BADLY
AFFECTED ESPECIALLY WHILE THE SNOW IS FALLING. GIVEN THE
COMBINATION OF ALL OF THESE CONDITIONS AND IMPACTS...HAVE ISSUED A
WINTER STORM WARNING FOR MUCH OF THE FORECAST AREA FROM LATE THIS
EVENING THROUGH LATE SUNDAY EVENING.

THE SNOW WILL GRADUALLY END ON SUNDAY EVENING AS THE
AFOREMENTIONED HIGH PRESSURE RIDGE BUILDS INTO THE AREA BRINGING
MUCH COOLER WEATHER ESPECIALLY WITH THE FRESH SNOW PACK IN PLACE.
IOWA WILL THEN REMAIN BENEATH GENERALLY NORTHWESTERLY 500 MB FLOW
FOR THE BULK OF NEXT WEEK...PREVENTING ANY SIGNIFICANT WARMING AND
PREVENTING THE SNOW FROM MELTING MUCH. A SERIES OF MOSTLY WEAK
IMPULSES WILL MOVE THROUGH THIS NORTHWEST FLOW PRODUCING
ADDITIONAL LIGHT SNOW AT TIMES. THE STRONGEST SUCH WAVE MAY
PRODUCE ACCUMULATING SNOWFALL SOMEWHERE AROUND TUESDAY NIGHT...AND
WHILE AMOUNTS APPEAR LIGHT IT MAY STILL HAVE SOME TRAVEL IMPACTS
WITH DITCHES ALREADY FULL. THIS SYSTEM WILL ALSO PUSH THROUGH A
REINFORCING SHOT OF COOL AIR WHICH COULD MAKE WEDNESDAY NIGHT INTO
THURSDAY MORNING THE COLDEST PERIOD OF THE WEEK. TOWARD THURSDAY
AND FRIDAY THERE ARE SOME INDICATIONS OF WEAK RIDGING ALOFT AND
LOW LEVEL WARM AIR ADVECTION...BUT THESE EFFECTS WILL LIKELY BE
TEMPERED BY THE DEEP SNOW PACK EXPECTED TO BE IN PLACE.

&&

.AVIATION...31/06Z
ISSUED AT 1141 PM CST FRI JAN 30 2015

DEVELOPING LOW TO THE SOUTHWEST WILL AFFECT IA SAT INTO SUNDAY.
VFR CONDITIONS WILL DETERIORATE TO MVFR SAT WITH PRECIP AND CIGS.
MIXED PCPN IN THE SRN TAF SITES SATURDAY AFTERNOON AND
EVENING...SNOW IN THE NORTH. IFR TO LIFR STATEWIDE IN SNOW AND
STRATUS SATURDAY NIGHT.

OUTLOOK...CONDITIONS WILL IMPROVE SLOWLY SUNDAY WITH CLEARING
SUNDAY NIGHT INTO MON. NEXT WEATHER SYSTEM TO AFFECT THE AREA BY
MONDAY NIGHT.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...

WINTER STORM WARNING FROM HIGHWAY 3 SOUTH TO THE MISSOUR BORDER
FROM 7 PM THIS EVENING THROUGH 9 PM SUNDAY EVENING.

WINTER WEATHER ADVISORY NORTH OF HIGHWAY 3 FROM 7 PM THIS EVENING
THROUGH 9 PM SUNDAY EVENING.

&&

$$

SHORT TERM...SMALL
LONG TERM...LEE
AVIATION...MS JAN 15





000
FXUS63 KDMX 310544
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1144 PM CST FRI JAN 30 2015

.UPDATE...
ISSUED AT 850 PM CST FRI JAN 30 2015

UPDATE SHORTLY...EXPANDED THE WATCH A ROW FARTHER NORTH. LITTLE
CHANGE OTHERWISE.

&&

.SHORT TERM /TONIGHT/...
ISSUED AT 340 PM CST FRI JAN 30 2015

SURFACE HIGH PRESSURE WILL CONTINUE TO SLIDE EASTWARD TONIGHT
INTO SATURDAY MORNING AND ALLOW FOR WAA TO DEVELOP OVERNIGHT. A
DECENT SURGE OF MID-LEVEL THETA-E ADVECTION BRINGS INTO CLOUD
COVER OVER THE SOUTHWEST PAST 06Z AND PUSHES FURTHER NORTHEAST
INTO OVER MUCH OF THE FORECAST AREA BY 12Z SATURDAY. THE BETTER
FORCING AND DEEP MOISTURE MOVE INTO SOUTHWEST IOWA PAST 12Z AND
THUS HAVE MINIMAL POPS GOING IN THE FAR SOUTHWEST CORNER OF THE
CWA B/T 10-12Z SATURDAY. FOR TEMPS TONIGHT...WENT CLOSER TO THE
RAP FOR LOWS.

.LONG TERM /SATURDAY THROUGH FRIDAY/...
ISSUED AT 340 PM CST FRI JAN 30 2015

PLENTY TO DEAL WITH AS SYSTEM APPROACHES AND THE MODEL SOLUTIONS
CONTINUE TO EVOLVE. CURRENTLY...ALL 12Z RUNS INDICATE THE NORTHERN
STREAM SYSTEM WILL BE STRONGER AND DIG SOUTHEAST INTO THE PLAINS
INTO SUNDAY MORNING AND INTO THE OHIO VALLEY BY SUNDAY NIGHT. WITH
THE STRONGER SYSTEM...THE MOISTURE PLUME FROM THE SOUTHWEST WILL
BE PULLED FARTHER NORTH AND WEST THAN PREVIOUS RUNS HAVE INDICATED
WITH MORE PRECIPITATION EXPECTED ACROSS THE FORECAST AREA. IN
ADDITION...THE SURFACE FRONT WILL BE FARTHER NORTH THAN IN
PREVIOUS FORECAST WITH RAIN/SNOW LINE MAKING IT SOMEWHAT FARTHER
NORTH AS WELL. INITIAL PRECIPITATION WILL BE FORCED BY ISENTROPIC
LIFT AND GOOD MID-LEVEL FRONTOGENETICAL FORCING...ESPECIALLY INTO
SATURDAY NIGHT. THEREAFTER...WITH THE APPROACH OF THE UPPER
WAVE...STRONG MID LEVEL KINEMATICS WILL ALLOW THE PRECIPITATION TO
PERSIST INTO SUNDAY BEFORE FINALLY ENDING BY LATE IN THE DAY AS
THE SYSTEM PULLS EAST.

ANTICIPATE THE PRECIPITATION TO SPREAD NORTHWARD ACROSS THE CWA
FROM SOUTHWEST TO NORTHEAST DURING THE DAY SATURDAY. WITH SURFACE
FRONT SETTLING NEAR THE HWY 30/I80 CORRIDOR BY AFTERNOON...
ANTICIPATE RAIN GENERALLY SOUTH OF THE FRONT WITH SNOW NORTH.
HOWEVER...TO THE NORTH...PRECIPITATION WILL NOT ARRIVE UNTIL LATER
AND DONT ANTICIPATE MUCH ACCUMULATION UNTIL THE EVENING. TO THE
SOUTH...RAIN/SNOW TRANSITION LINE WILL MOVE SLOWLY SOUTHWARD WITH
THE FRONT BUT WILL ACCELERATE SOUTHWARD AROUND SUNSET AS DAYTIME
HEATING DIES OFF AND INCREASED LIFT HELPS SOUNDINGS DROP TOWARD
FREEZING IN THE LOW LEVELS. ONCE THE TRANSITION IN THE SOUTH TO
SNOW IS MADE...THE SNOW WILL CONTINUE WITH THE AFOREMENTIONED
FORCING UNTIL IT PASSES BY LATE SUNDAY AFTERNOON. AS FOR SNOWFALL
RATES...ANTICIPATE THE HIGHEST RATES SATURDAY NIGHT ACROSS
SOUTHERN IOWA WHERE FRONTOGENETICAL FORCING SETS UP WITH THOSE
RATES DECREASING BY SUNDAY MORNING. ANOTHER ROUND OF HIGHER RATES
WILL OCCUR AROUND MIDDAY SUNDAY AS STRONG UPPER FORCING MOVES
ACROSS THE STATE AND SOUNDINGS DEVELOP A DEEP DENDRITIC LAYER.
AS FOR AMOUNTS...MODELS CONTINUE TO EXPAND MORE SNOW NORTHWARD
THROUGH THE STATE WITH A GOOD 3 TO 6 INCHES NORTH OF HWY 30 AND 5
TO 9 INCHES WITH LOCALIZED HIGHER AMOUNTS SOUTH OF HWY 30. QUICK
LOOK AT 18Z NAM WOULD SUGGEST THE POSSIBILITY OF HIGHER AMOUNTS
EVEN FARTHER NORTH AND THIS WILL NEED TO BE TAKEN INTO ACCOUNT IN
SUBSEQUENT SHIFTS SHOULD THE OTHER MODELS FOLLOW SUIT. THE WINTER
STORM WATCH WILL REMAIN IN PLACE WITH THE LIKELIHOOD OF ADVISORIES
AND WARNINGS NEEDED ACROSS THE ENTIRE CWA SEEMING QUITE HIGH.

WINDS WILL ALSO INCREASE BY LATE SATURDAY NIGHT INTO SUNDAY AS THE
PRESSURE GRADIENT TIGHTENS. THIS WILL LIKELY LEAD TO SOME BLOWING
AND DRIFTING OF SNOW ON SUNDAY ALONG WITH REDUCED VISIBILITIES...
ESPECIALLY IN RURAL AREAS. MUCH COLDER AIR WILL ALSO WORK IN
DURING THE DAY WITH WIND CHILLS ALSO CRASHING BELOW ZERO BY SUNDAY
NIGHT AS TEMPERATURES DROP TO NEAR ZERO OR BELOW OVER MUCH OF THE
AREA. AFTER THIS SYSTEM DEPARTS...WARM ADVECTION WILL KICK BACK IN
BY LATE MONDAY TO MONDAY NIGHT WITH ANOTHER THREAT OF SNOW AND A
BRIEF WARMUP ON TUESDAY. THE BROAD NORTHWEST FLOW WILL PERSIST
WITH COLD TEMPERATURES FROM MUCH OF THE WEEK.

&&

.AVIATION...31/06Z
ISSUED AT 1141 PM CST FRI JAN 30 2015

DEVELOPING LOW TO THE SOUTHWEST WILL AFFECT IA SAT INTO SUNDAY.
VFR CONDITIONS WILL DETERIORATE TO MVFR SAT WITH PRECIP AND CIGS.
MIXED PCPN IN THE SRN TAF SITES SATURDAY AFTERNOON AND
EVENING...SNOW IN THE NORTH. IFR TO LIFR STATEWIDE IN SNOW AND
STRATUS SATURDAY NIGHT.

OUTLOOK...CONDITIONS WILL IMPROVE SLOWLY SUNDAY WITH CLEARING
SUNDAY NIGHT INTO MON. NEXT WEATHER SYSTEM TO AFFECT THE AREA BY
MONDAY NIGHT.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY
AFTERNOON FOR ADAIR-ADAMS-APPANOOSE-BOONE-CLARKE-DALLAS-DAVIS-
DECATUR-JASPER-LUCAS-MADISON-MAHASKA-MARION-MARSHALL-MONROE-POLK-
POWESHIEK-RINGGOLD-STORY-TAMA-TAYLOR-UNION-WAPELLO-WARREN-WAYNE.

&&

$$

UPDATE...MS JAN 15
SHORT TERM...PODRAZIK
LONG TERM...COGIL
AVIATION...MS JAN 15





000
FXUS63 KDMX 310544
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1144 PM CST FRI JAN 30 2015

.UPDATE...
ISSUED AT 850 PM CST FRI JAN 30 2015

UPDATE SHORTLY...EXPANDED THE WATCH A ROW FARTHER NORTH. LITTLE
CHANGE OTHERWISE.

&&

.SHORT TERM /TONIGHT/...
ISSUED AT 340 PM CST FRI JAN 30 2015

SURFACE HIGH PRESSURE WILL CONTINUE TO SLIDE EASTWARD TONIGHT
INTO SATURDAY MORNING AND ALLOW FOR WAA TO DEVELOP OVERNIGHT. A
DECENT SURGE OF MID-LEVEL THETA-E ADVECTION BRINGS INTO CLOUD
COVER OVER THE SOUTHWEST PAST 06Z AND PUSHES FURTHER NORTHEAST
INTO OVER MUCH OF THE FORECAST AREA BY 12Z SATURDAY. THE BETTER
FORCING AND DEEP MOISTURE MOVE INTO SOUTHWEST IOWA PAST 12Z AND
THUS HAVE MINIMAL POPS GOING IN THE FAR SOUTHWEST CORNER OF THE
CWA B/T 10-12Z SATURDAY. FOR TEMPS TONIGHT...WENT CLOSER TO THE
RAP FOR LOWS.

.LONG TERM /SATURDAY THROUGH FRIDAY/...
ISSUED AT 340 PM CST FRI JAN 30 2015

PLENTY TO DEAL WITH AS SYSTEM APPROACHES AND THE MODEL SOLUTIONS
CONTINUE TO EVOLVE. CURRENTLY...ALL 12Z RUNS INDICATE THE NORTHERN
STREAM SYSTEM WILL BE STRONGER AND DIG SOUTHEAST INTO THE PLAINS
INTO SUNDAY MORNING AND INTO THE OHIO VALLEY BY SUNDAY NIGHT. WITH
THE STRONGER SYSTEM...THE MOISTURE PLUME FROM THE SOUTHWEST WILL
BE PULLED FARTHER NORTH AND WEST THAN PREVIOUS RUNS HAVE INDICATED
WITH MORE PRECIPITATION EXPECTED ACROSS THE FORECAST AREA. IN
ADDITION...THE SURFACE FRONT WILL BE FARTHER NORTH THAN IN
PREVIOUS FORECAST WITH RAIN/SNOW LINE MAKING IT SOMEWHAT FARTHER
NORTH AS WELL. INITIAL PRECIPITATION WILL BE FORCED BY ISENTROPIC
LIFT AND GOOD MID-LEVEL FRONTOGENETICAL FORCING...ESPECIALLY INTO
SATURDAY NIGHT. THEREAFTER...WITH THE APPROACH OF THE UPPER
WAVE...STRONG MID LEVEL KINEMATICS WILL ALLOW THE PRECIPITATION TO
PERSIST INTO SUNDAY BEFORE FINALLY ENDING BY LATE IN THE DAY AS
THE SYSTEM PULLS EAST.

ANTICIPATE THE PRECIPITATION TO SPREAD NORTHWARD ACROSS THE CWA
FROM SOUTHWEST TO NORTHEAST DURING THE DAY SATURDAY. WITH SURFACE
FRONT SETTLING NEAR THE HWY 30/I80 CORRIDOR BY AFTERNOON...
ANTICIPATE RAIN GENERALLY SOUTH OF THE FRONT WITH SNOW NORTH.
HOWEVER...TO THE NORTH...PRECIPITATION WILL NOT ARRIVE UNTIL LATER
AND DONT ANTICIPATE MUCH ACCUMULATION UNTIL THE EVENING. TO THE
SOUTH...RAIN/SNOW TRANSITION LINE WILL MOVE SLOWLY SOUTHWARD WITH
THE FRONT BUT WILL ACCELERATE SOUTHWARD AROUND SUNSET AS DAYTIME
HEATING DIES OFF AND INCREASED LIFT HELPS SOUNDINGS DROP TOWARD
FREEZING IN THE LOW LEVELS. ONCE THE TRANSITION IN THE SOUTH TO
SNOW IS MADE...THE SNOW WILL CONTINUE WITH THE AFOREMENTIONED
FORCING UNTIL IT PASSES BY LATE SUNDAY AFTERNOON. AS FOR SNOWFALL
RATES...ANTICIPATE THE HIGHEST RATES SATURDAY NIGHT ACROSS
SOUTHERN IOWA WHERE FRONTOGENETICAL FORCING SETS UP WITH THOSE
RATES DECREASING BY SUNDAY MORNING. ANOTHER ROUND OF HIGHER RATES
WILL OCCUR AROUND MIDDAY SUNDAY AS STRONG UPPER FORCING MOVES
ACROSS THE STATE AND SOUNDINGS DEVELOP A DEEP DENDRITIC LAYER.
AS FOR AMOUNTS...MODELS CONTINUE TO EXPAND MORE SNOW NORTHWARD
THROUGH THE STATE WITH A GOOD 3 TO 6 INCHES NORTH OF HWY 30 AND 5
TO 9 INCHES WITH LOCALIZED HIGHER AMOUNTS SOUTH OF HWY 30. QUICK
LOOK AT 18Z NAM WOULD SUGGEST THE POSSIBILITY OF HIGHER AMOUNTS
EVEN FARTHER NORTH AND THIS WILL NEED TO BE TAKEN INTO ACCOUNT IN
SUBSEQUENT SHIFTS SHOULD THE OTHER MODELS FOLLOW SUIT. THE WINTER
STORM WATCH WILL REMAIN IN PLACE WITH THE LIKELIHOOD OF ADVISORIES
AND WARNINGS NEEDED ACROSS THE ENTIRE CWA SEEMING QUITE HIGH.

WINDS WILL ALSO INCREASE BY LATE SATURDAY NIGHT INTO SUNDAY AS THE
PRESSURE GRADIENT TIGHTENS. THIS WILL LIKELY LEAD TO SOME BLOWING
AND DRIFTING OF SNOW ON SUNDAY ALONG WITH REDUCED VISIBILITIES...
ESPECIALLY IN RURAL AREAS. MUCH COLDER AIR WILL ALSO WORK IN
DURING THE DAY WITH WIND CHILLS ALSO CRASHING BELOW ZERO BY SUNDAY
NIGHT AS TEMPERATURES DROP TO NEAR ZERO OR BELOW OVER MUCH OF THE
AREA. AFTER THIS SYSTEM DEPARTS...WARM ADVECTION WILL KICK BACK IN
BY LATE MONDAY TO MONDAY NIGHT WITH ANOTHER THREAT OF SNOW AND A
BRIEF WARMUP ON TUESDAY. THE BROAD NORTHWEST FLOW WILL PERSIST
WITH COLD TEMPERATURES FROM MUCH OF THE WEEK.

&&

.AVIATION...31/06Z
ISSUED AT 1141 PM CST FRI JAN 30 2015

DEVELOPING LOW TO THE SOUTHWEST WILL AFFECT IA SAT INTO SUNDAY.
VFR CONDITIONS WILL DETERIORATE TO MVFR SAT WITH PRECIP AND CIGS.
MIXED PCPN IN THE SRN TAF SITES SATURDAY AFTERNOON AND
EVENING...SNOW IN THE NORTH. IFR TO LIFR STATEWIDE IN SNOW AND
STRATUS SATURDAY NIGHT.

OUTLOOK...CONDITIONS WILL IMPROVE SLOWLY SUNDAY WITH CLEARING
SUNDAY NIGHT INTO MON. NEXT WEATHER SYSTEM TO AFFECT THE AREA BY
MONDAY NIGHT.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY
AFTERNOON FOR ADAIR-ADAMS-APPANOOSE-BOONE-CLARKE-DALLAS-DAVIS-
DECATUR-JASPER-LUCAS-MADISON-MAHASKA-MARION-MARSHALL-MONROE-POLK-
POWESHIEK-RINGGOLD-STORY-TAMA-TAYLOR-UNION-WAPELLO-WARREN-WAYNE.

&&

$$

UPDATE...MS JAN 15
SHORT TERM...PODRAZIK
LONG TERM...COGIL
AVIATION...MS JAN 15




000
FXUS63 KDMX 310251
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
851 PM CST FRI JAN 30 2015

.UPDATE...
ISSUED AT 850 PM CST FRI JAN 30 2015

UPDATE SHORTLY...EXPANDED THE WATCH A ROW FARTHER NORTH. LITTLE
CHANGE OTHERWISE.


&&

.SHORT TERM /TONIGHT/...
ISSUED AT 340 PM CST FRI JAN 30 2015

SURFACE HIGH PRESSURE WILL CONTINUE TO SLIDE EASTWARD TONIGHT
INTO SATURDAY MORNING AND ALLOW FOR WAA TO DEVELOP OVERNIGHT. A
DECENT SURGE OF MID-LEVEL THETA-E ADVECTION BRINGS INTO CLOUD
COVER OVER THE SOUTHWEST PAST 06Z AND PUSHES FURTHER NORTHEAST
INTO OVER MUCH OF THE FORECAST AREA BY 12Z SATURDAY. THE BETTER
FORCING AND DEEP MOISTURE MOVE INTO SOUTHWEST IOWA PAST 12Z AND
THUS HAVE MINIMAL POPS GOING IN THE FAR SOUTHWEST CORNER OF THE
CWA B/T 10-12Z SATURDAY. FOR TEMPS TONIGHT...WENT CLOSER TO THE
RAP FOR LOWS.

.LONG TERM /SATURDAY THROUGH FRIDAY/...
ISSUED AT 340 PM CST FRI JAN 30 2015

PLENTY TO DEAL WITH AS SYSTEM APPROACHES AND THE MODEL SOLUTIONS
CONTINUE TO EVOLVE. CURRENTLY...ALL 12Z RUNS INDICATE THE NORTHERN
STREAM SYSTEM WILL BE STRONGER AND DIG SOUTHEAST INTO THE PLAINS
INTO SUNDAY MORNING AND INTO THE OHIO VALLEY BY SUNDAY NIGHT. WITH
THE STRONGER SYSTEM...THE MOISTURE PLUME FROM THE SOUTHWEST WILL
BE PULLED FARTHER NORTH AND WEST THAN PREVIOUS RUNS HAVE INDICATED
WITH MORE PRECIPITATION EXPECTED ACROSS THE FORECAST AREA. IN
ADDITION...THE SURFACE FRONT WILL BE FARTHER NORTH THAN IN
PREVIOUS FORECAST WITH RAIN/SNOW LINE MAKING IT SOMEWHAT FARTHER
NORTH AS WELL. INITIAL PRECIPITATION WILL BE FORCED BY ISENTROPIC
LIFT AND GOOD MID-LEVEL FRONTOGENETICAL FORCING...ESPECIALLY INTO
SATURDAY NIGHT. THEREAFTER...WITH THE APPROACH OF THE UPPER
WAVE...STRONG MID LEVEL KINEMATICS WILL ALLOW THE PRECIPITATION TO
PERSIST INTO SUNDAY BEFORE FINALLY ENDING BY LATE IN THE DAY AS
THE SYSTEM PULLS EAST.

ANTICIPATE THE PRECIPITATION TO SPREAD NORTHWARD ACROSS THE CWA
FROM SOUTHWEST TO NORTHEAST DURING THE DAY SATURDAY. WITH SURFACE
FRONT SETTLING NEAR THE HWY 30/I80 CORRIDOR BY AFTERNOON...
ANTICIPATE RAIN GENERALLY SOUTH OF THE FRONT WITH SNOW NORTH.
HOWEVER...TO THE NORTH...PRECIPITATION WILL NOT ARRIVE UNTIL LATER
AND DONT ANTICIPATE MUCH ACCUMULATION UNTIL THE EVENING. TO THE
SOUTH...RAIN/SNOW TRANSITION LINE WILL MOVE SLOWLY SOUTHWARD WITH
THE FRONT BUT WILL ACCELERATE SOUTHWARD AROUND SUNSET AS DAYTIME
HEATING DIES OFF AND INCREASED LIFT HELPS SOUNDINGS DROP TOWARD
FREEZING IN THE LOW LEVELS. ONCE THE TRANSITION IN THE SOUTH TO
SNOW IS MADE...THE SNOW WILL CONTINUE WITH THE AFOREMENTIONED
FORCING UNTIL IT PASSES BY LATE SUNDAY AFTERNOON. AS FOR SNOWFALL
RATES...ANTICIPATE THE HIGHEST RATES SATURDAY NIGHT ACROSS
SOUTHERN IOWA WHERE FRONTOGENETICAL FORCING SETS UP WITH THOSE
RATES DECREASING BY SUNDAY MORNING. ANOTHER ROUND OF HIGHER RATES
WILL OCCUR AROUND MIDDAY SUNDAY AS STRONG UPPER FORCING MOVES
ACROSS THE STATE AND SOUNDINGS DEVELOP A DEEP DENDRITIC LAYER.
AS FOR AMOUNTS...MODELS CONTINUE TO EXPAND MORE SNOW NORTHWARD
THROUGH THE STATE WITH A GOOD 3 TO 6 INCHES NORTH OF HWY 30 AND 5
TO 9 INCHES WITH LOCALIZED HIGHER AMOUNTS SOUTH OF HWY 30. QUICK
LOOK AT 18Z NAM WOULD SUGGEST THE POSSIBILITY OF HIGHER AMOUNTS
EVEN FARTHER NORTH AND THIS WILL NEED TO BE TAKEN INTO ACCOUNT IN
SUBSEQUENT SHIFTS SHOULD THE OTHER MODELS FOLLOW SUIT. THE WINTER
STORM WATCH WILL REMAIN IN PLACE WITH THE LIKELIHOOD OF ADVISORIES
AND WARNINGS NEEDED ACROSS THE ENTIRE CWA SEEMING QUITE HIGH.

WINDS WILL ALSO INCREASE BY LATE SATURDAY NIGHT INTO SUNDAY AS THE
PRESSURE GRADIENT TIGHTENS. THIS WILL LIKELY LEAD TO SOME BLOWING
AND DRIFTING OF SNOW ON SUNDAY ALONG WITH REDUCED VISIBILITIES...
ESPECIALLY IN RURAL AREAS. MUCH COLDER AIR WILL ALSO WORK IN
DURING THE DAY WITH WIND CHILLS ALSO CRASHING BELOW ZERO BY SUNDAY
NIGHT AS TEMPERATURES DROP TO NEAR ZERO OR BELOW OVER MUCH OF THE
AREA. AFTER THIS SYSTEM DEPARTS...WARM ADVECTION WILL KICK BACK IN
BY LATE MONDAY TO MONDAY NIGHT WITH ANOTHER THREAT OF SNOW AND A
BRIEF WARMUP ON TUESDAY. THE BROAD NORTHWEST FLOW WILL PERSIST
WITH COLD TEMPERATURES FROM MUCH OF THE WEEK.

&&

.AVIATION...31/00Z
ISSUED AT 518 PM CST FRI JAN 30 2015

HIGH PRESSURE OVER EASTERN IA WILL MOVE EAST AS LOW
PRESSURE DEVELOPS TO  THE SOUTHWEST. VFR CONDITIONS TONIGHT WILL
DETERIORATE FROM SOUTHWEST TO NORTHEAST ON SATURDAY WITH MIXED
RAIN AND SNOW SOUTH AND SNOW NORTH ALONG WITH LOWERING CIGS.

OUTLOOK...WIDESPREAD IFR TO LIFR CONDITIONS IN STRATUS AND SNOW
SATURDAY NIGHT INTO SUNDAY MORNING. SOME IMPROVEMENT SUNDAY WITH
CLEARING EXPECTED LATER SUNDAY NIGHT INTO MONDAY.


&&

.DMX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY
AFTERNOON FOR ADAIR-ADAMS-APPANOOSE-BOONE-CLARKE-DALLAS-DAVIS-
DECATUR-JASPER-LUCAS-MADISON-MAHASKA-MARION-MARSHALL-MONROE-POLK-
POWESHIEK-RINGGOLD-STORY-TAMA-TAYLOR-UNION-WAPELLO-WARREN-WAYNE.

&&

$$

UPDATE...MS JAN 15
SHORT TERM...PODRAZIK
LONG TERM...COGIL
AVIATION...MS JAN 15




000
FXUS63 KDMX 310251
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
851 PM CST FRI JAN 30 2015

.UPDATE...
ISSUED AT 850 PM CST FRI JAN 30 2015

UPDATE SHORTLY...EXPANDED THE WATCH A ROW FARTHER NORTH. LITTLE
CHANGE OTHERWISE.


&&

.SHORT TERM /TONIGHT/...
ISSUED AT 340 PM CST FRI JAN 30 2015

SURFACE HIGH PRESSURE WILL CONTINUE TO SLIDE EASTWARD TONIGHT
INTO SATURDAY MORNING AND ALLOW FOR WAA TO DEVELOP OVERNIGHT. A
DECENT SURGE OF MID-LEVEL THETA-E ADVECTION BRINGS INTO CLOUD
COVER OVER THE SOUTHWEST PAST 06Z AND PUSHES FURTHER NORTHEAST
INTO OVER MUCH OF THE FORECAST AREA BY 12Z SATURDAY. THE BETTER
FORCING AND DEEP MOISTURE MOVE INTO SOUTHWEST IOWA PAST 12Z AND
THUS HAVE MINIMAL POPS GOING IN THE FAR SOUTHWEST CORNER OF THE
CWA B/T 10-12Z SATURDAY. FOR TEMPS TONIGHT...WENT CLOSER TO THE
RAP FOR LOWS.

.LONG TERM /SATURDAY THROUGH FRIDAY/...
ISSUED AT 340 PM CST FRI JAN 30 2015

PLENTY TO DEAL WITH AS SYSTEM APPROACHES AND THE MODEL SOLUTIONS
CONTINUE TO EVOLVE. CURRENTLY...ALL 12Z RUNS INDICATE THE NORTHERN
STREAM SYSTEM WILL BE STRONGER AND DIG SOUTHEAST INTO THE PLAINS
INTO SUNDAY MORNING AND INTO THE OHIO VALLEY BY SUNDAY NIGHT. WITH
THE STRONGER SYSTEM...THE MOISTURE PLUME FROM THE SOUTHWEST WILL
BE PULLED FARTHER NORTH AND WEST THAN PREVIOUS RUNS HAVE INDICATED
WITH MORE PRECIPITATION EXPECTED ACROSS THE FORECAST AREA. IN
ADDITION...THE SURFACE FRONT WILL BE FARTHER NORTH THAN IN
PREVIOUS FORECAST WITH RAIN/SNOW LINE MAKING IT SOMEWHAT FARTHER
NORTH AS WELL. INITIAL PRECIPITATION WILL BE FORCED BY ISENTROPIC
LIFT AND GOOD MID-LEVEL FRONTOGENETICAL FORCING...ESPECIALLY INTO
SATURDAY NIGHT. THEREAFTER...WITH THE APPROACH OF THE UPPER
WAVE...STRONG MID LEVEL KINEMATICS WILL ALLOW THE PRECIPITATION TO
PERSIST INTO SUNDAY BEFORE FINALLY ENDING BY LATE IN THE DAY AS
THE SYSTEM PULLS EAST.

ANTICIPATE THE PRECIPITATION TO SPREAD NORTHWARD ACROSS THE CWA
FROM SOUTHWEST TO NORTHEAST DURING THE DAY SATURDAY. WITH SURFACE
FRONT SETTLING NEAR THE HWY 30/I80 CORRIDOR BY AFTERNOON...
ANTICIPATE RAIN GENERALLY SOUTH OF THE FRONT WITH SNOW NORTH.
HOWEVER...TO THE NORTH...PRECIPITATION WILL NOT ARRIVE UNTIL LATER
AND DONT ANTICIPATE MUCH ACCUMULATION UNTIL THE EVENING. TO THE
SOUTH...RAIN/SNOW TRANSITION LINE WILL MOVE SLOWLY SOUTHWARD WITH
THE FRONT BUT WILL ACCELERATE SOUTHWARD AROUND SUNSET AS DAYTIME
HEATING DIES OFF AND INCREASED LIFT HELPS SOUNDINGS DROP TOWARD
FREEZING IN THE LOW LEVELS. ONCE THE TRANSITION IN THE SOUTH TO
SNOW IS MADE...THE SNOW WILL CONTINUE WITH THE AFOREMENTIONED
FORCING UNTIL IT PASSES BY LATE SUNDAY AFTERNOON. AS FOR SNOWFALL
RATES...ANTICIPATE THE HIGHEST RATES SATURDAY NIGHT ACROSS
SOUTHERN IOWA WHERE FRONTOGENETICAL FORCING SETS UP WITH THOSE
RATES DECREASING BY SUNDAY MORNING. ANOTHER ROUND OF HIGHER RATES
WILL OCCUR AROUND MIDDAY SUNDAY AS STRONG UPPER FORCING MOVES
ACROSS THE STATE AND SOUNDINGS DEVELOP A DEEP DENDRITIC LAYER.
AS FOR AMOUNTS...MODELS CONTINUE TO EXPAND MORE SNOW NORTHWARD
THROUGH THE STATE WITH A GOOD 3 TO 6 INCHES NORTH OF HWY 30 AND 5
TO 9 INCHES WITH LOCALIZED HIGHER AMOUNTS SOUTH OF HWY 30. QUICK
LOOK AT 18Z NAM WOULD SUGGEST THE POSSIBILITY OF HIGHER AMOUNTS
EVEN FARTHER NORTH AND THIS WILL NEED TO BE TAKEN INTO ACCOUNT IN
SUBSEQUENT SHIFTS SHOULD THE OTHER MODELS FOLLOW SUIT. THE WINTER
STORM WATCH WILL REMAIN IN PLACE WITH THE LIKELIHOOD OF ADVISORIES
AND WARNINGS NEEDED ACROSS THE ENTIRE CWA SEEMING QUITE HIGH.

WINDS WILL ALSO INCREASE BY LATE SATURDAY NIGHT INTO SUNDAY AS THE
PRESSURE GRADIENT TIGHTENS. THIS WILL LIKELY LEAD TO SOME BLOWING
AND DRIFTING OF SNOW ON SUNDAY ALONG WITH REDUCED VISIBILITIES...
ESPECIALLY IN RURAL AREAS. MUCH COLDER AIR WILL ALSO WORK IN
DURING THE DAY WITH WIND CHILLS ALSO CRASHING BELOW ZERO BY SUNDAY
NIGHT AS TEMPERATURES DROP TO NEAR ZERO OR BELOW OVER MUCH OF THE
AREA. AFTER THIS SYSTEM DEPARTS...WARM ADVECTION WILL KICK BACK IN
BY LATE MONDAY TO MONDAY NIGHT WITH ANOTHER THREAT OF SNOW AND A
BRIEF WARMUP ON TUESDAY. THE BROAD NORTHWEST FLOW WILL PERSIST
WITH COLD TEMPERATURES FROM MUCH OF THE WEEK.

&&

.AVIATION...31/00Z
ISSUED AT 518 PM CST FRI JAN 30 2015

HIGH PRESSURE OVER EASTERN IA WILL MOVE EAST AS LOW
PRESSURE DEVELOPS TO  THE SOUTHWEST. VFR CONDITIONS TONIGHT WILL
DETERIORATE FROM SOUTHWEST TO NORTHEAST ON SATURDAY WITH MIXED
RAIN AND SNOW SOUTH AND SNOW NORTH ALONG WITH LOWERING CIGS.

OUTLOOK...WIDESPREAD IFR TO LIFR CONDITIONS IN STRATUS AND SNOW
SATURDAY NIGHT INTO SUNDAY MORNING. SOME IMPROVEMENT SUNDAY WITH
CLEARING EXPECTED LATER SUNDAY NIGHT INTO MONDAY.


&&

.DMX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY
AFTERNOON FOR ADAIR-ADAMS-APPANOOSE-BOONE-CLARKE-DALLAS-DAVIS-
DECATUR-JASPER-LUCAS-MADISON-MAHASKA-MARION-MARSHALL-MONROE-POLK-
POWESHIEK-RINGGOLD-STORY-TAMA-TAYLOR-UNION-WAPELLO-WARREN-WAYNE.

&&

$$

UPDATE...MS JAN 15
SHORT TERM...PODRAZIK
LONG TERM...COGIL
AVIATION...MS JAN 15





000
FXUS63 KDMX 302321
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
521 PM CST FRI JAN 30 2015

.SHORT TERM /TONIGHT/...
ISSUED AT 340 PM CST FRI JAN 30 2015

SURFACE HIGH PRESSURE WILL CONTINUE TO SLIDE EASTWARD TONIGHT
INTO SATURDAY MORNING AND ALLOW FOR WAA TO DEVELOP OVERNIGHT. A
DECENT SURGE OF MID-LEVEL THETA-E ADVECTION BRINGS INTO CLOUD
COVER OVER THE SOUTHWEST PAST 06Z AND PUSHES FURTHER NORTHEAST
INTO OVER MUCH OF THE FORECAST AREA BY 12Z SATURDAY. THE BETTER
FORCING AND DEEP MOISTURE MOVE INTO SOUTHWEST IOWA PAST 12Z AND
THUS HAVE MINIMAL POPS GOING IN THE FAR SOUTHWEST CORNER OF THE
CWA B/T 10-12Z SATURDAY. FOR TEMPS TONIGHT...WENT CLOSER TO THE
RAP FOR LOWS.

.LONG TERM /SATURDAY THROUGH FRIDAY/...
ISSUED AT 340 PM CST FRI JAN 30 2015

PLENTY TO DEAL WITH AS SYSTEM APPROACHES AND THE MODEL SOLUTIONS
CONTINUE TO EVOLVE. CURRENTLY...ALL 12Z RUNS INDICATE THE NORTHERN
STREAM SYSTEM WILL BE STRONGER AND DIG SOUTHEAST INTO THE PLAINS
INTO SUNDAY MORNING AND INTO THE OHIO VALLEY BY SUNDAY NIGHT. WITH
THE STRONGER SYSTEM...THE MOISTURE PLUME FROM THE SOUTHWEST WILL
BE PULLED FARTHER NORTH AND WEST THAN PREVIOUS RUNS HAVE INDICATED
WITH MORE PRECIPITATION EXPECTED ACROSS THE FORECAST AREA. IN
ADDITION...THE SURFACE FRONT WILL BE FARTHER NORTH THAN IN
PREVIOUS FORECAST WITH RAIN/SNOW LINE MAKING IT SOMEWHAT FARTHER
NORTH AS WELL. INITIAL PRECIPITATION WILL BE FORCED BY ISENTROPIC
LIFT AND GOOD MID-LEVEL FRONTOGENETICAL FORCING...ESPECIALLY INTO
SATURDAY NIGHT. THEREAFTER...WITH THE APPROACH OF THE UPPER
WAVE...STRONG MID LEVEL KINEMATICS WILL ALLOW THE PRECIPITATION TO
PERSIST INTO SUNDAY BEFORE FINALLY ENDING BY LATE IN THE DAY AS
THE SYSTEM PULLS EAST.

ANTICIPATE THE PRECIPITATION TO SPREAD NORTHWARD ACROSS THE CWA
FROM SOUTHWEST TO NORTHEAST DURING THE DAY SATURDAY. WITH SURFACE
FRONT SETTLING NEAR THE HWY 30/I80 CORRIDOR BY AFTERNOON...
ANTICIPATE RAIN GENERALLY SOUTH OF THE FRONT WITH SNOW NORTH.
HOWEVER...TO THE NORTH...PRECIPITATION WILL NOT ARRIVE UNTIL LATER
AND DONT ANTICIPATE MUCH ACCUMULATION UNTIL THE EVENING. TO THE
SOUTH...RAIN/SNOW TRANSITION LINE WILL MOVE SLOWLY SOUTHWARD WITH
THE FRONT BUT WILL ACCELERATE SOUTHWARD AROUND SUNSET AS DAYTIME
HEATING DIES OFF AND INCREASED LIFT HELPS SOUNDINGS DROP TOWARD
FREEZING IN THE LOW LEVELS. ONCE THE TRANSITION IN THE SOUTH TO
SNOW IS MADE...THE SNOW WILL CONTINUE WITH THE AFOREMENTIONED
FORCING UNTIL IT PASSES BY LATE SUNDAY AFTERNOON. AS FOR SNOWFALL
RATES...ANTICIPATE THE HIGHEST RATES SATURDAY NIGHT ACROSS
SOUTHERN IOWA WHERE FRONTOGENETICAL FORCING SETS UP WITH THOSE
RATES DECREASING BY SUNDAY MORNING. ANOTHER ROUND OF HIGHER RATES
WILL OCCUR AROUND MIDDAY SUNDAY AS STRONG UPPER FORCING MOVES
ACROSS THE STATE AND SOUNDINGS DEVELOP A DEEP DENDRITIC LAYER.
AS FOR AMOUNTS...MODELS CONTINUE TO EXPAND MORE SNOW NORTHWARD
THROUGH THE STATE WITH A GOOD 3 TO 6 INCHES NORTH OF HWY 30 AND 5
TO 9 INCHES WITH LOCALIZED HIGHER AMOUNTS SOUTH OF HWY 30. QUICK
LOOK AT 18Z NAM WOULD SUGGEST THE POSSIBILITY OF HIGHER AMOUNTS
EVEN FARTHER NORTH AND THIS WILL NEED TO BE TAKEN INTO ACCOUNT IN
SUBSEQUENT SHIFTS SHOULD THE OTHER MODELS FOLLOW SUIT. THE WINTER
STORM WATCH WILL REMAIN IN PLACE WITH THE LIKELIHOOD OF ADVISORIES
ANDWARNINGS NEEDED ACROSS THE ENTIRE CWA SEEMING QUITE HIGH.

WINDS WILL ALSO INCREASE BY LATE SATURDAY NIGHT INTO SUNDAY AS THE
PRESSURE GRADIENT TIGHTENS. THIS WILL LIKELY LEAD TO SOME BLOWING
AND DRIFTING OF SNOW ON SUNDAY ALONG WITH REDUCED VISIBILITIES...
ESPECIALLY IN RURAL AREAS. MUCH COLDER AIR WILL ALSO WORK IN
DURING THE DAY WITH WIND CHILLS ALSO CRASHING BELOW ZERO BY SUNDAY
NIGHT AS TEMPERATURES DROP TO NEAR ZERO OR BELOW OVER MUCH OF THE
AREA. AFTER THIS SYSTEM DEPARTS...WARM ADVECTION WILL KICK BACK IN
BY LATE MONDAY TO MONDAY NIGHT WITH ANOTHER THREAT OF SNOW AND A
BRIEF WARMUP ON TUESDAY. THE BROAD NORTHWEST FLOW WILL PERSIST
WITH COLD TEMPERATURES FROM MUCH OF THE WEEK.

&&

.AVIATION...31/00Z
ISSUED AT 518 PM CST FRI JAN 30 2015

HIGH PRESSURE OVER EASTERN IA WILL MOVE EAST AS LOW
PRESSUREDEVELOPSTO THE SOUTHWEST. VFR CONDITIONS TONIGHT WILL
DETERIORATE FROM SOUTHWEST TO NORTHEAST ON SATURDAY WITH MIXED
RAIN AND SNOW SOUTH AND SNOW NORTH ALONG WITH LOWERING CIGS.

OUTLOOK...WIDESPREAD IFR TO LIFR CONDITIONS IN STRATUS AND SNOW
SATURDAY NIGHT INTO SUNDAY MORNING. SOME IMPROVEMENT SUNDAY WITH
CLEARING EXPECTED LATER SUNDAY NIGHT INTO MONDAY.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY
AFTERNOON FOR ADAIR-ADAMS-APPANOOSE-CLARKE-DALLAS-DAVIS-DECATUR-
JASPER-LUCAS-MADISON-MAHASKA-MARION-MONROE-POLK-POWESHIEK-
RINGGOLD-TAYLOR-UNION-WAPELLO-WARREN-WAYNE.

&&

$$

SHORT TERM...PODRAZIK
LONG TERM...COGIL
AVIATION...MS JAN 15




000
FXUS63 KDMX 302321
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
521 PM CST FRI JAN 30 2015

.SHORT TERM /TONIGHT/...
ISSUED AT 340 PM CST FRI JAN 30 2015

SURFACE HIGH PRESSURE WILL CONTINUE TO SLIDE EASTWARD TONIGHT
INTO SATURDAY MORNING AND ALLOW FOR WAA TO DEVELOP OVERNIGHT. A
DECENT SURGE OF MID-LEVEL THETA-E ADVECTION BRINGS INTO CLOUD
COVER OVER THE SOUTHWEST PAST 06Z AND PUSHES FURTHER NORTHEAST
INTO OVER MUCH OF THE FORECAST AREA BY 12Z SATURDAY. THE BETTER
FORCING AND DEEP MOISTURE MOVE INTO SOUTHWEST IOWA PAST 12Z AND
THUS HAVE MINIMAL POPS GOING IN THE FAR SOUTHWEST CORNER OF THE
CWA B/T 10-12Z SATURDAY. FOR TEMPS TONIGHT...WENT CLOSER TO THE
RAP FOR LOWS.

.LONG TERM /SATURDAY THROUGH FRIDAY/...
ISSUED AT 340 PM CST FRI JAN 30 2015

PLENTY TO DEAL WITH AS SYSTEM APPROACHES AND THE MODEL SOLUTIONS
CONTINUE TO EVOLVE. CURRENTLY...ALL 12Z RUNS INDICATE THE NORTHERN
STREAM SYSTEM WILL BE STRONGER AND DIG SOUTHEAST INTO THE PLAINS
INTO SUNDAY MORNING AND INTO THE OHIO VALLEY BY SUNDAY NIGHT. WITH
THE STRONGER SYSTEM...THE MOISTURE PLUME FROM THE SOUTHWEST WILL
BE PULLED FARTHER NORTH AND WEST THAN PREVIOUS RUNS HAVE INDICATED
WITH MORE PRECIPITATION EXPECTED ACROSS THE FORECAST AREA. IN
ADDITION...THE SURFACE FRONT WILL BE FARTHER NORTH THAN IN
PREVIOUS FORECAST WITH RAIN/SNOW LINE MAKING IT SOMEWHAT FARTHER
NORTH AS WELL. INITIAL PRECIPITATION WILL BE FORCED BY ISENTROPIC
LIFT AND GOOD MID-LEVEL FRONTOGENETICAL FORCING...ESPECIALLY INTO
SATURDAY NIGHT. THEREAFTER...WITH THE APPROACH OF THE UPPER
WAVE...STRONG MID LEVEL KINEMATICS WILL ALLOW THE PRECIPITATION TO
PERSIST INTO SUNDAY BEFORE FINALLY ENDING BY LATE IN THE DAY AS
THE SYSTEM PULLS EAST.

ANTICIPATE THE PRECIPITATION TO SPREAD NORTHWARD ACROSS THE CWA
FROM SOUTHWEST TO NORTHEAST DURING THE DAY SATURDAY. WITH SURFACE
FRONT SETTLING NEAR THE HWY 30/I80 CORRIDOR BY AFTERNOON...
ANTICIPATE RAIN GENERALLY SOUTH OF THE FRONT WITH SNOW NORTH.
HOWEVER...TO THE NORTH...PRECIPITATION WILL NOT ARRIVE UNTIL LATER
AND DONT ANTICIPATE MUCH ACCUMULATION UNTIL THE EVENING. TO THE
SOUTH...RAIN/SNOW TRANSITION LINE WILL MOVE SLOWLY SOUTHWARD WITH
THE FRONT BUT WILL ACCELERATE SOUTHWARD AROUND SUNSET AS DAYTIME
HEATING DIES OFF AND INCREASED LIFT HELPS SOUNDINGS DROP TOWARD
FREEZING IN THE LOW LEVELS. ONCE THE TRANSITION IN THE SOUTH TO
SNOW IS MADE...THE SNOW WILL CONTINUE WITH THE AFOREMENTIONED
FORCING UNTIL IT PASSES BY LATE SUNDAY AFTERNOON. AS FOR SNOWFALL
RATES...ANTICIPATE THE HIGHEST RATES SATURDAY NIGHT ACROSS
SOUTHERN IOWA WHERE FRONTOGENETICAL FORCING SETS UP WITH THOSE
RATES DECREASING BY SUNDAY MORNING. ANOTHER ROUND OF HIGHER RATES
WILL OCCUR AROUND MIDDAY SUNDAY AS STRONG UPPER FORCING MOVES
ACROSS THE STATE AND SOUNDINGS DEVELOP A DEEP DENDRITIC LAYER.
AS FOR AMOUNTS...MODELS CONTINUE TO EXPAND MORE SNOW NORTHWARD
THROUGH THE STATE WITH A GOOD 3 TO 6 INCHES NORTH OF HWY 30 AND 5
TO 9 INCHES WITH LOCALIZED HIGHER AMOUNTS SOUTH OF HWY 30. QUICK
LOOK AT 18Z NAM WOULD SUGGEST THE POSSIBILITY OF HIGHER AMOUNTS
EVEN FARTHER NORTH AND THIS WILL NEED TO BE TAKEN INTO ACCOUNT IN
SUBSEQUENT SHIFTS SHOULD THE OTHER MODELS FOLLOW SUIT. THE WINTER
STORM WATCH WILL REMAIN IN PLACE WITH THE LIKELIHOOD OF ADVISORIES
ANDWARNINGS NEEDED ACROSS THE ENTIRE CWA SEEMING QUITE HIGH.

WINDS WILL ALSO INCREASE BY LATE SATURDAY NIGHT INTO SUNDAY AS THE
PRESSURE GRADIENT TIGHTENS. THIS WILL LIKELY LEAD TO SOME BLOWING
AND DRIFTING OF SNOW ON SUNDAY ALONG WITH REDUCED VISIBILITIES...
ESPECIALLY IN RURAL AREAS. MUCH COLDER AIR WILL ALSO WORK IN
DURING THE DAY WITH WIND CHILLS ALSO CRASHING BELOW ZERO BY SUNDAY
NIGHT AS TEMPERATURES DROP TO NEAR ZERO OR BELOW OVER MUCH OF THE
AREA. AFTER THIS SYSTEM DEPARTS...WARM ADVECTION WILL KICK BACK IN
BY LATE MONDAY TO MONDAY NIGHT WITH ANOTHER THREAT OF SNOW AND A
BRIEF WARMUP ON TUESDAY. THE BROAD NORTHWEST FLOW WILL PERSIST
WITH COLD TEMPERATURES FROM MUCH OF THE WEEK.

&&

.AVIATION...31/00Z
ISSUED AT 518 PM CST FRI JAN 30 2015

HIGH PRESSURE OVER EASTERN IA WILL MOVE EAST AS LOW
PRESSUREDEVELOPSTO THE SOUTHWEST. VFR CONDITIONS TONIGHT WILL
DETERIORATE FROM SOUTHWEST TO NORTHEAST ON SATURDAY WITH MIXED
RAIN AND SNOW SOUTH AND SNOW NORTH ALONG WITH LOWERING CIGS.

OUTLOOK...WIDESPREAD IFR TO LIFR CONDITIONS IN STRATUS AND SNOW
SATURDAY NIGHT INTO SUNDAY MORNING. SOME IMPROVEMENT SUNDAY WITH
CLEARING EXPECTED LATER SUNDAY NIGHT INTO MONDAY.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY
AFTERNOON FOR ADAIR-ADAMS-APPANOOSE-CLARKE-DALLAS-DAVIS-DECATUR-
JASPER-LUCAS-MADISON-MAHASKA-MARION-MONROE-POLK-POWESHIEK-
RINGGOLD-TAYLOR-UNION-WAPELLO-WARREN-WAYNE.

&&

$$

SHORT TERM...PODRAZIK
LONG TERM...COGIL
AVIATION...MS JAN 15





000
FXUS63 KDMX 302139
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
339 PM CST FRI JAN 30 2015

.SHORT TERM /TONIGHT/...
ISSUED AT 340 PM CST FRI JAN 30 2015

SURFACE HIGH PRESSURE WILL CONTINUE TO SLIDE EASTWARD TONIGHT
INTO SATURDAY MORNING AND ALLOW FOR WAA TO DEVELOP OVERNIGHT. A
DECENT SURGE OF MID-LEVEL THETA-E ADVECTION BRINGS INTO CLOUD
COVER OVER THE SOUTHWEST PAST 06Z AND PUSHES FURTHER NORTHEAST
INTO OVER MUCH OF THE FORECAST AREA BY 12Z SATURDAY. THE BETTER
FORCING AND DEEP MOISTURE MOVE INTO SOUTHWEST IOWA PAST 12Z AND
THUS HAVE MINIMAL POPS GOING IN THE FAR SOUTHWEST CORNER OF THE
CWA B/T 10-12Z SATURDAY. FOR TEMPS TONIGHT...WENT CLOSER TO THE
RAP FOR LOWS.

.LONG TERM /SATURDAY THROUGH FRIDAY/...
ISSUED AT 340 PM CST FRI JAN 30 2015

PLENTY TO DEAL WITH AS SYSTEM APPROACHES AND THE MODEL SOLUTIONS
CONTINUE TO EVOLVE. CURRENTLY...ALL 12Z RUNS INDICATE THE NORTHERN
STREAM SYSTEM WILL BE STRONGER AND DIG SOUTHEAST INTO THE PLAINS
INTO SUNDAY MORNING AND INTO THE OHIO VALLEY BY SUNDAY NIGHT. WITH
THE STRONGER SYSTEM...THE MOISTURE PLUME FROM THE SOUTHWEST WILL
BE PULLED FARTHER NORTH AND WEST THAN PREVIOUS RUNS HAVE INDICATED
WITH MORE PRECIPITATION EXPECTED ACROSS THE FORECAST AREA. IN
ADDITION...THE SURFACE FRONT WILL BE FARTHER NORTH THAN IN
PREVIOUS FORECAST WITH RAIN/SNOW LINE MAKING IT SOMEWHAT FARTHER
NORTH AS WELL. INITIAL PRECIPITATION WILL BE FORCED BY ISENTROPIC
LIFT AND GOOD MID-LEVEL FRONTOGENETICAL FORCING...ESPECIALLY INTO
SATURDAY NIGHT. THEREAFTER...WITH THE APPROACH OF THE UPPER
WAVE...STRONG MID LEVEL KINEMATICS WILL ALLOW THE PRECIPITATION TO
PERSIST INTO SUNDAY BEFORE FINALLY ENDING BY LATE IN THE DAY AS
THE SYSTEM PULLS EAST.

ANTICIPATE THE PRECIPITATION TO SPREAD NORTHWARD ACROSS THE CWA
FROM SOUTHWEST TO NORTHEAST DURING THE DAY SATURDAY. WITH SURFACE
FRONT SETTLING NEAR THE HWY 30/I80 CORRIDOR BY AFTERNOON...
ANTICIPATE RAIN GENERALLY SOUTH OF THE FRONT WITH SNOW NORTH.
HOWEVER...TO THE NORTH...PRECIPITATION WILL NOT ARRIVE UNTIL LATER
AND DONT ANTICIPATE MUCH ACCUMULATION UNTIL THE EVENING. TO THE
SOUTH...RAIN/SNOW TRANSITION LINE WILL MOVE SLOWLY SOUTHWARD WITH
THE FRONT BUT WILL ACCELERATE SOUTHWARD AROUND SUNSET AS DAYTIME
HEATING DIES OFF AND INCREASED LIFT HELPS SOUNDINGS DROP TOWARD
FREEZING IN THE LOW LEVELS. ONCE THE TRANSITION IN THE SOUTH TO
SNOW IS MADE...THE SNOW WILL CONTINUE WITH THE AFOREMENTIONED
FORCING UNTIL IT PASSES BY LATE SUNDAY AFTERNOON. AS FOR SNOWFALL
RATES...ANTICIPATE THE HIGHEST RATES SATURDAY NIGHT ACROSS
SOUTHERN IOWA WHERE FRONTOGENETICAL FORCING SETS UP WITH THOSE
RATES DECREASING BY SUNDAY MORNING. ANOTHER ROUND OF HIGHER RATES
WILL OCCUR AROUND MIDDAY SUNDAY AS STRONG UPPER FORCING MOVES
ACROSS THE STATE AND SOUNDINGS DEVELOP A DEEP DENDRITIC LAYER.
AS FOR AMOUNTS...MODELS CONTINUE TO EXPAND MORE SNOW NORTHWARD
THROUGH THE STATE WITH A GOOD 3 TO 6 INCHES NORTH OF HWY 30 AND 5
TO 9 INCHES WITH LOCALIZED HIGHER AMOUNTS SOUTH OF HWY 30. QUICK
LOOK AT 18Z NAM WOULD SUGGEST THE POSSIBILITY OF HIGHER AMOUNTS
EVEN FARTHER NORTH AND THIS WILL NEED TO BE TAKEN INTO ACCOUNT IN
SUBSEQUENT SHIFTS SHOULD THE OTHER MODELS FOLLOW SUIT. THE WINTER
STORM WATCH WILL REMAIN IN PLACE WITH THE LIKELIHOOD OF ADVISORIESAND
WARNINGS NEEDED ACROSS THE ENTIRE CWA SEEMING QUITE HIGH.

WINDS WILL ALSO INCREASE BY LATE SATURDAY NIGHT INTO SUNDAY AS THE
PRESSURE GRADIENT TIGHTENS. THIS WILL LIKELY LEAD TO SOME BLOWING
AND DRIFTING OF SNOW ON SUNDAY ALONG WITH REDUCED VISIBILITIES...
ESPECIALLY IN RURAL AREAS. MUCH COLDER AIR WILL ALSO WORK IN
DURING THE DAY WITH WIND CHILLS ALSO CRASHING BELOW ZERO BY SUNDAY
NIGHT AS TEMPERATURES DROP TO NEAR ZERO OR BELOW OVER MUCH OF THE
AREA. AFTER THIS SYSTEM DEPARTS...WARM ADVECTION WILL KICK BACK IN
BY LATE MONDAY TO MONDAY NIGHT WITH ANOTHER THREAT OF SNOW AND A
BRIEF WARMUP ON TUESDAY. THE BROAD NORTHWEST FLOW WILL PERSIST
WITH COLD TEMPERATURES FROM MUCH OF THE WEEK.

&&

.AVIATION...30/18Z
ISSUED AT 1142 AM CST FRI JAN 30 2015

VFR CONDITIONS WILL PREVAIL THROUGH THIS AFTERNOON AND TONIGHT FOR
ALL TAF SITES AS HIGH PRESSURE SLOWLY MOVES EAST. WINDS WILL SHIFT
AND INCREASE OUT OF THE SOUTH THIS EVENING. HAVE INTRODUCED MVFR
CIGS AT DSM/OTM AND MVFR VIS AT OTM BY SATURDAY MORNING WITH THE
ONSET OF PRECIP. INCREASED CONFIDENCE IFR/LIFR CONDITIONS ARE
POSSIBLE BY SATURDAY EVENING AND MAY NEED TO BE ADDRESSED WITH
NEXT TAF ISSUANCE.


&&

.DMX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY
AFTERNOON FOR ADAIR-ADAMS-APPANOOSE-CLARKE-DALLAS-DAVIS-DECATUR-
JASPER-LUCAS-MADISON-MAHASKA-MARION-MONROE-POLK-POWESHIEK-
RINGGOLD-TAYLOR-UNION-WAPELLO-WARREN-WAYNE.

&&

$$

SHORT TERM...PODRAZIK
LONG TERM...COGIL
AVIATION...PODRAZIK




000
FXUS63 KDMX 301742
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1142 AM CST FRI JAN 30 2015

.UPDATE...
ISSUED AT 1142 AM CST FRI JAN 30 2015

MODELS CONTINUE TO BECOME MORE BULLISH ON SNOWFALL ACROSS THE
FORECAST AREA WITH THE WEEKEND SYSTEM.  12Z RUNS CONTINUE TO EXPAND
SNOWFALL ACROSS THE ENTIRE FORECAST AREA AS ISENTROPIC LIFT AND
MOISTURE SURGE NORTHWARD INTO THE STATE ON SATURDAY.  STILL A BAND
OF STRONG FRONTOGENETICAL FORCING ACROSS THE SOUTH ON SATURDAY NIGHT
WITH GOOD KINEMATIC FORCING FROM UPPER WAVE CROSSING THE STATE ON
SUNDAY.  COMBINATION OF FORCING BETWEEN THE TWO SHOULD BE SUFFICIENT
TO PRODUCE SNOW TOTAL APPROACHING THE 24 HOUR CRITERIA FOR WARNING
IN THE SOUTHEAST PORTIONS OF THE CWA.  THEREFORE...HAVE HOISTED A
WATCH ESSENTIALLY ALONG AND SOUTH OF I80 IN THE CWA FOR SATURDAY
NIGHT INTO SUNDAY FOR SNOW TOTALS AND EVENTUALLY SOME BLOWING SNOW
ON SUNDAY AS PRESSURE GRADIENT TIGHTENS AND NORTH WINDS INCREASE.

&&

.SHORT TERM /TODAY/...
ISSUED AT 421 AM CST FRI JAN 30 2015

THERE IS LITTLE SENSIBLE WEATHER OF CONCERN IN THIS PERIOD. A WEAK
SHORT WAVE CURRENTLY OVER MT...WHICH SEEMS TO BE MORE STRONGLY
REFLECTED IN WATER VAPOR IMAGERY THAN THE MODELS...AND IS ALREADY
PRODUCING WEAK BUT MOISTURE STARVED LIFT THROUGH THE MID MO VALLEY.
MOISTURE IS SO LIMITED THAT EVEN CLOUDS ARE STRUGGLING TO DEVELOP
HOWEVER.

TEMP WISE...NAM...GFS...HI RES ARW/NMM RAW MODEL TEMPS AND NAM MOS
ALL SEEM TOO WARM AT THE MOMENT WHILE HRRR...RAP AND GFS MOS ARE
PERFORMING BETTER.  WHILE THE LATTER MODELS ARE CURRENTLY BETTER
CAPTURING THE COOLER TEMPS...THEY ALSO REBOUND JUST AS MUCH AS THE
ONES WITH A WARM BIAS.  THUS HAVE TEMPERED THE DEGREE OF REBOUND
FROM WHAT WAS DEPICTED YESTERDAY JUST SLIGHTLY.

.LONG TERM /TONIGHT THROUGH THURSDAY/...
ISSUED AT 421 AM CST FRI JAN 30 2015

TONIGHT THROUGH SUNDAY NIGHT

MAJOR LONG TERM FOCUS IS ON SNOWFALL EVENT FOR THIS WEEKEND. AFTER
HIGH RUN TO RUN INCONSISTENCY ALL WEEK...THE 12Z THU AND 00Z FRI
RUNS FINALLY SEEM TO BE CONVERGING TO A SOLUTION. LONG STORY
SHORT...IT IS TIME TO BUY ON ACCUMULATING SNOWFALL IN OUR CWA.

NOW HERE`S THE LONG STORY...AN UPPER LEVEL TROUGH CAN BE PICKED UP
VERY EASILY ON WATER VAPOR IMAGERY COMING ON SHORE NEAR THE BAJA
PENINSULA. THIS TROUGH WILL BE MOVING OVER THE SOUTHWESTERN US
FRIDAY...PULLING MOISTURE NORTHWARD. MEANWHILE...A FAST MOVING
TROUGH WILL BE COMING DOWN THOUGH EASTERN CANADA AND RACE THROUGH
THE DAKOTAS FRIDAY INTO SATURDAY. THE MODELS SEEM TO BE HANDLING
THIS TROUGH WELL NOW...AND WE WILL HAVE TO WATCH TO SEE IF ITS
STRENGTH VARIES WHEN IT COMES ONSHORE AND CAN BE MORE READILY
SAMPLED. THESE TWO SYSTEMS WILL GRADUALLY PHASE OVER THE MIDWEST AND
WILL LEAD TO SNOW ACROSS OUR CWA. PRECIP SHOULD BE ARRIVING IN OUR
SOUTHWESTERN CWA BY 12Z-15Z SAT. FCST SOUNDINGS SHOW A WARM NOSE
WHICH PEAKS AT AROUND 2C AT 2500 FT. SFC TEMPS AT THIS TIME WILL BE
NEAR FREEZING...SO PRECIP WILL LIKELY HAVE A SLEET/SN/RN COMPONENT
TO IT. SFC TEMPS THEN WARM TO THE UPPER 30S...SO PRECIP WILL CHANGE
TO RAIN. NEAR SUNSET...TEMPS SHOULD COOL TO WHERE P-TYPE IS ALL SNOW
FOR THE REMAINDER OF THIS EVENT. P-TYPE SATURDAY WILL BE A BIG
PLAYER IN SNOWFALL TOTALS ACROSS OUR SOUTH. WITH SATURDAY MORNING
LOOKING VERY OVERCAST FROM TOP-DOWN CLOUD INCREASES...HAVE BUMPED
TEMPS UP FROM GUIDANCE. THIS WILL OBVIOUSLY YIELD LOWER SNOW AMOUNTS
THAN COOLER MODEL SOLUTIONS.

THERE IS VERY STRONG FRONTOGENETICAL FORCING THROUGHOUT THIS EVENT.
ALL MODELS NOW MOVING BAND OF STRONG SFC MOISTURE TRANSPORT WITH
CONVERGENCE BASICALLY RIGHT ALONG I-80 TO SERVE AS A FOCUSING
MECHANISM FOR PRECIP. COLD AIR WILL BE ADVECTED NORTHWARD OF THIS
BOUNDARY SATURDAY NIGHT WHICH WILL SUSTAIN THIS BOUNDARY INTO
SUNDAY. TO QUANTIFY LOW LEVEL MOISTURE...THERE IS SOME MODEL
VARIATION. SOURCE REGION FOR SFC DWPTS FOR THIS EVENT IS THE LOWER
TRANS PECOS OF WEST TEXAS. THE NAM INITIALIZES A LITTLE HIGH ON
DWPTS AND THE GFS INITIALIZES LOW. THE EURO IS IN THE
MIDDLE...WITH A LEAN CLOSER TO THE NAM. THESE INITIALIZATION
DIFFERENCES ARE CARRIED THROUGHOUT THE DURATION OF THIS SYSTEM AS
THE NAM IS CLEARLY THE MOST BULLISH ON SNOWFALL AND QPF AND THE
GFS THE MOST BEARISH. REGARDLESS OF MODEL...CROSS SECTIONS CLEARLY
SHOW THERE IS MOISTURE TRANSPORT AND ISENTROPIC LIFT INTO THE
DENDRITIC ZONE...WHICH RUNS VERY DEEP. THE PEAK OF THIS FORCING
LOOKS TO RUN FROM AROUND 03Z TO 09Z SUNDAY NEAR THE BOUNDARY.

FOR SNOWFALL TOTALS...THERE IS QUITE A DIFFERENCE IN THE COBB
OUTPUTS. GENERALLY THE 06Z GFS COBB OUTPUT HAS RELATIVELY LITTLE
SNOW...WHEREAS THE NAM IS COMPARATIVELY OFF THE CHARTS.
DIFFERENCES ATTRIBUTED TO GFS COBB PRODUCING LOW SNOWFALL RATIOS
BECAUSE IT IS NOT GENERATING LIFT. THE NAM...ON THE OTHER HAND HAS
20:1 RATIOS SUNDAY...WHICH IS OBVIOUSLY QUITE HIGH...GIVEN SFC
TEMPS STILL IN THE 30S. AS HINTED AT BEFORE...WENT CLOSER TO THE
EURO...WHICH WAS IN THE MIDDLE...WITH A SLIGHT BUMP TO THE NAM. IN
ALL...SNOW RATIOS AND SFC TEMPS SATURDAY WILL BE A BIG FACTOR IN
SNOWFALL TOTALS AND MAY OSCILLATE SLIGHTLY BETWEEN NOW AND
SATURDAY. GENERALLY TAKING A SOMEWHAT CONSERVATIVE STANCE ATTM
WITH 4 TO 6 INCHES NEAR AND SOUTH OF INTERSTATE 80 AND 1 TO 3
INCHES FROM IA/MN BORDER TO HIGHWAY 30.

AS THIS SYSTEM PUSHES OFF TO THE EAST SUNDAY...IT WILL LEAVE BEHIND
FALLING TEMPERATURES DURING THE DAY SUNDAY. RECENT MODEL RUNS HAVE
ALSO BEEN STRENGTHENING THE LOW LEVEL MIXED LAYER...PLACING 25KT
WINDS AT ITS TOP. THEREFORE...AM EXPECTING STRONG WINDS SUNDAY
GUSTING UPWARDS OF 20 KTS TO 25 KTS...WHICH COULD LEAD TO DRIFTING
OF SNOW.

MONDAY THROUGH THURSDAY

OUR RECENT STRETCH OF MILD WEATHER WILL BE A DISTANT MEMORY BY THE
END OF NEXT WEEK WITH A FAIRLY ACTIVE AND OVERALL COLD PATTERN. THE
CENTRAL CONUS WILL BE INFLUENCED BY A BROAD BUT FAIRLY LOW AMPLITUDE
MEAN TROUGH WITH THE PASSAGE OF MULTIPLE WEAK SHORT WAVES. THIS
KEEPS AN EXTENDED PERIOD OF LOW END CHANCES IN THE FORECAST MON
THROUGH WED.  ANY ACCUMULATIONS LOOK MINOR AT THIS POINT WITH THE
FORCING FAIRLY TRANSIENT.

TEMPERATURES WILL BE COLD AND BELOW NORMAL MON...AND MAY REBOUND
BRIEFLY INTO TUE...BUT WILL LIKELY TURN THE OTHER DIRECTION SHARPLY
FOR THE LATTER HALF OF THE NEXT WORK WEEK.  THE PASSAGE OF THE
SYSTEM AROUND WED WILL END OUR PRECIP CHANCES INTO THU BUT ALSO
AMPLIFY THE PATTERN AND BRING A COLD FRONT FOLLOWED BY STRONG ARCTIC
HIGH PRESSURE. 00Z ECMWF AND GFS BOTH DEPICT IA/MN HIGH PRESSURE
AROUND 1040MB SO HAVE LOWERED TEMPS. LOWS WED NIGHT NOW DIP INTO THE
SINGLE DIGITS ABOVE AND BELOW ZERO WITH HIGHS THU NO BETTER THAN THE
TEENS. WITH WIDESPREAD SNOW COVER WOULD NOT BE SURPRISED TO HAVE
FORECAST TEMPS THROUGHOUT THIS ENTIRE PERIOD END UP TOO WARM...BUT
ARE AT LEAST HEADING IN THE RIGHT DIRECTION.

&&

.AVIATION...30/18Z
ISSUED AT 1142 AM CST FRI JAN 30 2015

VFR CONDITIONS WILL PREVAIL THROUGH THIS AFTERNOON AND TONIGHT FOR
ALL TAF SITES AS HIGH PRESSURE SLOWLY MOVES EAST. WINDS WILL SHIFT
AND INCREASE OUT OF THE SOUTH THIS EVENING. HAVE INTRODUCED MVFR
CIGS AT DSM/OTM AND MVFR VIS AT OTM BY SATURDAY MORNING WITH THE
ONSET OF PRECIP. INCREASED CONFIDENCE IFR/LIFR CONDITIONS ARE
POSSIBLE BY SATURDAY EVENING AND MAY NEED TO BE ADDRESSED WITH
NEXT TAF ISSUANCE.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY
AFTERNOON FOR ADAIR-ADAMS-APPANOOSE-CLARKE-DALLAS-DAVIS-DECATUR-
JASPER-LUCAS-MADISON-MAHASKA-MARION-MONROE-POLK-POWESHIEK-
RINGGOLD-TAYLOR-UNION-WAPELLO-WARREN-WAYNE.

&&

$$

UPDATE...COGIL
SHORT TERM...SMALL
LONG TERM...KOTENBERG/SMALL
AVIATION...PODRAZIK





000
FXUS63 KDMX 301742
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1142 AM CST FRI JAN 30 2015

.UPDATE...
ISSUED AT 1142 AM CST FRI JAN 30 2015

MODELS CONTINUE TO BECOME MORE BULLISH ON SNOWFALL ACROSS THE
FORECAST AREA WITH THE WEEKEND SYSTEM.  12Z RUNS CONTINUE TO EXPAND
SNOWFALL ACROSS THE ENTIRE FORECAST AREA AS ISENTROPIC LIFT AND
MOISTURE SURGE NORTHWARD INTO THE STATE ON SATURDAY.  STILL A BAND
OF STRONG FRONTOGENETICAL FORCING ACROSS THE SOUTH ON SATURDAY NIGHT
WITH GOOD KINEMATIC FORCING FROM UPPER WAVE CROSSING THE STATE ON
SUNDAY.  COMBINATION OF FORCING BETWEEN THE TWO SHOULD BE SUFFICIENT
TO PRODUCE SNOW TOTAL APPROACHING THE 24 HOUR CRITERIA FOR WARNING
IN THE SOUTHEAST PORTIONS OF THE CWA.  THEREFORE...HAVE HOISTED A
WATCH ESSENTIALLY ALONG AND SOUTH OF I80 IN THE CWA FOR SATURDAY
NIGHT INTO SUNDAY FOR SNOW TOTALS AND EVENTUALLY SOME BLOWING SNOW
ON SUNDAY AS PRESSURE GRADIENT TIGHTENS AND NORTH WINDS INCREASE.

&&

.SHORT TERM /TODAY/...
ISSUED AT 421 AM CST FRI JAN 30 2015

THERE IS LITTLE SENSIBLE WEATHER OF CONCERN IN THIS PERIOD. A WEAK
SHORT WAVE CURRENTLY OVER MT...WHICH SEEMS TO BE MORE STRONGLY
REFLECTED IN WATER VAPOR IMAGERY THAN THE MODELS...AND IS ALREADY
PRODUCING WEAK BUT MOISTURE STARVED LIFT THROUGH THE MID MO VALLEY.
MOISTURE IS SO LIMITED THAT EVEN CLOUDS ARE STRUGGLING TO DEVELOP
HOWEVER.

TEMP WISE...NAM...GFS...HI RES ARW/NMM RAW MODEL TEMPS AND NAM MOS
ALL SEEM TOO WARM AT THE MOMENT WHILE HRRR...RAP AND GFS MOS ARE
PERFORMING BETTER.  WHILE THE LATTER MODELS ARE CURRENTLY BETTER
CAPTURING THE COOLER TEMPS...THEY ALSO REBOUND JUST AS MUCH AS THE
ONES WITH A WARM BIAS.  THUS HAVE TEMPERED THE DEGREE OF REBOUND
FROM WHAT WAS DEPICTED YESTERDAY JUST SLIGHTLY.

.LONG TERM /TONIGHT THROUGH THURSDAY/...
ISSUED AT 421 AM CST FRI JAN 30 2015

TONIGHT THROUGH SUNDAY NIGHT

MAJOR LONG TERM FOCUS IS ON SNOWFALL EVENT FOR THIS WEEKEND. AFTER
HIGH RUN TO RUN INCONSISTENCY ALL WEEK...THE 12Z THU AND 00Z FRI
RUNS FINALLY SEEM TO BE CONVERGING TO A SOLUTION. LONG STORY
SHORT...IT IS TIME TO BUY ON ACCUMULATING SNOWFALL IN OUR CWA.

NOW HERE`S THE LONG STORY...AN UPPER LEVEL TROUGH CAN BE PICKED UP
VERY EASILY ON WATER VAPOR IMAGERY COMING ON SHORE NEAR THE BAJA
PENINSULA. THIS TROUGH WILL BE MOVING OVER THE SOUTHWESTERN US
FRIDAY...PULLING MOISTURE NORTHWARD. MEANWHILE...A FAST MOVING
TROUGH WILL BE COMING DOWN THOUGH EASTERN CANADA AND RACE THROUGH
THE DAKOTAS FRIDAY INTO SATURDAY. THE MODELS SEEM TO BE HANDLING
THIS TROUGH WELL NOW...AND WE WILL HAVE TO WATCH TO SEE IF ITS
STRENGTH VARIES WHEN IT COMES ONSHORE AND CAN BE MORE READILY
SAMPLED. THESE TWO SYSTEMS WILL GRADUALLY PHASE OVER THE MIDWEST AND
WILL LEAD TO SNOW ACROSS OUR CWA. PRECIP SHOULD BE ARRIVING IN OUR
SOUTHWESTERN CWA BY 12Z-15Z SAT. FCST SOUNDINGS SHOW A WARM NOSE
WHICH PEAKS AT AROUND 2C AT 2500 FT. SFC TEMPS AT THIS TIME WILL BE
NEAR FREEZING...SO PRECIP WILL LIKELY HAVE A SLEET/SN/RN COMPONENT
TO IT. SFC TEMPS THEN WARM TO THE UPPER 30S...SO PRECIP WILL CHANGE
TO RAIN. NEAR SUNSET...TEMPS SHOULD COOL TO WHERE P-TYPE IS ALL SNOW
FOR THE REMAINDER OF THIS EVENT. P-TYPE SATURDAY WILL BE A BIG
PLAYER IN SNOWFALL TOTALS ACROSS OUR SOUTH. WITH SATURDAY MORNING
LOOKING VERY OVERCAST FROM TOP-DOWN CLOUD INCREASES...HAVE BUMPED
TEMPS UP FROM GUIDANCE. THIS WILL OBVIOUSLY YIELD LOWER SNOW AMOUNTS
THAN COOLER MODEL SOLUTIONS.

THERE IS VERY STRONG FRONTOGENETICAL FORCING THROUGHOUT THIS EVENT.
ALL MODELS NOW MOVING BAND OF STRONG SFC MOISTURE TRANSPORT WITH
CONVERGENCE BASICALLY RIGHT ALONG I-80 TO SERVE AS A FOCUSING
MECHANISM FOR PRECIP. COLD AIR WILL BE ADVECTED NORTHWARD OF THIS
BOUNDARY SATURDAY NIGHT WHICH WILL SUSTAIN THIS BOUNDARY INTO
SUNDAY. TO QUANTIFY LOW LEVEL MOISTURE...THERE IS SOME MODEL
VARIATION. SOURCE REGION FOR SFC DWPTS FOR THIS EVENT IS THE LOWER
TRANS PECOS OF WEST TEXAS. THE NAM INITIALIZES A LITTLE HIGH ON
DWPTS AND THE GFS INITIALIZES LOW. THE EURO IS IN THE
MIDDLE...WITH A LEAN CLOSER TO THE NAM. THESE INITIALIZATION
DIFFERENCES ARE CARRIED THROUGHOUT THE DURATION OF THIS SYSTEM AS
THE NAM IS CLEARLY THE MOST BULLISH ON SNOWFALL AND QPF AND THE
GFS THE MOST BEARISH. REGARDLESS OF MODEL...CROSS SECTIONS CLEARLY
SHOW THERE IS MOISTURE TRANSPORT AND ISENTROPIC LIFT INTO THE
DENDRITIC ZONE...WHICH RUNS VERY DEEP. THE PEAK OF THIS FORCING
LOOKS TO RUN FROM AROUND 03Z TO 09Z SUNDAY NEAR THE BOUNDARY.

FOR SNOWFALL TOTALS...THERE IS QUITE A DIFFERENCE IN THE COBB
OUTPUTS. GENERALLY THE 06Z GFS COBB OUTPUT HAS RELATIVELY LITTLE
SNOW...WHEREAS THE NAM IS COMPARATIVELY OFF THE CHARTS.
DIFFERENCES ATTRIBUTED TO GFS COBB PRODUCING LOW SNOWFALL RATIOS
BECAUSE IT IS NOT GENERATING LIFT. THE NAM...ON THE OTHER HAND HAS
20:1 RATIOS SUNDAY...WHICH IS OBVIOUSLY QUITE HIGH...GIVEN SFC
TEMPS STILL IN THE 30S. AS HINTED AT BEFORE...WENT CLOSER TO THE
EURO...WHICH WAS IN THE MIDDLE...WITH A SLIGHT BUMP TO THE NAM. IN
ALL...SNOW RATIOS AND SFC TEMPS SATURDAY WILL BE A BIG FACTOR IN
SNOWFALL TOTALS AND MAY OSCILLATE SLIGHTLY BETWEEN NOW AND
SATURDAY. GENERALLY TAKING A SOMEWHAT CONSERVATIVE STANCE ATTM
WITH 4 TO 6 INCHES NEAR AND SOUTH OF INTERSTATE 80 AND 1 TO 3
INCHES FROM IA/MN BORDER TO HIGHWAY 30.

AS THIS SYSTEM PUSHES OFF TO THE EAST SUNDAY...IT WILL LEAVE BEHIND
FALLING TEMPERATURES DURING THE DAY SUNDAY. RECENT MODEL RUNS HAVE
ALSO BEEN STRENGTHENING THE LOW LEVEL MIXED LAYER...PLACING 25KT
WINDS AT ITS TOP. THEREFORE...AM EXPECTING STRONG WINDS SUNDAY
GUSTING UPWARDS OF 20 KTS TO 25 KTS...WHICH COULD LEAD TO DRIFTING
OF SNOW.

MONDAY THROUGH THURSDAY

OUR RECENT STRETCH OF MILD WEATHER WILL BE A DISTANT MEMORY BY THE
END OF NEXT WEEK WITH A FAIRLY ACTIVE AND OVERALL COLD PATTERN. THE
CENTRAL CONUS WILL BE INFLUENCED BY A BROAD BUT FAIRLY LOW AMPLITUDE
MEAN TROUGH WITH THE PASSAGE OF MULTIPLE WEAK SHORT WAVES. THIS
KEEPS AN EXTENDED PERIOD OF LOW END CHANCES IN THE FORECAST MON
THROUGH WED.  ANY ACCUMULATIONS LOOK MINOR AT THIS POINT WITH THE
FORCING FAIRLY TRANSIENT.

TEMPERATURES WILL BE COLD AND BELOW NORMAL MON...AND MAY REBOUND
BRIEFLY INTO TUE...BUT WILL LIKELY TURN THE OTHER DIRECTION SHARPLY
FOR THE LATTER HALF OF THE NEXT WORK WEEK.  THE PASSAGE OF THE
SYSTEM AROUND WED WILL END OUR PRECIP CHANCES INTO THU BUT ALSO
AMPLIFY THE PATTERN AND BRING A COLD FRONT FOLLOWED BY STRONG ARCTIC
HIGH PRESSURE. 00Z ECMWF AND GFS BOTH DEPICT IA/MN HIGH PRESSURE
AROUND 1040MB SO HAVE LOWERED TEMPS. LOWS WED NIGHT NOW DIP INTO THE
SINGLE DIGITS ABOVE AND BELOW ZERO WITH HIGHS THU NO BETTER THAN THE
TEENS. WITH WIDESPREAD SNOW COVER WOULD NOT BE SURPRISED TO HAVE
FORECAST TEMPS THROUGHOUT THIS ENTIRE PERIOD END UP TOO WARM...BUT
ARE AT LEAST HEADING IN THE RIGHT DIRECTION.

&&

.AVIATION...30/18Z
ISSUED AT 1142 AM CST FRI JAN 30 2015

VFR CONDITIONS WILL PREVAIL THROUGH THIS AFTERNOON AND TONIGHT FOR
ALL TAF SITES AS HIGH PRESSURE SLOWLY MOVES EAST. WINDS WILL SHIFT
AND INCREASE OUT OF THE SOUTH THIS EVENING. HAVE INTRODUCED MVFR
CIGS AT DSM/OTM AND MVFR VIS AT OTM BY SATURDAY MORNING WITH THE
ONSET OF PRECIP. INCREASED CONFIDENCE IFR/LIFR CONDITIONS ARE
POSSIBLE BY SATURDAY EVENING AND MAY NEED TO BE ADDRESSED WITH
NEXT TAF ISSUANCE.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY
AFTERNOON FOR ADAIR-ADAMS-APPANOOSE-CLARKE-DALLAS-DAVIS-DECATUR-
JASPER-LUCAS-MADISON-MAHASKA-MARION-MONROE-POLK-POWESHIEK-
RINGGOLD-TAYLOR-UNION-WAPELLO-WARREN-WAYNE.

&&

$$

UPDATE...COGIL
SHORT TERM...SMALL
LONG TERM...KOTENBERG/SMALL
AVIATION...PODRAZIK




000
FXUS63 KDMX 301136
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
536 AM CST FRI JAN 30 2015

.SHORT TERM /TODAY/...
ISSUED AT 421 AM CST FRI JAN 30 2015

THERE IS LITTLE SENSIBLE WEATHER OF CONCERN IN THIS PERIOD. A WEAK
SHORT WAVE CURRENTLY OVER MT...WHICH SEEMS TO BE MORE STRONGLY
REFLECTED IN WATER VAPOR IMAGERY THAN THE MODELS...AND IS ALREADY
PRODUCING WEAK BUT MOISTURE STARVED LIFT THROUGH THE MID MO VALLEY.
MOISTURE IS SO LIMITED THAT EVEN CLOUDS ARE STRUGGLING TO DEVELOP
HOWEVER.

TEMP WISE...NAM...GFS...HI RES ARW/NMM RAW MODEL TEMPS AND NAM MOS
ALL SEEM TOO WARM AT THE MOMENT WHILE HRRR...RAP AND GFS MOS ARE
PERFORMING BETTER.  WHILE THE LATTER MODELS ARE CURRENTLY BETTER
CAPTURING THE COOLER TEMPS...THEY ALSO REBOUND JUST AS MUCH AS THE
ONES WITH A WARM BIAS.  THUS HAVE TEMPERED THE DEGREE OF REBOUND
FROM WHAT WAS DEPICTED YESTERDAY JUST SLIGHTLY.

.LONG TERM /TONIGHT THROUGH THURSDAY/...
ISSUED AT 421 AM CST FRI JAN 30 2015

TONIGHT THROUGH SUNDAY NIGHT

MAJOR LONG TERM FOCUS IS ON SNOWFALL EVENT FOR THIS WEEKEND. AFTER
HIGH RUN TO RUN INCONSISTENCY ALL WEEK...THE 12Z THU AND 00Z FRI
RUNS FINALLY SEEM TO BE CONVERGING TO A SOLUTION. LONG STORY
SHORT...IT IS TIME TO BUY ON ACCUMULATING SNOWFALL IN OUR CWA.

NOW HERE`S THE LONG STORY...AN UPPER LEVEL TROUGH CAN BE PICKED UP
VERY EASILY ON WATER VAPOR IMAGERY COMING ON SHORE NEAR THE BAJA
PENINSULA. THIS TROUGH WILL BE MOVING OVER THE SOUTHWESTERN US
FRIDAY...PULLING MOISTURE NORTHWARD. MEANWHILE...A FAST MOVING
TROUGH WILL BE COMING DOWN THOUGH EASTERN CANADA AND RACE THROUGH
THE DAKOTAS FRIDAY INTO SATURDAY. THE MODELS SEEM TO BE HANDLING
THIS TROUGH WELL NOW...AND WE WILL HAVE TO WATCH TO SEE IF ITS
STRENGTH VARIES WHEN IT COMES ONSHORE AND CAN BE MORE READILY
SAMPLED. THESE TWO SYSTEMS WILL GRADUALLY PHASE OVER THE MIDWEST AND
WILL LEAD TO SNOW ACROSS OUR CWA. PRECIP SHOULD BE ARRIVING IN OUR
SOUTHWESTERN CWA BY 12Z-15Z SAT. FCST SOUNDINGS SHOW A WARM NOSE
WHICH PEAKS AT AROUND 2C AT 2500 FT. SFC TEMPS AT THIS TIME WILL BE
NEAR FREEZING...SO PRECIP WILL LIKELY HAVE A SLEET/SN/RN COMPONENT
TO IT. SFC TEMPS THEN WARM TO THE UPPER 30S...SO PRECIP WILL CHANGE
TO RAIN. NEAR SUNSET...TEMPS SHOULD COOL TO WHERE P-TYPE IS ALL SNOW
FOR THE REMAINDER OF THIS EVENT. P-TYPE SATURDAY WILL BE A BIG
PLAYER IN SNOWFALL TOTALS ACROSS OUR SOUTH. WITH SATURDAY MORNING
LOOKING VERY OVERCAST FROM TOP-DOWN CLOUD INCREASES...HAVE BUMPED
TEMPS UP FROM GUIDANCE. THIS WILL OBVIOUSLY YIELD LOWER SNOW AMOUNTS
THAN COOLER MODEL SOLUTIONS.

THERE IS VERY STRONG FRONTOGENETICAL FORCING THROUGHOUT THIS EVENT.
ALL MODELS NOW MOVING BAND OF STRONG SFC MOISTURE TRANSPORT WITH
CONVERGENCE BASICALLY RIGHT ALONG I-80 TO SERVE AS A FOCUSING
MECHANISM FOR PRECIP. COLD AIR WILL BE ADVECTED NORTHWARD OF THIS
BOUNDARY SATURDAY NIGHT WHICH WILL SUSTAIN THIS BOUNDARY INTO
SUNDAY. TO QUANTIFY LOW LEVEL MOISTURE...THERE IS SOME MODEL
VARIATION. SOURCE REGION FOR SFC DWPTS FOR THIS EVENT IS THE LOWER
TRANS PECOS OF WEST TEXAS. THE NAM INITIALIZES A LITTLE HIGH ON
DWPTS AND THE GFS INITIALIZES LOW. THE EURO IS IN THE
MIDDLE...WITH A LEAN CLOSER TO THE NAM. THESE INITIALIZATION
DIFFERENCES ARE CARRIED THROUGHOUT THE DURATION OF THIS SYSTEM AS
THE NAM IS CLEARLY THE MOST BULLISH ON SNOWFALL AND QPF AND THE
GFS THE MOST BEARISH. REGARDLESS OF MODEL...CROSS SECTIONS CLEARLY
SHOW THERE IS MOISTURE TRANSPORT AND ISENTROPIC LIFT INTO THE
DENDRITIC ZONE...WHICH RUNS VERY DEEP. THE PEAK OF THIS FORCING
LOOKS TO RUN FROM AROUND 03Z TO 09Z SUNDAY NEAR THE BOUNDARY.

FOR SNOWFALL TOTALS...THERE IS QUITE A DIFFERENCE IN THE COBB
OUTPUTS. GENERALLY THE 06Z GFS COBB OUTPUT HAS RELATIVELY LITTLE
SNOW...WHEREAS THE NAM IS COMPARATIVELY OFF THE CHARTS.
DIFFERENCES ATTRIBUTED TO GFS COBB PRODUCING LOW SNOWFALL RATIOS
BECAUSE IT IS NOT GENERATING LIFT. THE NAM...ON THE OTHER HAND HAS
20:1 RATIOS SUNDAY...WHICH IS OBVIOUSLY QUITE HIGH...GIVEN SFC
TEMPS STILL IN THE 30S. AS HINTED AT BEFORE...WENT CLOSER TO THE
EURO...WHICH WAS IN THE MIDDLE...WITH A SLIGHT BUMP TO THE NAM. IN
ALL...SNOW RATIOS AND SFC TEMPS SATURDAY WILL BE A BIG FACTOR IN
SNOWFALL TOTALS AND MAY OSCILLATE SLIGHTLY BETWEEN NOW AND
SATURDAY. GENERALLY TAKING A SOMEWHAT CONSERVATIVE STANCE ATTM
WITH 4 TO 6 INCHES NEAR AND SOUTH OF INTERSTATE 80 AND 1 TO 3
INCHES FROM IA/MN BORDER TO HIGHWAY 30.

AS THIS SYSTEM PUSHES OFF TO THE EAST SUNDAY...IT WILL LEAVE BEHIND
FALLING TEMPERATURES DURING THE DAY SUNDAY. RECENT MODEL RUNS HAVE
ALSO BEEN STRENGTHENING THE LOW LEVEL MIXED LAYER...PLACING 25KT
WINDS AT ITS TOP. THEREFORE...AM EXPECTING STRONG WINDS SUNDAY
GUSTING UPWARDS OF 20 KTS TO 25 KTS...WHICH COULD LEAD TO DRIFTING
OF SNOW.

MONDAY THROUGH THURSDAY

OUR RECENT STRETCH OF MILD WEATHER WILL BE A DISTANT MEMORY BY THE
END OF NEXT WEEK WITH A FAIRLY ACTIVE AND OVERALL COLD PATTERN. THE
CENTRAL CONUS WILL BE INFLUENCED BY A BROAD BUT FAIRLY LOW AMPLITUDE
MEAN TROUGH WITH THE PASSAGE OF MULTIPLE WEAK SHORT WAVES. THIS
KEEPS AN EXTENDED PERIOD OF LOW END CHANCES IN THE FORECAST MON
THROUGH WED.  ANY ACCUMULATIONS LOOK MINOR AT THIS POINT WITH THE
FORCING FAIRLY TRANSIENT.

TEMPERATURES WILL BE COLD AND BELOW NORMAL MON...AND MAY REBOUND
BRIEFLY INTO TUE...BUT WILL LIKELY TURN THE OTHER DIRECTION SHARPLY
FOR THE LATTER HALF OF THE NEXT WORK WEEK.  THE PASSAGE OF THE
SYSTEM AROUND WED WILL END OUR PRECIP CHANCES INTO THU BUT ALSO
AMPLIFY THE PATTERN AND BRING A COLD FRONT FOLLOWED BY STRONG ARCTIC
HIGH PRESSURE. 00Z ECMWF AND GFS BOTH DEPICT IA/MN HIGH PRESSURE
AROUND 1040MB SO HAVE LOWERED TEMPS. LOWS WED NIGHT NOW DIP INTO THE
SINGLE DIGITS ABOVE AND BELOW ZERO WITH HIGHS THU NO BETTER THAN THE
TEENS. WITH WIDESPREAD SNOW COVER WOULD NOT BE SURPRISED TO HAVE
FORECAST TEMPS THROUGHOUT THIS ENTIRE PERIOD END UP TOO WARM...BUT
ARE AT LEAST HEADING IN THE RIGHT DIRECTION.

&&

.AVIATION...30/12Z
ISSUED AT 535 AM CST FRI JAN 30 2015

LITTLE OF CONCERN THROUGH THE PERIOD WITH VFR CONDITIONS AND
RELATIVELY LIGHT WINDS ANTICIPATED. VERY PATCHY MVFR STRATUS EARLY
THIS MORNING IS NOT EXPECTED TO AFFECT TAF SITES THIS MORNING.
OTHERWISE NOTHING MORE THAN GRADUALLY INCREASING HIGH CLOUDINESS.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...SMALL
LONG TERM...KOTENBERG/SMALL
AVIATION...SMALL




000
FXUS63 KDMX 301136
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
536 AM CST FRI JAN 30 2015

.SHORT TERM /TODAY/...
ISSUED AT 421 AM CST FRI JAN 30 2015

THERE IS LITTLE SENSIBLE WEATHER OF CONCERN IN THIS PERIOD. A WEAK
SHORT WAVE CURRENTLY OVER MT...WHICH SEEMS TO BE MORE STRONGLY
REFLECTED IN WATER VAPOR IMAGERY THAN THE MODELS...AND IS ALREADY
PRODUCING WEAK BUT MOISTURE STARVED LIFT THROUGH THE MID MO VALLEY.
MOISTURE IS SO LIMITED THAT EVEN CLOUDS ARE STRUGGLING TO DEVELOP
HOWEVER.

TEMP WISE...NAM...GFS...HI RES ARW/NMM RAW MODEL TEMPS AND NAM MOS
ALL SEEM TOO WARM AT THE MOMENT WHILE HRRR...RAP AND GFS MOS ARE
PERFORMING BETTER.  WHILE THE LATTER MODELS ARE CURRENTLY BETTER
CAPTURING THE COOLER TEMPS...THEY ALSO REBOUND JUST AS MUCH AS THE
ONES WITH A WARM BIAS.  THUS HAVE TEMPERED THE DEGREE OF REBOUND
FROM WHAT WAS DEPICTED YESTERDAY JUST SLIGHTLY.

.LONG TERM /TONIGHT THROUGH THURSDAY/...
ISSUED AT 421 AM CST FRI JAN 30 2015

TONIGHT THROUGH SUNDAY NIGHT

MAJOR LONG TERM FOCUS IS ON SNOWFALL EVENT FOR THIS WEEKEND. AFTER
HIGH RUN TO RUN INCONSISTENCY ALL WEEK...THE 12Z THU AND 00Z FRI
RUNS FINALLY SEEM TO BE CONVERGING TO A SOLUTION. LONG STORY
SHORT...IT IS TIME TO BUY ON ACCUMULATING SNOWFALL IN OUR CWA.

NOW HERE`S THE LONG STORY...AN UPPER LEVEL TROUGH CAN BE PICKED UP
VERY EASILY ON WATER VAPOR IMAGERY COMING ON SHORE NEAR THE BAJA
PENINSULA. THIS TROUGH WILL BE MOVING OVER THE SOUTHWESTERN US
FRIDAY...PULLING MOISTURE NORTHWARD. MEANWHILE...A FAST MOVING
TROUGH WILL BE COMING DOWN THOUGH EASTERN CANADA AND RACE THROUGH
THE DAKOTAS FRIDAY INTO SATURDAY. THE MODELS SEEM TO BE HANDLING
THIS TROUGH WELL NOW...AND WE WILL HAVE TO WATCH TO SEE IF ITS
STRENGTH VARIES WHEN IT COMES ONSHORE AND CAN BE MORE READILY
SAMPLED. THESE TWO SYSTEMS WILL GRADUALLY PHASE OVER THE MIDWEST AND
WILL LEAD TO SNOW ACROSS OUR CWA. PRECIP SHOULD BE ARRIVING IN OUR
SOUTHWESTERN CWA BY 12Z-15Z SAT. FCST SOUNDINGS SHOW A WARM NOSE
WHICH PEAKS AT AROUND 2C AT 2500 FT. SFC TEMPS AT THIS TIME WILL BE
NEAR FREEZING...SO PRECIP WILL LIKELY HAVE A SLEET/SN/RN COMPONENT
TO IT. SFC TEMPS THEN WARM TO THE UPPER 30S...SO PRECIP WILL CHANGE
TO RAIN. NEAR SUNSET...TEMPS SHOULD COOL TO WHERE P-TYPE IS ALL SNOW
FOR THE REMAINDER OF THIS EVENT. P-TYPE SATURDAY WILL BE A BIG
PLAYER IN SNOWFALL TOTALS ACROSS OUR SOUTH. WITH SATURDAY MORNING
LOOKING VERY OVERCAST FROM TOP-DOWN CLOUD INCREASES...HAVE BUMPED
TEMPS UP FROM GUIDANCE. THIS WILL OBVIOUSLY YIELD LOWER SNOW AMOUNTS
THAN COOLER MODEL SOLUTIONS.

THERE IS VERY STRONG FRONTOGENETICAL FORCING THROUGHOUT THIS EVENT.
ALL MODELS NOW MOVING BAND OF STRONG SFC MOISTURE TRANSPORT WITH
CONVERGENCE BASICALLY RIGHT ALONG I-80 TO SERVE AS A FOCUSING
MECHANISM FOR PRECIP. COLD AIR WILL BE ADVECTED NORTHWARD OF THIS
BOUNDARY SATURDAY NIGHT WHICH WILL SUSTAIN THIS BOUNDARY INTO
SUNDAY. TO QUANTIFY LOW LEVEL MOISTURE...THERE IS SOME MODEL
VARIATION. SOURCE REGION FOR SFC DWPTS FOR THIS EVENT IS THE LOWER
TRANS PECOS OF WEST TEXAS. THE NAM INITIALIZES A LITTLE HIGH ON
DWPTS AND THE GFS INITIALIZES LOW. THE EURO IS IN THE
MIDDLE...WITH A LEAN CLOSER TO THE NAM. THESE INITIALIZATION
DIFFERENCES ARE CARRIED THROUGHOUT THE DURATION OF THIS SYSTEM AS
THE NAM IS CLEARLY THE MOST BULLISH ON SNOWFALL AND QPF AND THE
GFS THE MOST BEARISH. REGARDLESS OF MODEL...CROSS SECTIONS CLEARLY
SHOW THERE IS MOISTURE TRANSPORT AND ISENTROPIC LIFT INTO THE
DENDRITIC ZONE...WHICH RUNS VERY DEEP. THE PEAK OF THIS FORCING
LOOKS TO RUN FROM AROUND 03Z TO 09Z SUNDAY NEAR THE BOUNDARY.

FOR SNOWFALL TOTALS...THERE IS QUITE A DIFFERENCE IN THE COBB
OUTPUTS. GENERALLY THE 06Z GFS COBB OUTPUT HAS RELATIVELY LITTLE
SNOW...WHEREAS THE NAM IS COMPARATIVELY OFF THE CHARTS.
DIFFERENCES ATTRIBUTED TO GFS COBB PRODUCING LOW SNOWFALL RATIOS
BECAUSE IT IS NOT GENERATING LIFT. THE NAM...ON THE OTHER HAND HAS
20:1 RATIOS SUNDAY...WHICH IS OBVIOUSLY QUITE HIGH...GIVEN SFC
TEMPS STILL IN THE 30S. AS HINTED AT BEFORE...WENT CLOSER TO THE
EURO...WHICH WAS IN THE MIDDLE...WITH A SLIGHT BUMP TO THE NAM. IN
ALL...SNOW RATIOS AND SFC TEMPS SATURDAY WILL BE A BIG FACTOR IN
SNOWFALL TOTALS AND MAY OSCILLATE SLIGHTLY BETWEEN NOW AND
SATURDAY. GENERALLY TAKING A SOMEWHAT CONSERVATIVE STANCE ATTM
WITH 4 TO 6 INCHES NEAR AND SOUTH OF INTERSTATE 80 AND 1 TO 3
INCHES FROM IA/MN BORDER TO HIGHWAY 30.

AS THIS SYSTEM PUSHES OFF TO THE EAST SUNDAY...IT WILL LEAVE BEHIND
FALLING TEMPERATURES DURING THE DAY SUNDAY. RECENT MODEL RUNS HAVE
ALSO BEEN STRENGTHENING THE LOW LEVEL MIXED LAYER...PLACING 25KT
WINDS AT ITS TOP. THEREFORE...AM EXPECTING STRONG WINDS SUNDAY
GUSTING UPWARDS OF 20 KTS TO 25 KTS...WHICH COULD LEAD TO DRIFTING
OF SNOW.

MONDAY THROUGH THURSDAY

OUR RECENT STRETCH OF MILD WEATHER WILL BE A DISTANT MEMORY BY THE
END OF NEXT WEEK WITH A FAIRLY ACTIVE AND OVERALL COLD PATTERN. THE
CENTRAL CONUS WILL BE INFLUENCED BY A BROAD BUT FAIRLY LOW AMPLITUDE
MEAN TROUGH WITH THE PASSAGE OF MULTIPLE WEAK SHORT WAVES. THIS
KEEPS AN EXTENDED PERIOD OF LOW END CHANCES IN THE FORECAST MON
THROUGH WED.  ANY ACCUMULATIONS LOOK MINOR AT THIS POINT WITH THE
FORCING FAIRLY TRANSIENT.

TEMPERATURES WILL BE COLD AND BELOW NORMAL MON...AND MAY REBOUND
BRIEFLY INTO TUE...BUT WILL LIKELY TURN THE OTHER DIRECTION SHARPLY
FOR THE LATTER HALF OF THE NEXT WORK WEEK.  THE PASSAGE OF THE
SYSTEM AROUND WED WILL END OUR PRECIP CHANCES INTO THU BUT ALSO
AMPLIFY THE PATTERN AND BRING A COLD FRONT FOLLOWED BY STRONG ARCTIC
HIGH PRESSURE. 00Z ECMWF AND GFS BOTH DEPICT IA/MN HIGH PRESSURE
AROUND 1040MB SO HAVE LOWERED TEMPS. LOWS WED NIGHT NOW DIP INTO THE
SINGLE DIGITS ABOVE AND BELOW ZERO WITH HIGHS THU NO BETTER THAN THE
TEENS. WITH WIDESPREAD SNOW COVER WOULD NOT BE SURPRISED TO HAVE
FORECAST TEMPS THROUGHOUT THIS ENTIRE PERIOD END UP TOO WARM...BUT
ARE AT LEAST HEADING IN THE RIGHT DIRECTION.

&&

.AVIATION...30/12Z
ISSUED AT 535 AM CST FRI JAN 30 2015

LITTLE OF CONCERN THROUGH THE PERIOD WITH VFR CONDITIONS AND
RELATIVELY LIGHT WINDS ANTICIPATED. VERY PATCHY MVFR STRATUS EARLY
THIS MORNING IS NOT EXPECTED TO AFFECT TAF SITES THIS MORNING.
OTHERWISE NOTHING MORE THAN GRADUALLY INCREASING HIGH CLOUDINESS.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...SMALL
LONG TERM...KOTENBERG/SMALL
AVIATION...SMALL





000
FXUS63 KDMX 301025
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
425 AM CST FRI JAN 30 2015

.SHORT TERM /TODAY/...
ISSUED AT 421 AM CST FRI JAN 30 2015

THERE IS LITTLE SENSIBLE WEATHER OF CONCERN IN THIS PERIOD. A WEAK
SHORT WAVE CURRENTLY OVER MT...WHICH SEEMS TO BE MORE STRONGLY
REFLECTED IN WATER VAPOR IMAGERY THAN THE MODELS...AND IS ALREADY
PRODUCING WEAK BUT MOISTURE STARVED LIFT THROUGH THE MID MO VALLEY.
MOISTURE IS SO LIMITED THAT EVEN CLOUDS ARE STRUGGLING TO DEVELOP
HOWEVER.

TEMP WISE...NAM...GFS...HI RES ARW/NMM RAW MODEL TEMPS AND NAM MOS
ALL SEEM TOO WARM AT THE MOMENT WHILE HRRR...RAP AND GFS MOS ARE
PERFORMING BETTER.  WHILE THE LATTER MODELS ARE CURRENTLY BETTER
CAPTURING THE COOLER TEMPS...THEY ALSO REBOUND JUST AS MUCH AS THE
ONES WITH A WARM BIAS.  THUS HAVE TEMPERED THE DEGREE OF REBOUND
FROM WHAT WAS DEPICTED YESTERDAY JUST SLIGHTLY.

.LONG TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 421 AM CST FRI JAN 30 2015

MAJOR LONG TERM FOCUS IS ON SNOWFALL EVENT FOR THIS WEEKEND. AFTER
HIGH RUN TO RUN INCONSISTENCY ALL WEEK...THE 12Z THU AND 00Z FRI
RUNS FINALLY SEEM TO BE CONVERGING TO A SOLUTION. LONG STORY
SHORT...IT IS TIME TO BUY ON ACCUMULATING SNOWFALL IN OUR CWA.

NOW HERE`S THE LONG STORY...AN UPPER LEVEL TROUGH CAN BE PICKED UP
VERY EASILY ON WATER VAPOR IMAGERY COMING ON SHORE NEAR THE BAJA
PENINSULA. THIS TROUGH WILL BE MOVING OVER THE SOUTHWESTERN US
FRIDAY...PULLING MOISTURE NORTHWARD. MEANWHILE...A FAST MOVING
TROUGH WILL BE COMING DOWN THOUGH EASTERN CANADA AND RACE THROUGH
THE DAKOTAS FRIDAY INTO SATURDAY. THE MODELS SEEM TO BE HANDLING
THIS TROUGH WELL NOW...AND WE WILL HAVE TO WATCH TO SEE IF ITS
STRENGTH VARIES WHEN IT COMES ONSHORE AND CAN BE MORE READILY
SAMPLED. THESE TWO SYSTEMS WILL GRADUALLY PHASE OVER THE MIDWEST AND
WILL LEAD TO SNOW ACROSS OUR CWA. PRECIP SHOULD BE ARRIVING IN OUR
SOUTHWESTERN CWA BY 12Z-15Z SAT. FCST SOUNDINGS SHOW A WARM NOSE
WHICH PEAKS AT AROUND 2C AT 2500 FT. SFC TEMPS AT THIS TIME WILL BE
NEAR FREEZING...SO PRECIP WILL LIKELY HAVE A SLEET/SN/RN COMPONENT
TO IT. SFC TEMPS THEN WARM TO THE UPPER 30S...SO PRECIP WILL CHANGE
TO RAIN. NEAR SUNSET...TEMPS SHOULD COOL TO WHERE P-TYPE IS ALL SNOW
FOR THE REMAINDER OF THIS EVENT. P-TYPE SATURDAY WILL BE A BIG
PLAYER IN SNOWFALL TOTALS ACROSS OUR SOUTH. WITH SATURDAY MORNING
LOOKING VERY OVERCAST FROM TOP-DOWN CLOUD INCREASES...HAVE BUMPED
TEMPS UP FROM GUIDANCE. THIS WILL OBVIOUSLY YIELD LOWER SNOW AMOUNTS
THAN COOLER MODEL SOLUTIONS.

THERE IS VERY STRONG FRONTOGENETICAL FORCING THROUGHOUT THIS EVENT.
ALL MODELS NOW MOVING BAND OF STRONG SFC MOISTURE TRANSPORT WITH
CONVERGENCE BASICALLY RIGHT ALONG I-80 TO SERVE AS A FOCUSING
MECHANISM FOR PRECIP. COLD AIR WILL BE ADVECTED NORTHWARD OF THIS
BOUNDARY SATURDAY NIGHT WHICH WILL SUSTAIN THIS BOUNDARY INTO
SUNDAY. TO QUANTIFY LOW LEVEL MOISTURE...THERE IS SOME MODEL
VARIATION. SOURCE REGION FOR SFC DWPTS FOR THIS EVENT IS THE LOWER
TRANS PECOS OF WEST TEXAS. THE NAM INITIALIZES A LITTLE HIGH ON
DWPTS AND THE GFS INITIALIZES LOW. THE EURO IS IN THE
MIDDLE...WITH A LEAN CLOSER TO THE NAM. THESE INITIALIZATION
DIFFERENCES ARE CARRIED THROUGHOUT THE DURATION OF THIS SYSTEM AS
THE NAM IS CLEARLY THE MOST BULLISH ON SNOWFALL AND QPF AND THE
GFS THE MOST BEARISH. REGARDLESS OF MODEL...CROSS SECTIONS CLEARLY
SHOW THERE IS MOISTURE TRANSPORT AND ISENTROPIC LIFT INTO THE
DENDRITIC ZONE...WHICH RUNS VERY DEEP. THE PEAK OF THIS FORCING
LOOKS TO RUN FROM AROUND 03Z TO 09Z SUNDAY NEAR THE BOUNDARY.

FOR SNOWFALL TOTALS...THERE IS QUITE A DIFFERENCE IN THE COBB
OUTPUTS. GENERALLY THE 06Z GFS COBB OUTPUT HAS RELATIVELY LITTLE
SNOW...WHEREAS THE NAM IS COMPARATIVELY OFF THE CHARTS.
DIFFERENCES ATTRIBUTED TO GFS COBB PRODUCING LOW SNOWFALL RATIOS
BECAUSE IT IS NOT GENERATING LIFT. THE NAM...ON THE OTHER HAND HAS
20:1 RATIOS SUNDAY...WHICH IS OBVIOUSLY QUITE HIGH...GIVEN SFC
TEMPS STILL IN THE 30S. AS HINTED AT BEFORE...WENT CLOSER TO THE
EURO...WHICH WAS IN THE MIDDLE...WITH A SLIGHT BUMP TO THE NAM. IN
ALL...SNOW RATIOS AND SFC TEMPS SATURDAY WILL BE A BIG FACTOR IN
SNOWFALL TOTALS AND MAY OSCILLATE SLIGHTLY BETWEEN NOW AND
SATURDAY. GENERALLY TAKING A SOMEWHAT CONSERVATIVE STANCE ATTM
WITH 4 TO 6 INCHES NEAR AND SOUTH OF INTERSTATE 80 AND 1 TO 3
INCHES FROM IA/MN BORDER TO HIGHWAY 30.

AS THIS SYSTEM PUSHES OFF TO THE EAST SUNDAY...IT WILL LEAVE BEHIND
FALLING TEMPERATURES DURING THE DAY SUNDAY. RECENT MODEL RUNS HAVE
ALSO BEEN STRENGTHENING THE LOW LEVEL MIXED LAYER...PLACING 25KT
WINDS AT ITS TOP. THEREFORE...AM EXPECTING STRONG WINDS SUNDAY
GUSTING UPWARDS OF 20 KTS TO 25 KTS...WHICH COULD LEAD TO DRIFTING
OF SNOW.

.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 421 AM CST FRI JAN 30 2015

OUR RECENT STRETCH OF MILD WEATHER WILL BE A DISTANT MEMORY BY THE
END OF NEXT WEEK WITH A FAIRLY ACTIVE AND OVERALL COLD PATTERN. THE
CENTRAL CONUS WILL BE INFLUENCED BY A BROAD BUT FAIRLY LOW AMPLITUDE
MEAN TROUGH WITH THE PASSAGE OF MULTIPLE WEAK SHORT WAVES. THIS
KEEPS AN EXTENDED PERIOD OF LOW END CHANCES IN THE FORECAST MON
THROUGH WED.  ANY ACCUMULATIONS LOOK MINOR AT THIS POINT WITH THE
FORCING FAIRLY TRANSIENT.

TEMPERATURES WILL BE COLD AND BELOW NORMAL MON...AND MAY REBOUND
BRIEFLY INTO TUE...BUT WILL LIKELY TURN THE OTHER DIRECTION SHARPLY
FOR THE LATTER HALF OF THE NEXT WORK WEEK.  THE PASSAGE OF THE
SYSTEM AROUND WED WILL END OUR PRECIP CHANCES INTO THU BUT ALSO
AMPLIFY THE PATTERN AND BRING A COLD FRONT FOLLOWED BY STRONG ARCTIC
HIGH PRESSURE. 00Z ECMWF AND GFS BOTH DEPICT IA/MN HIGH PRESSURE
AROUND 1040MB SO HAVE LOWERED TEMPS. LOWS WED NIGHT NOW DIP INTO THE
SINGLE DIGITS ABOVE AND BELOW ZERO WITH HIGHS THU NO BETTER THAN THE
TEENS. WITH WIDESPREAD SNOW COVER WOULD NOT BE SURPRISED TO HAVE
FORECAST TEMPS THROUGHOUT THIS ENTIRE PERIOD END UP TOO WARM...BUT
ARE AT LEAST HEADING IN THE RIGHT DIRECTION.

&&

.AVIATION...30/06Z
ISSUED AT 1130 PM CST THU JAN 29 2015

CIGS SCATTERING ACROSS CNTRL IA AND EXPECT VFR CONDITIONS AT ALL
SITES THOUGH MUCH OF THE PERIOD. KOTM WILL EXPERIENCE MVFR CIGS
INITIALLY THEN BECOME VFR BY 08Z. NORTHWEST WINDS WILL SWITCH TO
THE SOUTH TO SOUTHWEST ON FRIDAY.


&&

.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...SMALL
LONG TERM...KOTENBERG/SMALL
AVIATION...DONAVON




000
FXUS63 KDMX 301025
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
425 AM CST FRI JAN 30 2015

.SHORT TERM /TODAY/...
ISSUED AT 421 AM CST FRI JAN 30 2015

THERE IS LITTLE SENSIBLE WEATHER OF CONCERN IN THIS PERIOD. A WEAK
SHORT WAVE CURRENTLY OVER MT...WHICH SEEMS TO BE MORE STRONGLY
REFLECTED IN WATER VAPOR IMAGERY THAN THE MODELS...AND IS ALREADY
PRODUCING WEAK BUT MOISTURE STARVED LIFT THROUGH THE MID MO VALLEY.
MOISTURE IS SO LIMITED THAT EVEN CLOUDS ARE STRUGGLING TO DEVELOP
HOWEVER.

TEMP WISE...NAM...GFS...HI RES ARW/NMM RAW MODEL TEMPS AND NAM MOS
ALL SEEM TOO WARM AT THE MOMENT WHILE HRRR...RAP AND GFS MOS ARE
PERFORMING BETTER.  WHILE THE LATTER MODELS ARE CURRENTLY BETTER
CAPTURING THE COOLER TEMPS...THEY ALSO REBOUND JUST AS MUCH AS THE
ONES WITH A WARM BIAS.  THUS HAVE TEMPERED THE DEGREE OF REBOUND
FROM WHAT WAS DEPICTED YESTERDAY JUST SLIGHTLY.

.LONG TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 421 AM CST FRI JAN 30 2015

MAJOR LONG TERM FOCUS IS ON SNOWFALL EVENT FOR THIS WEEKEND. AFTER
HIGH RUN TO RUN INCONSISTENCY ALL WEEK...THE 12Z THU AND 00Z FRI
RUNS FINALLY SEEM TO BE CONVERGING TO A SOLUTION. LONG STORY
SHORT...IT IS TIME TO BUY ON ACCUMULATING SNOWFALL IN OUR CWA.

NOW HERE`S THE LONG STORY...AN UPPER LEVEL TROUGH CAN BE PICKED UP
VERY EASILY ON WATER VAPOR IMAGERY COMING ON SHORE NEAR THE BAJA
PENINSULA. THIS TROUGH WILL BE MOVING OVER THE SOUTHWESTERN US
FRIDAY...PULLING MOISTURE NORTHWARD. MEANWHILE...A FAST MOVING
TROUGH WILL BE COMING DOWN THOUGH EASTERN CANADA AND RACE THROUGH
THE DAKOTAS FRIDAY INTO SATURDAY. THE MODELS SEEM TO BE HANDLING
THIS TROUGH WELL NOW...AND WE WILL HAVE TO WATCH TO SEE IF ITS
STRENGTH VARIES WHEN IT COMES ONSHORE AND CAN BE MORE READILY
SAMPLED. THESE TWO SYSTEMS WILL GRADUALLY PHASE OVER THE MIDWEST AND
WILL LEAD TO SNOW ACROSS OUR CWA. PRECIP SHOULD BE ARRIVING IN OUR
SOUTHWESTERN CWA BY 12Z-15Z SAT. FCST SOUNDINGS SHOW A WARM NOSE
WHICH PEAKS AT AROUND 2C AT 2500 FT. SFC TEMPS AT THIS TIME WILL BE
NEAR FREEZING...SO PRECIP WILL LIKELY HAVE A SLEET/SN/RN COMPONENT
TO IT. SFC TEMPS THEN WARM TO THE UPPER 30S...SO PRECIP WILL CHANGE
TO RAIN. NEAR SUNSET...TEMPS SHOULD COOL TO WHERE P-TYPE IS ALL SNOW
FOR THE REMAINDER OF THIS EVENT. P-TYPE SATURDAY WILL BE A BIG
PLAYER IN SNOWFALL TOTALS ACROSS OUR SOUTH. WITH SATURDAY MORNING
LOOKING VERY OVERCAST FROM TOP-DOWN CLOUD INCREASES...HAVE BUMPED
TEMPS UP FROM GUIDANCE. THIS WILL OBVIOUSLY YIELD LOWER SNOW AMOUNTS
THAN COOLER MODEL SOLUTIONS.

THERE IS VERY STRONG FRONTOGENETICAL FORCING THROUGHOUT THIS EVENT.
ALL MODELS NOW MOVING BAND OF STRONG SFC MOISTURE TRANSPORT WITH
CONVERGENCE BASICALLY RIGHT ALONG I-80 TO SERVE AS A FOCUSING
MECHANISM FOR PRECIP. COLD AIR WILL BE ADVECTED NORTHWARD OF THIS
BOUNDARY SATURDAY NIGHT WHICH WILL SUSTAIN THIS BOUNDARY INTO
SUNDAY. TO QUANTIFY LOW LEVEL MOISTURE...THERE IS SOME MODEL
VARIATION. SOURCE REGION FOR SFC DWPTS FOR THIS EVENT IS THE LOWER
TRANS PECOS OF WEST TEXAS. THE NAM INITIALIZES A LITTLE HIGH ON
DWPTS AND THE GFS INITIALIZES LOW. THE EURO IS IN THE
MIDDLE...WITH A LEAN CLOSER TO THE NAM. THESE INITIALIZATION
DIFFERENCES ARE CARRIED THROUGHOUT THE DURATION OF THIS SYSTEM AS
THE NAM IS CLEARLY THE MOST BULLISH ON SNOWFALL AND QPF AND THE
GFS THE MOST BEARISH. REGARDLESS OF MODEL...CROSS SECTIONS CLEARLY
SHOW THERE IS MOISTURE TRANSPORT AND ISENTROPIC LIFT INTO THE
DENDRITIC ZONE...WHICH RUNS VERY DEEP. THE PEAK OF THIS FORCING
LOOKS TO RUN FROM AROUND 03Z TO 09Z SUNDAY NEAR THE BOUNDARY.

FOR SNOWFALL TOTALS...THERE IS QUITE A DIFFERENCE IN THE COBB
OUTPUTS. GENERALLY THE 06Z GFS COBB OUTPUT HAS RELATIVELY LITTLE
SNOW...WHEREAS THE NAM IS COMPARATIVELY OFF THE CHARTS.
DIFFERENCES ATTRIBUTED TO GFS COBB PRODUCING LOW SNOWFALL RATIOS
BECAUSE IT IS NOT GENERATING LIFT. THE NAM...ON THE OTHER HAND HAS
20:1 RATIOS SUNDAY...WHICH IS OBVIOUSLY QUITE HIGH...GIVEN SFC
TEMPS STILL IN THE 30S. AS HINTED AT BEFORE...WENT CLOSER TO THE
EURO...WHICH WAS IN THE MIDDLE...WITH A SLIGHT BUMP TO THE NAM. IN
ALL...SNOW RATIOS AND SFC TEMPS SATURDAY WILL BE A BIG FACTOR IN
SNOWFALL TOTALS AND MAY OSCILLATE SLIGHTLY BETWEEN NOW AND
SATURDAY. GENERALLY TAKING A SOMEWHAT CONSERVATIVE STANCE ATTM
WITH 4 TO 6 INCHES NEAR AND SOUTH OF INTERSTATE 80 AND 1 TO 3
INCHES FROM IA/MN BORDER TO HIGHWAY 30.

AS THIS SYSTEM PUSHES OFF TO THE EAST SUNDAY...IT WILL LEAVE BEHIND
FALLING TEMPERATURES DURING THE DAY SUNDAY. RECENT MODEL RUNS HAVE
ALSO BEEN STRENGTHENING THE LOW LEVEL MIXED LAYER...PLACING 25KT
WINDS AT ITS TOP. THEREFORE...AM EXPECTING STRONG WINDS SUNDAY
GUSTING UPWARDS OF 20 KTS TO 25 KTS...WHICH COULD LEAD TO DRIFTING
OF SNOW.

.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 421 AM CST FRI JAN 30 2015

OUR RECENT STRETCH OF MILD WEATHER WILL BE A DISTANT MEMORY BY THE
END OF NEXT WEEK WITH A FAIRLY ACTIVE AND OVERALL COLD PATTERN. THE
CENTRAL CONUS WILL BE INFLUENCED BY A BROAD BUT FAIRLY LOW AMPLITUDE
MEAN TROUGH WITH THE PASSAGE OF MULTIPLE WEAK SHORT WAVES. THIS
KEEPS AN EXTENDED PERIOD OF LOW END CHANCES IN THE FORECAST MON
THROUGH WED.  ANY ACCUMULATIONS LOOK MINOR AT THIS POINT WITH THE
FORCING FAIRLY TRANSIENT.

TEMPERATURES WILL BE COLD AND BELOW NORMAL MON...AND MAY REBOUND
BRIEFLY INTO TUE...BUT WILL LIKELY TURN THE OTHER DIRECTION SHARPLY
FOR THE LATTER HALF OF THE NEXT WORK WEEK.  THE PASSAGE OF THE
SYSTEM AROUND WED WILL END OUR PRECIP CHANCES INTO THU BUT ALSO
AMPLIFY THE PATTERN AND BRING A COLD FRONT FOLLOWED BY STRONG ARCTIC
HIGH PRESSURE. 00Z ECMWF AND GFS BOTH DEPICT IA/MN HIGH PRESSURE
AROUND 1040MB SO HAVE LOWERED TEMPS. LOWS WED NIGHT NOW DIP INTO THE
SINGLE DIGITS ABOVE AND BELOW ZERO WITH HIGHS THU NO BETTER THAN THE
TEENS. WITH WIDESPREAD SNOW COVER WOULD NOT BE SURPRISED TO HAVE
FORECAST TEMPS THROUGHOUT THIS ENTIRE PERIOD END UP TOO WARM...BUT
ARE AT LEAST HEADING IN THE RIGHT DIRECTION.

&&

.AVIATION...30/06Z
ISSUED AT 1130 PM CST THU JAN 29 2015

CIGS SCATTERING ACROSS CNTRL IA AND EXPECT VFR CONDITIONS AT ALL
SITES THOUGH MUCH OF THE PERIOD. KOTM WILL EXPERIENCE MVFR CIGS
INITIALLY THEN BECOME VFR BY 08Z. NORTHWEST WINDS WILL SWITCH TO
THE SOUTH TO SOUTHWEST ON FRIDAY.


&&

.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...SMALL
LONG TERM...KOTENBERG/SMALL
AVIATION...DONAVON





000
FXUS63 KDMX 300530
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1130 PM CST THU JAN 29 2015

.SHORT TERM /TONIGHT/...
ISSUED AT 315 PM CST THU JAN 29 2015

MAIN FORECAST CONCERN DEALT WITH LINGERING STRATUS DECK
AND TEMPERATURES AS A RESULT OF THE LINGERING CLOUD COVER. LEANED
TOWARD THE NAM/RAP/HRRR FOR CLOUD COVER AND LOW LEVEL RH THIS
EVENING. SOUNDINGS SUGGEST THE INVERSION CONTINUES THROUGH FRIDAY
MORNING AND POTENTIALLY TRAPPING THE LOW LEVEL MOISTURE/STRATUS OVER
CENTRAL IOWA DURING MUCH OF THE NIGHT. THERE IS A DECENT BREAK IN
THE CLOUD DECK OVER NORTH-CENTRAL IOWA AND INTO SOUTHERN MINNESOTA
AS OF 21Z...AND THE HRRR HAS SOMEWHAT PICKED UP ON THIS TREND AND
SLOWLY ERODES THE STRATUS BY AROUND 05Z ACROSS IOWA/MINNESOTA. HAVE
STRATUS SLOWLY ERODING DURING THE EVENING HOURS WITH THE NORTHEAST
SLOWEST TO CLEAR OUT.

CAA CONTINUES THROUGHOUT MUCH OF THE NIGHT BEFORE THE SURFACE RIDGE
SLIDES INTO NORTHERN IOWA FRIDAY MORNING AND FINALLY ALLOWING THE
WINDS TO BECOME LIGHT AND VARIABLE. SO ANY RADIATIONAL COOLING WILL
BE CLOSER TO SUNRISE. WITH THE TEMPERATURES REMAINING FAIRLY COLD
THIS AFTERNOON...LEANED TOWARD THE RAP FOR LOWS TONIGHT AS IT SEEMED
TO HAVE A BETTER HANDLE ON TEMP AND CLOUD COVER TRENDS.

.LONG TERM /FRIDAY THROUGH THURSDAY/...
ISSUED AT 315 PM CST THU JAN 29 2015

MUCH OF THE LONG TERM FORECAST WILL BE DOMINATED BY BROAD
NORTHWEST FLOW AND A SERIES OF WAVES MOVING THROUGH THE FLOW.
SURFACE RIDGING WILL BE ACROSS THE STATE AT THE BEGINNING OF THE
LONGER TERM TOMORROW MORNING WITH FRIDAY BEING THE BEST DAY OUT OF
REMAINDER OF THE FORECAST. WARM ADVECTION WILL INCREASE BY LATER
IN THE DAY AS SOUTHERLY SURFACE FLOW RESUMES AND READINGS ONCE
AGAIN ABOVE NORMAL. A DECENT PRESSURE GRADIENT KEEPING WINDS UP ON
FRIDAY NIGHT ALONG WITH INCREASING CLOUDINESS WILL HELP KEEP
TEMPERATURES QUITE WARM OVERNIGHT. MAY BEGIN TO SEE SOME LIGHT
PRECIPITATION IN THE FAR SOUTHWEST TOWARD DAYBREAK BUT THE BULK OF
THE SYSTEM WILL COME IN LATER PERIODS.

MOVING INTO THE WEEKEND...ALL FOCUS SHIFTS TO A SHORTWAVE TOPPING
THE WESTERN RIDGE AND ITS INTERACTION WITH A VERY MOIST UPPER LOW
ACROSS THE SOUTHWEST UNITED STATES. THE 12Z MODELS ARE BEGINNING
TO CLUSTER AROUND A SOLUTION OF DROPPING THE NORTHERN SHORTWAVE
SOUTHEAST WITH SUFFICIENT AMPLITUDE TO BRING THE MOISTURE PLUME
FAR ENOUGH NORTH TO IMPACT IOWA...AT LEAST THE SOUTHERN HALF OR
SO. INITIALLY...A SHORTWAVE THAT PASSES THROUGH THE GREAT LAKES
AREA FRIDAY NIGHT WILL SEND A COLD FRONT SOUTHWARD THRU THE
FORECAST AREA ON SATURDAY. MEANWHILE..INCREASING ISENTROPIC LIFT
AND MOISTURE ADVECTION WILL LEAD TO PRECIPITATION DEVELOPMENT
ACROSS SOUTHERN IOWA ON SATURDAY MORNING AHEAD OF THE BOUNDARY.
THE PRECIPITATION WILL LIKELY BE RAIN IN FAR SOUTHERN IOWA WITH
TEMPERATURES IN THE MID TO UPPER 30S. HOWEVER...A TRANSITION TO
SNOW IS LIKELY BY I80 OR HWY30 AS COLDER AIR IS ENCOUNTERED WITH
THE SOUTHWARD MOVING BOUNDARY. FORCING WILL SUSTAIN AND INCREASE
INTO SATURDAY NIGHT WITH DECENT MID LEVEL FRONTOGENETICAL FORCING
ACROSS THE SOUTHERN IOWA. ANY RAIN IN THE SOUTH ON SATURDAY WILL
TRANSITION TO SNOW IN THE EVENING AS COLD AIR CONTINUES TO DEEPEN
AND SPREAD SOUTHWARD BEHIND THE BOUNDARY. BY LATE SATURDAY NIGHT
INTO SUNDAY...DECENT MID LEVEL FORCING FROM APPROACHING SOUTHEAST
MOVING SHORTWAVE WILL HELP SNOW TO CONTINUE DURING THE DAY.
EVENTUALLY...THE FORCING WILL SHIFT TO THE EAST BY LATE IN THE DAY
WITH THE SNOW ENDING. THERE WILL BE A TIGHT GRADIENT OF SNOWFALL
ON NORTHERN SIDE OF PRECIPITATION SHIELD AND THEREFORE THE SNOW
AMOUNTS THAT ACCOMPANY THIS SYSTEM. AT THIS POINT...THE GRADIENT
APPEARS NEAR THE I80 CORRIDOR ALTHOUGH THIS WILL LIKELY MOVE WITH
SUBSEQUENT INFORMATION. GIVEN THE LONG DURATION OF THIS EVENT...IT
DOESNT APPEAR WARNING CRITERIA WILL BE MET...ALTHOUGH THE
COMBINATION OF WINDS AND SNOW MAY BE ENOUGH TO BOOST US INTO
WARNING. GIVEN THE CHANGES IN MODEL RUNS OVER THE PAST 36
HOURS...WILL WAIT ON ANY HEADLINES BUT BEGIN TO HIGHLIGHT MORE IN
THE HWO AND OTHER PRODUCTS. AMOUNTS OF AROUND 6 INCHES SEEM
POSSIBLE NEAR THE MO BORDER WITH 2-5 IN CENTRAL IOWA...AND AN INCH
OR LESS ACROSS THE NORTH.

MUCH COLDER AIR WILL FILTER INTO THE STATE FOR NEXT WEEK WITH A
SERIES OF SHORTWAVES PASSING THROUGH THE REGION. THIS WILL BRING
THE THREAT OF SNOW MONDAY NIGHT INTO TUESDAY WITH REINFORCING
SHOTS OF COLDER AIR.

&&

.AVIATION...30/06Z
ISSUED AT 1130 PM CST THU JAN 29 2015

CIGS SCATTERING ACROSS CNTRL IA AND EXPECT VFR CONDITIONS AT ALL
SITES THOUGH MUCH OF THE PERIOD. KOTM WILL EXPERIENCE MVFR CIGS
INITIALLY THEN BECOME VFR BY 08Z. NORTHWEST WINDS WILL SWITCH TO
THE SOUTH TO SOUTHWEST ON FRIDAY.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...PODRAZIK
LONG TERM...COGIL
AVIATION...DONAVON




000
FXUS63 KDMX 300530
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1130 PM CST THU JAN 29 2015

.SHORT TERM /TONIGHT/...
ISSUED AT 315 PM CST THU JAN 29 2015

MAIN FORECAST CONCERN DEALT WITH LINGERING STRATUS DECK
AND TEMPERATURES AS A RESULT OF THE LINGERING CLOUD COVER. LEANED
TOWARD THE NAM/RAP/HRRR FOR CLOUD COVER AND LOW LEVEL RH THIS
EVENING. SOUNDINGS SUGGEST THE INVERSION CONTINUES THROUGH FRIDAY
MORNING AND POTENTIALLY TRAPPING THE LOW LEVEL MOISTURE/STRATUS OVER
CENTRAL IOWA DURING MUCH OF THE NIGHT. THERE IS A DECENT BREAK IN
THE CLOUD DECK OVER NORTH-CENTRAL IOWA AND INTO SOUTHERN MINNESOTA
AS OF 21Z...AND THE HRRR HAS SOMEWHAT PICKED UP ON THIS TREND AND
SLOWLY ERODES THE STRATUS BY AROUND 05Z ACROSS IOWA/MINNESOTA. HAVE
STRATUS SLOWLY ERODING DURING THE EVENING HOURS WITH THE NORTHEAST
SLOWEST TO CLEAR OUT.

CAA CONTINUES THROUGHOUT MUCH OF THE NIGHT BEFORE THE SURFACE RIDGE
SLIDES INTO NORTHERN IOWA FRIDAY MORNING AND FINALLY ALLOWING THE
WINDS TO BECOME LIGHT AND VARIABLE. SO ANY RADIATIONAL COOLING WILL
BE CLOSER TO SUNRISE. WITH THE TEMPERATURES REMAINING FAIRLY COLD
THIS AFTERNOON...LEANED TOWARD THE RAP FOR LOWS TONIGHT AS IT SEEMED
TO HAVE A BETTER HANDLE ON TEMP AND CLOUD COVER TRENDS.

.LONG TERM /FRIDAY THROUGH THURSDAY/...
ISSUED AT 315 PM CST THU JAN 29 2015

MUCH OF THE LONG TERM FORECAST WILL BE DOMINATED BY BROAD
NORTHWEST FLOW AND A SERIES OF WAVES MOVING THROUGH THE FLOW.
SURFACE RIDGING WILL BE ACROSS THE STATE AT THE BEGINNING OF THE
LONGER TERM TOMORROW MORNING WITH FRIDAY BEING THE BEST DAY OUT OF
REMAINDER OF THE FORECAST. WARM ADVECTION WILL INCREASE BY LATER
IN THE DAY AS SOUTHERLY SURFACE FLOW RESUMES AND READINGS ONCE
AGAIN ABOVE NORMAL. A DECENT PRESSURE GRADIENT KEEPING WINDS UP ON
FRIDAY NIGHT ALONG WITH INCREASING CLOUDINESS WILL HELP KEEP
TEMPERATURES QUITE WARM OVERNIGHT. MAY BEGIN TO SEE SOME LIGHT
PRECIPITATION IN THE FAR SOUTHWEST TOWARD DAYBREAK BUT THE BULK OF
THE SYSTEM WILL COME IN LATER PERIODS.

MOVING INTO THE WEEKEND...ALL FOCUS SHIFTS TO A SHORTWAVE TOPPING
THE WESTERN RIDGE AND ITS INTERACTION WITH A VERY MOIST UPPER LOW
ACROSS THE SOUTHWEST UNITED STATES. THE 12Z MODELS ARE BEGINNING
TO CLUSTER AROUND A SOLUTION OF DROPPING THE NORTHERN SHORTWAVE
SOUTHEAST WITH SUFFICIENT AMPLITUDE TO BRING THE MOISTURE PLUME
FAR ENOUGH NORTH TO IMPACT IOWA...AT LEAST THE SOUTHERN HALF OR
SO. INITIALLY...A SHORTWAVE THAT PASSES THROUGH THE GREAT LAKES
AREA FRIDAY NIGHT WILL SEND A COLD FRONT SOUTHWARD THRU THE
FORECAST AREA ON SATURDAY. MEANWHILE..INCREASING ISENTROPIC LIFT
AND MOISTURE ADVECTION WILL LEAD TO PRECIPITATION DEVELOPMENT
ACROSS SOUTHERN IOWA ON SATURDAY MORNING AHEAD OF THE BOUNDARY.
THE PRECIPITATION WILL LIKELY BE RAIN IN FAR SOUTHERN IOWA WITH
TEMPERATURES IN THE MID TO UPPER 30S. HOWEVER...A TRANSITION TO
SNOW IS LIKELY BY I80 OR HWY30 AS COLDER AIR IS ENCOUNTERED WITH
THE SOUTHWARD MOVING BOUNDARY. FORCING WILL SUSTAIN AND INCREASE
INTO SATURDAY NIGHT WITH DECENT MID LEVEL FRONTOGENETICAL FORCING
ACROSS THE SOUTHERN IOWA. ANY RAIN IN THE SOUTH ON SATURDAY WILL
TRANSITION TO SNOW IN THE EVENING AS COLD AIR CONTINUES TO DEEPEN
AND SPREAD SOUTHWARD BEHIND THE BOUNDARY. BY LATE SATURDAY NIGHT
INTO SUNDAY...DECENT MID LEVEL FORCING FROM APPROACHING SOUTHEAST
MOVING SHORTWAVE WILL HELP SNOW TO CONTINUE DURING THE DAY.
EVENTUALLY...THE FORCING WILL SHIFT TO THE EAST BY LATE IN THE DAY
WITH THE SNOW ENDING. THERE WILL BE A TIGHT GRADIENT OF SNOWFALL
ON NORTHERN SIDE OF PRECIPITATION SHIELD AND THEREFORE THE SNOW
AMOUNTS THAT ACCOMPANY THIS SYSTEM. AT THIS POINT...THE GRADIENT
APPEARS NEAR THE I80 CORRIDOR ALTHOUGH THIS WILL LIKELY MOVE WITH
SUBSEQUENT INFORMATION. GIVEN THE LONG DURATION OF THIS EVENT...IT
DOESNT APPEAR WARNING CRITERIA WILL BE MET...ALTHOUGH THE
COMBINATION OF WINDS AND SNOW MAY BE ENOUGH TO BOOST US INTO
WARNING. GIVEN THE CHANGES IN MODEL RUNS OVER THE PAST 36
HOURS...WILL WAIT ON ANY HEADLINES BUT BEGIN TO HIGHLIGHT MORE IN
THE HWO AND OTHER PRODUCTS. AMOUNTS OF AROUND 6 INCHES SEEM
POSSIBLE NEAR THE MO BORDER WITH 2-5 IN CENTRAL IOWA...AND AN INCH
OR LESS ACROSS THE NORTH.

MUCH COLDER AIR WILL FILTER INTO THE STATE FOR NEXT WEEK WITH A
SERIES OF SHORTWAVES PASSING THROUGH THE REGION. THIS WILL BRING
THE THREAT OF SNOW MONDAY NIGHT INTO TUESDAY WITH REINFORCING
SHOTS OF COLDER AIR.

&&

.AVIATION...30/06Z
ISSUED AT 1130 PM CST THU JAN 29 2015

CIGS SCATTERING ACROSS CNTRL IA AND EXPECT VFR CONDITIONS AT ALL
SITES THOUGH MUCH OF THE PERIOD. KOTM WILL EXPERIENCE MVFR CIGS
INITIALLY THEN BECOME VFR BY 08Z. NORTHWEST WINDS WILL SWITCH TO
THE SOUTH TO SOUTHWEST ON FRIDAY.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...PODRAZIK
LONG TERM...COGIL
AVIATION...DONAVON





000
FXUS63 KDMX 292343
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
543 PM CST THU JAN 29 2015

.SHORT TERM /TONIGHT/...
ISSUED AT 315 PM CST THU JAN 29 2015

MAIN FORECAST CONCERN DEALT WITH LINGERING STRATUS DECK
AND TEMPERATURES AS A RESULT OF THE LINGERING CLOUD COVER. LEANED
TOWARD THE NAM/RAP/HRRR FOR CLOUD COVER AND LOW LEVEL RH THIS
EVENING. SOUNDINGS SUGGEST THE INVERSION CONTINUES THROUGH FRIDAY
MORNING AND POTENTIALLY TRAPPING THE LOW LEVEL MOISTURE/STRATUS OVER
CENTRAL IOWA DURING MUCH OF THE NIGHT. THERE IS A DECENT BREAK IN
THE CLOUD DECK OVER NORTH-CENTRAL IOWA AND INTO SOUTHERN MINNESOTA
AS OF 21Z...AND THE HRRR HAS SOMEWHAT PICKED UP ON THIS TREND AND
SLOWLY ERODES THE STRATUS BY AROUND 05Z ACROSS IOWA/MINNESOTA. HAVE
STRATUS SLOWLY ERODING DURING THE EVENING HOURS WITH THE NORTHEAST
SLOWEST TO CLEAR OUT.

CAA CONTINUES THROUGHOUT MUCH OF THE NIGHT BEFORE THE SURFACE RIDGE
SLIDES INTO NORTHERN IOWA FRIDAY MORNING AND FINALLY ALLOWING THE
WINDS TO BECOME LIGHT AND VARIABLE. SO ANY RADIATIONAL COOLING WILL
BE CLOSER TO SUNRISE. WITH THE TEMPERATURES REMAINING FAIRLY COLD
THIS AFTERNOON...LEANED TOWARD THE RAP FOR LOWS TONIGHT AS IT SEEMED
TO HAVE A BETTER HANDLE ON TEMP AND CLOUD COVER TRENDS.

.LONG TERM /FRIDAY THROUGH THURSDAY/...
ISSUED AT 315 PM CST THU JAN 29 2015

MUCH OF THE LONG TERM FORECAST WILL BE DOMINATED BY BROAD
NORTHWEST FLOW AND A SERIES OF WAVES MOVING THROUGH THE FLOW.
SURFACE RIDGING WILL BE ACROSS THE STATE AT THE BEGINNING OF THE
LONGER TERM TOMORROW MORNING WITH FRIDAY BEING THE BEST DAY OUT OF
REMAINDER OF THE FORECAST. WARM ADVECTION WILL INCREASE BY LATER
IN THE DAY AS SOUTHERLY SURFACE FLOW RESUMES AND READINGS ONCE
AGAIN ABOVE NORMAL. A DECENT PRESSURE GRADIENT KEEPING WINDS UP ON
FRIDAY NIGHT ALONG WITH INCREASING CLOUDINESS WILL HELP KEEP
TEMPERATURES QUITE WARM OVERNIGHT. MAY BEGIN TO SEE SOME LIGHT
PRECIPITATION IN THE FAR SOUTHWEST TOWARD DAYBREAK BUT THE BULK OF
THE SYSTEM WILL COME IN LATER PERIODS.

MOVING INTO THE WEEKEND...ALL FOCUS SHIFTS TO A SHORTWAVE TOPPING
THE WESTERN RIDGE AND ITS INTERACTION WITH A VERY MOIST UPPER LOW
ACROSS THE SOUTHWEST UNITED STATES. THE 12Z MODELS ARE BEGINNING
TO CLUSTER AROUND A SOLUTION OF DROPPING THE NORTHERN SHORTWAVE
SOUTHEAST WITH SUFFICIENT AMPLITUDE TO BRING THE MOISTURE PLUME
FAR ENOUGH NORTH TO IMPACT IOWA...AT LEAST THE SOUTHERN HALF OR
SO. INITIALLY...A SHORTWAVE THAT PASSES THROUGH THE GREAT LAKES
AREA FRIDAY NIGHT WILL SEND A COLD FRONT SOUTHWARD THRU THE
FORECAST AREA ON SATURDAY. MEANWHILE..INCREASING ISENTROPIC LIFT
AND MOISTURE ADVECTION WILL LEAD TO PRECIPITATION DEVELOPMENT
ACROSS SOUTHERN IOWA ON SATURDAY MORNING AHEAD OF THE BOUNDARY.
THE PRECIPITATION WILL LIKELY BE RAIN IN FAR SOUTHERN IOWA WITH
TEMPERATURES IN THE MID TO UPPER 30S. HOWEVER...A TRANSITION TO
SNOW IS LIKELY BY I80 OR HWY30 AS COLDER AIR IS ENCOUNTERED WITH
THE SOUTHWARD MOVING BOUNDARY. FORCING WILL SUSTAIN AND INCREASE
INTO SATURDAY NIGHT WITH DECENT MID LEVEL FRONTOGENETICAL FORCING
ACROSS THE SOUTHERN IOWA. ANY RAIN IN THE SOUTH ON SATURDAY WILL
TRANSITION TO SNOW IN THE EVENING AS COLD AIR CONTINUES TO DEEPEN
AND SPREAD SOUTHWARD BEHIND THE BOUNDARY. BY LATE SATURDAY NIGHT
INTO SUNDAY...DECENT MID LEVEL FORCING FROM APPROACHING SOUTHEAST
MOVING SHORTWAVE WILL HELP SNOW TO CONTINUE DURING THE DAY.
EVENTUALLY...THE FORCING WILL SHIFT TO THE EAST BY LATE IN THE DAY
WITH THE SNOW ENDING. THERE WILL BE A TIGHT GRADIENT OF SNOWFALL
ON NORTHERN SIDE OF PRECIPITATION SHIELD AND THEREFORE THE SNOW
AMOUNTS THAT ACCOMPANY THIS SYSTEM. AT THIS POINT...THE GRADIENT
APPEARS NEAR THE I80 CORRIDOR ALTHOUGH THIS WILL LIKELY MOVE WITH
SUBSEQUENT INFORMATION. GIVEN THE LONG DURATION OF THIS EVENT...IT
DOESNT APPEAR WARNING CRITERIA WILL BE MET...ALTHOUGH THE
COMBINATION OF WINDS AND SNOW MAY BE ENOUGH TO BOOST US INTO
WARNING. GIVEN THE CHANGES IN MODEL RUNS OVER THE PAST 36
HOURS...WILL WAIT ON ANY HEADLINES BUT BEGIN TO HIGHLIGHT MORE IN
THE HWO AND OTHER PRODUCTS. AMOUNTS OF AROUND 6 INCHES SEEM
POSSIBLE NEAR THE MO BORDER WITH 2-5 IN CENTRAL IOWA...AND AN INCH
OR LESS ACROSS THE NORTH.

MUCH COLDER AIR WILL FILTER INTO THE STATE FOR NEXT WEEK WITH A
SERIES OF SHORTWAVES PASSING THROUGH THE REGION. THIS WILL BRING
THE THREAT OF SNOW MONDAY NIGHT INTO TUESDAY WITH REINFORCING
SHOTS OF COLDER AIR.

&&

.AVIATION...30/00Z
ISSUED AT 542 PM CST THU JAN 29 2015

WIDESPREAD MVFR CIGS ACROSS CENTRAL IA WILL GRADUALLY DIMINISH
OVERNIGHT AS VFR CONDITIONS MOVE SOUTH OUT OF MINNESOTA. A BRIEF
PERIOD WITH CIGS BELOW 2 KFT MAY OCCUR EARLY THIS EVENING. GUSTY
NORTHWEST WINDS WILL ALSO DIMINISH OVERNIGHT AND BECOME SOUTH TO
SOUTHWEST AT 10 MPH OR LESS ON FRIDAY.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...PODRAZIK
LONG TERM...COGIL
AVIATION...DONAVON




000
FXUS63 KDMX 292343
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
543 PM CST THU JAN 29 2015

.SHORT TERM /TONIGHT/...
ISSUED AT 315 PM CST THU JAN 29 2015

MAIN FORECAST CONCERN DEALT WITH LINGERING STRATUS DECK
AND TEMPERATURES AS A RESULT OF THE LINGERING CLOUD COVER. LEANED
TOWARD THE NAM/RAP/HRRR FOR CLOUD COVER AND LOW LEVEL RH THIS
EVENING. SOUNDINGS SUGGEST THE INVERSION CONTINUES THROUGH FRIDAY
MORNING AND POTENTIALLY TRAPPING THE LOW LEVEL MOISTURE/STRATUS OVER
CENTRAL IOWA DURING MUCH OF THE NIGHT. THERE IS A DECENT BREAK IN
THE CLOUD DECK OVER NORTH-CENTRAL IOWA AND INTO SOUTHERN MINNESOTA
AS OF 21Z...AND THE HRRR HAS SOMEWHAT PICKED UP ON THIS TREND AND
SLOWLY ERODES THE STRATUS BY AROUND 05Z ACROSS IOWA/MINNESOTA. HAVE
STRATUS SLOWLY ERODING DURING THE EVENING HOURS WITH THE NORTHEAST
SLOWEST TO CLEAR OUT.

CAA CONTINUES THROUGHOUT MUCH OF THE NIGHT BEFORE THE SURFACE RIDGE
SLIDES INTO NORTHERN IOWA FRIDAY MORNING AND FINALLY ALLOWING THE
WINDS TO BECOME LIGHT AND VARIABLE. SO ANY RADIATIONAL COOLING WILL
BE CLOSER TO SUNRISE. WITH THE TEMPERATURES REMAINING FAIRLY COLD
THIS AFTERNOON...LEANED TOWARD THE RAP FOR LOWS TONIGHT AS IT SEEMED
TO HAVE A BETTER HANDLE ON TEMP AND CLOUD COVER TRENDS.

.LONG TERM /FRIDAY THROUGH THURSDAY/...
ISSUED AT 315 PM CST THU JAN 29 2015

MUCH OF THE LONG TERM FORECAST WILL BE DOMINATED BY BROAD
NORTHWEST FLOW AND A SERIES OF WAVES MOVING THROUGH THE FLOW.
SURFACE RIDGING WILL BE ACROSS THE STATE AT THE BEGINNING OF THE
LONGER TERM TOMORROW MORNING WITH FRIDAY BEING THE BEST DAY OUT OF
REMAINDER OF THE FORECAST. WARM ADVECTION WILL INCREASE BY LATER
IN THE DAY AS SOUTHERLY SURFACE FLOW RESUMES AND READINGS ONCE
AGAIN ABOVE NORMAL. A DECENT PRESSURE GRADIENT KEEPING WINDS UP ON
FRIDAY NIGHT ALONG WITH INCREASING CLOUDINESS WILL HELP KEEP
TEMPERATURES QUITE WARM OVERNIGHT. MAY BEGIN TO SEE SOME LIGHT
PRECIPITATION IN THE FAR SOUTHWEST TOWARD DAYBREAK BUT THE BULK OF
THE SYSTEM WILL COME IN LATER PERIODS.

MOVING INTO THE WEEKEND...ALL FOCUS SHIFTS TO A SHORTWAVE TOPPING
THE WESTERN RIDGE AND ITS INTERACTION WITH A VERY MOIST UPPER LOW
ACROSS THE SOUTHWEST UNITED STATES. THE 12Z MODELS ARE BEGINNING
TO CLUSTER AROUND A SOLUTION OF DROPPING THE NORTHERN SHORTWAVE
SOUTHEAST WITH SUFFICIENT AMPLITUDE TO BRING THE MOISTURE PLUME
FAR ENOUGH NORTH TO IMPACT IOWA...AT LEAST THE SOUTHERN HALF OR
SO. INITIALLY...A SHORTWAVE THAT PASSES THROUGH THE GREAT LAKES
AREA FRIDAY NIGHT WILL SEND A COLD FRONT SOUTHWARD THRU THE
FORECAST AREA ON SATURDAY. MEANWHILE..INCREASING ISENTROPIC LIFT
AND MOISTURE ADVECTION WILL LEAD TO PRECIPITATION DEVELOPMENT
ACROSS SOUTHERN IOWA ON SATURDAY MORNING AHEAD OF THE BOUNDARY.
THE PRECIPITATION WILL LIKELY BE RAIN IN FAR SOUTHERN IOWA WITH
TEMPERATURES IN THE MID TO UPPER 30S. HOWEVER...A TRANSITION TO
SNOW IS LIKELY BY I80 OR HWY30 AS COLDER AIR IS ENCOUNTERED WITH
THE SOUTHWARD MOVING BOUNDARY. FORCING WILL SUSTAIN AND INCREASE
INTO SATURDAY NIGHT WITH DECENT MID LEVEL FRONTOGENETICAL FORCING
ACROSS THE SOUTHERN IOWA. ANY RAIN IN THE SOUTH ON SATURDAY WILL
TRANSITION TO SNOW IN THE EVENING AS COLD AIR CONTINUES TO DEEPEN
AND SPREAD SOUTHWARD BEHIND THE BOUNDARY. BY LATE SATURDAY NIGHT
INTO SUNDAY...DECENT MID LEVEL FORCING FROM APPROACHING SOUTHEAST
MOVING SHORTWAVE WILL HELP SNOW TO CONTINUE DURING THE DAY.
EVENTUALLY...THE FORCING WILL SHIFT TO THE EAST BY LATE IN THE DAY
WITH THE SNOW ENDING. THERE WILL BE A TIGHT GRADIENT OF SNOWFALL
ON NORTHERN SIDE OF PRECIPITATION SHIELD AND THEREFORE THE SNOW
AMOUNTS THAT ACCOMPANY THIS SYSTEM. AT THIS POINT...THE GRADIENT
APPEARS NEAR THE I80 CORRIDOR ALTHOUGH THIS WILL LIKELY MOVE WITH
SUBSEQUENT INFORMATION. GIVEN THE LONG DURATION OF THIS EVENT...IT
DOESNT APPEAR WARNING CRITERIA WILL BE MET...ALTHOUGH THE
COMBINATION OF WINDS AND SNOW MAY BE ENOUGH TO BOOST US INTO
WARNING. GIVEN THE CHANGES IN MODEL RUNS OVER THE PAST 36
HOURS...WILL WAIT ON ANY HEADLINES BUT BEGIN TO HIGHLIGHT MORE IN
THE HWO AND OTHER PRODUCTS. AMOUNTS OF AROUND 6 INCHES SEEM
POSSIBLE NEAR THE MO BORDER WITH 2-5 IN CENTRAL IOWA...AND AN INCH
OR LESS ACROSS THE NORTH.

MUCH COLDER AIR WILL FILTER INTO THE STATE FOR NEXT WEEK WITH A
SERIES OF SHORTWAVES PASSING THROUGH THE REGION. THIS WILL BRING
THE THREAT OF SNOW MONDAY NIGHT INTO TUESDAY WITH REINFORCING
SHOTS OF COLDER AIR.

&&

.AVIATION...30/00Z
ISSUED AT 542 PM CST THU JAN 29 2015

WIDESPREAD MVFR CIGS ACROSS CENTRAL IA WILL GRADUALLY DIMINISH
OVERNIGHT AS VFR CONDITIONS MOVE SOUTH OUT OF MINNESOTA. A BRIEF
PERIOD WITH CIGS BELOW 2 KFT MAY OCCUR EARLY THIS EVENING. GUSTY
NORTHWEST WINDS WILL ALSO DIMINISH OVERNIGHT AND BECOME SOUTH TO
SOUTHWEST AT 10 MPH OR LESS ON FRIDAY.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...PODRAZIK
LONG TERM...COGIL
AVIATION...DONAVON





000
FXUS63 KDMX 292115
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
315 PM CST THU JAN 29 2015

.SHORT TERM /TONIGHT/...
ISSUED AT 315 PM CST THU JAN 29 2015

MAIN FORECAST CONCERN DEALT WITH LINGERING STRATUS DECK
AND TEMPERATURES AS A RESULT OF THE LINGERING CLOUD COVER. LEANED
TOWARD THE NAM/RAP/HRRR FOR CLOUD COVER AND LOW LEVEL RH THIS
EVENING. SOUNDINGS SUGGEST THE INVERSION CONTINUES THROUGH FRIDAY
MORNING AND POTENTIALLY TRAPPING THE LOW LEVEL MOISTURE/STRATUS OVER
CENTRAL IOWA DURING MUCH OF THE NIGHT. THERE IS A DECENT BREAK IN
THE CLOUD DECK OVER NORTH-CENTRAL IOWA AND INTO SOUTHERN MINNESOTA
AS OF 21Z...AND THE HRRR HAS SOMEWHAT PICKED UP ON THIS TREND AND
SLOWLY ERODES THE STRATUS BY AROUND 05Z ACROSS IOWA/MINNESOTA. HAVE
STRATUS SLOWLY ERODING DURING THE EVENING HOURS WITH THE NORTHEAST
SLOWEST TO CLEAR OUT.

CAA CONTINUES THROUGHOUT MUCH OF THE NIGHT BEFORE THE SURFACE RIDGE
SLIDES INTO NORTHERN IOWA FRIDAY MORNING AND FINALLY ALLOWING THE
WINDS TO BECOME LIGHT AND VARIABLE. SO ANY RADIATIONAL COOLING WILL
BE CLOSER TO SUNRISE. WITH THE TEMPERATURES REMAINING FAIRLY COLD
THIS AFTERNOON...LEANED TOWARD THE RAP FOR LOWS TONIGHT AS IT SEEMED
TO HAVE A BETTER HANDLE ON TEMP AND CLOUD COVER TRENDS.

.LONG TERM /FRIDAY THROUGH THURSDAY/...
ISSUED AT 315 PM CST THU JAN 29 2015

MUCH OF THE LONG TERM FORECAST WILL BE DOMINATED BY BROAD
NORTHWEST FLOW AND A SERIES OF WAVES MOVING THROUGH THE FLOW.
SURFACE RIDGING WILL BE ACROSS THE STATE AT THE BEGINNING OF THE
LONGER TERM TOMORROW MORNING WITH FRIDAY BEING THE BEST DAY OUT OF
REMAINDER OF THE FORECAST. WARM ADVECTION WILL INCREASE BY LATER
IN THE DAY AS SOUTHERLY SURFACE FLOW RESUMES AND READINGS ONCE
AGAIN ABOVE NORMAL. A DECENT PRESSURE GRADIENT KEEPING WINDS UP ON
FRIDAY NIGHT ALONG WITH INCREASING CLOUDINESS WILL HELP KEEP
TEMPERATURES QUITE WARM OVERNIGHT. MAY BEGIN TO SEE SOME LIGHT
PRECIPITATION IN THE FAR SOUTHWEST TOWARD DAYBREAK BUT THE BULK OF
THE SYSTEM WILL COME IN LATER PERIODS.

MOVING INTO THE WEEKEND...ALL FOCUS SHIFTS TO A SHORTWAVE TOPPING
THE WESTERN RIDGE AND ITS INTERACTION WITH A VERY MOIST UPPER LOW
ACROSS THE SOUTHWEST UNITED STATES. THE 12Z MODELS ARE BEGINNING
TO CLUSTER AROUND A SOLUTION OF DROPPING THE NORTHERN SHORTWAVE
SOUTHEAST WITH SUFFICIENT AMPLITUDE TO BRING THE MOISTURE PLUME
FAR ENOUGH NORTH TO IMPACT IOWA...AT LEAST THE SOUTHERN HALF OR
SO. INITIALLY...A SHORTWAVE THAT PASSES THROUGH THE GREAT LAKES
AREA FRIDAY NIGHT WILL SEND A COLD FRONT SOUTHWARD THRU THE
FORECAST AREA ON SATURDAY. MEANWHILE..INCREASING ISENTROPIC LIFT
AND MOISTURE ADVECTION WILL LEAD TO PRECIPITATION DEVELOPMENT
ACROSS SOUTHERN IOWA ON SATURDAY MORNING AHEAD OF THE BOUNDARY.
THE PRECIPITATION WILL LIKELY BE RAIN IN FAR SOUTHERN IOWA WITH
TEMPERATURES IN THE MID TO UPPER 30S. HOWEVER...A TRANSITION TO
SNOW IS LIKELY BY I80 OR HWY30 AS COLDER AIR IS ENCOUNTERED WITH
THE SOUTHWARD MOVING BOUNDARY. FORCING WILL SUSTAIN AND INCREASE
INTO SATURDAY NIGHT WITH DECENT MID LEVEL FRONTOGENETICAL FORCING
ACROSS THE SOUTHERN IOWA. ANY RAIN IN THE SOUTH ON SATURDAY WILL
TRANSITION TO SNOW IN THE EVENING AS COLD AIR CONTINUES TO DEEPEN
AND SPREAD SOUTHWARD BEHIND THE BOUNDARY. BY LATE SATURDAY NIGHT
INTO SUNDAY...DECENT MID LEVEL FORCING FROM APPROACHING SOUTHEAST
MOVING SHORTWAVE WILL HELP SNOW TO CONTINUE DURING THE DAY.
EVENTUALLY...THE FORCING WILL SHIFT TO THE EAST BY LATE IN THE DAY
WITH THE SNOW ENDING. THERE WILL BE A TIGHT GRADIENT OF SNOWFALL
ON NORTHERN SIDE OF PRECIPITATION SHIELD AND THEREFORE THE SNOW
AMOUNTS THAT ACCOMPANY THIS SYSTEM. AT THIS POINT...THE GRADIENT
APPEARS NEAR THE I80 CORRIDOR ALTHOUGH THIS WILL LIKELY MOVE WITH
SUBSEQUENT INFORMATION. GIVEN THE LONG DURATION OF THIS EVENT...IT
DOESNT APPEAR WARNING CRITERIA WILL BE MET...ALTHOUGH THE
COMBINATION OF WINDS AND SNOW MAY BE ENOUGH TO BOOST US INTO
WARNING. GIVEN THE CHANGES IN MODEL RUNS OVER THE PAST 36
HOURS...WILL WAIT ON ANY HEADLINES BUT BEGIN TO HIGHLIGHT MORE IN
THE HWO AND OTHER PRODUCTS. AMOUNTS OF AROUND 6 INCHES SEEM
POSSIBLE NEAR THE MO BORDER WITH 2-5 IN CENTRAL IOWA...AND AN INCH
OR LESS ACROSS THE NORTH.

MUCH COLDER AIR WILL FILTER INTO THE STATE FOR NEXT WEEK WITH A
SERIES OF SHORTWAVES PASSING THROUGH THE REGION. THIS WILL BRING
THE THREAT OF SNOW MONDAY NIGHT INTO TUESDAY WITH REINFORCING
SHOTS OF COLDER AIR.

&&

.AVIATION...29/18Z
ISSUED AT 1126 AM CST THU JAN 29 2015

MVFR CIGS LOOK TO PERSIST THROUGH THIS EVENING AND POTENTIALLY
INTO FRIDAY MORNING. CONFIDENCE IS HIGHER AT MCW/ALO AND EVEN OTM
FOR THE STRATUS TO LINGER A BIT LONGER...BUT CERTAINLY FOD AND DSM
EXTENDED THE MVFR CIGS TIME FRAME THROUGH LATE THIS EVENING.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...PODRAZIK
LONG TERM...COGIL
AVIATION...PODRAZIK





000
FXUS63 KDMX 292115
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
315 PM CST THU JAN 29 2015

.SHORT TERM /TONIGHT/...
ISSUED AT 315 PM CST THU JAN 29 2015

MAIN FORECAST CONCERN DEALT WITH LINGERING STRATUS DECK
AND TEMPERATURES AS A RESULT OF THE LINGERING CLOUD COVER. LEANED
TOWARD THE NAM/RAP/HRRR FOR CLOUD COVER AND LOW LEVEL RH THIS
EVENING. SOUNDINGS SUGGEST THE INVERSION CONTINUES THROUGH FRIDAY
MORNING AND POTENTIALLY TRAPPING THE LOW LEVEL MOISTURE/STRATUS OVER
CENTRAL IOWA DURING MUCH OF THE NIGHT. THERE IS A DECENT BREAK IN
THE CLOUD DECK OVER NORTH-CENTRAL IOWA AND INTO SOUTHERN MINNESOTA
AS OF 21Z...AND THE HRRR HAS SOMEWHAT PICKED UP ON THIS TREND AND
SLOWLY ERODES THE STRATUS BY AROUND 05Z ACROSS IOWA/MINNESOTA. HAVE
STRATUS SLOWLY ERODING DURING THE EVENING HOURS WITH THE NORTHEAST
SLOWEST TO CLEAR OUT.

CAA CONTINUES THROUGHOUT MUCH OF THE NIGHT BEFORE THE SURFACE RIDGE
SLIDES INTO NORTHERN IOWA FRIDAY MORNING AND FINALLY ALLOWING THE
WINDS TO BECOME LIGHT AND VARIABLE. SO ANY RADIATIONAL COOLING WILL
BE CLOSER TO SUNRISE. WITH THE TEMPERATURES REMAINING FAIRLY COLD
THIS AFTERNOON...LEANED TOWARD THE RAP FOR LOWS TONIGHT AS IT SEEMED
TO HAVE A BETTER HANDLE ON TEMP AND CLOUD COVER TRENDS.

.LONG TERM /FRIDAY THROUGH THURSDAY/...
ISSUED AT 315 PM CST THU JAN 29 2015

MUCH OF THE LONG TERM FORECAST WILL BE DOMINATED BY BROAD
NORTHWEST FLOW AND A SERIES OF WAVES MOVING THROUGH THE FLOW.
SURFACE RIDGING WILL BE ACROSS THE STATE AT THE BEGINNING OF THE
LONGER TERM TOMORROW MORNING WITH FRIDAY BEING THE BEST DAY OUT OF
REMAINDER OF THE FORECAST. WARM ADVECTION WILL INCREASE BY LATER
IN THE DAY AS SOUTHERLY SURFACE FLOW RESUMES AND READINGS ONCE
AGAIN ABOVE NORMAL. A DECENT PRESSURE GRADIENT KEEPING WINDS UP ON
FRIDAY NIGHT ALONG WITH INCREASING CLOUDINESS WILL HELP KEEP
TEMPERATURES QUITE WARM OVERNIGHT. MAY BEGIN TO SEE SOME LIGHT
PRECIPITATION IN THE FAR SOUTHWEST TOWARD DAYBREAK BUT THE BULK OF
THE SYSTEM WILL COME IN LATER PERIODS.

MOVING INTO THE WEEKEND...ALL FOCUS SHIFTS TO A SHORTWAVE TOPPING
THE WESTERN RIDGE AND ITS INTERACTION WITH A VERY MOIST UPPER LOW
ACROSS THE SOUTHWEST UNITED STATES. THE 12Z MODELS ARE BEGINNING
TO CLUSTER AROUND A SOLUTION OF DROPPING THE NORTHERN SHORTWAVE
SOUTHEAST WITH SUFFICIENT AMPLITUDE TO BRING THE MOISTURE PLUME
FAR ENOUGH NORTH TO IMPACT IOWA...AT LEAST THE SOUTHERN HALF OR
SO. INITIALLY...A SHORTWAVE THAT PASSES THROUGH THE GREAT LAKES
AREA FRIDAY NIGHT WILL SEND A COLD FRONT SOUTHWARD THRU THE
FORECAST AREA ON SATURDAY. MEANWHILE..INCREASING ISENTROPIC LIFT
AND MOISTURE ADVECTION WILL LEAD TO PRECIPITATION DEVELOPMENT
ACROSS SOUTHERN IOWA ON SATURDAY MORNING AHEAD OF THE BOUNDARY.
THE PRECIPITATION WILL LIKELY BE RAIN IN FAR SOUTHERN IOWA WITH
TEMPERATURES IN THE MID TO UPPER 30S. HOWEVER...A TRANSITION TO
SNOW IS LIKELY BY I80 OR HWY30 AS COLDER AIR IS ENCOUNTERED WITH
THE SOUTHWARD MOVING BOUNDARY. FORCING WILL SUSTAIN AND INCREASE
INTO SATURDAY NIGHT WITH DECENT MID LEVEL FRONTOGENETICAL FORCING
ACROSS THE SOUTHERN IOWA. ANY RAIN IN THE SOUTH ON SATURDAY WILL
TRANSITION TO SNOW IN THE EVENING AS COLD AIR CONTINUES TO DEEPEN
AND SPREAD SOUTHWARD BEHIND THE BOUNDARY. BY LATE SATURDAY NIGHT
INTO SUNDAY...DECENT MID LEVEL FORCING FROM APPROACHING SOUTHEAST
MOVING SHORTWAVE WILL HELP SNOW TO CONTINUE DURING THE DAY.
EVENTUALLY...THE FORCING WILL SHIFT TO THE EAST BY LATE IN THE DAY
WITH THE SNOW ENDING. THERE WILL BE A TIGHT GRADIENT OF SNOWFALL
ON NORTHERN SIDE OF PRECIPITATION SHIELD AND THEREFORE THE SNOW
AMOUNTS THAT ACCOMPANY THIS SYSTEM. AT THIS POINT...THE GRADIENT
APPEARS NEAR THE I80 CORRIDOR ALTHOUGH THIS WILL LIKELY MOVE WITH
SUBSEQUENT INFORMATION. GIVEN THE LONG DURATION OF THIS EVENT...IT
DOESNT APPEAR WARNING CRITERIA WILL BE MET...ALTHOUGH THE
COMBINATION OF WINDS AND SNOW MAY BE ENOUGH TO BOOST US INTO
WARNING. GIVEN THE CHANGES IN MODEL RUNS OVER THE PAST 36
HOURS...WILL WAIT ON ANY HEADLINES BUT BEGIN TO HIGHLIGHT MORE IN
THE HWO AND OTHER PRODUCTS. AMOUNTS OF AROUND 6 INCHES SEEM
POSSIBLE NEAR THE MO BORDER WITH 2-5 IN CENTRAL IOWA...AND AN INCH
OR LESS ACROSS THE NORTH.

MUCH COLDER AIR WILL FILTER INTO THE STATE FOR NEXT WEEK WITH A
SERIES OF SHORTWAVES PASSING THROUGH THE REGION. THIS WILL BRING
THE THREAT OF SNOW MONDAY NIGHT INTO TUESDAY WITH REINFORCING
SHOTS OF COLDER AIR.

&&

.AVIATION...29/18Z
ISSUED AT 1126 AM CST THU JAN 29 2015

MVFR CIGS LOOK TO PERSIST THROUGH THIS EVENING AND POTENTIALLY
INTO FRIDAY MORNING. CONFIDENCE IS HIGHER AT MCW/ALO AND EVEN OTM
FOR THE STRATUS TO LINGER A BIT LONGER...BUT CERTAINLY FOD AND DSM
EXTENDED THE MVFR CIGS TIME FRAME THROUGH LATE THIS EVENING.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...PODRAZIK
LONG TERM...COGIL
AVIATION...PODRAZIK




000
FXUS63 KDMX 291726
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1126 AM CST THU JAN 29 2015

...UPDATED AVIATION DISCUSSION...

.SHORT TERM /TODAY/...
ISSUED AT 354 AM CST THU JAN 29 2015

PRIMARY QUESTIONS THIS MORNING WILL BE WINDS AND LIGHT PRECIP
TRENDS. IR SATELLITE IMAGERY NICELY SHOWS COMPACT SHORT WAVE PASSING
THROUGH IA AT THE MOMENT WHICH HAS BEEN PRODUCING SOME VERY LIGHT
SNOW ALOFT AND POSSIBLY CONTRIBUTING TO SEEDER/FEEDER LIGHT DRIZZLE
AT THE SURFACE.  FARTHER UPSTREAM WATER VAPOR IMAGERY INDICATES
ANOTHER WAVE FROM THE DAKOTAS INTO MN WITH MORE LIMITED MOISTURE.
ANY FORCING WITH THAT FEATURE APPEARS TO BE WEAK AND POSSIBLY JUST
PHASED WITH THE IA VORT CENTER WITH MID CLOUDS INTO MN.  ANY ICE
INTRODUCTION AND LIGHT SNOW/FLURRY POTENTIAL WITH THE CLOUD
ENHANCEMENT IS FLEETING AND NOT WORTH OF MENTION THIS MORNING.
PRECIP WOULD NEED TO COME FROM THE AT LEAST 1KM THICK STRATUS LAYER.
MODEL CROSS SECTIONS DO NOT SHOW MUCH IN THE WAY OF LIFT HOWEVER SO
MEASURABLE POTENTIAL IS NIL.  WILL JUST MENTION PATCHY LIGHT DRIZZLE
OR FREEZING DRIZZLE NORTH HALF DEPENDING ON SURFACE TEMPS.  PRECIP
SHOULD BE VERY LIGHT...IF AND WHEN IT OCCURS...SO DO NOT EXPECT ANY
TRAVEL PROBLEMS.

WIND GUSTS REACHED 40KTS OR HIGHER OVER WRN IA JUST AFTER
MIDNIGHT...SUGGESTING SURFACE GUSTS WERE TAPPING WINDS TO TOP OF
MIXED LAYER /1KM/.  GUSTS AND SUSTAINED SPEEDS HAVE DIMINISHED
SOMEWHAT HOWEVER WITH ONLY A HANDFUL OF SITES NOW AT EITHER ADVISORY
CRITERIA. 500M WINDS CONTINUE TO GRADUALLY DIMINISH THIS
MORNING...AS SHOULD SUSTAINED SURFACE WINDS WITH ISALLOBARIC MAX
EXITING THE STATE...SO ADVISORY MAY BE MARGINAL AT THIS POINT BUT
PUBLIC SENSIBLE WEATHER PERCEPTION FAVORS KEEPING IT THROUGH
EXPIRATION TIME.

09Z SURFACE ANALYSIS SHOWS FAIRLY HOMOGENEOUS AIRMASS FROM IA
UPSTREAM SO TEMPS ARE NOT EXPECTED TO DROP QUICKLY.  SHOULD SEE A
VERY GRADUAL DROP INTO THE MORNING WITH ONLY A MINOR REBOUND BY
AFTERNOON.  CONFIDENCE IN CLOUD TRENDS IS NOT GREAT...BUT MODEL
CONSENSUS SUGGESTS CLOUDS MAY AT LEAST PARTIALLY BREAK UP BY
AFTERNOON.

.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
ISSUED AT 354 AM CST THU JAN 29 2015

WITH HIGH PRESSURE ROLLING THROUGH THE REGION TO START THE LONG TERM
FCST PERIOD OFF...FRIDAY WILL BE QUIET. SUNSHINE PLUS 850MB TEMPS
OF -2C TO -4C SHOULD HELP THE CWA STAY ABOVE NORMAL WITH TEMPS IN
THE 40S AND 30S.

THE MAIN FORECAST HIGHLIGHT FOR THE NEXT WEEK IS THE SATURDAY INTO
SUNDAY MORNING ACCUMULATING SNOWFALL POTENTIAL. 06Z THU WATER VAPOR
IMAGERY PICKING UP AN UPPER LOW WHICH IS SLATED TO COME ONSHORE NEAR
THE BAJA PENINSULA THURSDAY INTO FRIDAY. MODELS TRYING TO PHASE
AN INVERTED TROUGH...WHICH WILL BE POOLING MOISTURE FROM THE GULF
OF MEXICO...WITH THIS UPPER LOW. ALL MODELS PRODUCE A BAND OF
MOISTURE CONVERGENCE ALONG A BOUNDARY TO SERVE AS A FOCUSING
MECHANISM FOR PRECIP. THE CHALLENGING PART OF THIS FCST HAS BEEN
PEGGING DOWN THE TRACK OF THIS SYSTEM. THE MODELS HAVE BEEN
BOUNCING ALL OVER THE PLACE AND RUN TO RUN CONSISTENCY HAS BEEN
POOR AT BEST. THE NAM IS THE MOST EXCITED WITH THIS SYSTEM AS IT
IS THE FURTHEST NORTH AND MOST AMPLIFIED. THE GFS HAS BEEN THE
LEAST CONSISTENT MODEL OVER THE PAST FEW DAYS AND IS THE FURTHEST
SOUTH WITH THIS SYSTEM. THE EURO LIES SOMEWHAT IN THE MIDDLE AND
HAS BEEN THE MOST CONSISTENT WITH THIS SYSTEM...SO WILL INITIALLY
LEAN TOWARDS THE EURO AND STEER AWAY FROM THE GFS. WITH MORE
RECENT OUTPUTS...A STRONG 1040MB ARCTIC HIGH HAS BEEN INTRODUCED
OVER THE DAKOTAS. THIS HIGH WILL BE WORTH KEEPING AN EYE ON AS IT
MAY HAMMER PRECIP CHANCES...ESPECIALLY ACROSS OUR NORTH...IF IT
IS PLACED FURTHER SOUTH IN FUTURE MODEL RUNS.

SOUNDINGS EASILY SATURATE ALOFT BY 18Z SATURDAY AND CONTINUE TO
SATURATE FROM TOP DOWN AS SYSTEM APPROACHES. BY 00Z SUN...SOUTHERN
IOWA BEGINS TO SATURATE NEAR THE SFC AS DWPT DEPRESSIONS TIGHTEN.
MAX TEMPS SATURDAY TRENDING WARMER THE PAST FEW DAYS AND HAVE BEEN
BUMPED TO THE UPPER 30S/LOW 40S ALONG AND SOUTH OF INTERSTATE 80.
THIS WILL OBVIOUSLY KICK P-TYPE TO RAIN DURING PEAK HEATING HOURS.
SOUNDING PROFILE ALOFT DROPS TO BELOW FREEZING BY 00Z SUN. THUS
WHEN THE SUN GOES DOWN...PTYPE SHOULD CHANGE TO SNOW FAIRLY
QUICKLY GIVEN THE EXPECTED CAA. IN ALL HAVE ROUGHLY 1 TO 2 INCHES
OF SNOW GOING ACROSS OUR SOUTH. GIVEN THE RECENT MODEL
CONSISTENCY...CONFIDENCE IS NOT EXTREMELY HIGH AT THIS POINT SO
THERE MAY BE SOME VARIATION IN THIS SNOWFALL FORECAST OVER THE
NEXT FEW DAYS.

AT THIS POINT...THE BIGGEST DRIVER OF ADVERSE IMPACTS WILL BE THE
WINDS. TODAY`S MODEL RUNS HAVE SHOWN CONSISTENCY WITH DEVELOPING A
MIXED LAYER WHICH FEATURES 15KT TO 20KT WINDS AT ITS TOP. IT
APPEARS THESE WINDS SHOULD EASILY MIX DOWN TO THE SFC...SO HAVE
BUMPED UP WINDS FROM PVS FCST AND WILL NEED TO CONTINUE TO MONITOR
THIS TREND FOR STRONGER WINDS AS THEY WOULD LEAD TO GREATER
REDUCED VISIBILITIES DURING PERIODS OF SNOW.

BEHIND THIS SYSTEM FOR SUNDAY INTO THE MIDDLE OF NEXT WEEK...MODELS
HAVE BEEN ALL OVER THE PLACE FOR TEMPERATURES. THE ONLY CONSISTENT
TREND HAS BEEN A LOWERING OF TEMPERATURES FOR SUNDAY. WITH CLOUDS
EXPECTED AT LEAST THROUGHOUT THE MORNING...THIS SEEMS
REASONABLE...AND HAVE THUS LOWERED TEMPS FROM GUIDANCE A FEW
DEGREES. FOR TUESDAY...THE GFS RUN FROM 24 HOURS AGO HAD STRONG CAA
PRODUCING TEMPS OF 19/-1 AT KDSM AND NOW HAS 35/14. MAIN REASON FOR
DIFF IS MOST RECENT RUNS PROPAGATING LOW PRESSURE THROUGH CENTRAL
MN...PLACING OUR CWA IN SOUTHERLY FLOW. BEYOND THIS...CONFIDENCE
INCREASING THAT THE CWA WILL REMAIN IN NORTHERLY/NORTHWESTERLY FLOW
INTO NEXT WEEKEND...WHICH WOULD SUGGEST NEAR TO BELOW NORMAL
TEMPERATURES TO PERSIST.

&&

.AVIATION...29/18Z
ISSUED AT 1126 AM CST THU JAN 29 2015

MVFR CIGS LOOK TO PERSIST THROUGH THIS EVENING AND POTENTIALLY
INTO FRIDAY MORNING. CONFIDENCE IS HIGHER AT MCW/ALO AND EVEN OTM
FOR THE STRATUS TO LINGER A BIT LONGER...BUT CERTAINLY FOD AND DSM
EXTENDED THE MVFR CIGS TIME FRAME THROUGH LATE THIS EVENING.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...SMALL
LONG TERM...KOTENBERG
AVIATION...PODRAZIK





000
FXUS63 KDMX 291726
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1126 AM CST THU JAN 29 2015

...UPDATED AVIATION DISCUSSION...

.SHORT TERM /TODAY/...
ISSUED AT 354 AM CST THU JAN 29 2015

PRIMARY QUESTIONS THIS MORNING WILL BE WINDS AND LIGHT PRECIP
TRENDS. IR SATELLITE IMAGERY NICELY SHOWS COMPACT SHORT WAVE PASSING
THROUGH IA AT THE MOMENT WHICH HAS BEEN PRODUCING SOME VERY LIGHT
SNOW ALOFT AND POSSIBLY CONTRIBUTING TO SEEDER/FEEDER LIGHT DRIZZLE
AT THE SURFACE.  FARTHER UPSTREAM WATER VAPOR IMAGERY INDICATES
ANOTHER WAVE FROM THE DAKOTAS INTO MN WITH MORE LIMITED MOISTURE.
ANY FORCING WITH THAT FEATURE APPEARS TO BE WEAK AND POSSIBLY JUST
PHASED WITH THE IA VORT CENTER WITH MID CLOUDS INTO MN.  ANY ICE
INTRODUCTION AND LIGHT SNOW/FLURRY POTENTIAL WITH THE CLOUD
ENHANCEMENT IS FLEETING AND NOT WORTH OF MENTION THIS MORNING.
PRECIP WOULD NEED TO COME FROM THE AT LEAST 1KM THICK STRATUS LAYER.
MODEL CROSS SECTIONS DO NOT SHOW MUCH IN THE WAY OF LIFT HOWEVER SO
MEASURABLE POTENTIAL IS NIL.  WILL JUST MENTION PATCHY LIGHT DRIZZLE
OR FREEZING DRIZZLE NORTH HALF DEPENDING ON SURFACE TEMPS.  PRECIP
SHOULD BE VERY LIGHT...IF AND WHEN IT OCCURS...SO DO NOT EXPECT ANY
TRAVEL PROBLEMS.

WIND GUSTS REACHED 40KTS OR HIGHER OVER WRN IA JUST AFTER
MIDNIGHT...SUGGESTING SURFACE GUSTS WERE TAPPING WINDS TO TOP OF
MIXED LAYER /1KM/.  GUSTS AND SUSTAINED SPEEDS HAVE DIMINISHED
SOMEWHAT HOWEVER WITH ONLY A HANDFUL OF SITES NOW AT EITHER ADVISORY
CRITERIA. 500M WINDS CONTINUE TO GRADUALLY DIMINISH THIS
MORNING...AS SHOULD SUSTAINED SURFACE WINDS WITH ISALLOBARIC MAX
EXITING THE STATE...SO ADVISORY MAY BE MARGINAL AT THIS POINT BUT
PUBLIC SENSIBLE WEATHER PERCEPTION FAVORS KEEPING IT THROUGH
EXPIRATION TIME.

09Z SURFACE ANALYSIS SHOWS FAIRLY HOMOGENEOUS AIRMASS FROM IA
UPSTREAM SO TEMPS ARE NOT EXPECTED TO DROP QUICKLY.  SHOULD SEE A
VERY GRADUAL DROP INTO THE MORNING WITH ONLY A MINOR REBOUND BY
AFTERNOON.  CONFIDENCE IN CLOUD TRENDS IS NOT GREAT...BUT MODEL
CONSENSUS SUGGESTS CLOUDS MAY AT LEAST PARTIALLY BREAK UP BY
AFTERNOON.

.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
ISSUED AT 354 AM CST THU JAN 29 2015

WITH HIGH PRESSURE ROLLING THROUGH THE REGION TO START THE LONG TERM
FCST PERIOD OFF...FRIDAY WILL BE QUIET. SUNSHINE PLUS 850MB TEMPS
OF -2C TO -4C SHOULD HELP THE CWA STAY ABOVE NORMAL WITH TEMPS IN
THE 40S AND 30S.

THE MAIN FORECAST HIGHLIGHT FOR THE NEXT WEEK IS THE SATURDAY INTO
SUNDAY MORNING ACCUMULATING SNOWFALL POTENTIAL. 06Z THU WATER VAPOR
IMAGERY PICKING UP AN UPPER LOW WHICH IS SLATED TO COME ONSHORE NEAR
THE BAJA PENINSULA THURSDAY INTO FRIDAY. MODELS TRYING TO PHASE
AN INVERTED TROUGH...WHICH WILL BE POOLING MOISTURE FROM THE GULF
OF MEXICO...WITH THIS UPPER LOW. ALL MODELS PRODUCE A BAND OF
MOISTURE CONVERGENCE ALONG A BOUNDARY TO SERVE AS A FOCUSING
MECHANISM FOR PRECIP. THE CHALLENGING PART OF THIS FCST HAS BEEN
PEGGING DOWN THE TRACK OF THIS SYSTEM. THE MODELS HAVE BEEN
BOUNCING ALL OVER THE PLACE AND RUN TO RUN CONSISTENCY HAS BEEN
POOR AT BEST. THE NAM IS THE MOST EXCITED WITH THIS SYSTEM AS IT
IS THE FURTHEST NORTH AND MOST AMPLIFIED. THE GFS HAS BEEN THE
LEAST CONSISTENT MODEL OVER THE PAST FEW DAYS AND IS THE FURTHEST
SOUTH WITH THIS SYSTEM. THE EURO LIES SOMEWHAT IN THE MIDDLE AND
HAS BEEN THE MOST CONSISTENT WITH THIS SYSTEM...SO WILL INITIALLY
LEAN TOWARDS THE EURO AND STEER AWAY FROM THE GFS. WITH MORE
RECENT OUTPUTS...A STRONG 1040MB ARCTIC HIGH HAS BEEN INTRODUCED
OVER THE DAKOTAS. THIS HIGH WILL BE WORTH KEEPING AN EYE ON AS IT
MAY HAMMER PRECIP CHANCES...ESPECIALLY ACROSS OUR NORTH...IF IT
IS PLACED FURTHER SOUTH IN FUTURE MODEL RUNS.

SOUNDINGS EASILY SATURATE ALOFT BY 18Z SATURDAY AND CONTINUE TO
SATURATE FROM TOP DOWN AS SYSTEM APPROACHES. BY 00Z SUN...SOUTHERN
IOWA BEGINS TO SATURATE NEAR THE SFC AS DWPT DEPRESSIONS TIGHTEN.
MAX TEMPS SATURDAY TRENDING WARMER THE PAST FEW DAYS AND HAVE BEEN
BUMPED TO THE UPPER 30S/LOW 40S ALONG AND SOUTH OF INTERSTATE 80.
THIS WILL OBVIOUSLY KICK P-TYPE TO RAIN DURING PEAK HEATING HOURS.
SOUNDING PROFILE ALOFT DROPS TO BELOW FREEZING BY 00Z SUN. THUS
WHEN THE SUN GOES DOWN...PTYPE SHOULD CHANGE TO SNOW FAIRLY
QUICKLY GIVEN THE EXPECTED CAA. IN ALL HAVE ROUGHLY 1 TO 2 INCHES
OF SNOW GOING ACROSS OUR SOUTH. GIVEN THE RECENT MODEL
CONSISTENCY...CONFIDENCE IS NOT EXTREMELY HIGH AT THIS POINT SO
THERE MAY BE SOME VARIATION IN THIS SNOWFALL FORECAST OVER THE
NEXT FEW DAYS.

AT THIS POINT...THE BIGGEST DRIVER OF ADVERSE IMPACTS WILL BE THE
WINDS. TODAY`S MODEL RUNS HAVE SHOWN CONSISTENCY WITH DEVELOPING A
MIXED LAYER WHICH FEATURES 15KT TO 20KT WINDS AT ITS TOP. IT
APPEARS THESE WINDS SHOULD EASILY MIX DOWN TO THE SFC...SO HAVE
BUMPED UP WINDS FROM PVS FCST AND WILL NEED TO CONTINUE TO MONITOR
THIS TREND FOR STRONGER WINDS AS THEY WOULD LEAD TO GREATER
REDUCED VISIBILITIES DURING PERIODS OF SNOW.

BEHIND THIS SYSTEM FOR SUNDAY INTO THE MIDDLE OF NEXT WEEK...MODELS
HAVE BEEN ALL OVER THE PLACE FOR TEMPERATURES. THE ONLY CONSISTENT
TREND HAS BEEN A LOWERING OF TEMPERATURES FOR SUNDAY. WITH CLOUDS
EXPECTED AT LEAST THROUGHOUT THE MORNING...THIS SEEMS
REASONABLE...AND HAVE THUS LOWERED TEMPS FROM GUIDANCE A FEW
DEGREES. FOR TUESDAY...THE GFS RUN FROM 24 HOURS AGO HAD STRONG CAA
PRODUCING TEMPS OF 19/-1 AT KDSM AND NOW HAS 35/14. MAIN REASON FOR
DIFF IS MOST RECENT RUNS PROPAGATING LOW PRESSURE THROUGH CENTRAL
MN...PLACING OUR CWA IN SOUTHERLY FLOW. BEYOND THIS...CONFIDENCE
INCREASING THAT THE CWA WILL REMAIN IN NORTHERLY/NORTHWESTERLY FLOW
INTO NEXT WEEKEND...WHICH WOULD SUGGEST NEAR TO BELOW NORMAL
TEMPERATURES TO PERSIST.

&&

.AVIATION...29/18Z
ISSUED AT 1126 AM CST THU JAN 29 2015

MVFR CIGS LOOK TO PERSIST THROUGH THIS EVENING AND POTENTIALLY
INTO FRIDAY MORNING. CONFIDENCE IS HIGHER AT MCW/ALO AND EVEN OTM
FOR THE STRATUS TO LINGER A BIT LONGER...BUT CERTAINLY FOD AND DSM
EXTENDED THE MVFR CIGS TIME FRAME THROUGH LATE THIS EVENING.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...SMALL
LONG TERM...KOTENBERG
AVIATION...PODRAZIK




000
FXUS63 KDMX 291209
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
609 AM CST THU JAN 29 2015

.SHORT TERM /TODAY/...
ISSUED AT 354 AM CST THU JAN 29 2015

PRIMARY QUESTIONS THIS MORNING WILL BE WINDS AND LIGHT PRECIP
TRENDS. IR SATELLITE IMAGERY NICELY SHOWS COMPACT SHORT WAVE PASSING
THROUGH IA AT THE MOMENT WHICH HAS BEEN PRODUCING SOME VERY LIGHT
SNOW ALOFT AND POSSIBLY CONTRIBUTING TO SEEDER/FEEDER LIGHT DRIZZLE
AT THE SURFACE.  FARTHER UPSTREAM WATER VAPOR IMAGERY INDICATES
ANOTHER WAVE FROM THE DAKOTAS INTO MN WITH MORE LIMITED MOISTURE.
ANY FORCING WITH THAT FEATURE APPEARS TO BE WEAK AND POSSIBLY JUST
PHASED WITH THE IA VORT CENTER WITH MID CLOUDS INTO MN.  ANY ICE
INTRODUCTION AND LIGHT SNOW/FLURRY POTENTIAL WITH THE CLOUD
ENHANCEMENT IS FLEETING AND NOT WORTH OF MENTION THIS MORNING.
PRECIP WOULD NEED TO COME FROM THE AT LEAST 1KM THICK STRATUS LAYER.
MODEL CROSS SECTIONS DO NOT SHOW MUCH IN THE WAY OF LIFT HOWEVER SO
MEASURABLE POTENTIAL IS NIL.  WILL JUST MENTION PATCHY LIGHT DRIZZLE
OR FREEZING DRIZZLE NORTH HALF DEPENDING ON SURFACE TEMPS.  PRECIP
SHOULD BE VERY LIGHT...IF AND WHEN IT OCCURS...SO DO NOT EXPECT ANY
TRAVEL PROBLEMS.

WIND GUSTS REACHED 40KTS OR HIGHER OVER WRN IA JUST AFTER
MIDNIGHT...SUGGESTING SURFACE GUSTS WERE TAPPING WINDS TO TOP OF
MIXED LAYER /1KM/.  GUSTS AND SUSTAINED SPEEDS HAVE DIMINISHED
SOMEWHAT HOWEVER WITH ONLY A HANDFUL OF SITES NOW AT EITHER ADVISORY
CRITERIA. 500M WINDS CONTINUE TO GRADUALLY DIMINISH THIS
MORNING...AS SHOULD SUSTAINED SURFACE WINDS WITH ISALLOBARIC MAX
EXITING THE STATE...SO ADVISORY MAY BE MARGINAL AT THIS POINT BUT
PUBLIC SENSIBLE WEATHER PERCEPTION FAVORS KEEPING IT THROUGH
EXPIRATION TIME.

09Z SURFACE ANALYSIS SHOWS FAIRLY HOMOGENEOUS AIRMASS FROM IA
UPSTREAM SO TEMPS ARE NOT EXPECTED TO DROP QUICKLY.  SHOULD SEE A
VERY GRADUAL DROP INTO THE MORNING WITH ONLY A MINOR REBOUND BY
AFTERNOON.  CONFIDENCE IN CLOUD TRENDS IS NOT GREAT...BUT MODEL
CONSENSUS SUGGESTS CLOUDS MAY AT LEAST PARTIALLY BREAK UP BY
AFTERNOON.

.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
ISSUED AT 354 AM CST THU JAN 29 2015

WITH HIGH PRESSURE ROLLING THROUGH THE REGION TO START THE LONG TERM
FCST PERIOD OFF...FRIDAY WILL BE QUIET. SUNSHINE PLUS 850MB TEMPS
OF -2C TO -4C SHOULD HELP THE CWA STAY ABOVE NORMAL WITH TEMPS IN
THE 40S AND 30S.

THE MAIN FORECAST HIGHLIGHT FOR THE NEXT WEEK IS THE SATURDAY INTO
SUNDAY MORNING ACCUMULATING SNOWFALL POTENTIAL. 06Z THU WATER VAPOR
IMAGERY PICKING UP AN UPPER LOW WHICH IS SLATED TO COME ONSHORE NEAR
THE BAJA PENINSULA THURSDAY INTO FRIDAY. MODELS TRYING TO PHASE
AN INVERTED TROUGH...WHICH WILL BE POOLING MOISTURE FROM THE GULF
OF MEXICO...WITH THIS UPPER LOW. ALL MODELS PRODUCE A BAND OF
MOISTURE CONVERGENCE ALONG A BOUNDARY TO SERVE AS A FOCUSING
MECHANISM FOR PRECIP. THE CHALLENGING PART OF THIS FCST HAS BEEN
PEGGING DOWN THE TRACK OF THIS SYSTEM. THE MODELS HAVE BEEN
BOUNCING ALL OVER THE PLACE AND RUN TO RUN CONSISTENCY HAS BEEN
POOR AT BEST. THE NAM IS THE MOST EXCITED WITH THIS SYSTEM AS IT
IS THE FURTHEST NORTH AND MOST AMPLIFIED. THE GFS HAS BEEN THE
LEAST CONSISTENT MODEL OVER THE PAST FEW DAYS AND IS THE FURTHEST
SOUTH WITH THIS SYSTEM. THE EURO LIES SOMEWHAT IN THE MIDDLE AND
HAS BEEN THE MOST CONSISTENT WITH THIS SYSTEM...SO WILL INITIALLY
LEAN TOWARDS THE EURO AND STEER AWAY FROM THE GFS. WITH MORE
RECENT OUTPUTS...A STRONG 1040MB ARCTIC HIGH HAS BEEN INTRODUCED
OVER THE DAKOTAS. THIS HIGH WILL BE WORTH KEEPING AN EYE ON AS IT
MAY HAMMER PRECIP CHANCES...ESPECIALLY ACROSS OUR NORTH...IF IT
IS PLACED FURTHER SOUTH IN FUTURE MODEL RUNS.

SOUNDINGS EASILY SATURATE ALOFT BY 18Z SATURDAY AND CONTINUE TO
SATURATE FROM TOP DOWN AS SYSTEM APPROACHES. BY 00Z SUN...SOUTHERN
IOWA BEGINS TO SATURATE NEAR THE SFC AS DWPT DEPRESSIONS TIGHTEN.
MAX TEMPS SATURDAY TRENDING WARMER THE PAST FEW DAYS AND HAVE BEEN
BUMPED TO THE UPPER 30S/LOW 40S ALONG AND SOUTH OF INTERSTATE 80.
THIS WILL OBVIOUSLY KICK P-TYPE TO RAIN DURING PEAK HEATING HOURS.
SOUNDING PROFILE ALOFT DROPS TO BELOW FREEZING BY 00Z SUN. THUS
WHEN THE SUN GOES DOWN...PTYPE SHOULD CHANGE TO SNOW FAIRLY
QUICKLY GIVEN THE EXPECTED CAA. IN ALL HAVE ROUGHLY 1 TO 2 INCHES
OF SNOW GOING ACROSS OUR SOUTH. GIVEN THE RECENT MODEL
CONSISTENCY...CONFIDENCE IS NOT EXTREMELY HIGH AT THIS POINT SO
THERE MAY BE SOME VARIATION IN THIS SNOWFALL FORECAST OVER THE
NEXT FEW DAYS.

AT THIS POINT...THE BIGGEST DRIVER OF ADVERSE IMPACTS WILL BE THE
WINDS. TODAY`S MODEL RUNS HAVE SHOWN CONSISTENCY WITH DEVELOPING A
MIXED LAYER WHICH FEATURES 15KT TO 20KT WINDS AT ITS TOP. IT
APPEARS THESE WINDS SHOULD EASILY MIX DOWN TO THE SFC...SO HAVE
BUMPED UP WINDS FROM PVS FCST AND WILL NEED TO CONTINUE TO MONITOR
THIS TREND FOR STRONGER WINDS AS THEY WOULD LEAD TO GREATER
REDUCED VISIBILITIES DURING PERIODS OF SNOW.

BEHIND THIS SYSTEM FOR SUNDAY INTO THE MIDDLE OF NEXT WEEK...MODELS
HAVE BEEN ALL OVER THE PLACE FOR TEMPERATURES. THE ONLY CONSISTENT
TREND HAS BEEN A LOWERING OF TEMPERATURES FOR SUNDAY. WITH CLOUDS
EXPECTED AT LEAST THROUGHOUT THE MORNING...THIS SEEMS
REASONABLE...AND HAVE THUS LOWERED TEMPS FROM GUIDANCE A FEW
DEGREES. FOR TUESDAY...THE GFS RUN FROM 24 HOURS AGO HAD STRONG CAA
PRODUCING TEMPS OF 19/-1 AT KDSM AND NOW HAS 35/14. MAIN REASON FOR
DIFF IS MOST RECENT RUNS PROPAGATING LOW PRESSURE THROUGH CENTRAL
MN...PLACING OUR CWA IN SOUTHERLY FLOW. BEYOND THIS...CONFIDENCE
INCREASING THAT THE CWA WILL REMAIN IN NORTHERLY/NORTHWESTERLY FLOW
INTO NEXT WEEKEND...WHICH WOULD SUGGEST NEAR TO BELOW NORMAL
TEMPERATURES TO PERSIST.

&&

.AVIATION...29/12Z
ISSUED AT 605 AM CST THU JAN 29 2015

MAIN CONCERNS THIS MORNING WILL BE STRATUS AND WIND TRENDS.
WIDESPREAD STRATUS IS IN PLACE FROM IA UPSTREAM WITH PATCHY IFR
CIGS EMBEDDED WITHIN PREVAILING MVFR CONDITIONS. LITTLE CHANGE IN
CLOUD OR WIND TRENDS IS ANTICIPATED THROUGH AT LEAST MIDDAY WITH
NW WIND GUSTS OFTEN 30KTS OR BETTER. CONFIDENCE DECREASES LATER
TODAY HOWEVER...ESPECIALLY IN TERMS OF CLOUDS. HAVE KEPT MVFR
CIGS GOING 22Z-06Z NW-SE BUT CONFIDENCE WILL NOT INCREASE UNTIL
CLEARING BEGINS IN EARNEST AND TRENDS CAN BE BETTER CAPTURED.
WINDS WILL REMAIN GUSTY THROUGH THE DAYLIGHT HOURS THEN GRADUALLY
DIMINISH OVERNIGHT.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 9 AM CST THIS MORNING FOR ADAIR-ADAMS-
AUDUBON-BOONE-BUTLER-CALHOUN-CARROLL-CASS-CERRO GORDO-CLARKE-
CRAWFORD-DALLAS-DECATUR-EMMET-FRANKLIN-GREENE-GRUNDY-GUTHRIE-
HAMILTON-HANCOCK-HARDIN-HUMBOLDT-JASPER-KOSSUTH-LUCAS-MADISON-
MARION-MARSHALL-PALO ALTO-POCAHONTAS-POLK-RINGGOLD-SAC-STORY-
TAYLOR-UNION-WARREN-WEBSTER-WINNEBAGO-WORTH-WRIGHT.

&&

$$

SHORT TERM...SMALL
LONG TERM...KOTENBERG
AVIATION...SMALL





000
FXUS63 KDMX 291000
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
400 AM CST THU JAN 29 2015

.SHORT TERM /TODAY/...
ISSUED AT 354 AM CST THU JAN 29 2015

PRIMARY QUESTIONS THIS MORNING WILL BE WINDS AND LIGHT PRECIP
TRENDS. IR SATELLITE IMAGERY NICELY SHOWS COMPACT SHORT WAVE PASSING
THROUGH IA AT THE MOMENT WHICH HAS BEEN PRODUCING SOME VERY LIGHT
SNOW ALOFT AND POSSIBLY CONTRIBUTING TO SEEDER/FEEDER LIGHT DRIZZLE
AT THE SURFACE.  FARTHER UPSTREAM WATER VAPOR IMAGERY INDICATES
ANOTHER WAVE FROM THE DAKOTAS INTO MN WITH MORE LIMITED MOISTURE.
ANY FORCING WITH THAT FEATURE APPEARS TO BE WEAK AND POSSIBLY JUST
PHASED WITH THE IA VORT CENTER WITH MID CLOUDS INTO MN.  ANY ICE
INTRODUCTION AND LIGHT SNOW/FLURRY POTENTIAL WITH THE CLOUD
ENHANCEMENT IS FLEETING AND NOT WORTH OF MENTION THIS MORNING.
PRECIP WOULD NEED TO COME FROM THE AT LEAST 1KM THICK STRATUS LAYER.
MODEL CROSS SECTIONS DO NOT SHOW MUCH IN THE WAY OF LIFT HOWEVER SO
MEASURABLE POTENTIAL IS NIL.  WILL JUST MENTION PATCHY LIGHT DRIZZLE
OR FREEZING DRIZZLE NORTH HALF DEPENDING ON SURFACE TEMPS.  PRECIP
SHOULD BE VERY LIGHT...IF AND WHEN IT OCCURS...SO DO NOT EXPECT ANY
TRAVEL PROBLEMS.

WIND GUSTS REACHED 40KTS OR HIGHER OVER WRN IA JUST AFTER
MIDNIGHT...SUGGESTING SURFACE GUSTS WERE TAPPING WINDS TO TOP OF
MIXED LAYER /1KM/.  GUSTS AND SUSTAINED SPEEDS HAVE DIMINISHED
SOMEWHAT HOWEVER WITH ONLY A HANDFUL OF SITES NOW AT EITHER ADVISORY
CRITERIA. 500M WINDS CONTINUE TO GRADUALLY DIMINISH THIS MORNING
...AS SHOULD SUSTAINED SURFACE WINDS WITH ISALLOBARIC MAX EXITING
THE STATE...SO ADVISORY MAY BE MARGINAL AT THIS POINT BUT PUBLIC
SENSIBLE WEATHER PERCEPTION FAVORS KEEPING IT THROUGH EXPIRATION
TIME.

09Z SURFACE ANALYSIS SHOWS FAIRLY HOMOGENEOUS AIRMASS FROM IA
UPSTREAM SO TEMPS ARE NOT EXPECTED TO DROP QUICKLY.  SHOULD SEE A
VERY GRADUAL DROP INTO THE MORNING WITH ONLY A MINOR REBOUND BY
AFTERNOON.  CONFIDENCE IN CLOUD TRENDS IS NOT GREAT...BUT MODEL
CONSENSUS SUGGESTS CLOUDS MAY AT LEAST PARTIALLY BREAK UP BY
AFTERNOON.

.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
ISSUED AT 354 AM CST THU JAN 29 2015

WITH HIGH PRESSURE ROLLING THROUGH THE REGION TO START THE LONG TERM
FCST PERIOD OFF...FRIDAY WILL BE QUIET. SUNSHINE PLUS 850MB TEMPS
OF -2C TO -4C SHOULD HELP THE CWA STAY ABOVE NORMAL WITH TEMPS IN
THE 40S AND 30S.

THE MAIN FORECAST HIGHLIGHT FOR THE NEXT WEEK IS THE SATURDAY INTO
SUNDAY MORNING ACCUMULATING SNOWFALL POTENTIAL. 06Z THU WATER VAPOR
IMAGERY PICKING UP AN UPPER LOW WHICH IS SLATED TO COME ONSHORE NEAR
THE BAJA PENINSULA THURSDAY INTO FRIDAY. MODELS TRYING TO PHASE
AN INVERTED TROUGH...WHICH WILL BE POOLING MOISTURE FROM THE GULF
OF MEXICO...WITH THIS UPPER LOW. ALL MODELS PRODUCE A BAND OF
MOISTURE CONVERGENCE ALONG A BOUNDARY TO SERVE AS A FOCUSING
MECHANISM FOR PRECIP. THE CHALLENGING PART OF THIS FCST HAS BEEN
PEGGING DOWN THE TRACK OF THIS SYSTEM. THE MODELS HAVE BEEN
BOUNCING ALL OVER THE PLACE AND RUN TO RUN CONSISTENCY HAS BEEN
POOR AT BEST. THE NAM IS THE MOST EXCITED WITH THIS SYSTEM AS IT
IS THE FURTHEST NORTH AND MOST AMPLIFIED. THE GFS HAS BEEN THE
LEAST CONSISTENT MODEL OVER THE PAST FEW DAYS AND IS THE FURTHEST
SOUTH WITH THIS SYSTEM. THE EURO LIES SOMEWHAT IN THE MIDDLE AND
HAS BEEN THE MOST CONSISTENT WITH THIS SYSTEM...SO WILL INITIALLY
LEAN TOWARDS THE EURO AND STEER AWAY FROM THE GFS. WITH MORE
RECENT OUTPUTS...A STRONG 1040MB ARCTIC HIGH HAS BEEN INTRODUCED
OVER THE DAKOTAS. THIS HIGH WILL BE WORTH KEEPING AN EYE ON AS IT
MAY HAMMER PRECIP CHANCES...ESPECIALLY ACROSS OUR NORTH...IF IT
IS PLACED FURTHER SOUTH IN FUTURE MODEL RUNS.

SOUNDINGS EASILY SATURATE ALOFT BY 18Z SATURDAY AND CONTINUE TO
SATURATE FROM TOP DOWN AS SYSTEM APPROACHES. BY 00Z SUN...SOUTHERN
IOWA BEGINS TO SATURATE NEAR THE SFC AS DWPT DEPRESSIONS TIGHTEN.
MAX TEMPS SATURDAY TRENDING WARMER THE PAST FEW DAYS AND HAVE BEEN
BUMPED TO THE UPPER 30S/LOW 40S ALONG AND SOUTH OF INTERSTATE 80.
THIS WILL OBVIOUSLY KICK P-TYPE TO RAIN DURING PEAK HEATING HOURS.
SOUNDING PROFILE ALOFT DROPS TO BELOW FREEZING BY 00Z SUN. THUS
WHEN THE SUN GOES DOWN...PTYPE SHOULD CHANGE TO SNOW FAIRLY
QUICKLY GIVEN THE EXPECTED CAA. IN ALL HAVE ROUGHLY 1 TO 2 INCHES
OF SNOW GOING ACROSS OUR SOUTH. GIVEN THE RECENT MODEL
CONSISTENCY...CONFIDENCE IS NOT EXTREMELY HIGH AT THIS POINT SO
THERE MAY BE SOME VARIATION IN THIS SNOWFALL FORECAST OVER THE
NEXT FEW DAYS.

AT THIS POINT...THE BIGGEST DRIVER OF ADVERSE IMPACTS WILL BE THE
WINDS. TODAY`S MODEL RUNS HAVE SHOWN CONSISTENCY WITH DEVELOPING A
MIXED LAYER WHICH FEATURES 15KT TO 20KT WINDS AT ITS TOP. IT
APPEARS THESE WINDS SHOULD EASILY MIX DOWN TO THE SFC...SO HAVE
BUMPED UP WINDS FROM PVS FCST AND WILL NEED TO CONTINUE TO MONITOR
THIS TREND FOR STRONGER WINDS AS THEY WOULD LEAD TO GREATER
REDUCED VISIBILITIES DURING PERIODS OF SNOW.

BEHIND THIS SYSTEM FOR SUNDAY INTO THE MIDDLE OF NEXT WEEK...MODELS
HAVE BEEN ALL OVER THE PLACE FOR TEMPERATURES. THE ONLY CONSISTENT
TREND HAS BEEN A LOWERING OF TEMPERATURES FOR SUNDAY. WITH CLOUDS
EXPECTED AT LEAST THROUGHOUT THE MORNING...THIS SEEMS
REASONABLE...AND HAVE THUS LOWERED TEMPS FROM GUIDANCE A FEW
DEGREES. FOR TUESDAY...THE GFS RUN FROM 24 HOURS AGO HAD STRONG CAA
PRODUCING TEMPS OF 19/-1 AT KDSM AND NOW HAS 35/14. MAIN REASON FOR
DIFF IS MOST RECENT RUNS PROPAGATING LOW PRESSURE THROUGH CENTRAL
MN...PLACING OUR CWA IN SOUTHERLY FLOW. BEYOND THIS...CONFIDENCE
INCREASING THAT THE CWA WILL REMAIN IN NORTHERLY/NORTHWESTERLY FLOW
INTO NEXT WEEKEND...WHICH WOULD SUGGEST NEAR TO BELOW NORMAL
TEMPERATURES TO PERSIST.

&&

.AVIATION...29/06Z
ISSUED AT 1140 PM CST WED JAN 28 2015

GUSTY NORTHWEST WINDS AND IFR/MVFR STRATUS IS OVERSPREADING THE
AREA AND WILL PREVAIL THROUGH MUCH OF THURSDAY. A FEW AREAS OF
DRIZZLE POSSIBLE ESPECIALLY NEAR KMCW ALONG WITH VSBYS LESS THAN
2SM AT TIMES OVERNIGHT. SOME IMPROVEMENT EXPECTED LATE IN THE
PERIOD.


&&

.DMX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 9 AM CST THIS MORNING FOR ADAIR-ADAMS-
AUDUBON-BOONE-BUTLER-CALHOUN-CARROLL-CASS-CERRO GORDO-CLARKE-
CRAWFORD-DALLAS-DECATUR-EMMET-FRANKLIN-GREENE-GRUNDY-GUTHRIE-
HAMILTON-HANCOCK-HARDIN-HUMBOLDT-JASPER-KOSSUTH-LUCAS-MADISON-
MARION-MARSHALL-PALO ALTO-POCAHONTAS-POLK-RINGGOLD-SAC-STORY-
TAYLOR-UNION-WARREN-WEBSTER-WINNEBAGO-WORTH-WRIGHT.

&&

$$

SHORT TERM...SMALL
LONG TERM...KOTENBERG
AVIATION...DONAVON




000
FXUS63 KDMX 291000
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
400 AM CST THU JAN 29 2015

.SHORT TERM /TODAY/...
ISSUED AT 354 AM CST THU JAN 29 2015

PRIMARY QUESTIONS THIS MORNING WILL BE WINDS AND LIGHT PRECIP
TRENDS. IR SATELLITE IMAGERY NICELY SHOWS COMPACT SHORT WAVE PASSING
THROUGH IA AT THE MOMENT WHICH HAS BEEN PRODUCING SOME VERY LIGHT
SNOW ALOFT AND POSSIBLY CONTRIBUTING TO SEEDER/FEEDER LIGHT DRIZZLE
AT THE SURFACE.  FARTHER UPSTREAM WATER VAPOR IMAGERY INDICATES
ANOTHER WAVE FROM THE DAKOTAS INTO MN WITH MORE LIMITED MOISTURE.
ANY FORCING WITH THAT FEATURE APPEARS TO BE WEAK AND POSSIBLY JUST
PHASED WITH THE IA VORT CENTER WITH MID CLOUDS INTO MN.  ANY ICE
INTRODUCTION AND LIGHT SNOW/FLURRY POTENTIAL WITH THE CLOUD
ENHANCEMENT IS FLEETING AND NOT WORTH OF MENTION THIS MORNING.
PRECIP WOULD NEED TO COME FROM THE AT LEAST 1KM THICK STRATUS LAYER.
MODEL CROSS SECTIONS DO NOT SHOW MUCH IN THE WAY OF LIFT HOWEVER SO
MEASURABLE POTENTIAL IS NIL.  WILL JUST MENTION PATCHY LIGHT DRIZZLE
OR FREEZING DRIZZLE NORTH HALF DEPENDING ON SURFACE TEMPS.  PRECIP
SHOULD BE VERY LIGHT...IF AND WHEN IT OCCURS...SO DO NOT EXPECT ANY
TRAVEL PROBLEMS.

WIND GUSTS REACHED 40KTS OR HIGHER OVER WRN IA JUST AFTER
MIDNIGHT...SUGGESTING SURFACE GUSTS WERE TAPPING WINDS TO TOP OF
MIXED LAYER /1KM/.  GUSTS AND SUSTAINED SPEEDS HAVE DIMINISHED
SOMEWHAT HOWEVER WITH ONLY A HANDFUL OF SITES NOW AT EITHER ADVISORY
CRITERIA. 500M WINDS CONTINUE TO GRADUALLY DIMINISH THIS MORNING
...AS SHOULD SUSTAINED SURFACE WINDS WITH ISALLOBARIC MAX EXITING
THE STATE...SO ADVISORY MAY BE MARGINAL AT THIS POINT BUT PUBLIC
SENSIBLE WEATHER PERCEPTION FAVORS KEEPING IT THROUGH EXPIRATION
TIME.

09Z SURFACE ANALYSIS SHOWS FAIRLY HOMOGENEOUS AIRMASS FROM IA
UPSTREAM SO TEMPS ARE NOT EXPECTED TO DROP QUICKLY.  SHOULD SEE A
VERY GRADUAL DROP INTO THE MORNING WITH ONLY A MINOR REBOUND BY
AFTERNOON.  CONFIDENCE IN CLOUD TRENDS IS NOT GREAT...BUT MODEL
CONSENSUS SUGGESTS CLOUDS MAY AT LEAST PARTIALLY BREAK UP BY
AFTERNOON.

.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
ISSUED AT 354 AM CST THU JAN 29 2015

WITH HIGH PRESSURE ROLLING THROUGH THE REGION TO START THE LONG TERM
FCST PERIOD OFF...FRIDAY WILL BE QUIET. SUNSHINE PLUS 850MB TEMPS
OF -2C TO -4C SHOULD HELP THE CWA STAY ABOVE NORMAL WITH TEMPS IN
THE 40S AND 30S.

THE MAIN FORECAST HIGHLIGHT FOR THE NEXT WEEK IS THE SATURDAY INTO
SUNDAY MORNING ACCUMULATING SNOWFALL POTENTIAL. 06Z THU WATER VAPOR
IMAGERY PICKING UP AN UPPER LOW WHICH IS SLATED TO COME ONSHORE NEAR
THE BAJA PENINSULA THURSDAY INTO FRIDAY. MODELS TRYING TO PHASE
AN INVERTED TROUGH...WHICH WILL BE POOLING MOISTURE FROM THE GULF
OF MEXICO...WITH THIS UPPER LOW. ALL MODELS PRODUCE A BAND OF
MOISTURE CONVERGENCE ALONG A BOUNDARY TO SERVE AS A FOCUSING
MECHANISM FOR PRECIP. THE CHALLENGING PART OF THIS FCST HAS BEEN
PEGGING DOWN THE TRACK OF THIS SYSTEM. THE MODELS HAVE BEEN
BOUNCING ALL OVER THE PLACE AND RUN TO RUN CONSISTENCY HAS BEEN
POOR AT BEST. THE NAM IS THE MOST EXCITED WITH THIS SYSTEM AS IT
IS THE FURTHEST NORTH AND MOST AMPLIFIED. THE GFS HAS BEEN THE
LEAST CONSISTENT MODEL OVER THE PAST FEW DAYS AND IS THE FURTHEST
SOUTH WITH THIS SYSTEM. THE EURO LIES SOMEWHAT IN THE MIDDLE AND
HAS BEEN THE MOST CONSISTENT WITH THIS SYSTEM...SO WILL INITIALLY
LEAN TOWARDS THE EURO AND STEER AWAY FROM THE GFS. WITH MORE
RECENT OUTPUTS...A STRONG 1040MB ARCTIC HIGH HAS BEEN INTRODUCED
OVER THE DAKOTAS. THIS HIGH WILL BE WORTH KEEPING AN EYE ON AS IT
MAY HAMMER PRECIP CHANCES...ESPECIALLY ACROSS OUR NORTH...IF IT
IS PLACED FURTHER SOUTH IN FUTURE MODEL RUNS.

SOUNDINGS EASILY SATURATE ALOFT BY 18Z SATURDAY AND CONTINUE TO
SATURATE FROM TOP DOWN AS SYSTEM APPROACHES. BY 00Z SUN...SOUTHERN
IOWA BEGINS TO SATURATE NEAR THE SFC AS DWPT DEPRESSIONS TIGHTEN.
MAX TEMPS SATURDAY TRENDING WARMER THE PAST FEW DAYS AND HAVE BEEN
BUMPED TO THE UPPER 30S/LOW 40S ALONG AND SOUTH OF INTERSTATE 80.
THIS WILL OBVIOUSLY KICK P-TYPE TO RAIN DURING PEAK HEATING HOURS.
SOUNDING PROFILE ALOFT DROPS TO BELOW FREEZING BY 00Z SUN. THUS
WHEN THE SUN GOES DOWN...PTYPE SHOULD CHANGE TO SNOW FAIRLY
QUICKLY GIVEN THE EXPECTED CAA. IN ALL HAVE ROUGHLY 1 TO 2 INCHES
OF SNOW GOING ACROSS OUR SOUTH. GIVEN THE RECENT MODEL
CONSISTENCY...CONFIDENCE IS NOT EXTREMELY HIGH AT THIS POINT SO
THERE MAY BE SOME VARIATION IN THIS SNOWFALL FORECAST OVER THE
NEXT FEW DAYS.

AT THIS POINT...THE BIGGEST DRIVER OF ADVERSE IMPACTS WILL BE THE
WINDS. TODAY`S MODEL RUNS HAVE SHOWN CONSISTENCY WITH DEVELOPING A
MIXED LAYER WHICH FEATURES 15KT TO 20KT WINDS AT ITS TOP. IT
APPEARS THESE WINDS SHOULD EASILY MIX DOWN TO THE SFC...SO HAVE
BUMPED UP WINDS FROM PVS FCST AND WILL NEED TO CONTINUE TO MONITOR
THIS TREND FOR STRONGER WINDS AS THEY WOULD LEAD TO GREATER
REDUCED VISIBILITIES DURING PERIODS OF SNOW.

BEHIND THIS SYSTEM FOR SUNDAY INTO THE MIDDLE OF NEXT WEEK...MODELS
HAVE BEEN ALL OVER THE PLACE FOR TEMPERATURES. THE ONLY CONSISTENT
TREND HAS BEEN A LOWERING OF TEMPERATURES FOR SUNDAY. WITH CLOUDS
EXPECTED AT LEAST THROUGHOUT THE MORNING...THIS SEEMS
REASONABLE...AND HAVE THUS LOWERED TEMPS FROM GUIDANCE A FEW
DEGREES. FOR TUESDAY...THE GFS RUN FROM 24 HOURS AGO HAD STRONG CAA
PRODUCING TEMPS OF 19/-1 AT KDSM AND NOW HAS 35/14. MAIN REASON FOR
DIFF IS MOST RECENT RUNS PROPAGATING LOW PRESSURE THROUGH CENTRAL
MN...PLACING OUR CWA IN SOUTHERLY FLOW. BEYOND THIS...CONFIDENCE
INCREASING THAT THE CWA WILL REMAIN IN NORTHERLY/NORTHWESTERLY FLOW
INTO NEXT WEEKEND...WHICH WOULD SUGGEST NEAR TO BELOW NORMAL
TEMPERATURES TO PERSIST.

&&

.AVIATION...29/06Z
ISSUED AT 1140 PM CST WED JAN 28 2015

GUSTY NORTHWEST WINDS AND IFR/MVFR STRATUS IS OVERSPREADING THE
AREA AND WILL PREVAIL THROUGH MUCH OF THURSDAY. A FEW AREAS OF
DRIZZLE POSSIBLE ESPECIALLY NEAR KMCW ALONG WITH VSBYS LESS THAN
2SM AT TIMES OVERNIGHT. SOME IMPROVEMENT EXPECTED LATE IN THE
PERIOD.


&&

.DMX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 9 AM CST THIS MORNING FOR ADAIR-ADAMS-
AUDUBON-BOONE-BUTLER-CALHOUN-CARROLL-CASS-CERRO GORDO-CLARKE-
CRAWFORD-DALLAS-DECATUR-EMMET-FRANKLIN-GREENE-GRUNDY-GUTHRIE-
HAMILTON-HANCOCK-HARDIN-HUMBOLDT-JASPER-KOSSUTH-LUCAS-MADISON-
MARION-MARSHALL-PALO ALTO-POCAHONTAS-POLK-RINGGOLD-SAC-STORY-
TAYLOR-UNION-WARREN-WEBSTER-WINNEBAGO-WORTH-WRIGHT.

&&

$$

SHORT TERM...SMALL
LONG TERM...KOTENBERG
AVIATION...DONAVON





000
FXUS63 KDMX 290540
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1140 PM CST WED JAN 28 2015

.SHORT TERM /TONIGHT/...
ISSUED AT 323 PM CST WED JAN 28 2015

LOW PRESSURE OVER EASTERN NEBRASKA WILL MOVE EAST AND PASS EAST
OF THE CWA BY LATER TONIGHT. STRONG NWLY WINDS WILL OVERSPREAD THE
STATE TONIGHT AS THE ISALLOBARIC COUPLET MOVES THROUGH. WILL
BEGIN WITH A WIND ADVISORY OVER THE WEST PART OF THE CWA AROUND
06Z...WITH IT REACHING THE EASTERN PART BEFORE 11Z. PRECIP WILL BE
LIMITED WITH LIMITED MOISTURE...BUT TO EXPECT SOME LIGHT PRECIP
OVER THE NORTHEAST...WITH PATCHY DRIZZLE OVER THE CENTRAL
COUNTIES. FEEL THE DRIZZLE THREAT WILL END BEFORE THE SUB-
FREEZING TEMPS GET INTO THE CENTRAL COUNTIES AND DID NOT PLAY WITH
ANY FREEZING PRECIP OTHER THAN THE NORTHEAST. EVEN SO...DO NOT
EXPECT THERE TO BE ENOUGH TO CAUSE MAJOR ISSUES.

.LONG TERM /THURSDAY THROUGH WEDNESDAY/...
ISSUED AT 323 PM CST WED JAN 28 2015

MODEL SOUNDINGS CONTINUE TO INDICATE LOW END ADVISORY GUST
POTENTIAL THROUGH MID MORNING THURSDAY WITH 42-48KTS AT TOP OF
MIXED LAYER IN FORECAST SOUNDINGS IN MUCH OF CENTRAL IOWA.
HOWEVER...THE BIGGEST PUSH OF COLD AIR AND STRONGEST WINDS OFF THE
SURFACE WILL OCCUR NEAR 12Z WITH WINDS WEAKENING SLOWLY THROUGH
THE DAY. WITH THE POTENTIAL GUSTS LOWERING THROUGH THE MORNING AND
A GRADUAL DECLINE IN SUSTAINED WINDS...WILL LET THE ADVISORY GO AT
15Z. CLOUDS ALSO LOOK TO REMAIN IN PLACE FOR MUCH OF THE MORNING
ALTHOUGH DRYING IN THE SOUNDINGS OCCURS BY AFTERNOON WITH SOME
PARTLY SUNNY CONDITIONS AFTER MIDDAY IN MANY LOCATIONS.

FOCUS REALLY THEN SHIFTS TO THE WEEKEND SYSTEM AND ASSOCIATED
PRECIPITATION POTENTIAL. 00Z/06Z MODEL RUNS WERE EXTREMELY BULLISH
WITH THIS SYSTEM IN REGARDS TO HEAVY PRECIPITATION THIS WEEKEND.
THE CONCERN WITH THIS SYSTEM IS THE STRENGTH OF THE NORTHERN
SYSTEM AND THE PHASING WITH LARGE UPPER LOW IN THE SOUTHWESTERN
UNITED STATES. THE OLDER RUNS WERE STRONGER WITH THIS NORTHERN
SYSTEM AND WITH THE SUBSEQUENT PHASING AS WELL. THIS PULLED MUCH
MORE MOISTURE NORTHWARD ALONG AND INVERTED TROF AND PRODUCED A
LARGE AMOUNT OF SNOWFALL ACROSS IOWA.  IN CONTRAST...THE CURRENT
12Z RUNS HAVE A QUICKER NORTHERN WAVE WITH LITTLE PHASING AND
SUBSEQUENTLY A MUCH DRIER SOLUTION IN IOWA. THERE STILL EXISTS A
LARGE SPREAD IN GFS ENSEMBLE MEMBERS AND THEREFORE UNCERTAINTY
REMAINS HIGH. HAVE CUT BACK ON POPS SUBSTANTIALLY DURING THE DAY
SATURDAY AND KEPT THE HIGHEST POPS IN THE SOUTH AND EAST ON
SATURDAY NIGHT INTO SUNDAY. AT THIS POINT...LIGHT ACCUMULATIONS
ARE ANTICIPATED BEFORE THE SNOW ENDS ON SUNDAY. THEREAFTER...MUCH
COLDER AIR OVERSPREAD THE STATE WITH READINGS BELOW NORMAL INTO
NEXT WEEK. THERE WILL ALSO BE LOW CHANCES FOR POPS RETURNING FROM
TIME TO TIME AS WEAK SYSTEM PASS THROUGH THE FAST NORTHWEST FLOW.

&&

.AVIATION...29/06Z
ISSUED AT 1140 PM CST WED JAN 28 2015

GUSTY NORTHWEST WINDS AND IFR/MVFR STRATUS IS OVERSPREADING THE
AREA AND WILL PREVAIL THROUGH MUCH OF THURSDAY. A FEW AREAS OF
DRIZZLE POSSIBLE ESPECIALLY NEAR KMCW ALONG WITH VSBYS LESS THAN
2SM AT TIMES OVERNIGHT. SOME IMPROVEMENT EXPECTED LATE IN THE
PERIOD.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 4 AM TO 9 AM CST THURSDAY FOR BUTLER-CERRO
GORDO-CLARKE-DECATUR-FRANKLIN-GRUNDY-HARDIN-JASPER-LUCAS-MADISON-
MARION-MARSHALL-POLK-RINGGOLD-STORY-UNION-WARREN-WORTH.

WIND ADVISORY UNTIL 9 AM CST THURSDAY FOR ADAIR-ADAMS-AUDUBON-
BOONE-CALHOUN-CARROLL-CASS-CRAWFORD-DALLAS-EMMET-GREENE-GUTHRIE-
HAMILTON-HANCOCK-HUMBOLDT-KOSSUTH-PALO ALTO-POCAHONTAS-SAC-
TAYLOR-WEBSTER-WINNEBAGO-WRIGHT.

&&

$$

SHORT TERM...MS
LONG TERM...COGIL
AVIATION...DONAVON




000
FXUS63 KDMX 290540
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1140 PM CST WED JAN 28 2015

.SHORT TERM /TONIGHT/...
ISSUED AT 323 PM CST WED JAN 28 2015

LOW PRESSURE OVER EASTERN NEBRASKA WILL MOVE EAST AND PASS EAST
OF THE CWA BY LATER TONIGHT. STRONG NWLY WINDS WILL OVERSPREAD THE
STATE TONIGHT AS THE ISALLOBARIC COUPLET MOVES THROUGH. WILL
BEGIN WITH A WIND ADVISORY OVER THE WEST PART OF THE CWA AROUND
06Z...WITH IT REACHING THE EASTERN PART BEFORE 11Z. PRECIP WILL BE
LIMITED WITH LIMITED MOISTURE...BUT TO EXPECT SOME LIGHT PRECIP
OVER THE NORTHEAST...WITH PATCHY DRIZZLE OVER THE CENTRAL
COUNTIES. FEEL THE DRIZZLE THREAT WILL END BEFORE THE SUB-
FREEZING TEMPS GET INTO THE CENTRAL COUNTIES AND DID NOT PLAY WITH
ANY FREEZING PRECIP OTHER THAN THE NORTHEAST. EVEN SO...DO NOT
EXPECT THERE TO BE ENOUGH TO CAUSE MAJOR ISSUES.

.LONG TERM /THURSDAY THROUGH WEDNESDAY/...
ISSUED AT 323 PM CST WED JAN 28 2015

MODEL SOUNDINGS CONTINUE TO INDICATE LOW END ADVISORY GUST
POTENTIAL THROUGH MID MORNING THURSDAY WITH 42-48KTS AT TOP OF
MIXED LAYER IN FORECAST SOUNDINGS IN MUCH OF CENTRAL IOWA.
HOWEVER...THE BIGGEST PUSH OF COLD AIR AND STRONGEST WINDS OFF THE
SURFACE WILL OCCUR NEAR 12Z WITH WINDS WEAKENING SLOWLY THROUGH
THE DAY. WITH THE POTENTIAL GUSTS LOWERING THROUGH THE MORNING AND
A GRADUAL DECLINE IN SUSTAINED WINDS...WILL LET THE ADVISORY GO AT
15Z. CLOUDS ALSO LOOK TO REMAIN IN PLACE FOR MUCH OF THE MORNING
ALTHOUGH DRYING IN THE SOUNDINGS OCCURS BY AFTERNOON WITH SOME
PARTLY SUNNY CONDITIONS AFTER MIDDAY IN MANY LOCATIONS.

FOCUS REALLY THEN SHIFTS TO THE WEEKEND SYSTEM AND ASSOCIATED
PRECIPITATION POTENTIAL. 00Z/06Z MODEL RUNS WERE EXTREMELY BULLISH
WITH THIS SYSTEM IN REGARDS TO HEAVY PRECIPITATION THIS WEEKEND.
THE CONCERN WITH THIS SYSTEM IS THE STRENGTH OF THE NORTHERN
SYSTEM AND THE PHASING WITH LARGE UPPER LOW IN THE SOUTHWESTERN
UNITED STATES. THE OLDER RUNS WERE STRONGER WITH THIS NORTHERN
SYSTEM AND WITH THE SUBSEQUENT PHASING AS WELL. THIS PULLED MUCH
MORE MOISTURE NORTHWARD ALONG AND INVERTED TROF AND PRODUCED A
LARGE AMOUNT OF SNOWFALL ACROSS IOWA.  IN CONTRAST...THE CURRENT
12Z RUNS HAVE A QUICKER NORTHERN WAVE WITH LITTLE PHASING AND
SUBSEQUENTLY A MUCH DRIER SOLUTION IN IOWA. THERE STILL EXISTS A
LARGE SPREAD IN GFS ENSEMBLE MEMBERS AND THEREFORE UNCERTAINTY
REMAINS HIGH. HAVE CUT BACK ON POPS SUBSTANTIALLY DURING THE DAY
SATURDAY AND KEPT THE HIGHEST POPS IN THE SOUTH AND EAST ON
SATURDAY NIGHT INTO SUNDAY. AT THIS POINT...LIGHT ACCUMULATIONS
ARE ANTICIPATED BEFORE THE SNOW ENDS ON SUNDAY. THEREAFTER...MUCH
COLDER AIR OVERSPREAD THE STATE WITH READINGS BELOW NORMAL INTO
NEXT WEEK. THERE WILL ALSO BE LOW CHANCES FOR POPS RETURNING FROM
TIME TO TIME AS WEAK SYSTEM PASS THROUGH THE FAST NORTHWEST FLOW.

&&

.AVIATION...29/06Z
ISSUED AT 1140 PM CST WED JAN 28 2015

GUSTY NORTHWEST WINDS AND IFR/MVFR STRATUS IS OVERSPREADING THE
AREA AND WILL PREVAIL THROUGH MUCH OF THURSDAY. A FEW AREAS OF
DRIZZLE POSSIBLE ESPECIALLY NEAR KMCW ALONG WITH VSBYS LESS THAN
2SM AT TIMES OVERNIGHT. SOME IMPROVEMENT EXPECTED LATE IN THE
PERIOD.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 4 AM TO 9 AM CST THURSDAY FOR BUTLER-CERRO
GORDO-CLARKE-DECATUR-FRANKLIN-GRUNDY-HARDIN-JASPER-LUCAS-MADISON-
MARION-MARSHALL-POLK-RINGGOLD-STORY-UNION-WARREN-WORTH.

WIND ADVISORY UNTIL 9 AM CST THURSDAY FOR ADAIR-ADAMS-AUDUBON-
BOONE-CALHOUN-CARROLL-CASS-CRAWFORD-DALLAS-EMMET-GREENE-GUTHRIE-
HAMILTON-HANCOCK-HUMBOLDT-KOSSUTH-PALO ALTO-POCAHONTAS-SAC-
TAYLOR-WEBSTER-WINNEBAGO-WRIGHT.

&&

$$

SHORT TERM...MS
LONG TERM...COGIL
AVIATION...DONAVON





000
FXUS63 KDMX 282338
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
538 PM CST WED JAN 28 2015

.SHORT TERM /TONIGHT/...
ISSUED AT 323 PM CST WED JAN 28 2015

LOW PRESSURE OVER EASTERN NEBRASKA WILL MOVE EAST AND PASS EAST
OF THE CWA BY LATER TONIGHT. STRONG NWLY WINDS WILL OVERSPREAD THE
STATE TONIGHT AS THE ISALLOBARIC COUPLET MOVES THROUGH. WILL
BEGIN WITH A WIND ADVISORY OVER THE WEST PART OF THE CWA AROUND
06Z...WITH IT REACHING THE EASTERN PART BEFORE 11Z. PRECIP WILL BE
LIMITED WITH LIMITED MOISTURE...BUT TO EXPECT SOME LIGHT PRECIP
OVER THE NORTHEAST...WITH PATCHY DRIZZLE OVER THE CENTRAL
COUNTIES. FEEL THE DRIZZLE THREAT WILL END BEFORE THE SUB-
FREEZING TEMPS GET INTO THE CENTRAL COUNTIES AND DID NOT PLAY WITH
ANY FREEZING PRECIP OTHER THAN THE NORTHEAST. EVEN SO...DO NOT
EXPECT THERE TO BE ENOUGH TO CAUSE MAJOR ISSUES.

.LONG TERM /THURSDAY THROUGH WEDNESDAY/...
ISSUED AT 323 PM CST WED JAN 28 2015

MODEL SOUNDINGS CONTINUE TO INDICATE LOW END ADVISORY GUST
POTENTIAL THROUGH MID MORNING THURSDAY WITH 42-48KTS AT TOP OF
MIXED LAYER IN FORECAST SOUNDINGS IN MUCH OF CENTRAL IOWA.
HOWEVER...THE BIGGEST PUSH OF COLD AIR AND STRONGEST WINDS OFF THE
SURFACE WILL OCCUR NEAR 12Z WITH WINDS WEAKENING SLOWLY THROUGH
THE DAY. WITH THE POTENTIAL GUSTS LOWERING THROUGH THE MORNING AND
A GRADUAL DECLINE IN SUSTAINED WINDS...WILL LET THE ADVISORY GO AT
15Z. CLOUDS ALSO LOOK TO REMAIN IN PLACE FOR MUCH OF THE MORNING
ALTHOUGH DRYING IN THE SOUNDINGS OCCURS BY AFTERNOON WITH SOME
PARTLY SUNNY CONDITIONS AFTER MIDDAY IN MANY LOCATIONS.

FOCUS REALLY THEN SHIFTS TO THE WEEKEND SYSTEM AND ASSOCIATED
PRECIPITATION POTENTIAL. 00Z/06Z MODEL RUNS WERE EXTREMELY BULLISH
WITH THIS SYSTEM IN REGARDS TO HEAVY PRECIPITATION THIS WEEKEND.
THE CONCERN WITH THIS SYSTEM IS THE STRENGTH OF THE NORTHERN
SYSTEM AND THE PHASING WITH LARGE UPPER LOW IN THE SOUTHWESTERN
UNITED STATES. THE OLDER RUNS WERE STRONGER WITH THIS NORTHERN
SYSTEM AND WITH THE SUBSEQUENT PHASING AS WELL. THIS PULLED MUCH
MORE MOISTURE NORTHWARD ALONG AND INVERTED TROF AND PRODUCED A
LARGE AMOUNT OF SNOWFALL ACROSS IOWA.  IN CONTRAST...THE CURRENT
12Z RUNS HAVE A QUICKER NORTHERN WAVE WITH LITTLE PHASING AND
SUBSEQUENTLY A MUCH DRIER SOLUTION IN IOWA. THERE STILL EXISTS A
LARGE SPREAD IN GFS ENSEMBLE MEMBERS AND THEREFORE UNCERTAINTY
REMAINS HIGH. HAVE CUT BACK ON POPS SUBSTANTIALLY DURING THE DAY
SATURDAY AND KEPT THE HIGHEST POPS IN THE SOUTH AND EAST ON
SATURDAY NIGHT INTO SUNDAY. AT THIS POINT...LIGHT ACCUMULATIONS
ARE ANTICIPATED BEFORE THE SNOW ENDS ON SUNDAY. THEREAFTER...MUCH
COLDER AIR OVERSPREAD THE STATE WITH READINGS BELOW NORMAL INTO
NEXT WEEK. THERE WILL ALSO BE LOW CHANCES FOR POPS RETURNING FROM
TIME TO TIME AS WEAK SYSTEM PASS THROUGH THE FAST NORTHWEST FLOW.

&&

.AVIATION...29/00Z
ISSUED AT 538 PM CST WED JAN 28 2015

COLD FRONTAL PASSAGE OVERNIGHT WILL BRING STRONG AND GUSTY NW
WINDS THAT WILL CONTINUE THURSDAY. A PERIOD OF WIDESPREAD IFR CIGS
ALSO ANTICIPATED OVERNIGHT WITH SOME VSBY RESTRICTIONS DUE TO FOG.
CIGS SHOULD GRADUALLY LIFT TO MVFR BY THE AFTERNOON.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 4 AM TO 9 AM CST THURSDAY FOR BUTLER-CERRO
GORDO-CLARKE-DECATUR-FRANKLIN-GRUNDY-HARDIN-JASPER-LUCAS-MADISON-
MARION-MARSHALL-POLK-RINGGOLD-STORY-UNION-WARREN-WORTH.

WIND ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM CST THURSDAY FOR
ADAIR-ADAMS-AUDUBON-BOONE-CALHOUN-CARROLL-CASS-CRAWFORD-DALLAS-
EMMET-GREENE-GUTHRIE-HAMILTON-HANCOCK-HUMBOLDT-KOSSUTH-PALO ALTO-
POCAHONTAS-SAC-TAYLOR-WEBSTER-WINNEBAGO-WRIGHT.

&&

$$

SHORT TERM...MS
LONG TERM...COGIL
AVIATION...DONAVON




000
FXUS63 KDMX 282338
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
538 PM CST WED JAN 28 2015

.SHORT TERM /TONIGHT/...
ISSUED AT 323 PM CST WED JAN 28 2015

LOW PRESSURE OVER EASTERN NEBRASKA WILL MOVE EAST AND PASS EAST
OF THE CWA BY LATER TONIGHT. STRONG NWLY WINDS WILL OVERSPREAD THE
STATE TONIGHT AS THE ISALLOBARIC COUPLET MOVES THROUGH. WILL
BEGIN WITH A WIND ADVISORY OVER THE WEST PART OF THE CWA AROUND
06Z...WITH IT REACHING THE EASTERN PART BEFORE 11Z. PRECIP WILL BE
LIMITED WITH LIMITED MOISTURE...BUT TO EXPECT SOME LIGHT PRECIP
OVER THE NORTHEAST...WITH PATCHY DRIZZLE OVER THE CENTRAL
COUNTIES. FEEL THE DRIZZLE THREAT WILL END BEFORE THE SUB-
FREEZING TEMPS GET INTO THE CENTRAL COUNTIES AND DID NOT PLAY WITH
ANY FREEZING PRECIP OTHER THAN THE NORTHEAST. EVEN SO...DO NOT
EXPECT THERE TO BE ENOUGH TO CAUSE MAJOR ISSUES.

.LONG TERM /THURSDAY THROUGH WEDNESDAY/...
ISSUED AT 323 PM CST WED JAN 28 2015

MODEL SOUNDINGS CONTINUE TO INDICATE LOW END ADVISORY GUST
POTENTIAL THROUGH MID MORNING THURSDAY WITH 42-48KTS AT TOP OF
MIXED LAYER IN FORECAST SOUNDINGS IN MUCH OF CENTRAL IOWA.
HOWEVER...THE BIGGEST PUSH OF COLD AIR AND STRONGEST WINDS OFF THE
SURFACE WILL OCCUR NEAR 12Z WITH WINDS WEAKENING SLOWLY THROUGH
THE DAY. WITH THE POTENTIAL GUSTS LOWERING THROUGH THE MORNING AND
A GRADUAL DECLINE IN SUSTAINED WINDS...WILL LET THE ADVISORY GO AT
15Z. CLOUDS ALSO LOOK TO REMAIN IN PLACE FOR MUCH OF THE MORNING
ALTHOUGH DRYING IN THE SOUNDINGS OCCURS BY AFTERNOON WITH SOME
PARTLY SUNNY CONDITIONS AFTER MIDDAY IN MANY LOCATIONS.

FOCUS REALLY THEN SHIFTS TO THE WEEKEND SYSTEM AND ASSOCIATED
PRECIPITATION POTENTIAL. 00Z/06Z MODEL RUNS WERE EXTREMELY BULLISH
WITH THIS SYSTEM IN REGARDS TO HEAVY PRECIPITATION THIS WEEKEND.
THE CONCERN WITH THIS SYSTEM IS THE STRENGTH OF THE NORTHERN
SYSTEM AND THE PHASING WITH LARGE UPPER LOW IN THE SOUTHWESTERN
UNITED STATES. THE OLDER RUNS WERE STRONGER WITH THIS NORTHERN
SYSTEM AND WITH THE SUBSEQUENT PHASING AS WELL. THIS PULLED MUCH
MORE MOISTURE NORTHWARD ALONG AND INVERTED TROF AND PRODUCED A
LARGE AMOUNT OF SNOWFALL ACROSS IOWA.  IN CONTRAST...THE CURRENT
12Z RUNS HAVE A QUICKER NORTHERN WAVE WITH LITTLE PHASING AND
SUBSEQUENTLY A MUCH DRIER SOLUTION IN IOWA. THERE STILL EXISTS A
LARGE SPREAD IN GFS ENSEMBLE MEMBERS AND THEREFORE UNCERTAINTY
REMAINS HIGH. HAVE CUT BACK ON POPS SUBSTANTIALLY DURING THE DAY
SATURDAY AND KEPT THE HIGHEST POPS IN THE SOUTH AND EAST ON
SATURDAY NIGHT INTO SUNDAY. AT THIS POINT...LIGHT ACCUMULATIONS
ARE ANTICIPATED BEFORE THE SNOW ENDS ON SUNDAY. THEREAFTER...MUCH
COLDER AIR OVERSPREAD THE STATE WITH READINGS BELOW NORMAL INTO
NEXT WEEK. THERE WILL ALSO BE LOW CHANCES FOR POPS RETURNING FROM
TIME TO TIME AS WEAK SYSTEM PASS THROUGH THE FAST NORTHWEST FLOW.

&&

.AVIATION...29/00Z
ISSUED AT 538 PM CST WED JAN 28 2015

COLD FRONTAL PASSAGE OVERNIGHT WILL BRING STRONG AND GUSTY NW
WINDS THAT WILL CONTINUE THURSDAY. A PERIOD OF WIDESPREAD IFR CIGS
ALSO ANTICIPATED OVERNIGHT WITH SOME VSBY RESTRICTIONS DUE TO FOG.
CIGS SHOULD GRADUALLY LIFT TO MVFR BY THE AFTERNOON.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 4 AM TO 9 AM CST THURSDAY FOR BUTLER-CERRO
GORDO-CLARKE-DECATUR-FRANKLIN-GRUNDY-HARDIN-JASPER-LUCAS-MADISON-
MARION-MARSHALL-POLK-RINGGOLD-STORY-UNION-WARREN-WORTH.

WIND ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM CST THURSDAY FOR
ADAIR-ADAMS-AUDUBON-BOONE-CALHOUN-CARROLL-CASS-CRAWFORD-DALLAS-
EMMET-GREENE-GUTHRIE-HAMILTON-HANCOCK-HUMBOLDT-KOSSUTH-PALO ALTO-
POCAHONTAS-SAC-TAYLOR-WEBSTER-WINNEBAGO-WRIGHT.

&&

$$

SHORT TERM...MS
LONG TERM...COGIL
AVIATION...DONAVON





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