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000
FXUS01 KWBC 270733
PMDSPD

SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
333 AM EDT WED AUG 27 2014

VALID 12Z WED AUG 27 2014 - 12Z FRI AUG 29 2014

...THE FLASH FLOOD THREAT CONTINUES FOR PORTIONS OF THE CENTRAL
PLAINS THROUGH THURSDAY MORNING, AND MOVES INTO THE MIDWESTERN
STATES BY THURSDAY AFTERNOON...

...A SLIGHT RISK FOR SEVERE THUNDERSTORMS IS POSSIBLE FOR PARTS OF
NEBRASKA AND KANSAS ON WEDNESDAY...


TROPICAL MOISTURE LIFTING INTO THE FOUR CORNERS REGION OF THE
COUNTRY WILL INTERACT WITH AN AREA OF UPPER LEVEL ENERGY ADVANCING
EASTWARD ACROSS THE CENTRAL ROCKIES. THIS IS EXPECTED TO CONTINUE
TO PRODUCE AN EXPANSIVE AREA OF SHOWERS AND THUNDERSTORMS FROM THE
CENTRAL/SOUTHERN ROCKIES TO THE MIDWEST ON WEDNESDAY AND THURSDAY.
THE HEAVIEST AND MOST ORGANIZED OF THE CONVECTIVE ACTIVITY IS
EXPECTED TO RIDE ALONG A NEARLY STATIONARY SURFACE BOUNDARY
STRETCHED ACROSS THE CENTRAL PLAINS AND MIDDLE MISSISSIPPI VALLEY.
FOR WEDNESDAY INTO THURSDAY, WPC HAS HIGHLIGHTED A SLIGHT RISK FOR
FLASH FLOODING ACROSS MUCH OF CENTRAL AND EASTERN NEBRASKA INTO
WESTERN IOWA. IN ADDITION, SPC HAS ALSO HIGHLIGHTED A SLIGHT RISK
FOR SEVERE WEATHER FOR SOUTHERN NEBRASKA AND NORTHWEST KANSAS. AS
THE ENERGY ALOFT EJECTS INTO THE CENTRAL PLAINS ON THURSDAY, AND
THE SURFACE FRONT LIFTS SLOWLY NORTHWARD, THE HEAVY RAIN AND FLASH
FLOOD THREAT WILL MOVE INTO THE MIDDLE MISSISSIPPI VALLEY AND
PORTIONS OF THE UPPER MIDWEST.

MEANWHILE, THE EASTERN PORTION OF THE THIS BOUNDARY WILL MOVE EAST
AND SOUTHWARD AS A COLD FRONT ACROSS THE NORTHEAST, MID-ATLANTIC,
AND OHIO VALLEY ON WEDNESDAY. THIS SHOULD PRODUCE SCATTERED
SHOWERS AND STORMS ALONG THE FRONT, BUT GIVEN THE LACK OF UPPER
LEVEL SUPPORT, THE ACTIVITY SHOULD REMAIN FAIRLY LIGHT AND MAINLY
DRIVEN BY DIURNAL HEATING. DOWN SOUTH, WEAK ENERGY MOVING WESTWARD
INTO COASTAL TEXAS WILL BRING SHOWERS AND STORMS TO PORTIONS OF
THE WESTERN GULF COAST REGION THROUGHOUT THE FORECAST PERIOD.
WHILE THE HEAVIEST OF THE RAIN IS EXPECTED TO REMAIN OFFSHORE, A
FEW SCATTERED SHOWERS OR THUNDERSTORMS WILL LIKELY MAKE IT ONSHORE
TO COASTAL REGIONS OF TEXAS AND LOUISIANA.


MONARSKI


GRAPHICS AVAILABLE AT WWW.WPC.NCEP.NOAA.GOV
$$







000
FXUS01 KWBC 270733
PMDSPD

SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
333 AM EDT WED AUG 27 2014

VALID 12Z WED AUG 27 2014 - 12Z FRI AUG 29 2014

...THE FLASH FLOOD THREAT CONTINUES FOR PORTIONS OF THE CENTRAL
PLAINS THROUGH THURSDAY MORNING, AND MOVES INTO THE MIDWESTERN
STATES BY THURSDAY AFTERNOON...

...A SLIGHT RISK FOR SEVERE THUNDERSTORMS IS POSSIBLE FOR PARTS OF
NEBRASKA AND KANSAS ON WEDNESDAY...


TROPICAL MOISTURE LIFTING INTO THE FOUR CORNERS REGION OF THE
COUNTRY WILL INTERACT WITH AN AREA OF UPPER LEVEL ENERGY ADVANCING
EASTWARD ACROSS THE CENTRAL ROCKIES. THIS IS EXPECTED TO CONTINUE
TO PRODUCE AN EXPANSIVE AREA OF SHOWERS AND THUNDERSTORMS FROM THE
CENTRAL/SOUTHERN ROCKIES TO THE MIDWEST ON WEDNESDAY AND THURSDAY.
THE HEAVIEST AND MOST ORGANIZED OF THE CONVECTIVE ACTIVITY IS
EXPECTED TO RIDE ALONG A NEARLY STATIONARY SURFACE BOUNDARY
STRETCHED ACROSS THE CENTRAL PLAINS AND MIDDLE MISSISSIPPI VALLEY.
FOR WEDNESDAY INTO THURSDAY, WPC HAS HIGHLIGHTED A SLIGHT RISK FOR
FLASH FLOODING ACROSS MUCH OF CENTRAL AND EASTERN NEBRASKA INTO
WESTERN IOWA. IN ADDITION, SPC HAS ALSO HIGHLIGHTED A SLIGHT RISK
FOR SEVERE WEATHER FOR SOUTHERN NEBRASKA AND NORTHWEST KANSAS. AS
THE ENERGY ALOFT EJECTS INTO THE CENTRAL PLAINS ON THURSDAY, AND
THE SURFACE FRONT LIFTS SLOWLY NORTHWARD, THE HEAVY RAIN AND FLASH
FLOOD THREAT WILL MOVE INTO THE MIDDLE MISSISSIPPI VALLEY AND
PORTIONS OF THE UPPER MIDWEST.

MEANWHILE, THE EASTERN PORTION OF THE THIS BOUNDARY WILL MOVE EAST
AND SOUTHWARD AS A COLD FRONT ACROSS THE NORTHEAST, MID-ATLANTIC,
AND OHIO VALLEY ON WEDNESDAY. THIS SHOULD PRODUCE SCATTERED
SHOWERS AND STORMS ALONG THE FRONT, BUT GIVEN THE LACK OF UPPER
LEVEL SUPPORT, THE ACTIVITY SHOULD REMAIN FAIRLY LIGHT AND MAINLY
DRIVEN BY DIURNAL HEATING. DOWN SOUTH, WEAK ENERGY MOVING WESTWARD
INTO COASTAL TEXAS WILL BRING SHOWERS AND STORMS TO PORTIONS OF
THE WESTERN GULF COAST REGION THROUGHOUT THE FORECAST PERIOD.
WHILE THE HEAVIEST OF THE RAIN IS EXPECTED TO REMAIN OFFSHORE, A
FEW SCATTERED SHOWERS OR THUNDERSTORMS WILL LIKELY MAKE IT ONSHORE
TO COASTAL REGIONS OF TEXAS AND LOUISIANA.


MONARSKI


GRAPHICS AVAILABLE AT WWW.WPC.NCEP.NOAA.GOV
$$






000
FXUS02 KWBC 270634
PMDEPD

EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
234 AM EDT WED AUG 27 2014

VALID 12Z SAT AUG 30 2014 - 12Z WED SEP 03 2014

...OVERVIEW AND PREFERENCES...

EXPECT FAIRLY HIGH HGTS ALOFT... ANCHORED BY RIDGING OVER THE
SOUTHEAST... TO PREVAIL OVER THE EAST.  A TROUGH PROGRESSING FROM
THE WEST AND ACROSS THE NRN HALF OF THE PLAINS FOLLOWED BY
UPSTREAM ENERGY THAT COULD REACH THE NORTHWEST LATE IN THE PERIOD
WILL SUPPORT LOWER HGTS OVER THIS AREA.  MOST FEATURES CURRENTLY
EXHIBIT SOME MEANINGFUL SPREAD AND/OR CONTINUITY ADJUSTMENTS WITH
A 70/30 BLEND OF THE 12Z ECMWF MEAN/18Z GEFS MEAN CAPTURING THE
BEST COMBINATION OF RECENT TRENDS AND INTERMEDIATE POSITIONING OF
FEATURES RELATIVE TO THE FULL GUIDANCE SPREAD.


...GUIDANCE EVALUATION...

IN PRINCIPLE THERE HAS BEEN DECENT CLUSTERING/CONTINUITY WITH THE
UPR TROUGH REACHING THE WEST EARLY IN THE WEEKEND AND CONTINUING
INTO THE PLAINS EARLY NEXT WEEK... THOUGH SHRTWV DETAIL DIFFS IN
THE OPERATIONAL RUNS CONTINUE TO RESULT IN SPREAD FOR THE TIMING
OF THE LEADING SFC FRONT.  PREFER TO RELY ON THE ENSEMBLE MEANS
UNTIL THE OPERATIONAL SOLNS BEGIN TO SETTLE ON THE DETAILS.

AS SEEN YDAY MODEL/ENSEMBLE SPREAD BEGINS TO WIDEN CONSIDERABLY
FROM THE NRN PAC INTO NWRN CONUS LATE IN THE PERIOD.  THIS
ORIGINATES FROM DIVERGING OPINIONS ON THE HANDLING OF ENERGY
WITHIN A SRN BERING SEA INTO NRN PAC TROUGH AS OF DAY 4 SUN.  BY
DAY 7 WED THE MOST LIKELY SCENARIO IS FOR SOME DEGREE OF TROUGHING
TO REACH THE PAC NW ALBEIT WITHIN A FULL ENSEMBLE SPREAD THAT
INCLUDES ANY SCENARIO FROM A TROUGH TO A RIDGE.  THE 12Z CMC MEAN
SUPPORTS THE 12Z ECMWF MEAN THAT KEEPS THE TROUGH LESS AMPLIFIED
THAN THE 18Z GEFS MEAN... BUT NOTE THAT EVEN THE LATTER IS MODEST
RELATIVE TO THE 18Z GFS/12Z CMC.

GUIDANCE IS STILL IN THE PROCESS OF RESOLVING THE SFC DETAILS
AHEAD OF THE SHRTWV FCST TO TRACK NEWD FROM THE ERN PLAINS/MS VLY.
 OVER THE PAST 12-24 HRS LATEST GUIDANCE HAS GRAVITATED RATHER FAR
NWD WITH THE SFC WAVE TRACKING THROUGH THE GRTLKS AROUND DAY 4 SUN
AND WITH THE LEADING FRONT... SO THE UPDATED FCST REFLECTS THIS
ADJUSTMENT IN FRONTAL POSN AND CORRESPONDING TEMPS.  CONFIDENCE IS
STILL MODERATE AT BEST DUE TO SOME DEPENDENCE ON DIFFICULT TO
RESOLVE SMALLER SCALE DETAILS.  WITH THE SHRTWV ALOFT RECENT GFS
RUNS HAVE TENDED BE IN THE FASTER PORTION OF THE ENVELOPE.


...SENSIBLE WEATHER HIGHLIGHTS...

SYSTEM CROSSING THE WEST WILL SUPPORT AREAS OF RNFL ACROSS NRN
PARTS OF THE REGION... WITH THE LEADING FRONT THEN SUPPORTING A
BAND OF LOCALLY HVY CONVECTION FROM THE NRN PLAINS EWD/SEWD.  ALSO
EXPECT A FAIRLY BROAD AREA OF 5-15F BELOW NORMAL MAX TEMPS TO
EXTEND FROM THE NORTHWEST INTO THE NRN PLAINS WITH SOME MODERATION
LATER IN THE PERIOD.  FARTHER EWD MOIST FLOW AHEAD OF THE MID LVL
SHRTWV TRACKING NEWD FROM THE ERN PLAINS/MS VLY AS WELL AS
INTERACTION WITH THE SFC WAVE/FRONT OVER NRN PARTS OF THE EAST
WILL PROVIDE SOME ENHANCEMENT TO RNFL... WITH HIGHEST TOTALS MOST
LIKELY TO BE W OF THE APLCHNS AND FROM THE MID-UPR MS VLY INTO THE
NORTHEAST.  MAX TEMPS MAY REACH 10F OR SO ABOVE NORMAL FROM THE OH
VLY INTO NRN MID ATLC/SRN NEW ENGLAND DURING THE WEEKEND WITH THE
SOUTHEAST/MID ATLC MOST CONSISTENTLY ABOVE NORMAL THROUGH THE
PERIOD.

RAUSCH

$$







000
FXUS02 KWBC 270634
PMDEPD

EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
234 AM EDT WED AUG 27 2014

VALID 12Z SAT AUG 30 2014 - 12Z WED SEP 03 2014

...OVERVIEW AND PREFERENCES...

EXPECT FAIRLY HIGH HGTS ALOFT... ANCHORED BY RIDGING OVER THE
SOUTHEAST... TO PREVAIL OVER THE EAST.  A TROUGH PROGRESSING FROM
THE WEST AND ACROSS THE NRN HALF OF THE PLAINS FOLLOWED BY
UPSTREAM ENERGY THAT COULD REACH THE NORTHWEST LATE IN THE PERIOD
WILL SUPPORT LOWER HGTS OVER THIS AREA.  MOST FEATURES CURRENTLY
EXHIBIT SOME MEANINGFUL SPREAD AND/OR CONTINUITY ADJUSTMENTS WITH
A 70/30 BLEND OF THE 12Z ECMWF MEAN/18Z GEFS MEAN CAPTURING THE
BEST COMBINATION OF RECENT TRENDS AND INTERMEDIATE POSITIONING OF
FEATURES RELATIVE TO THE FULL GUIDANCE SPREAD.


...GUIDANCE EVALUATION...

IN PRINCIPLE THERE HAS BEEN DECENT CLUSTERING/CONTINUITY WITH THE
UPR TROUGH REACHING THE WEST EARLY IN THE WEEKEND AND CONTINUING
INTO THE PLAINS EARLY NEXT WEEK... THOUGH SHRTWV DETAIL DIFFS IN
THE OPERATIONAL RUNS CONTINUE TO RESULT IN SPREAD FOR THE TIMING
OF THE LEADING SFC FRONT.  PREFER TO RELY ON THE ENSEMBLE MEANS
UNTIL THE OPERATIONAL SOLNS BEGIN TO SETTLE ON THE DETAILS.

AS SEEN YDAY MODEL/ENSEMBLE SPREAD BEGINS TO WIDEN CONSIDERABLY
FROM THE NRN PAC INTO NWRN CONUS LATE IN THE PERIOD.  THIS
ORIGINATES FROM DIVERGING OPINIONS ON THE HANDLING OF ENERGY
WITHIN A SRN BERING SEA INTO NRN PAC TROUGH AS OF DAY 4 SUN.  BY
DAY 7 WED THE MOST LIKELY SCENARIO IS FOR SOME DEGREE OF TROUGHING
TO REACH THE PAC NW ALBEIT WITHIN A FULL ENSEMBLE SPREAD THAT
INCLUDES ANY SCENARIO FROM A TROUGH TO A RIDGE.  THE 12Z CMC MEAN
SUPPORTS THE 12Z ECMWF MEAN THAT KEEPS THE TROUGH LESS AMPLIFIED
THAN THE 18Z GEFS MEAN... BUT NOTE THAT EVEN THE LATTER IS MODEST
RELATIVE TO THE 18Z GFS/12Z CMC.

GUIDANCE IS STILL IN THE PROCESS OF RESOLVING THE SFC DETAILS
AHEAD OF THE SHRTWV FCST TO TRACK NEWD FROM THE ERN PLAINS/MS VLY.
 OVER THE PAST 12-24 HRS LATEST GUIDANCE HAS GRAVITATED RATHER FAR
NWD WITH THE SFC WAVE TRACKING THROUGH THE GRTLKS AROUND DAY 4 SUN
AND WITH THE LEADING FRONT... SO THE UPDATED FCST REFLECTS THIS
ADJUSTMENT IN FRONTAL POSN AND CORRESPONDING TEMPS.  CONFIDENCE IS
STILL MODERATE AT BEST DUE TO SOME DEPENDENCE ON DIFFICULT TO
RESOLVE SMALLER SCALE DETAILS.  WITH THE SHRTWV ALOFT RECENT GFS
RUNS HAVE TENDED BE IN THE FASTER PORTION OF THE ENVELOPE.


...SENSIBLE WEATHER HIGHLIGHTS...

SYSTEM CROSSING THE WEST WILL SUPPORT AREAS OF RNFL ACROSS NRN
PARTS OF THE REGION... WITH THE LEADING FRONT THEN SUPPORTING A
BAND OF LOCALLY HVY CONVECTION FROM THE NRN PLAINS EWD/SEWD.  ALSO
EXPECT A FAIRLY BROAD AREA OF 5-15F BELOW NORMAL MAX TEMPS TO
EXTEND FROM THE NORTHWEST INTO THE NRN PLAINS WITH SOME MODERATION
LATER IN THE PERIOD.  FARTHER EWD MOIST FLOW AHEAD OF THE MID LVL
SHRTWV TRACKING NEWD FROM THE ERN PLAINS/MS VLY AS WELL AS
INTERACTION WITH THE SFC WAVE/FRONT OVER NRN PARTS OF THE EAST
WILL PROVIDE SOME ENHANCEMENT TO RNFL... WITH HIGHEST TOTALS MOST
LIKELY TO BE W OF THE APLCHNS AND FROM THE MID-UPR MS VLY INTO THE
NORTHEAST.  MAX TEMPS MAY REACH 10F OR SO ABOVE NORMAL FROM THE OH
VLY INTO NRN MID ATLC/SRN NEW ENGLAND DURING THE WEEKEND WITH THE
SOUTHEAST/MID ATLC MOST CONSISTENTLY ABOVE NORMAL THROUGH THE
PERIOD.

RAUSCH

$$






000
FXUS01 KWBC 262008
PMDSPD

SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
407 PM EDT TUE AUG 26 2014

VALID 00Z WED AUG 27 2014 - 00Z FRI AUG 29 2014

...HEAVY RAIN POSSIBLE OVER THE CENTRAL PLAINS AND THE MIDDLE
MISSISSIPPI VALLEY...

A SLOW MOVING FRONT EXTENDING FROM THE LOWER GREAT LAKES WESTWARD
TO THE CENTRAL PLAINS WILL MOVE OFF THE NORTHEAST COAST BY
THURSDAY WHILE REMAINING STATIONARY FROM THE SOUTHERN MID-ATLANTIC
TO THE CENTRAL PLAINS.  SHOWERS AND THUNDERSTORMS WILL DEVELOP
ALONG AND AHEAD OF THE BOUNDARY FROM THE LOWER GREAT LAKES TO THE
OHIO VALLEY THAT WILL MOVE TO THE NORTHEAST COAST BY WEDNESDAY
EVENING.  THE SHOWERS AND THUNDERSTORMS WILL END OVERNIGHT
WEDNESDAY OVER THE MID-ATLANTIC TO THE OHIO VALLEY.

CLOSED LOW OVER THE GREAT BASIN WILL MOVE EASTWARD TO THE CENTRAL
ROCKIES BY THURSDAY.  THE ENERGY WILL HELP IN PRODUCING SHOWERS
AND THUNDERSTORMS OVER THE SOUTHWEST/GREAT BASIN INTO PARTS OF THE
SOUTHERN/CENTRAL ROCKIES AND THE CENTRAL PLAINS, WILL CONTINUE
OVER THE REGION THROUGH WEDNESDAY EVENING BEFORE WANING TO THE
CENTRAL ROCKIES BY THURSDAY.  MOISTURE WILL OVERRUN THE FRONT OVER
THE CENTRAL PLAINS/MIDDLE MISSISSIPPI VALLEY PRODUCING SHOWERS AND
THUNDERSTORMS OVER THE CENTRAL PLAINS/MIDDLE MISSISSIPPI VALLEY
THROUGH THURSDAY.  AS THE UPPER-LEVEL ENERGY APPROACHES FROM THE
WEST, SHOWERS AND THUNDERSTORMS WILL DEVELOP OVER PARTS OF THE
SOUTHERN PLAINS AND MOVING EASTWARD AWAY FROM THE SOUTHERN ROCKIES
WEDNESDAY NIGHT INTO THURSDAY.  SHOWERS AND THUNDERSTORMS WILL
EXPAND INTO PARTS OF THE UPPER MISSISSIPPI VALLEY/UPPER GREAT
LAKES BY THURSDAY MORNING.

ELSEWHERE, UPPER-LEVEL ENERGY OVER THE WESTERN GULF COAST WILL
TRIGGER SHOWERS AND THUNDERSTORMS OVER THE WESTERN/CENTRAL GULF
COAST THROUGH THURSDAY.


ZIEGENFELDER

GRAPHICS AVAILABLE AT WWW.WPC.NCEP.NOAA.GOV
$$







000
FXUS06 KWBC 261913
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT TUE AUGUST 26 2014

6-10 DAY OUTLOOK FOR SEP 01 - 05 2014

TODAY`S MODEL SOLUTIONS ARE IN GOOD AGREEMENT ON THE 500-HPA PATTERN FORECAST
FOR THE 6-10 DAY PERIOD. ALL MODELS ARE FORECASTING POSITIVE 500-HPA HEIGHT
ANOMALIES OVER THE NORTHERN PACIFIC, EXTENDING ACROSS THE ALEUTIANS AND THE
BERING SEA. DOWNSTREAM, NEGATIVE 500-HPA HEIGHT ANOMALIES ARE EXPECTED OVER
MAINLAND ALASKA AND THE NORTHERN ROCKIES WITH A TROUGH OVER THE NORTHWESTERN
CONUS. HOWEVER, THE 0Z ECMWF AND 0Z CANADIAN ENSEMBLE MEANS HAVE THE TROUGH
FURTHER EAST WITH POSITIVE 500-HPA HEIGHT ANOMALIES ENTERING PARTS OF THE WEST
COAST.

BELOW-NORMAL TEMPERATURE PROBABILITIES ARE ENHANCED FOR ALASKA EXCEPT THE
ALEUTIANS AND THE PANHANDLE, IN ASSOCIATION WITH THE NEGATIVE 500-HPA HEIGHT
ANOMALIES. BELOW-NORMAL TEMPERATURE PROBABILITIES ARE ENHANCED FOR THE
NORTHWESTERN CONUS NEAR BY THE TROUGH FORECAST IN THIS REGION.  OFFSHORE WINDS
FAVOR ABOVE NORMAL TEMPERATURES IN CALIFORNIA. ALL FORECAST TOOLS ARE IN
REASONABLY GOOD AGREEMENT ON THE FORECAST TEMPERATURE PATTERN ACROSS THE
CENTRAL AND EASTERN CONUS, WITH A MEAN FRONTAL POSITION FORECAST FROM THE GREAT
LAKES TOWARD THE SOUTHWESTERN U.S. ABOVE NORMAL TEMPERATURES ARE FAVORED SOUTH
OF THE FRONT, INCLUDING THE SOUTHERN PLAINS, SOUTHEAST, AND EASTERN U.S.

BELOW-MEDIAN PRECIPITATION CHANCES ARE ENHANCED FOR SOUTHERN ALASKA AND THE
ALEUTIANS RELATED TO THE PREDICTED RIDGE IN THE AREA, WHILE ABOVE-MEDIAN
PRECIPITATION IS FAVORED FOR NORTHERN ALASKA AND THE PANHANDLE. BELOW-MEDIAN
PRECIPITATION CHANCES ARE ENHANCED FOR THE NORTHWESTERN CONUS DUE TO NORTHERLY
FLOW BEHIND THE TROUGH. THE 500-HPA PATTERN IS FORECAST TO BE NOT FAVORABLE FOR
MONSOON ACTIVITY, INCREASING THE LIKELIHOOD FOR BELOW-MEDIAN PRECIPITATION IN
THE SOUTHWEST. WITH NEGATIVE HEIGHT ANOMALIES CENTERED OVER THE NORTHERN
PLAINS, ABOVE-MEDIAN PRECIPITATION IS FAVORED ALONG AND EAST OF THE ANOMALOUS
TROUGH AXIS ASSOCIATED WITH AN ACTIVE STORM TRACK.


TODAY`S OFFICIAL 500-HPA BLEND CONSISTS OF 20% OF TODAY`S 0Z GFS ENSEMBLE MEAN
CENTERED ON DAY 8, 20% OF TODAY`S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 8,
20% OF TODAY`S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY 8, 20% OF YESTERDAY`S
GFS SUPERENSEMBLE MEAN CENTERED ON DAY 7, AND 20% OF YESTERDAY`S 12Z EUROPEAN
ENSEMBLE MEAN CENTERED ON DAY 7


MODEL OF THE DAY: NO PREFERENCE.

FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOUT AVERAGE, 3 OUT OF 5, DUE TO
FAIRLY GOOD AGREEMENT AMONG THE MODELS AND TOOLS.

8-14 DAY OUTLOOK FOR SEP 03 - 09 2014

THE ENSEMBLE MEAN PREDICTIONS ON THE 500-HPA HEIGHT PATTERN FOR THE WEEK-2
PERIOD ARE IN FAIR AGREEMENT OVER NORTH AMERICA. A TROUGH IS PREDICTED OVER THE
NORTHERN ROCKIES, WHILE WEAK 500-HPA HEIGHT ANOMALIES ARE FORECASTOVER THE
CONUS. IN THE SOUTHERN TIER OF THE CONUS, MODEL ENSEMBLE MEAN SOLUTIONS ALSO
FORECAST A STRONG SUBTROPICAL RIDGE THERE. OVER THE ALASKA SECTOR, A CONSENSUS
OF THE ENSEMBLE MEAN SOLUTIONS FORECAST A RIDGE OVER THE NORTHERN PACIFIC AND
ALEUTIANS WITH POSITIVE 500-HPA HEIGHT ANOMALIES OVER THE STATE.

THERE ARE ENHANCED PROBABILITIES FOR NEAR- TO BELOW-NORMAL TEMPERATURES FOR
SOME AREAS OF THE NORTHERN ROCKIES AND NORTHERN PLAINS IN ASSOCIATION WITH AN
EXPECTED TROUGH. ENHANCED PROBABILITIES OF NEAR- TO ABOVE-NORMAL TEMPERATURES
ARE FAVORED FOR MUCH OF THE NORTHEAST, SOUTHERN CONUS, AND THE WEST COAST
CONSISTENT WITH NAEFS GUIDANCE AND BIAS CORRECTED TEMPERATURES FROM THE 0Z
ECMWF ENSEMBLES. ABOVE-NORMAL TEMPERATURES ARE FAVORED FOR MUCH OF THE WESTERN
ALASKA INCLUDING THE ALEUTIANS. THERE ARE ENHANCED PROBABILITIES FOR NEAR- TO
BELOW-NORMAL TEMPERATURES ACROSS EASTERN ALASKA.

ABOVE-MEDIAN PRECIPITATION IS FAVORED FOR MUCH OF THE EASTERN CONUS IN
ASSOCIATION WITH THE FORECAST TROUGH. NEAR- TO BELOW-MEDIAN PRECIPITATION
PROBABILITIES ARE ENHANCED FOR THE NORTHWESTERN CONUS AND TEXAS CONSISTENT WITH
NAEFS AND GEFS REFORECAST GUIDANCE. THERE ARE ENHANCED PROBABILITIES OF NEAR-
TO BELOW-MEDIAN PRECIPITATION FOR SOUTHERN ALASKA. NEAR- TO ABOVE-MEDIAN
PRECIPITATION IS FAVORED FOR NORTHERN ALASKA AND THE PANHANDLE.


THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF: 10% OF TODAY`S OPERATIONAL 6Z
GFS CENTERED ON DAY 11, 10% OF TODAY`S 0Z GFS ENSEMBLE MEAN CENTERED ON DAY 11,
20% OF TODAY`S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 11, 20% OF TODAY`S 0Z
CANADIAN ENSEMBLE MEAN CENTERED ON DAY 11, 10% OF YESTERDAY`S GFS SUPERENSEMBLE
MEAN CENTERED ON DAY 10, 20% OF YESTERDAY`S 12Z EUROPEAN ENSEMBLE MEAN CENTERED
ON DAY 10, AND 10% OF YESTERDAY`S 12Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY 10


FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: BELOW AVERAGE, 2 OUT OF 5, DUE
TO REASONABLE AGREEMENT AMONG MODEL TOOLS, OFFSET BY A LOW-AMPLITUDE FORECAST
PATTERN.

FORECASTER: QIN GINGER ZHANG

NOTES:


AUTOMATED FORECASTS ARE ISSUED ON SATURDAY AND SUNDAY. OCCASIONALLY MANUAL
INTERVENTION IS NECESSARY TO ADDRESS QUALITY CONTROL AND CONSISTENCY ISSUES.
IN THESE CASES, FORECASTS ARE MANUALLY DRAWN BUT A FULL DISCUSSION IS NOT
ISSUED.

THE NOTATION FOR THE CATEGORICAL FORECAST INDICATED ON THE MAPS IS
THE SAME AS THAT IN THE TABLES: A-ABOVE   N-NEAR NORMAL   B-BELOW

THE TEMPERATURE MAP SHOWS REGIONS WITH > 33% CHANCE OF BEING WARMER
(ORANGE, "A"), COLDER (BLUE, "B"), OR CLOSE TO (UNSHADED, "N")
HISTORICAL AVERAGE VALUES FOR THE CALENDAR PERIOD OF THE FORECAST
(DASHES, "F").  LABELS ON THE SHADED LINES GIVE THE PROBABILITY
(> 33%) OF THE MORE LIKELY CATEGORY (B OR A).  PROBABILITY OF N IS
ALWAYS < 40%.

THE PRECIPITATION MAP SHOWS REGIONS WITH > 33% CHANCE OF BEING
WETTER (GREEN, "A"), DRIER (TAN, "B"), OR CLOSE TO (UNSHADED, "N")
HISTORICAL MEDIAN VALUES FOR THE CALENDAR PERIOD OF THE FORECAST
(DASHES, "INCHES").  LABELS ON THE SHADED LINES GIVE THE PROBABILITY
(> 33%) OF THE MORE LIKELY CATEGORY (B OR A).  PROBABILITY OF N IS
ALWAYS < 40%.

IN THE SOUTHWEST AND OTHER CLIMATOLOGICALLY DRY REGIONS - THERE WILL
BE A GREATER THAN 33.3% CHANCE OF NO PRECIPITATION AND OCCASIONALLY
EVEN A NORMAL (I.E. MEDIAN) VALUE OF ZERO - ESPECIALLY DURING THE DRY
SEASONS.  IN SUCH CASES A FORECAST OF NEAR NORMAL IS EFFECTIVELY A
FORECAST OF LITTLE OR NO PRECIPITATION.

THE CLIMATE PREDICTION CENTER USES 1981-2010 BASE PERIOD MEANS FOR
TEMPERATURE...PRECIPITATION...AND 500-HPA HEIGHTS AS REFERENCE IN
THE CLIMATE OUTLOOKS.

THE NEXT SET OF LONG-LEAD MONTHLY AND SEASONAL OUTLOOKS WILL BE RELEASED ON
SEPTEMBER 18

ANALOGS TO THE 5 DAY MEAN OBSERVED PATTERN CENTERED 3 DAYS AGO (D-3)
FOR THE REGION FROM 20N TO 70N LATITUDE AND 175E TO 60W LONGITUDE
INCLUDE THE 5 DAY PERIODS CENTERED ON THE FOLLOWING DATES:
19800820 - 19510827 - 20020830 - 19730806 - 20020809


ANALOGS TO THE 7 DAY MEAN OBSERVED PATTERN CENTERED 4 DAYS AGO (D-4)
FOR THE REGION FROM 20N TO 70N LATITUDE AND 175E TO 60W LONGITUDE
INCLUDE THE 7 DAY PERIODS CENTERED ON THE FOLLOWING DATES:
19800821 - 19510827 - 20020830 - 19730806 - 20020809


6-10 DAY OUTLOOK TABLE
OUTLOOK FOR SEP 01 - 05 2014

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN
WASHINGTON  B    B     OREGON      B    B     NRN CALIF   A    N
SRN CALIF   A    N     IDAHO       B    B     NEVADA      N    B
W MONTANA   B    B     E MONTANA   B    N     WYOMING     B    B
UTAH        B    B     ARIZONA     A    B     COLORADO    B    B
NEW MEXICO  A    B     N DAKOTA    N    A     S DAKOTA    B    A
NEBRASKA    N    N     KANSAS      A    N     OKLAHOMA    A    N
N TEXAS     A    B     S TEXAS     A    B     W TEXAS     A    B
MINNESOTA   A    A     IOWA        A    A     MISSOURI    A    A
ARKANSAS    A    A     LOUISIANA   A    N     WISCONSIN   A    A
ILLINOIS    A    A     MISSISSIPPI A    A     MICHIGAN    A    A
INDIANA     A    A     OHIO        A    A     KENTUCKY    A    A
TENNESSEE   A    A     ALABAMA     A    A     NEW YORK    A    A
VERMONT     A    A     NEW HAMP    A    A     MAINE       A    A
MASS        A    A     CONN        A    A     RHODE IS    A    A
PENN        A    A     NEW JERSEY  A    A     W VIRGINIA  A    A
MARYLAND    A    A     DELAWARE    A    A     VIRGINIA    A    A
N CAROLINA  A    A     S CAROLINA  A    A     GEORGIA     A    A
FL PNHDL    A    A     FL PENIN    A    A     AK N SLOPE  B    A
AK ALEUTIAN A    B     AK WESTERN  B    B     AK INT BSN  B    A
AK S INT    B    B     AK SO COAST B    B     AK PNHDL    N    A



8-14 DAY OUTLOOK TABLE
OUTLOOK FOR SEP 03 - 09 2014

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN
WASHINGTON  N    B     OREGON      A    B     NRN CALIF   A    N
SRN CALIF   A    N     IDAHO       B    B     NEVADA      A    B
W MONTANA   B    B     E MONTANA   B    N     WYOMING     B    B
UTAH        N    B     ARIZONA     N    N     COLORADO    N    N
NEW MEXICO  N    N     N DAKOTA    B    A     S DAKOTA    B    A
NEBRASKA    N    N     KANSAS      N    N     OKLAHOMA    A    N
N TEXAS     A    B     S TEXAS     A    B     W TEXAS     A    B
MINNESOTA   N    A     IOWA        N    A     MISSOURI    N    A
ARKANSAS    A    A     LOUISIANA   A    A     WISCONSIN   N    A
ILLINOIS    N    A     MISSISSIPPI A    A     MICHIGAN    A    A
INDIANA     N    A     OHIO        N    A     KENTUCKY    A    A
TENNESSEE   A    A     ALABAMA     A    A     NEW YORK    A    A
VERMONT     A    A     NEW HAMP    A    A     MAINE       A    N
MASS        A    A     CONN        A    A     RHODE IS    A    A
PENN        A    A     NEW JERSEY  A    A     W VIRGINIA  A    A
MARYLAND    A    A     DELAWARE    A    A     VIRGINIA    A    A
N CAROLINA  A    A     S CAROLINA  A    A     GEORGIA     A    A
FL PNHDL    A    A     FL PENIN    A    A     AK N SLOPE  B    A
AK ALEUTIAN A    N     AK WESTERN  A    B     AK INT BSN  B    N
AK S INT    N    B     AK SO COAST A    B     AK PNHDL    N    A

                           LEGEND
TEMPS WITH RESPECT TO NORMAL     PCPN WITH RESPECT TO MEDIAN
A - ABOVE   N  - NEAR NORMAL     A - ABOVE   N - NEAR MEDIAN
B - BELOW                        B - BELOW

THE FORECAST CLASSES REPRESENT AVERAGES FOR EACH STATE. NORMAL
VALUES - WHICH MAY VARY WIDELY ACROSS SOME STATES - ARE
AVAILABLE FROM YOUR LOCAL WEATHER SERVICE FORECAST OFFICE.

FOR ADDITIONAL INFORMATION SEE MESSAGE FXUS06 KWBC - ON AWIPS AS
PMDMRD.

$$





000
FXCA20 KWBC 261830
PMDCA

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
230 PM EDT TUE AUG 26 2014

AT 15UTC...HURRICANE CRISTOBAL CENTERED NEAR 27.2N 71.7W...WITH
CENTRAL PRESSURE OF 988 HPA AND MAXIMUM SUSTAINED WINDS OF 65KT.
SEE NHC BULLETIN FOR OFFICIAL FORECAST.

DISCUSSION FROM AUGUST 26/00UTC: UPPER LEVEL ANALYSIS SHOWS A TUTT
WITH AXIS NORTH-NORTHEAST ACROSS SOUTHWEST STATES OF MEXICO TO THE
GULF COAST OF TEXAS. THIS SPLITS THE SUBTROPICAL RIDGE IN TWO
CELLS...WITH WESTERNMOST DOMINATING THE NORTHERN STATES OF
MEXICO/BAJA PENINSULA WHILE THE EASTERNMOST ENVELOPS THE
GULF-CENTRAL/SOUTHERN STATES OF MEXICO-CUBA AND MOST OF CENTRAL
AMERICA. UNDER INFLUENCE OF AN AMPLIFYING TROUGH OVER THE WESTERN
USA THIS PATTERN IS TO RAPIDLY EVOLVE. THROUGH THURSDAY AFTERNOON
THE TROUGH IS TO DEEPEN ACROSS NEW MEXICO TO NORTHERN
SONORA/CHIHUAHUA. AS IT PRESSES AGAINST THE RIDGE TO THE
SOUTH...THE RIDGE IS FORECAST TO GRADUALLY WEAKEN. RIDGE PATTERN
OVER THE GULF-CENTRAL AMERICA WILL BE MORE RESILIENT...AND AS THE
TROUGH DEEPENS TO THE WEST THIS WILL ALLOW THE RIDGE TO BUILD
NORTHWARD ACROSS THE SOUTHEAST USA. AS UPPER RIDGE PATTERN
EVOLVES...TUTT IS TO SPLIT IN TWO. NORTHERN HALF IS TO REMAIN OVER
EAST TEXAS-NORTHEAST MEXICO...WHILE THE SOUTHERN HALF QUICKLY
PULLS WEST INTO THE EASTERN TROPICAL PACIFIC. OVER NORTHWEST
MEXICO...AS UPPER LEVEL RIDGE WEAKENS...GUIDANCE SHOWING A
DECREASE IN DIURNAL CONVECTION ACROSS SONORA-SINALOA-CHIHUAHUA.
EARLY IN THE CYCLE EXPECTING ACCUMULATION OF 10-15MM/DAY AND
MAXIMA OF 20-40MM. THROUGH THURSDAY THIS DECREASES TO 05-10MM/DAY
AND MAXIMA OF 15-25MM. ACROSS CENTRAL MEXICO EXPECTING RAINFALL
AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-30MM. OVER SOUTHERN MEXICO
MOST ACTIVE CONVECTION IS EXPECTED ALONG THE PACIFIC COAST AS
ENHANCED BY A SURFACE TROUGH. THIS IS TO ALSO SUSTAIN COASTAL
CONVECTION ACROSS SOUTHERN GUATEMALA-EL SALVADOR/ SOUTHERN
HONDURAS TO NORTHWEST NICARAGUA...WITH RAINFALL AMOUNTS OF
10-15MM/DAY AND MAXIMA OF 20-35MM. THROUGH THURSDAY THIS INCREASES
TO 15-20MM/DAY AND MAXIMA OF 35-70MM.

A NORTH-TO-SOUTH MID/UPPER LEVEL TROUGH EXTENDS ALONG THE EASTERN
FRINGES OF THE SUBTROPICAL RIDGE...WITH AXIS ALONG 72W/73W.
ANOTHER RIDGE LIES TO THE EAST OF THIS TROUGH...ENVELOPING THE
ATLANTIC BASIN WHILE ANCHORING ON A CLOSED HIGH NEAR 30N 56W.
HURRICANE CRISTOBAL IS FORECAST TO LIFT NORTH BETWEEN THESE
SYSTEMS. AS IT PULLS AWAY...EXPECTING A DECREASE IN ASSOCIATED
CONVECTION ACROSS THE SOUTHEAST BAHAMAS-TURKS AND CAICOS.
MEANWHILE...IT IS TO FAVOR ADDITIONAL RAINFALL AMOUNTS OF
05-10MM/DAY AND MAXIMA OF 15-20MM IN SCATTERED DEEP CONVECTION.

DEEP MID LEVEL TROUGH PATTERN OVER THE WESTERN ATLANTIC SUSTAINS
AN INDUCED INVERTED TROUGH OVER THE CARIBBEAN...WITH AXIS NORTH
FROM GULF OF URABA/ EASTERN PANAMA TO JAMAICA/EASTERN CUBA. TROUGH
IS FORECAST TO MEANDER WESTWARD ACROSS THE CENTRAL CARIBBEAN AS
DISPLACED BY PREVAILING EASTERLY TRADES...MOVING TO CENTRAL
AMERICA EARLY ON THURSDAY MORNING. AS IT MEANDERS OVER THE CENTRAL
CARIBBEAN IT IS TO INTERACT WITH THE EASTERN PACIFIC ITCZ AND THE
NEAR EQUATORIAL TROUGH. OVER NORTHWEST COLOMBIA-EASTERN PANAMA
THIS IS TO FAVOR RAINFALL AMOUNTS OF 15-20MM/DAY AND MAXIMA OF
35-70MM. THROUGH THURSDAY THIS DECREASES TO 10-15MM/DAY AND MAXIMA
OF 20-40MM. ACROSS WESTERN PANAMA-COSTA RICA INITIALLY EXPECTING
RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-40MM...INCREASING
TO MAXIMA OF 25-50MM ON WEDNESDAY-THURSDAY. AS THE TROUGH MEANDERS
WEST INTO NICARAGUA/NORTHEAST HONDURAS IT IS TO THEN FAVOR
RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-35MM. THE TROUGH
IS TO ALSO ENHANCE CONVECTION ACROSS JAMAICA-EASTERN CUBA EARLY IN
THE CYCLE...WITH RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF
20-35MM. AS MOISTURE POOLS ACROSS CUBA MAXIMA INCREASES TO 25-50MM
ON WEDNESDAY AFTERNOON.

ALSO AT UPPER LEVELS...A TUTT EXTENDS NORTH ACROSS WESTERN
VENEZUELA TO THE EASTERN CARIBBEAN. THROUGH THIS EVENING THIS IS
TO MEANDER WEST INTO EASTERN COLOMBIA-SOUTHERN
HISPANIOLA...REACHING THE CENTRAL CARIBBEAN/GULF OF URABA LATER ON
WEDNESDAY. AS IT IS TO REMAIN CUT OFF FROM THE FLOW...THIS IS TO
THEN WEAKEN WHILE MEANDERING FARTHER WEST. EARLY IN THE CYCLE IT
IS TO ENHANCE CONVECTION ACROSS PUERTO RICO AND THE DOMINICAN
REPUBLIC...TO FAVOR RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF
15-25MM. MOST ACTIVE TO THE SOUTH IS EXPECTED IN INTERACTION WITH
THE NEAR EQUATORIAL TROUGH OVER VENEZUELA AND COLOMBIA...WHERE IT
IS TO FAVOR RAINFALL AMOUNTS OF 15-20MM/DAY AND MAXIMA OF 35-70MM.

ANOTHER TUTT IS TO RETROGRESS ACROSS THE ATLANTIC...WITH CLOSED
LOW MOVING NORTH OF PUERTO RICO BY MIDDAY ON THURSDAY. IT IS TO
THEN MEANDER NORTH OF THE FORECAST AREA THROUGH THE END OF THE
WEEK. AT MID LEVELS IT IS TO REFLECT AS AN INVERTED TROUGH OVER
THE LEEWARD ISLES BY MIDDAY ON THURSDAY. THIS MEANDERS WEST ACROSS
THE VIRGIN ISLES TO PUERTO RICO LATER IN THE DAY. POSITIVE
INTERACTION WITH A TROPICAL WAVE ENTERING THE BASIN IS
LIKELY...SEE BELOW FOR DETAILS.

TROPICAL/EASTERLY WAVES INITIALIZED AT 12UTC
INITIAL  24     36     48     60     72     84     96     TYPE
41W     45W    49W    52W    55W    58W    60W     62W     TW
50W     54W    58W    62W    65W    69W    73W     76W     TW

A TROPICAL WAVE ALONG 41W REACHES FRENCH GUIANA LATER ON
WEDNESDAY...WHERE IT IS TO FAVOR RAINFALL AMOUNTS OF 00-05MM/DAY
AND MAXIMA OF 10MM. THIS IS TO ENTER THE FRENCH/LEEWARD ISLES
EARLY ON FRIDAY...WHERE IT IS TO FAVOR RAINFALL AMOUNTS OF
05-10MM/DAY AND MAXIMA OF 15-20MM. IN INTERACTION WITH A TUTT IT
IS TO THEN SUSTAIN RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF
20-30MM.

A TROPICAL WAVE ALONG 50W AND SOUTH OF 15N MOVES ACROSS THE
GUIANAS EARLY IN THE CYCLE...TO SUSTAIN RAINFALL AMOUNTS OF
05-10MM/DAY AND MAXIMA OF 15-25MM. OVER NORTHEAST VENEZUELA AND
THE WINDWARD ISLES EXPECTING ACCUMULATION OF 10-15MM/DAY AND
MAXIMA OF 20-30MM. OVER THE EASTERN CARIBBEAN MOST ACTIVE
CONVECTION IS EXPECTED TO THE SOUTH OF 15N/16N...WHILE OVER
VENEZUELA IN INTERACTION WITH THE NET IT IS TO SUSTAIN RAINFALL
AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-35MM. THROUGH THURSDAY IT
DECREASES TO 05-10MM/DAY AND MAXIMA OF 15-20MM AS IT ENTERS
COLOMBIA.

VALVERDE...IMN (COSTA RICA)
MEDINA...ONAMET (REPUBLICA DOMINICANA)
DAVISON...WPC(USA)
$$






000
FXCA20 KWBC 261830
PMDCA

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
230 PM EDT TUE AUG 26 2014

AT 15UTC...HURRICANE CRISTOBAL CENTERED NEAR 27.2N 71.7W...WITH
CENTRAL PRESSURE OF 988 HPA AND MAXIMUM SUSTAINED WINDS OF 65KT.
SEE NHC BULLETIN FOR OFFICIAL FORECAST.

DISCUSSION FROM AUGUST 26/00UTC: UPPER LEVEL ANALYSIS SHOWS A TUTT
WITH AXIS NORTH-NORTHEAST ACROSS SOUTHWEST STATES OF MEXICO TO THE
GULF COAST OF TEXAS. THIS SPLITS THE SUBTROPICAL RIDGE IN TWO
CELLS...WITH WESTERNMOST DOMINATING THE NORTHERN STATES OF
MEXICO/BAJA PENINSULA WHILE THE EASTERNMOST ENVELOPS THE
GULF-CENTRAL/SOUTHERN STATES OF MEXICO-CUBA AND MOST OF CENTRAL
AMERICA. UNDER INFLUENCE OF AN AMPLIFYING TROUGH OVER THE WESTERN
USA THIS PATTERN IS TO RAPIDLY EVOLVE. THROUGH THURSDAY AFTERNOON
THE TROUGH IS TO DEEPEN ACROSS NEW MEXICO TO NORTHERN
SONORA/CHIHUAHUA. AS IT PRESSES AGAINST THE RIDGE TO THE
SOUTH...THE RIDGE IS FORECAST TO GRADUALLY WEAKEN. RIDGE PATTERN
OVER THE GULF-CENTRAL AMERICA WILL BE MORE RESILIENT...AND AS THE
TROUGH DEEPENS TO THE WEST THIS WILL ALLOW THE RIDGE TO BUILD
NORTHWARD ACROSS THE SOUTHEAST USA. AS UPPER RIDGE PATTERN
EVOLVES...TUTT IS TO SPLIT IN TWO. NORTHERN HALF IS TO REMAIN OVER
EAST TEXAS-NORTHEAST MEXICO...WHILE THE SOUTHERN HALF QUICKLY
PULLS WEST INTO THE EASTERN TROPICAL PACIFIC. OVER NORTHWEST
MEXICO...AS UPPER LEVEL RIDGE WEAKENS...GUIDANCE SHOWING A
DECREASE IN DIURNAL CONVECTION ACROSS SONORA-SINALOA-CHIHUAHUA.
EARLY IN THE CYCLE EXPECTING ACCUMULATION OF 10-15MM/DAY AND
MAXIMA OF 20-40MM. THROUGH THURSDAY THIS DECREASES TO 05-10MM/DAY
AND MAXIMA OF 15-25MM. ACROSS CENTRAL MEXICO EXPECTING RAINFALL
AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-30MM. OVER SOUTHERN MEXICO
MOST ACTIVE CONVECTION IS EXPECTED ALONG THE PACIFIC COAST AS
ENHANCED BY A SURFACE TROUGH. THIS IS TO ALSO SUSTAIN COASTAL
CONVECTION ACROSS SOUTHERN GUATEMALA-EL SALVADOR/ SOUTHERN
HONDURAS TO NORTHWEST NICARAGUA...WITH RAINFALL AMOUNTS OF
10-15MM/DAY AND MAXIMA OF 20-35MM. THROUGH THURSDAY THIS INCREASES
TO 15-20MM/DAY AND MAXIMA OF 35-70MM.

A NORTH-TO-SOUTH MID/UPPER LEVEL TROUGH EXTENDS ALONG THE EASTERN
FRINGES OF THE SUBTROPICAL RIDGE...WITH AXIS ALONG 72W/73W.
ANOTHER RIDGE LIES TO THE EAST OF THIS TROUGH...ENVELOPING THE
ATLANTIC BASIN WHILE ANCHORING ON A CLOSED HIGH NEAR 30N 56W.
HURRICANE CRISTOBAL IS FORECAST TO LIFT NORTH BETWEEN THESE
SYSTEMS. AS IT PULLS AWAY...EXPECTING A DECREASE IN ASSOCIATED
CONVECTION ACROSS THE SOUTHEAST BAHAMAS-TURKS AND CAICOS.
MEANWHILE...IT IS TO FAVOR ADDITIONAL RAINFALL AMOUNTS OF
05-10MM/DAY AND MAXIMA OF 15-20MM IN SCATTERED DEEP CONVECTION.

DEEP MID LEVEL TROUGH PATTERN OVER THE WESTERN ATLANTIC SUSTAINS
AN INDUCED INVERTED TROUGH OVER THE CARIBBEAN...WITH AXIS NORTH
FROM GULF OF URABA/ EASTERN PANAMA TO JAMAICA/EASTERN CUBA. TROUGH
IS FORECAST TO MEANDER WESTWARD ACROSS THE CENTRAL CARIBBEAN AS
DISPLACED BY PREVAILING EASTERLY TRADES...MOVING TO CENTRAL
AMERICA EARLY ON THURSDAY MORNING. AS IT MEANDERS OVER THE CENTRAL
CARIBBEAN IT IS TO INTERACT WITH THE EASTERN PACIFIC ITCZ AND THE
NEAR EQUATORIAL TROUGH. OVER NORTHWEST COLOMBIA-EASTERN PANAMA
THIS IS TO FAVOR RAINFALL AMOUNTS OF 15-20MM/DAY AND MAXIMA OF
35-70MM. THROUGH THURSDAY THIS DECREASES TO 10-15MM/DAY AND MAXIMA
OF 20-40MM. ACROSS WESTERN PANAMA-COSTA RICA INITIALLY EXPECTING
RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-40MM...INCREASING
TO MAXIMA OF 25-50MM ON WEDNESDAY-THURSDAY. AS THE TROUGH MEANDERS
WEST INTO NICARAGUA/NORTHEAST HONDURAS IT IS TO THEN FAVOR
RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-35MM. THE TROUGH
IS TO ALSO ENHANCE CONVECTION ACROSS JAMAICA-EASTERN CUBA EARLY IN
THE CYCLE...WITH RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF
20-35MM. AS MOISTURE POOLS ACROSS CUBA MAXIMA INCREASES TO 25-50MM
ON WEDNESDAY AFTERNOON.

ALSO AT UPPER LEVELS...A TUTT EXTENDS NORTH ACROSS WESTERN
VENEZUELA TO THE EASTERN CARIBBEAN. THROUGH THIS EVENING THIS IS
TO MEANDER WEST INTO EASTERN COLOMBIA-SOUTHERN
HISPANIOLA...REACHING THE CENTRAL CARIBBEAN/GULF OF URABA LATER ON
WEDNESDAY. AS IT IS TO REMAIN CUT OFF FROM THE FLOW...THIS IS TO
THEN WEAKEN WHILE MEANDERING FARTHER WEST. EARLY IN THE CYCLE IT
IS TO ENHANCE CONVECTION ACROSS PUERTO RICO AND THE DOMINICAN
REPUBLIC...TO FAVOR RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF
15-25MM. MOST ACTIVE TO THE SOUTH IS EXPECTED IN INTERACTION WITH
THE NEAR EQUATORIAL TROUGH OVER VENEZUELA AND COLOMBIA...WHERE IT
IS TO FAVOR RAINFALL AMOUNTS OF 15-20MM/DAY AND MAXIMA OF 35-70MM.

ANOTHER TUTT IS TO RETROGRESS ACROSS THE ATLANTIC...WITH CLOSED
LOW MOVING NORTH OF PUERTO RICO BY MIDDAY ON THURSDAY. IT IS TO
THEN MEANDER NORTH OF THE FORECAST AREA THROUGH THE END OF THE
WEEK. AT MID LEVELS IT IS TO REFLECT AS AN INVERTED TROUGH OVER
THE LEEWARD ISLES BY MIDDAY ON THURSDAY. THIS MEANDERS WEST ACROSS
THE VIRGIN ISLES TO PUERTO RICO LATER IN THE DAY. POSITIVE
INTERACTION WITH A TROPICAL WAVE ENTERING THE BASIN IS
LIKELY...SEE BELOW FOR DETAILS.

TROPICAL/EASTERLY WAVES INITIALIZED AT 12UTC
INITIAL  24     36     48     60     72     84     96     TYPE
41W     45W    49W    52W    55W    58W    60W     62W     TW
50W     54W    58W    62W    65W    69W    73W     76W     TW

A TROPICAL WAVE ALONG 41W REACHES FRENCH GUIANA LATER ON
WEDNESDAY...WHERE IT IS TO FAVOR RAINFALL AMOUNTS OF 00-05MM/DAY
AND MAXIMA OF 10MM. THIS IS TO ENTER THE FRENCH/LEEWARD ISLES
EARLY ON FRIDAY...WHERE IT IS TO FAVOR RAINFALL AMOUNTS OF
05-10MM/DAY AND MAXIMA OF 15-20MM. IN INTERACTION WITH A TUTT IT
IS TO THEN SUSTAIN RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF
20-30MM.

A TROPICAL WAVE ALONG 50W AND SOUTH OF 15N MOVES ACROSS THE
GUIANAS EARLY IN THE CYCLE...TO SUSTAIN RAINFALL AMOUNTS OF
05-10MM/DAY AND MAXIMA OF 15-25MM. OVER NORTHEAST VENEZUELA AND
THE WINDWARD ISLES EXPECTING ACCUMULATION OF 10-15MM/DAY AND
MAXIMA OF 20-30MM. OVER THE EASTERN CARIBBEAN MOST ACTIVE
CONVECTION IS EXPECTED TO THE SOUTH OF 15N/16N...WHILE OVER
VENEZUELA IN INTERACTION WITH THE NET IT IS TO SUSTAIN RAINFALL
AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-35MM. THROUGH THURSDAY IT
DECREASES TO 05-10MM/DAY AND MAXIMA OF 15-20MM AS IT ENTERS
COLOMBIA.

VALVERDE...IMN (COSTA RICA)
MEDINA...ONAMET (REPUBLICA DOMINICANA)
DAVISON...WPC(USA)
$$







000
FXSA20 KWBC 261523
PMDSA

SOUTH AMERICA FORECAST DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1123 AM EDT TUE AUG 26 2014

GFS DATA AT FTPPRD.NCEP.NOAA.GOV/PUB/DATA/NCCF/COM/GFS/PROD/

MODEL DISCUSSION (VALID FROM AUGUST 26 AT 00UTC): GLOBAL MODELS
AGREE ON GENERAL PATTERN EVOLUTION THROUGH 60-72 HRS...THEN START
TO DIVERGE ON THE TIMING AND AMPLITUDE OF SHORT WAVE PERTURBATIONS
ENTERING THE DOMAIN. THIS IS ALSO RESULTING IN CYCLE-TO-CYCLE
INCONSISTENCIES AS MODELS MAKE PATTERN CORRECTIONS. AS A
RESULT...CONFIDENCE IN THE FORECAST BEYOND 72/84 HRS IS LOW.

DEEP MID LEVEL TROUGH ON THE NORTHERN STREAM CONTINUES TO DOMINATE
THE WEATHER ACROSS MID SECTIONS OF SOUTH AMERICA. IN A WEAK
STEERING FLOW...THE TROUGH IS TO MEANDER EAST ACROSS 45W/50W TO
SOUTHERN BRASIL EARLY IN THE CYCLE...WITH AXIS TO ANCHOR ON A
CLOSED LOW NEAR 41S 45W. THROUGH 48 HRS THE TROUGH IS TO SLOWLY
PULL ACROSS 40W...WHILE THE CLOSED LOW GRADUALLY WEAKEN/FILLS. BY
72-96 HRS THE TROUGH IS TO THEN STRETCH TO THE NORTHWEST ALONG 35S
25W TO RIO DE JANEIRO/SOUTHEAST BRASIL. AT LOW LEVELS IT SUSTAINS
A DEEP OCCLUDED LOW EAST OF THE BUENOS AIRES PROVINCE. THROUGH 24
HRS THIS IS TO DEEPEN TO A 990 HPA LOW WHILE DRIFTING TO THE
EAST-SOUTHEAST...AND BY 36-60 HRS IT IS TO DEEPEN TO A 986 HPA
LOW. AS THE SURFACE LOW/TROUGH MEANDERS TO THE
EAST-SOUTHEAST...AND A POLAR RIDGE BUILDS ACROSS ARGENTINA TO
PARAGUAY...THE ASSOCIATED FRONT IS TO MEANDER NORTH ACROSS RIO DE
JANEIRO-SOUTHERN MINAS GERAIS-MATO GROSSO IN BRASIL TO NORTHERN
BOLIVIA EARLY IN THE CYCLE. BUT AS THE POLAR TROUGH MOVES FARTHER
EAST...AND POLAR RIDGE EVOLVES...TRAILING END OF THE FRONT IS TO
START RETROGRESSING ACROSS MATO GROSSO TO MATO GROSSO DO
SUL-PARAGUAY-SOUTHERN BOLIVIA BY 72-84 HRS...WHERE IT IS TO
MEANDER THROUGH 96-108 HRS. AS THE FRONT UNDULATES NORTH ACROSS
BOLIVIA TO SOUTHERN PERU EARLY IN THE CYCLE IT IS TO TRIGGER
MODERATE CONVECTION WITH ACCUMULATION OF 15-25MM. THROUGH 48 HRS
THIS DECREASES TO 10-15MM. OTHER ACTIVITY IS EXPECTED ACROSS RIO
DE JANEIRO/ESPIRITO SANTO IN BRASIL BY 48-84 HRS...WITH RAINFALL
AMOUNTS OF 05-10MM/DAY. BY 96-120 HRS FOCUS OF THE COASTAL
CONVECTION SHIFTS TO EASTERN BAHIA...WITH ACCUMULATION OF 05-10MM.
AS THE TRAILING END OF THE FRONT MEANDERS SOUTH ACROSS PARAGUAY
LATER IN THE CYCLE...IT IS TO THEN TRIGGER SCATTERED CONVECTION
WITH ACCUMULATION OF 15-25MM. MOST ACTIVE ON THE SOUTHERN STATES
OF BRASIL-MISIONES IN ARGENTINA AND SOUTHEAST PARAGUAY.

BLOCKING MID/UPPER LEVEL RIDGE PATTERN PERSISTS ACROSS THE FAR
EASTERN PACIFIC/SOUTHERN CONE OF SOUTH AMERICA. THROUGH 36-48 HRS
THE RIDGE RELOCATES ACROSS CHILE TO ARGENTINA...WHERE IT IS TO
REMAIN THROUGH 96-120 HRS. SHORT WAVE PERTURBATIONS ON THE
NORTHERN AND SOUTHERN STREAM FLOW ARE TO PRESS AGAINST THE LONG
WAVE RIDGE. THROUGH 48-72 HRS SHORT WAVE PERTURBATIONS ARE TO
COMBINE INTO A BROAD TROUGH OVER THE EASTERN PACIFIC BETWEEN
100W-75W AND TO THE SOUTH OF 15S. AS THE RIDGE RELOCATES AND
WEAKENS...THIS WILL ALLOW SHORT WAVE ENERGY TO FOCUS ACROSS
SOUTHERN CHILE TO PATAGONIA IN ARGENTINA BY 72-96 HRS...INTO
CENTRAL REGIONS OF CHILE BY 108-120 HRS. AT LOW LEVELS...THE RIDGE
ALOFT IS TO SUSTAIN A SURFACE RIDGE ACROSS CHILE-ARGENTINA OVER
THE NEXT FEW DAYS...WHILE THE TROUGH ALOFT SUSTAINS A BROAD AREA
OF LOW PRESSURE OVER THE EASTERN PACIFIC. POLAR FRONTS ARE TO
REVOLVE AROUND THE MEANDERING PRESSURE TROUGH. BUT AS THEY CLASH
WITH THE RIDGE TO THE EAST...THEY ARE TO SHEAR SOUTH ACROSS TIERRA
DEL FUEGO/DRAKE PASSAGE...WHERE IT IS TO FAVOR LIGHT CONVECTION.
LATER IN THE CYCLE...AS THE SURFACE RIDGE STARTS TO
WEAKEN...FRONTS WILL PUSH EAST INTO SOUTHERN-CENTRAL PORTIONS OF
CHILE WHERE THEY ARE TO ENHANCE MOISTURE CONVERGENCE WHILE
TRIGGERING MODERATE RAINFALL AMOUNTS. BY 72-84 HRS IT IS TO FAVOR
RAINFALL AMOUNTS OF 05-10MM...AND BY 96-120 HRS THIS INCREASES TO
15-25MM WHILE CONVECTION BUILDS NORTH ACROSS CENTRAL CHILE.

AT 200 HPA...A HIGH OVER CENTRAL PERU ANCHORS A RIDGE OVER
NORTHWEST SOUTH AMERICA/EASTERN TROPICAL PACIFIC. THROUGH 24 HRS
THE HIGH IS TO RELOCATE TO ACRE IN BRASIL/NORTHERN BOLIVIA...WHILE
SIMULTANEOUSLY THE SUBEQUATORIAL RIDGE BUILDS ACROSS NORTHERN
BRASIL TO THE GUIANAS. THROUGH 60-72 HRS THE ONE TO THE SOUTH
WEAKENS/ NEARLY COLLAPSES...WHILE THE ONE TO THE NORTH ESTABLISHES
ACROSS NORTHERN SOUTH AMERICA. THE RIDGE ALOFT IS TO VENT
CONVECTION ACROSS EQUATORIAL SOUTH AMERICA...WITH ACCUMULATION OF
10-15MM. HIGHER AMOUNTS...HOWEVER...ARE EXPECTED ON THE LEE OF THE
ANDES OVER PERU-ECUADOR...WHERE MAXIMA IS TO PEAK AT 15-25MM.

JALFIN...SMN (ARGENTINA)
CAROCA...DMC (CHILE)
DAVISON...WPC (USA)
GALVEZ...WPC (USA)
$$






000
FXSA20 KWBC 261523
PMDSA

SOUTH AMERICA FORECAST DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1123 AM EDT TUE AUG 26 2014

GFS DATA AT FTPPRD.NCEP.NOAA.GOV/PUB/DATA/NCCF/COM/GFS/PROD/

MODEL DISCUSSION (VALID FROM AUGUST 26 AT 00UTC): GLOBAL MODELS
AGREE ON GENERAL PATTERN EVOLUTION THROUGH 60-72 HRS...THEN START
TO DIVERGE ON THE TIMING AND AMPLITUDE OF SHORT WAVE PERTURBATIONS
ENTERING THE DOMAIN. THIS IS ALSO RESULTING IN CYCLE-TO-CYCLE
INCONSISTENCIES AS MODELS MAKE PATTERN CORRECTIONS. AS A
RESULT...CONFIDENCE IN THE FORECAST BEYOND 72/84 HRS IS LOW.

DEEP MID LEVEL TROUGH ON THE NORTHERN STREAM CONTINUES TO DOMINATE
THE WEATHER ACROSS MID SECTIONS OF SOUTH AMERICA. IN A WEAK
STEERING FLOW...THE TROUGH IS TO MEANDER EAST ACROSS 45W/50W TO
SOUTHERN BRASIL EARLY IN THE CYCLE...WITH AXIS TO ANCHOR ON A
CLOSED LOW NEAR 41S 45W. THROUGH 48 HRS THE TROUGH IS TO SLOWLY
PULL ACROSS 40W...WHILE THE CLOSED LOW GRADUALLY WEAKEN/FILLS. BY
72-96 HRS THE TROUGH IS TO THEN STRETCH TO THE NORTHWEST ALONG 35S
25W TO RIO DE JANEIRO/SOUTHEAST BRASIL. AT LOW LEVELS IT SUSTAINS
A DEEP OCCLUDED LOW EAST OF THE BUENOS AIRES PROVINCE. THROUGH 24
HRS THIS IS TO DEEPEN TO A 990 HPA LOW WHILE DRIFTING TO THE
EAST-SOUTHEAST...AND BY 36-60 HRS IT IS TO DEEPEN TO A 986 HPA
LOW. AS THE SURFACE LOW/TROUGH MEANDERS TO THE
EAST-SOUTHEAST...AND A POLAR RIDGE BUILDS ACROSS ARGENTINA TO
PARAGUAY...THE ASSOCIATED FRONT IS TO MEANDER NORTH ACROSS RIO DE
JANEIRO-SOUTHERN MINAS GERAIS-MATO GROSSO IN BRASIL TO NORTHERN
BOLIVIA EARLY IN THE CYCLE. BUT AS THE POLAR TROUGH MOVES FARTHER
EAST...AND POLAR RIDGE EVOLVES...TRAILING END OF THE FRONT IS TO
START RETROGRESSING ACROSS MATO GROSSO TO MATO GROSSO DO
SUL-PARAGUAY-SOUTHERN BOLIVIA BY 72-84 HRS...WHERE IT IS TO
MEANDER THROUGH 96-108 HRS. AS THE FRONT UNDULATES NORTH ACROSS
BOLIVIA TO SOUTHERN PERU EARLY IN THE CYCLE IT IS TO TRIGGER
MODERATE CONVECTION WITH ACCUMULATION OF 15-25MM. THROUGH 48 HRS
THIS DECREASES TO 10-15MM. OTHER ACTIVITY IS EXPECTED ACROSS RIO
DE JANEIRO/ESPIRITO SANTO IN BRASIL BY 48-84 HRS...WITH RAINFALL
AMOUNTS OF 05-10MM/DAY. BY 96-120 HRS FOCUS OF THE COASTAL
CONVECTION SHIFTS TO EASTERN BAHIA...WITH ACCUMULATION OF 05-10MM.
AS THE TRAILING END OF THE FRONT MEANDERS SOUTH ACROSS PARAGUAY
LATER IN THE CYCLE...IT IS TO THEN TRIGGER SCATTERED CONVECTION
WITH ACCUMULATION OF 15-25MM. MOST ACTIVE ON THE SOUTHERN STATES
OF BRASIL-MISIONES IN ARGENTINA AND SOUTHEAST PARAGUAY.

BLOCKING MID/UPPER LEVEL RIDGE PATTERN PERSISTS ACROSS THE FAR
EASTERN PACIFIC/SOUTHERN CONE OF SOUTH AMERICA. THROUGH 36-48 HRS
THE RIDGE RELOCATES ACROSS CHILE TO ARGENTINA...WHERE IT IS TO
REMAIN THROUGH 96-120 HRS. SHORT WAVE PERTURBATIONS ON THE
NORTHERN AND SOUTHERN STREAM FLOW ARE TO PRESS AGAINST THE LONG
WAVE RIDGE. THROUGH 48-72 HRS SHORT WAVE PERTURBATIONS ARE TO
COMBINE INTO A BROAD TROUGH OVER THE EASTERN PACIFIC BETWEEN
100W-75W AND TO THE SOUTH OF 15S. AS THE RIDGE RELOCATES AND
WEAKENS...THIS WILL ALLOW SHORT WAVE ENERGY TO FOCUS ACROSS
SOUTHERN CHILE TO PATAGONIA IN ARGENTINA BY 72-96 HRS...INTO
CENTRAL REGIONS OF CHILE BY 108-120 HRS. AT LOW LEVELS...THE RIDGE
ALOFT IS TO SUSTAIN A SURFACE RIDGE ACROSS CHILE-ARGENTINA OVER
THE NEXT FEW DAYS...WHILE THE TROUGH ALOFT SUSTAINS A BROAD AREA
OF LOW PRESSURE OVER THE EASTERN PACIFIC. POLAR FRONTS ARE TO
REVOLVE AROUND THE MEANDERING PRESSURE TROUGH. BUT AS THEY CLASH
WITH THE RIDGE TO THE EAST...THEY ARE TO SHEAR SOUTH ACROSS TIERRA
DEL FUEGO/DRAKE PASSAGE...WHERE IT IS TO FAVOR LIGHT CONVECTION.
LATER IN THE CYCLE...AS THE SURFACE RIDGE STARTS TO
WEAKEN...FRONTS WILL PUSH EAST INTO SOUTHERN-CENTRAL PORTIONS OF
CHILE WHERE THEY ARE TO ENHANCE MOISTURE CONVERGENCE WHILE
TRIGGERING MODERATE RAINFALL AMOUNTS. BY 72-84 HRS IT IS TO FAVOR
RAINFALL AMOUNTS OF 05-10MM...AND BY 96-120 HRS THIS INCREASES TO
15-25MM WHILE CONVECTION BUILDS NORTH ACROSS CENTRAL CHILE.

AT 200 HPA...A HIGH OVER CENTRAL PERU ANCHORS A RIDGE OVER
NORTHWEST SOUTH AMERICA/EASTERN TROPICAL PACIFIC. THROUGH 24 HRS
THE HIGH IS TO RELOCATE TO ACRE IN BRASIL/NORTHERN BOLIVIA...WHILE
SIMULTANEOUSLY THE SUBEQUATORIAL RIDGE BUILDS ACROSS NORTHERN
BRASIL TO THE GUIANAS. THROUGH 60-72 HRS THE ONE TO THE SOUTH
WEAKENS/ NEARLY COLLAPSES...WHILE THE ONE TO THE NORTH ESTABLISHES
ACROSS NORTHERN SOUTH AMERICA. THE RIDGE ALOFT IS TO VENT
CONVECTION ACROSS EQUATORIAL SOUTH AMERICA...WITH ACCUMULATION OF
10-15MM. HIGHER AMOUNTS...HOWEVER...ARE EXPECTED ON THE LEE OF THE
ANDES OVER PERU-ECUADOR...WHERE MAXIMA IS TO PEAK AT 15-25MM.

JALFIN...SMN (ARGENTINA)
CAROCA...DMC (CHILE)
DAVISON...WPC (USA)
GALVEZ...WPC (USA)
$$







000
FXUS02 KWBC 261419
PMDEPD

EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1018 AM EDT TUE AUG 26 2014

VALID 12Z FRI AUG 29 2014 - 12Z TUE SEP 02 2014


THE 00Z/26 ENSEMBLE MEANS FROM THE VARIOUS MODELING CENTERS
FORTUNATELY PAINT THE SAME SYNOPTIC PICTURE AT THE MEDIUM RANGE,
INSTILLING GREATER THAN AVERAGE CONFIDENCE WITH THE LARGER SCALE
FEATURES. THE 00Z/26 ECMWF CAME CLOSEST TO THE MEANS OF THE
OPERATIONAL MODELS, SO USED A LIBERAL PORTION OF ITS MASS FIELDS
IN THE MANUAL BLEND FOR FRONTS AND PRESSURES. THE MESSAGE IS
RISING HEIGHTS IN THE EAST--WITH A COMMENSURATE RETREAT OF THE
POLAR FRONT--AND A SOUTHWARD-FROM-NORMAL DISPLACED POLAR JET OVER
THE WEST. IN THE MIDDLE IS WHERE ALL THE MOISTURE CONVERGES, WITH
THE ECMWF SUGGESTING THAT SEVERAL INCHES OF RAINFALL ARE IN STORE
FROM THE CENTRAL GULF COAST TO THE UPPER MIDWEST DAYS 3 THROUGH 7.
LESSER AMOUNTS ARE ANTICIPATED IN THE WASHINGTON OLYMPICS AND
CASCADES, WITH NO SIGN OF A LINGERING MONSOON FOR THE FAR
SOUTHWEST.


CISCO

$$






000
FXUS02 KWBC 261419
PMDEPD

EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1018 AM EDT TUE AUG 26 2014

VALID 12Z FRI AUG 29 2014 - 12Z TUE SEP 02 2014


THE 00Z/26 ENSEMBLE MEANS FROM THE VARIOUS MODELING CENTERS
FORTUNATELY PAINT THE SAME SYNOPTIC PICTURE AT THE MEDIUM RANGE,
INSTILLING GREATER THAN AVERAGE CONFIDENCE WITH THE LARGER SCALE
FEATURES. THE 00Z/26 ECMWF CAME CLOSEST TO THE MEANS OF THE
OPERATIONAL MODELS, SO USED A LIBERAL PORTION OF ITS MASS FIELDS
IN THE MANUAL BLEND FOR FRONTS AND PRESSURES. THE MESSAGE IS
RISING HEIGHTS IN THE EAST--WITH A COMMENSURATE RETREAT OF THE
POLAR FRONT--AND A SOUTHWARD-FROM-NORMAL DISPLACED POLAR JET OVER
THE WEST. IN THE MIDDLE IS WHERE ALL THE MOISTURE CONVERGES, WITH
THE ECMWF SUGGESTING THAT SEVERAL INCHES OF RAINFALL ARE IN STORE
FROM THE CENTRAL GULF COAST TO THE UPPER MIDWEST DAYS 3 THROUGH 7.
LESSER AMOUNTS ARE ANTICIPATED IN THE WASHINGTON OLYMPICS AND
CASCADES, WITH NO SIGN OF A LINGERING MONSOON FOR THE FAR
SOUTHWEST.


CISCO

$$







000
FXSA20 KWBC 261322
PMDSA

SOUTH AMERICA SYNOPTIC DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
921 AM EDT TUE AUG 26 2014

GFS DATA AT FTPPRD.NCEP.NOAA.GOV/PUB/DATA/NCCF/COM/GFS/PROD/

SYNOPSIS (VALID FROM AUGUST 26 AT 00UTC): AT 200 HPA...AN
UNUSUALLY STRONG CELL OF THE SUBTROPICAL RIDGE DOMINATES THE
EASTERN PACIFIC AND WESTERN PORTIONS OF SOUTH AMERICA. THE RIDGE
ANCHORS ON A CLOSED HIGH OVER ACRE IN BRASIL/CENTRAL PERU...WITH
AXIS WEST INTO THE EASTERN TROPICAL PACIFIC AND SOUTH ALONG 75W TO
SOUTHERN CHILE. THE RIDGE ALOFT IS VENTING ISOLATED CONVECTION
ACROSS PORTIONS OF PARA-AMAZONAS IN BRASIL...WITH MOST INTENSE
NORTH OF THE EQUATOR OVER VENEZUELA AND COLOMBIA. EAST OF THE
RIDGE...A TROUGH EXTENDS ALONG THE COAST OF ARGENTINA TO SOUTHERN
BRASIL. THIS IS INTERACTING WITH A SHORT WAVE TROUGH TO THE NORTH
AS THE LATTER EXTENDS ALONG 15S 46W TO THE GUIANAS.

AT 250 HPA...THE SOUTHERN POLAR HAS A FINGER WITH ENTRANCE AT 44S
88W...THEN ALONG 52S 80W...EXITING AT 47S 66W. IT REFORMS AT 48S
48W...ALONG 48S 33W...40S 13W...AND 38S 02W. THE NORTHERN POLAR
HAS ITS ENTRANCE AT 23S 96W...ALONG A 140KT MAXIMUM AT 27S
85W...EXITING AT 33S 79W. IT REFORMS AT 34S 70W...THEN ALONG A
150KT MAXIMUM AT 32S 65W...30S 57W...34S 50W...43S 48W...43S
32W...A 134KT MAXIMUM AT 37S 17W...AND A 130KT MAXIMUM AT 33S 05W.
THE SUBTROPICAL JET HAS ITS ENTRANCE AT 16S 105W...ALONG 17S
97W...20S 90W...26S 73W... EXITING AT 18S 55W. IT REFORMS BETWEEN
22S 46W AND 29S 39W. THE SUBTROPICAL JET REFORMS AT 32S 27W...THEN
ALONG 30S 15W...29S 09W...AND 32S 06E.

AT 500 HPA...MID LEVEL ANALYSIS SHOWS A CLOSED LOW NEAR 53S 93W
EXTENDING A TROUGH ALONG 40S 95W TO 30S 97W. THIS IS PHASING WITH
A SHORT WAVE TROUGH TO THE NORTH THAT CENTERS ON A LOW AT 24S 97W.
FARTHER EAST...A NORTH TO SOUTH RIDGE EXTENDS FROM SOUTHERN
PERU...ALONG 30S 75W...50S 76W...TO 60S 75W. EAST OF THIS AXIS...A
DEEP LOW NEAR 37S 57W ANCHORS A TROUGH OVER MID SECTIONS OF SOUTH
AMERICA WHILE FOCUSING SHORT WAVE ENERGY ACROSS URUGUAY-SOUTHERN
STATES OF BRASIL. A SHORT WAVE RIDGE TO THE EAST EXTENDS ALONG
38W/40W TO 45S.

SOUTH OVER THE CONTINENT...AT LOW LEVELS...A POLAR RIDGE ENVELOPS
THE SOUTHERN CONE AS IT CENTERS ON A 1029 HPA HIGH AT 43S 67W.
EAST OF THIS AXIS...A BROAD TROUGH DOMINATES THE WESTERN
ATLANTIC/MID SECTIONS OF SOUTH AMERICA...AS IT CENTERS ON AN
OCCLUDED 994 HPA LOW AT 36S 56W. THIS EXTENDS A FRONT ALONG 34S
59W...42S 57W...A 1004 HPA LOW AT 38S 46W...34S 44W...29S 46W...A
1006 HPA LOW AT 26S 48W...MATO GROSSO-RONDONIA IN BRASIL TO
NORTHERN BOLIVIA. THIS SUSTAINS SCATTERED DEEP CONVECTION ACROSS
THE SOUTHERN STATES OF BRASIL.

CAROCA...DMC (CHILE)
JALFIN...SMN (ARGENTINA)
DAVISON...WPC (USA)
$$






000
FXSA20 KWBC 261322
PMDSA

SOUTH AMERICA SYNOPTIC DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
921 AM EDT TUE AUG 26 2014

GFS DATA AT FTPPRD.NCEP.NOAA.GOV/PUB/DATA/NCCF/COM/GFS/PROD/

SYNOPSIS (VALID FROM AUGUST 26 AT 00UTC): AT 200 HPA...AN
UNUSUALLY STRONG CELL OF THE SUBTROPICAL RIDGE DOMINATES THE
EASTERN PACIFIC AND WESTERN PORTIONS OF SOUTH AMERICA. THE RIDGE
ANCHORS ON A CLOSED HIGH OVER ACRE IN BRASIL/CENTRAL PERU...WITH
AXIS WEST INTO THE EASTERN TROPICAL PACIFIC AND SOUTH ALONG 75W TO
SOUTHERN CHILE. THE RIDGE ALOFT IS VENTING ISOLATED CONVECTION
ACROSS PORTIONS OF PARA-AMAZONAS IN BRASIL...WITH MOST INTENSE
NORTH OF THE EQUATOR OVER VENEZUELA AND COLOMBIA. EAST OF THE
RIDGE...A TROUGH EXTENDS ALONG THE COAST OF ARGENTINA TO SOUTHERN
BRASIL. THIS IS INTERACTING WITH A SHORT WAVE TROUGH TO THE NORTH
AS THE LATTER EXTENDS ALONG 15S 46W TO THE GUIANAS.

AT 250 HPA...THE SOUTHERN POLAR HAS A FINGER WITH ENTRANCE AT 44S
88W...THEN ALONG 52S 80W...EXITING AT 47S 66W. IT REFORMS AT 48S
48W...ALONG 48S 33W...40S 13W...AND 38S 02W. THE NORTHERN POLAR
HAS ITS ENTRANCE AT 23S 96W...ALONG A 140KT MAXIMUM AT 27S
85W...EXITING AT 33S 79W. IT REFORMS AT 34S 70W...THEN ALONG A
150KT MAXIMUM AT 32S 65W...30S 57W...34S 50W...43S 48W...43S
32W...A 134KT MAXIMUM AT 37S 17W...AND A 130KT MAXIMUM AT 33S 05W.
THE SUBTROPICAL JET HAS ITS ENTRANCE AT 16S 105W...ALONG 17S
97W...20S 90W...26S 73W... EXITING AT 18S 55W. IT REFORMS BETWEEN
22S 46W AND 29S 39W. THE SUBTROPICAL JET REFORMS AT 32S 27W...THEN
ALONG 30S 15W...29S 09W...AND 32S 06E.

AT 500 HPA...MID LEVEL ANALYSIS SHOWS A CLOSED LOW NEAR 53S 93W
EXTENDING A TROUGH ALONG 40S 95W TO 30S 97W. THIS IS PHASING WITH
A SHORT WAVE TROUGH TO THE NORTH THAT CENTERS ON A LOW AT 24S 97W.
FARTHER EAST...A NORTH TO SOUTH RIDGE EXTENDS FROM SOUTHERN
PERU...ALONG 30S 75W...50S 76W...TO 60S 75W. EAST OF THIS AXIS...A
DEEP LOW NEAR 37S 57W ANCHORS A TROUGH OVER MID SECTIONS OF SOUTH
AMERICA WHILE FOCUSING SHORT WAVE ENERGY ACROSS URUGUAY-SOUTHERN
STATES OF BRASIL. A SHORT WAVE RIDGE TO THE EAST EXTENDS ALONG
38W/40W TO 45S.

SOUTH OVER THE CONTINENT...AT LOW LEVELS...A POLAR RIDGE ENVELOPS
THE SOUTHERN CONE AS IT CENTERS ON A 1029 HPA HIGH AT 43S 67W.
EAST OF THIS AXIS...A BROAD TROUGH DOMINATES THE WESTERN
ATLANTIC/MID SECTIONS OF SOUTH AMERICA...AS IT CENTERS ON AN
OCCLUDED 994 HPA LOW AT 36S 56W. THIS EXTENDS A FRONT ALONG 34S
59W...42S 57W...A 1004 HPA LOW AT 38S 46W...34S 44W...29S 46W...A
1006 HPA LOW AT 26S 48W...MATO GROSSO-RONDONIA IN BRASIL TO
NORTHERN BOLIVIA. THIS SUSTAINS SCATTERED DEEP CONVECTION ACROSS
THE SOUTHERN STATES OF BRASIL.

CAROCA...DMC (CHILE)
JALFIN...SMN (ARGENTINA)
DAVISON...WPC (USA)
$$







000
FXCA20 KWBC 261108
PMDCA

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
708 AM EDT TUE AUG 26 2014

PRELIMINARY DISCUSSION FOR PUERTO RICO AND THE USVI. AT UPPER
LEVELS...RETROGRESSING TUTT NOW EXTENDS FROM NORTHWEST VENEZUELA
TO THE MONA PASSAGE. AS IT MOVES WEST ACROSS THE BASIN THIS FAVORS
ORGANIZED DEEP CONVECTION ACROSS VENEZUELA...WHILE OVER THE
NORTHEAST CARIBBEAN ITS EFFECTS LIMIT TO WIDELY ISOLATED
CONVECTIVE CELLS NEAR PUERTO RICO-SAINT CROIX. AT LOW LEVELS...A
BROAD RIDGE OVER THE ATLANTIC FAVORS A LONG FETCH
SOUTH-SOUTHEASTERLY FLOW ACROSS THE EASTERN CARIBBEAN. THIS IS
ADVECTING MOISTURE NORTHWARD ACROSS THE ISLAND CHAIN INTO THE
NORTHEAST CARIBBEAN...WITH PWAT SOUTH OF PUERTO RICO PEAKING AT
40-45MM PER SATELLITE DERIVED ANALYSIS.

BUILDING MID LEVEL RIDGE IS TO RAPIDLY DISPLACE THE TUTT WEST
ACROSS THE CARIBBEAN BASIN...WITH AXIS TO CROSS 70W EARLY THIS
EVENING. MEANWHILE...IN A MOIST SOUTH-SOUTHEASTERLY LOW LEVEL
FLOW...THIS IS TO RESULT IN ENOUGH INSTABILITY FOR A FEW SHOWERS
AND POSSIBLE THUNDERSTORMS TO DEVELOP ACROSS THE FORECAST AREA.
CELL BUILDING OVER SAINT CROIX ARE TO LIFT ACROSS VIEQUES TO
EASTERN PUERTO RICO INTO THE SAN JUAN METRO AREA...WITH RAINFALL
AMOUNTS TO PEAK BETWEEN 10-15MM. SIMULTANEOUSLY...MID MORNING
DIURNAL CONVECTION IS LIKELY TO FORM ACROSS THE CORDILLERA
CENTRAL...WHERE WE EXPECT MODERATE RAINFALL AMOUNTS. THE MOST
ACTIVE IS EXPECTED ACROSS NORTHERN PUERTO RICO TO THE WEST OF
DORADO/TOA BAJA AS ENHANCED BY SEA BREEZE CONVERGENCE. ALTHOUGH
SHOWING FAVORABLE UPPER DYNAMICS...GLOBAL AND REGIONAL MODELS ARE
DOWNPLAYING THIS POSSIBILITY. BUT WITH DEEP LAYER MOIST ADVECTION
IT IS HARD TO RULE OUT THIS POSSIBILITY. EXPECTING CELLS TO
CLUSTER ALONG THE NORTH COAST DURING EARLY AFTERNOON HOURS TO
FAVOR MAXIMA OF 20-35MM.

IN A PROLIFIC ENVIRONMENT...ANOTHER TUTT IS TO RETROGRESS ACROSS
THE ATLANTIC...WITH CLOSED LOW NORTH OF PUERTO RICO BY MIDDAY ON
THURSDAY. IT IS TO THEN MEANDER NORTH OF THE FORECAST AREA THROUGH
THE END OF THE WEEK...WHEN A SHORT WAVE RIDGE MOVES IN AND
DISPLACES THE TUTT WEST. AT MID LEVELS IT IS TO REFLECT AS AN
INVERTED TROUGH ACROSS THE FORECAST AREA...AND THIS MIGHT BE
STRONG ENOUGH TO ENHANCE SOME OF THE DIURNAL ACTIVITY. BUT AS
PREVAILING EASTERLY WINDS RETURN TO THE BASIN...THE MOST ACTIVE IS
TO DEVELOP ON THE WESTERN INTERIOR PORTIONS OF PUERTO RICO AND EL
YUNQUE RAINFOREST. MORE WIDESPREAD ACTIVITY IS EXPECTED ON
SATURDAY TO SUNDAY WHEN A WELL ORGANIZED TROPICAL WAVE IS TO ENTER
THE FORECAST AREA.

VALVERDE...IMN (COSTA RICA)
MEDINA...ONAMET (REPUBLICA DOMINICANA)
DAVISON...WPC(USA)
$$







000
FXCA20 KWBC 261108
PMDCA

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
708 AM EDT TUE AUG 26 2014

PRELIMINARY DISCUSSION FOR PUERTO RICO AND THE USVI. AT UPPER
LEVELS...RETROGRESSING TUTT NOW EXTENDS FROM NORTHWEST VENEZUELA
TO THE MONA PASSAGE. AS IT MOVES WEST ACROSS THE BASIN THIS FAVORS
ORGANIZED DEEP CONVECTION ACROSS VENEZUELA...WHILE OVER THE
NORTHEAST CARIBBEAN ITS EFFECTS LIMIT TO WIDELY ISOLATED
CONVECTIVE CELLS NEAR PUERTO RICO-SAINT CROIX. AT LOW LEVELS...A
BROAD RIDGE OVER THE ATLANTIC FAVORS A LONG FETCH
SOUTH-SOUTHEASTERLY FLOW ACROSS THE EASTERN CARIBBEAN. THIS IS
ADVECTING MOISTURE NORTHWARD ACROSS THE ISLAND CHAIN INTO THE
NORTHEAST CARIBBEAN...WITH PWAT SOUTH OF PUERTO RICO PEAKING AT
40-45MM PER SATELLITE DERIVED ANALYSIS.

BUILDING MID LEVEL RIDGE IS TO RAPIDLY DISPLACE THE TUTT WEST
ACROSS THE CARIBBEAN BASIN...WITH AXIS TO CROSS 70W EARLY THIS
EVENING. MEANWHILE...IN A MOIST SOUTH-SOUTHEASTERLY LOW LEVEL
FLOW...THIS IS TO RESULT IN ENOUGH INSTABILITY FOR A FEW SHOWERS
AND POSSIBLE THUNDERSTORMS TO DEVELOP ACROSS THE FORECAST AREA.
CELL BUILDING OVER SAINT CROIX ARE TO LIFT ACROSS VIEQUES TO
EASTERN PUERTO RICO INTO THE SAN JUAN METRO AREA...WITH RAINFALL
AMOUNTS TO PEAK BETWEEN 10-15MM. SIMULTANEOUSLY...MID MORNING
DIURNAL CONVECTION IS LIKELY TO FORM ACROSS THE CORDILLERA
CENTRAL...WHERE WE EXPECT MODERATE RAINFALL AMOUNTS. THE MOST
ACTIVE IS EXPECTED ACROSS NORTHERN PUERTO RICO TO THE WEST OF
DORADO/TOA BAJA AS ENHANCED BY SEA BREEZE CONVERGENCE. ALTHOUGH
SHOWING FAVORABLE UPPER DYNAMICS...GLOBAL AND REGIONAL MODELS ARE
DOWNPLAYING THIS POSSIBILITY. BUT WITH DEEP LAYER MOIST ADVECTION
IT IS HARD TO RULE OUT THIS POSSIBILITY. EXPECTING CELLS TO
CLUSTER ALONG THE NORTH COAST DURING EARLY AFTERNOON HOURS TO
FAVOR MAXIMA OF 20-35MM.

IN A PROLIFIC ENVIRONMENT...ANOTHER TUTT IS TO RETROGRESS ACROSS
THE ATLANTIC...WITH CLOSED LOW NORTH OF PUERTO RICO BY MIDDAY ON
THURSDAY. IT IS TO THEN MEANDER NORTH OF THE FORECAST AREA THROUGH
THE END OF THE WEEK...WHEN A SHORT WAVE RIDGE MOVES IN AND
DISPLACES THE TUTT WEST. AT MID LEVELS IT IS TO REFLECT AS AN
INVERTED TROUGH ACROSS THE FORECAST AREA...AND THIS MIGHT BE
STRONG ENOUGH TO ENHANCE SOME OF THE DIURNAL ACTIVITY. BUT AS
PREVAILING EASTERLY WINDS RETURN TO THE BASIN...THE MOST ACTIVE IS
TO DEVELOP ON THE WESTERN INTERIOR PORTIONS OF PUERTO RICO AND EL
YUNQUE RAINFOREST. MORE WIDESPREAD ACTIVITY IS EXPECTED ON
SATURDAY TO SUNDAY WHEN A WELL ORGANIZED TROPICAL WAVE IS TO ENTER
THE FORECAST AREA.

VALVERDE...IMN (COSTA RICA)
MEDINA...ONAMET (REPUBLICA DOMINICANA)
DAVISON...WPC(USA)
$$






000
FXUS01 KWBC 260745
PMDSPD

SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
344 AM EDT TUE AUG 26 2014

VALID 12Z TUE AUG 26 2014 - 12Z THU AUG 28 2014

...A THREAT FOR FLASH FLOODING IS EXPECTED THROUGH EARLY THURSDAY
ACROSS THE CENTRAL PLAINS AND INTO THE MIDDLE MISSISSIPPI VALLEY...

...HOT AND HUMID CONDITIONS WILL BE COMMONPLACE OVER THE CENTER OF
THE COUNTRY...


A SPLIT FLOW REGIME WILL BE FEATURED THIS WEEK AS AN UPPER TROUGH
CUTS OFF OVER THE CENTRAL GREAT BASIN. THIS SYSTEM SHOULD
GRADUALLY SLIDE EASTWARD WITH ITS FORWARD MOTION BEING SLUGGISH AT
TIMES GIVEN ITS POSITION WELL SOUTH OF THE PREVAILING WESTERLIES.
MOISTURE LIFTING INTO THE FOUR CORNERS WILL INTERACT WITH THE
ADVANCING TROUGH SPAWNING AN EXPANSIVE AREA OF SHOWERS AND
THUNDERSTORMS. MUCH OF THE ACTIVITY SHOULD FOCUS ACROSS THE
TERRAIN WHERE LOCALIZED UPSLOPE FLOW WILL ENHANCE VERTICAL
MOTIONS. THE ACTIVITY EMERGING OFF THE HIGHER TERRAIN OF THE
ROCKIES SHOULD CARRY A FAIRLY ORGANIZED THUNDERSTORM COMPLEX INTO
THE CENTRAL PLAINS. THERE WILL BE ADDITIONAL LIFT IN THE
ATMOSPHERE AS A WEST TO EAST FRONTAL BOUNDARY WILL BE NEARLY
STALLED ACROSS THE REGION. MULTIPLE ROUNDS OF CONVECTION ARE
EXPECTED AS A SERIES OF IMPULSES MIGRATE EASTWARD AHEAD OF THE
APPROACHING UPPER TROUGH. AN AREA SPANNING NORTHEASTERN COLORADO
EASTWARD THROUGH NEBRASKA AND INTO WESTERN IOWA IS BEING
HIGHLIGHTED FOR A THREAT FOR FLASH FLOODING. THE WPC PRECIPITATION
DESKS INDICATE AREAL AVERAGES OF 2 TO 4 INCHES OF RAINFALL ARE
LIKELY THROUGH EARLY THURSDAY ACROSS CENTRAL TO EASTERN NEBRASKA.

WHILE PRECIPITATION IS LIKELY FROM THE UPPER GREAT LAKES EASTWARD
INTO THE NORTHEASTERN STATES, IT WILL BE MUCH LIGHTER IN NATURE.
THERE ARE NO DISCERNIBLE FEATURES ALOFT THAT WILL PROVIDE MUCH OF
A TRIGGER TO SUSTAIN ACTIVE CONVECTION. ANY ACTIVITY THAT DOES
DEVELOP WILL FORM FROM DAYTIME HEATING AND WEAK LIFT ALONG THE
ADVANCING COLD FRONT. HOWEVER, THIS FRONTAL PASSAGE WILL USHER
AWAY FROM THE HUMID AIR DEVELOPING BY MID-WEEK AND ALLOW COOLER
AND DRIER CONDITIONS TO SETTLE IN FROM THE NORTHWEST. A SURFACE
HIGH BUILDING IN OVER THE GREAT LAKES WILL BRING TRANQUIL
CONDITIONS TO MUCH OF THE NORTHEASTERN U.S. BY LATER IN THE WORK
WEEK.

THE EAST TO WEST BOUNDARY STALLING ACROSS THE CENTER OF THE NATION
WILL MAINTAIN A FAIRLY EXTENSIVE TEMPERATURE CONTRAST. WHILE HIGHS
IN THE 70S SHOULD BE COMMONPLACE IN THE COOL SECTOR, IT WILL BE
QUITE THE OPPOSITE SOUTH OF THE WAVY FRONT. HOT AND HUMID
CONDITIONS ARE FORECAST TO PREVAIL OVER THE SOUTHERN/CENTRAL
PLAINS EASTWARD INTO THE MISSISSIPPI RIVER VALLEY WHERE HIGHS PUSH
WELL INTO THE 90S. ADDING THE ELEMENT OF HUMIDITY WILL MAKE
TEMPERATURES FEEL CLOSER TO 105 DEGREES FAHRENHEIT.

AN AREA OF DISTURBED WEATHER SLIDING WESTWARD ACROSS THE GULF OF
MEXICO WILL ENHANCE THE THREAT FOR SHOWERS AND THUNDERSTORMS,
PARTICULARLY ALONG THE WESTERN GULF COAST. THIS IS WHERE THE
BETTER MOISTURE IS EXPECTED TO BE DIRECTED. ADDITIONALLY, STRONG
LOW-LEVEL CONVERGENCE ALONG AN INVERTED TROUGH IS FORECAST ALONG
THE TEXAS COASTLINE WHICH WILL ENHANCE LIFT IN THE ATMOSPHERE.


RUBIN-OSTER

GRAPHICS AVAILABLE AT WWW.WPC.NCEP.NOAA.GOV
$$






000
FXUS01 KWBC 260745
PMDSPD

SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
344 AM EDT TUE AUG 26 2014

VALID 12Z TUE AUG 26 2014 - 12Z THU AUG 28 2014

...A THREAT FOR FLASH FLOODING IS EXPECTED THROUGH EARLY THURSDAY
ACROSS THE CENTRAL PLAINS AND INTO THE MIDDLE MISSISSIPPI VALLEY...

...HOT AND HUMID CONDITIONS WILL BE COMMONPLACE OVER THE CENTER OF
THE COUNTRY...


A SPLIT FLOW REGIME WILL BE FEATURED THIS WEEK AS AN UPPER TROUGH
CUTS OFF OVER THE CENTRAL GREAT BASIN. THIS SYSTEM SHOULD
GRADUALLY SLIDE EASTWARD WITH ITS FORWARD MOTION BEING SLUGGISH AT
TIMES GIVEN ITS POSITION WELL SOUTH OF THE PREVAILING WESTERLIES.
MOISTURE LIFTING INTO THE FOUR CORNERS WILL INTERACT WITH THE
ADVANCING TROUGH SPAWNING AN EXPANSIVE AREA OF SHOWERS AND
THUNDERSTORMS. MUCH OF THE ACTIVITY SHOULD FOCUS ACROSS THE
TERRAIN WHERE LOCALIZED UPSLOPE FLOW WILL ENHANCE VERTICAL
MOTIONS. THE ACTIVITY EMERGING OFF THE HIGHER TERRAIN OF THE
ROCKIES SHOULD CARRY A FAIRLY ORGANIZED THUNDERSTORM COMPLEX INTO
THE CENTRAL PLAINS. THERE WILL BE ADDITIONAL LIFT IN THE
ATMOSPHERE AS A WEST TO EAST FRONTAL BOUNDARY WILL BE NEARLY
STALLED ACROSS THE REGION. MULTIPLE ROUNDS OF CONVECTION ARE
EXPECTED AS A SERIES OF IMPULSES MIGRATE EASTWARD AHEAD OF THE
APPROACHING UPPER TROUGH. AN AREA SPANNING NORTHEASTERN COLORADO
EASTWARD THROUGH NEBRASKA AND INTO WESTERN IOWA IS BEING
HIGHLIGHTED FOR A THREAT FOR FLASH FLOODING. THE WPC PRECIPITATION
DESKS INDICATE AREAL AVERAGES OF 2 TO 4 INCHES OF RAINFALL ARE
LIKELY THROUGH EARLY THURSDAY ACROSS CENTRAL TO EASTERN NEBRASKA.

WHILE PRECIPITATION IS LIKELY FROM THE UPPER GREAT LAKES EASTWARD
INTO THE NORTHEASTERN STATES, IT WILL BE MUCH LIGHTER IN NATURE.
THERE ARE NO DISCERNIBLE FEATURES ALOFT THAT WILL PROVIDE MUCH OF
A TRIGGER TO SUSTAIN ACTIVE CONVECTION. ANY ACTIVITY THAT DOES
DEVELOP WILL FORM FROM DAYTIME HEATING AND WEAK LIFT ALONG THE
ADVANCING COLD FRONT. HOWEVER, THIS FRONTAL PASSAGE WILL USHER
AWAY FROM THE HUMID AIR DEVELOPING BY MID-WEEK AND ALLOW COOLER
AND DRIER CONDITIONS TO SETTLE IN FROM THE NORTHWEST. A SURFACE
HIGH BUILDING IN OVER THE GREAT LAKES WILL BRING TRANQUIL
CONDITIONS TO MUCH OF THE NORTHEASTERN U.S. BY LATER IN THE WORK
WEEK.

THE EAST TO WEST BOUNDARY STALLING ACROSS THE CENTER OF THE NATION
WILL MAINTAIN A FAIRLY EXTENSIVE TEMPERATURE CONTRAST. WHILE HIGHS
IN THE 70S SHOULD BE COMMONPLACE IN THE COOL SECTOR, IT WILL BE
QUITE THE OPPOSITE SOUTH OF THE WAVY FRONT. HOT AND HUMID
CONDITIONS ARE FORECAST TO PREVAIL OVER THE SOUTHERN/CENTRAL
PLAINS EASTWARD INTO THE MISSISSIPPI RIVER VALLEY WHERE HIGHS PUSH
WELL INTO THE 90S. ADDING THE ELEMENT OF HUMIDITY WILL MAKE
TEMPERATURES FEEL CLOSER TO 105 DEGREES FAHRENHEIT.

AN AREA OF DISTURBED WEATHER SLIDING WESTWARD ACROSS THE GULF OF
MEXICO WILL ENHANCE THE THREAT FOR SHOWERS AND THUNDERSTORMS,
PARTICULARLY ALONG THE WESTERN GULF COAST. THIS IS WHERE THE
BETTER MOISTURE IS EXPECTED TO BE DIRECTED. ADDITIONALLY, STRONG
LOW-LEVEL CONVERGENCE ALONG AN INVERTED TROUGH IS FORECAST ALONG
THE TEXAS COASTLINE WHICH WILL ENHANCE LIFT IN THE ATMOSPHERE.


RUBIN-OSTER

GRAPHICS AVAILABLE AT WWW.WPC.NCEP.NOAA.GOV
$$







000
FXUS02 KWBC 260635
PMDEPD

EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
234 AM EDT TUE AUG 26 2014

VALID 12Z FRI AUG 29 2014 - 12Z TUE SEP 02 2014

...OVERVIEW AND PREFERENCES...

LATEST GUIDANCE MAINTAINS A FCST OF LOW AMPLITUDE MEAN FLOW WITH
THE MAIN BAND OF WESTERLIES ACROSS THE NRN CONUS AND SRN CANADA.
WITHIN THIS STREAM THE PRIMARY FEATURES OF NOTE WILL BE TROUGH
BRUSHING THE EXTREME NRN TIER/UPR GRTLKS/NORTHEAST FRI INTO
SUN/MON FOLLOWED BY A MUCH STRONGER TROUGH PROGRESSING INTO AND
THROUGH THE WEST DURING THE WEEKEND AND CONTINUING EWD ACROSS THE
NRN TIER.  MEANWHILE SEPARATION FROM THE WESTERLIES SHOULD LEAD TO
RELATIVELY SLOW MOVEMENT OF A TROUGH OVER THE PLAINS AS OF FRI.
RIDGES CNTRD OFF BAJA CALIF AND NEAR THE SERN COAST WILL GRADUALLY
FLATTEN BUT STILL SPAN ACROSS THE SOUTH THROUGH EARLY NEXT WEEK.
SPREAD/VARIABILITY OF INDIVIDUAL MODEL SOLNS COMBINED WITH
RELATIVE AGREEMENT/CONTINUITY OF THE ENSEMBLE MEANS RECOMMEND
MAINTAINING EMPHASIS ON THE MEANS FOR THIS CYCLE... BY WAY OF A
60/20/20 BLEND OF THE 12Z ECMWF MEAN/12Z NAEFS MEAN/18Z GEFS MEAN.
 THE ONLY EXCEPTION IS FOR DAYS 3-4 FRI-SAT WHEN A MINORITY
COMPONENT OF THE 12Z ECMWF IS INCLUDED AND THE 18Z GEFS MEAN IS
EXCLUDED ON DAY 3.


...GUIDANCE EVALUATION...

THERE IS GOOD AGREEMENT IN PRINCIPLE FOR THE TROUGH ALOFT REACHING
THE WEST BY THE WEEKEND AND CONTINUING ACROSS THE NRN TIER STATES
THEREAFTER.  INDIVIDUAL RUNS OF THE GFS/ECMWF AND OTHER MODELS
HAVE VARIED SOMEWHAT IN TROUGH AMPLITUDE/TIMING AND THUS WITH
PROGRESSION OF THE LEADING SFC FRONT... SO WOULD LIKE TO MAINTAIN
A MORE STABLE SOLN AS SEEN IN THE ENSEMBLE MEANS.  THERE IS STILL
A NARROW WINDOW OF OPPORTUNITY FOR SOME UPR LVL ERN PAC TROPICAL
MSTR/ENERGY TO BE PULLED INTO THE WEST BEFORE SUN THOUGH WITH NO
CLEAR CONSENSUS YET AS TO THE EXTENT.  ONCE THIS TROUGH DEPARTS
FROM THE WEST THE ENSEMBLE SPREAD AND RUN TO RUN MODEL
INCONSISTENCY SUGGEST A PERIOD OF LOWER FCST CONFIDENCE IN SHRTWV
DETAILS FROM THE NERN PAC INTO THE WRN CONUS.

AS OF 12Z FRI THERE ARE ALREADY QUESTION MARKS ABOUT THE SFC
DETAILS AHEAD OF THE SLOW MOVING PLAINS TROUGH ALOFT.  THROUGH THE
18Z CYCLE THE GFS/GEFS HAD BEEN ON THEIR OWN WITH A FARTHER N/NE
TRACK OF A WEAK SFC WAVE INTO THE UPR MS VLY/GRTLKS ASSOC WITH AN
AREA OF CONCENTRATED QPF/PSBL FEEDBACK... THUS FAVORING A
CONSENSUS OF OTHER SOLNS.  THE 00Z UKMET HAS JOINED THE GFS/GEFS
IDEA THOUGH.  CONSULT THE MODEL DIAGNOSTIC DISCUSSION PMDHMD FOR
LATEST MODEL COMPARISONS/PREFS THROUGH 12Z FRI.

AS THE PLAINS TROUGH DRIFTS EWD THE EXACT HANDLING OF ITS CORE
ALONG WITH AMPLITUDE OF THE NRN STREAM TROUGH BRUSHING THE
NORTHEAST WILL DETERMINE THE SWD EXTENT OF THE SFC FRONT FCST TO
EXTEND FROM THE NORTHEAST INTO THE LWR GRTLKS AND BACK TO THE
SYSTEM EMERGING OVER THE NRN PLAINS.  THE LAST COUPLE RUNS OF THE
ECMWF AS WELL AS THE 00Z GFS KEEP THE PLAINS SHRTWV SUFFICIENTLY
WELL DEFINED AND THE NRN STREAM TROUGH SUFFICIENTLY FLAT TO
SUPPORT A RATHER FAR NWD WAVY FRONTAL BNDRY RELATIVE TO THE
ENSEMBLE MEANS.  THIS ALTERNATIVE SCENARIO IS WORTH MONITORING
GIVEN THAT THE OPERATIONAL RUNS COULD HAVE A BETTER HANDLE ON THE
DETAIL OF THE PLAINS SHRTWV.  CONFIDENCE IS NOT QUITE HIGH ENOUGH
YET TO TREND AWAY FROM THE MORE STABLE ENSEMBLE MEANS THOUGH.


...SENSIBLE WEATHER HIGHLIGHTS...

THE SLOW MOVING TROUGH INITIALLY OVER THE PLAINS ALONG WITH A SFC
FRONT PUSHING E/SE FROM THE NRN TIER SHOULD ULTIMATELY SUPPORT A
BROAD AREA OF RNFL ACROSS THE CNTRL/ERN STATES... WITH MOST
GUIDANCE SUGGESTING SOME ENHANCEMENT OF MSTR DUE TO DEEP LAYER
FLOW FROM THE WRN-CNTRL GULF FROM FRI INTO THE WEEKEND.  CURRENTLY
EXPECT HEAVIEST RNFL FOR THE OVERALL PERIOD TO EXTEND FROM THE
CNTRL PLAINS INTO PORTIONS OF THE GRTLKS/NORTHEAST BUT WITH
POTENTIAL ALSO JUST SWD OF THIS AXIS AS WELL AS NEAR THE GULF
COAST.  UPSTREAM THE UPR TROUGH/LEADING FRONTAL SYSTEM CROSSING
THE WEST AND EVENTUALLY APPROACHING THE GRTLKS WILL BE ACCOMPANIED
BY RNFL OF VARYING INTENSITY.  THIS LATTER SYSTEM WILL BRING A
NOTICEABLE COOLING TREND WITH HIGHS UP TO 10F OR SO BELOW NORMAL
FROM THE NORTHWEST INTO THE NRN PLAINS BY SUN-TUE.  THE SOUTHEAST
SHOULD SEE THE MOST CONSISTENTLY ABOVE NORMAL READINGS DURING THE
PERIOD.

RAUSCH
$$






000
FXUS02 KWBC 260635
PMDEPD

EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
234 AM EDT TUE AUG 26 2014

VALID 12Z FRI AUG 29 2014 - 12Z TUE SEP 02 2014

...OVERVIEW AND PREFERENCES...

LATEST GUIDANCE MAINTAINS A FCST OF LOW AMPLITUDE MEAN FLOW WITH
THE MAIN BAND OF WESTERLIES ACROSS THE NRN CONUS AND SRN CANADA.
WITHIN THIS STREAM THE PRIMARY FEATURES OF NOTE WILL BE TROUGH
BRUSHING THE EXTREME NRN TIER/UPR GRTLKS/NORTHEAST FRI INTO
SUN/MON FOLLOWED BY A MUCH STRONGER TROUGH PROGRESSING INTO AND
THROUGH THE WEST DURING THE WEEKEND AND CONTINUING EWD ACROSS THE
NRN TIER.  MEANWHILE SEPARATION FROM THE WESTERLIES SHOULD LEAD TO
RELATIVELY SLOW MOVEMENT OF A TROUGH OVER THE PLAINS AS OF FRI.
RIDGES CNTRD OFF BAJA CALIF AND NEAR THE SERN COAST WILL GRADUALLY
FLATTEN BUT STILL SPAN ACROSS THE SOUTH THROUGH EARLY NEXT WEEK.
SPREAD/VARIABILITY OF INDIVIDUAL MODEL SOLNS COMBINED WITH
RELATIVE AGREEMENT/CONTINUITY OF THE ENSEMBLE MEANS RECOMMEND
MAINTAINING EMPHASIS ON THE MEANS FOR THIS CYCLE... BY WAY OF A
60/20/20 BLEND OF THE 12Z ECMWF MEAN/12Z NAEFS MEAN/18Z GEFS MEAN.
 THE ONLY EXCEPTION IS FOR DAYS 3-4 FRI-SAT WHEN A MINORITY
COMPONENT OF THE 12Z ECMWF IS INCLUDED AND THE 18Z GEFS MEAN IS
EXCLUDED ON DAY 3.


...GUIDANCE EVALUATION...

THERE IS GOOD AGREEMENT IN PRINCIPLE FOR THE TROUGH ALOFT REACHING
THE WEST BY THE WEEKEND AND CONTINUING ACROSS THE NRN TIER STATES
THEREAFTER.  INDIVIDUAL RUNS OF THE GFS/ECMWF AND OTHER MODELS
HAVE VARIED SOMEWHAT IN TROUGH AMPLITUDE/TIMING AND THUS WITH
PROGRESSION OF THE LEADING SFC FRONT... SO WOULD LIKE TO MAINTAIN
A MORE STABLE SOLN AS SEEN IN THE ENSEMBLE MEANS.  THERE IS STILL
A NARROW WINDOW OF OPPORTUNITY FOR SOME UPR LVL ERN PAC TROPICAL
MSTR/ENERGY TO BE PULLED INTO THE WEST BEFORE SUN THOUGH WITH NO
CLEAR CONSENSUS YET AS TO THE EXTENT.  ONCE THIS TROUGH DEPARTS
FROM THE WEST THE ENSEMBLE SPREAD AND RUN TO RUN MODEL
INCONSISTENCY SUGGEST A PERIOD OF LOWER FCST CONFIDENCE IN SHRTWV
DETAILS FROM THE NERN PAC INTO THE WRN CONUS.

AS OF 12Z FRI THERE ARE ALREADY QUESTION MARKS ABOUT THE SFC
DETAILS AHEAD OF THE SLOW MOVING PLAINS TROUGH ALOFT.  THROUGH THE
18Z CYCLE THE GFS/GEFS HAD BEEN ON THEIR OWN WITH A FARTHER N/NE
TRACK OF A WEAK SFC WAVE INTO THE UPR MS VLY/GRTLKS ASSOC WITH AN
AREA OF CONCENTRATED QPF/PSBL FEEDBACK... THUS FAVORING A
CONSENSUS OF OTHER SOLNS.  THE 00Z UKMET HAS JOINED THE GFS/GEFS
IDEA THOUGH.  CONSULT THE MODEL DIAGNOSTIC DISCUSSION PMDHMD FOR
LATEST MODEL COMPARISONS/PREFS THROUGH 12Z FRI.

AS THE PLAINS TROUGH DRIFTS EWD THE EXACT HANDLING OF ITS CORE
ALONG WITH AMPLITUDE OF THE NRN STREAM TROUGH BRUSHING THE
NORTHEAST WILL DETERMINE THE SWD EXTENT OF THE SFC FRONT FCST TO
EXTEND FROM THE NORTHEAST INTO THE LWR GRTLKS AND BACK TO THE
SYSTEM EMERGING OVER THE NRN PLAINS.  THE LAST COUPLE RUNS OF THE
ECMWF AS WELL AS THE 00Z GFS KEEP THE PLAINS SHRTWV SUFFICIENTLY
WELL DEFINED AND THE NRN STREAM TROUGH SUFFICIENTLY FLAT TO
SUPPORT A RATHER FAR NWD WAVY FRONTAL BNDRY RELATIVE TO THE
ENSEMBLE MEANS.  THIS ALTERNATIVE SCENARIO IS WORTH MONITORING
GIVEN THAT THE OPERATIONAL RUNS COULD HAVE A BETTER HANDLE ON THE
DETAIL OF THE PLAINS SHRTWV.  CONFIDENCE IS NOT QUITE HIGH ENOUGH
YET TO TREND AWAY FROM THE MORE STABLE ENSEMBLE MEANS THOUGH.


...SENSIBLE WEATHER HIGHLIGHTS...

THE SLOW MOVING TROUGH INITIALLY OVER THE PLAINS ALONG WITH A SFC
FRONT PUSHING E/SE FROM THE NRN TIER SHOULD ULTIMATELY SUPPORT A
BROAD AREA OF RNFL ACROSS THE CNTRL/ERN STATES... WITH MOST
GUIDANCE SUGGESTING SOME ENHANCEMENT OF MSTR DUE TO DEEP LAYER
FLOW FROM THE WRN-CNTRL GULF FROM FRI INTO THE WEEKEND.  CURRENTLY
EXPECT HEAVIEST RNFL FOR THE OVERALL PERIOD TO EXTEND FROM THE
CNTRL PLAINS INTO PORTIONS OF THE GRTLKS/NORTHEAST BUT WITH
POTENTIAL ALSO JUST SWD OF THIS AXIS AS WELL AS NEAR THE GULF
COAST.  UPSTREAM THE UPR TROUGH/LEADING FRONTAL SYSTEM CROSSING
THE WEST AND EVENTUALLY APPROACHING THE GRTLKS WILL BE ACCOMPANIED
BY RNFL OF VARYING INTENSITY.  THIS LATTER SYSTEM WILL BRING A
NOTICEABLE COOLING TREND WITH HIGHS UP TO 10F OR SO BELOW NORMAL
FROM THE NORTHWEST INTO THE NRN PLAINS BY SUN-TUE.  THE SOUTHEAST
SHOULD SEE THE MOST CONSISTENTLY ABOVE NORMAL READINGS DURING THE
PERIOD.

RAUSCH
$$







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