000
FXUS63 KDTX 190739
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
339 AM EDT WED JUN 19 2013
.SHORT TERM...TODAY AND TONIGHT
SPRAWLING HIGH PRESSURE SYSTEM EXTENDING FROM THE UPPER MS VALLEY TO
WESTERN QUEBEC WILL MAINTAIN CONTROL ACROSS THE REGION OVER THE NEXT
24 HOURS. THIS WILL RETAIN A SEASONABLY COOLER AND MORE STABLE
ENVIRONMENT AS WEAK LOW LEVEL EASTERLY FLOW TUCKED BENEATH BROAD MID
LEVEL NORTHWESTERLIES LIMIT THE DIURNAL RECOVERY TO SIMPLE DIABATIC
HEATING PROVIDED BY STRONG MID JUNE SUNSHINE. THIS WILL TRANSLATE
INTO HIGHS OF LOWER TO MIDDLE 70S...AGAIN SLIGHTLY COOLER ALONG THE
THUMB WITH THE ONSHORE WIND OFF THE COOLER WATERS CUTTING SLIGHTLY
INTO THE THERMAL RESPONSE. A CLEAR SKY...WEAKENING GRADIENT AND
DRY PROFILE WILL AGAIN PROMOTE GOOD RADIATIONAL COOLING. COLDEST
LOCALES AGAIN DIPPING INTO THE 40S.
&&
.LONG TERM...THURSDAY THROUGH TUESDAY
THE UPPER PATTERN ACROSS THE NORTHERN UNITED STATES WILL DEAMPLIFY
OVER THE NEXT COUPLE OF DAYS AS THE LARGE PAC NW LOW SHIFTS INLAND
AND EMBEDDED MID-LEVEL IMPULSES TRIGGER EPISODIC CONVECTION ACROSS
THE NORTHERN PLAINS. THE SIMULTANEOUS EASTWARD MIGRATION AND
DAMPENING OF THE DOWNSTREAM RIDGE OVER THE CENTRAL CONUS WILL FORCE
CANADIAN HIGH PRESSURE TO EXIT TO THE EAST AND FORCE SOUTHERLY
RETURN FLOW TO SPREAD INTO THE LOWER PENINSULA BEGINNING ON
THURSDAY. A NOTEWORTHY MODERATION OF TEMPERATURES WILL BE THE RESULT
AS DAYTIME HIGHS RISE TO 80 FOR THURSDAY AND SOLIDLY INTO THE
MID-80S ON FRIDAY, PARTICULARLY FOR WESTERN PORTIONS OF THE CWA AWAY
FROM POTENTIAL LAKE SHADOW IMPACTS.
A SIGNIFICANT TRANSITION IN THE LOCAL WX WILL THEN COMMENCE FROM
SATURDAY ONWARD AS MID-LEVEL WESTERLIES EMERGE ACROSS THE
NORTHERN TIER IN RESPONSE TO THE COLLAPSE OF THE MID-LEVEL RIDGE.
THIS WILL ALLOW A MOIST AND HUMID AIRMASS TO SPILL INTO THE REGION
WHICH SHOULD HAVE NO PROBLEM YIELDING HIGH TEMPERATURES NEAR 90
DEGREES ALONG WITH UPPER 60S/LOW 70S DEWPOINTS. GIVEN SOUTHEAST
MICHIGAN`S PROGGED FAVORABLE LOCATION ALONG THE INSTABILITY
GRADIENT AND NOSE OF THE VEERING LOW-LEVEL JET ON SATURDAY, HAVE
NO ARGUMENT WITH THE ECMWF`S SUGGESTION OF A CONVECTIVE COMPLEX
IMPACTING THE AREA ON SAT, PARTICULARLY GIVEN THE EXCELLENT
CONTINUITY OBSERVED IN RECENT CYCLES. WITH THIS IN MIND, LEANED
HEAVILY TOWARD A CONSERVATIVE HIGH TEMPERATURE FORECAST, AROUND 80
DEGREES, FOR SATURDAY.
THE RESERVOIR OF INSTABILITY AND ASSOCIATED SEVERE POTENTIAL WILL
CONTINUE TO BUILD SUNDAY INTO TUESDAY AS A ROBUST ZONALLY-ORIENTED
EML RIBBON BECOMES INCREASINGLY WELL-ESTABLISHED ACROSS THE GREAT
LAKES. PER THE USUAL, THIS WILL ALSO INTRODUCE STOUT MID-LEVEL
CAPPING AS EVIDENCED BY 00Z ECMWF 850MB TEMPS EXCEEDING 20C BY 00Z
MONDAY EVENING. AS A RESULT, BOTH HOT TEMPERATURES AND SEVERE
CONVECTIVE POTENTIAL WILL BE IN PLAY FOR SOUTHEAST MICHIGAN FROM
SUNDAY ONWARD. ALSO WORTH NOTING IS THAT MOIST BOUNDARY LAYER
CONDITIONS WILL LIMIT OVERNIGHT LOWS TO THE 70S.
&&
.MARINE...
CANADIAN HIGH PRESSURE WILL MAINTAIN CONTROL ACROSS THE REGION
THROUGH THURSDAY. THIS WILL PROVIDE A STRETCH OF FAVORABLE
MARINE CONDITIONS THROUGH THE END OF THE WEEK.
&&
.AVIATION...ISSUED 1234 AM EDT WED JUN 19 2013
//DISCUSSION...
VFR CONDITIONS EXPECTED THROUGH THE NEXT 24 HOURS AND BEYOND. HIGH
PRESSURE LOCKED OVER THE GREAT LAKES WILL PRODUCE FAVORABLE AVIATION
CONDITIONS THROUGH WEDNESDAY. CLEAR SKIES EXCEPT FOR A PATCH OF CI
TONIGHT AND THEN FEW TO SCT CU WEDNESDAY AFTERNOON. WINDS WILL
CONTINUE TO SLOWLY DIMINISH OVERNIGHT AND THEN VEER TO THE EAST.
LIGHT EAST WIND WILL CONTINUE ON WEDNESDAY AS THE HIGH DROPS FURTHER
SOUTH.
//DTW THRESHOLD THREATS...
* NONE
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...MR
LONG TERM....JVC
MARINE.......MR
AVIATION.....RBP
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
000
FXUS63 KDTX 190434
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1234 AM EDT WED JUN 19 2013
.AVIATION...
//DISCUSSION...
VFR CONDITIONS EXPECTED THROUGH THE NEXT 24 HOURS AND BEYOND. HIGH
PRESSURE LOCKED OVER THE GREAT LAKES WILL PRODUCE FAVORABLE AVIATION
CONDITIONS THROUGH WEDNESDAY. CLEAR SKIES EXCEPT FOR A PATCH OF CI
TONIGHT AND THEN FEW TO SCT CU WEDNESDAY AFTERNOON. WINDS WILL
CONTINUE TO SLOWLY DIMINISH OVERNIGHT AND THEN VEER TO THE EAST.
LIGHT EAST WIND WILL CONTINUE ON WEDNESDAY AS THE HIGH DROPS FURTHER
SOUTH.
//DTW THRESHOLD THREATS...
* NONE
&&
.PREV DISCUSSION...ISSUED 344 PM EDT TUE JUN 18 2013
SHORT TERM...THROUGH TONIGHT
SURFACE HIGH PRESSURE SYSTEM IS DROPPING INTO THE STATE FROM CANADA
THIS EVENING. THIS LOWER MI WILL BECOME FIRMLY ENTRENCHED UNDER THIS
HIGH BY WEDNESDAY MORNING. IN ADDITION...AN AREA OF MID LEVEL
SUBSIDENCE NORTH OF A SHORTWAVE DIVING SE THROUGH THE OHIO VALLEY
WILL HELP PRODUCE A DEEP LAYER OF DRY AIR THROUGH THE MID LEVELS OF
THE ATMOSPHERE. THE MAIN ISSUE WITH THIS FORECAST WILL BE MINIMUM
TEMPERATURES OVERNIGHT. DECREASING WINDS...HIGH PRESSURE CENTERED
OVER THE AREA...DECREASING SFC DEWPOINTS...AND CLEAR SKIES WOULD ALL
LEAD TO FAVORABLE RADIATIONAL COOLING. LAST NIGHT TEMPERATURES
ACROSS NORTHERN MI DROPPED INTO THE MID/UPPER 30S WITH SOME FROST
DEVELOPMENT. MODELS ARE CONTINUING TO SUGGEST THE NE WINDS WILL
NOT DECOUPLE AND STAY SOMEWHAT ELEVATED INTO THE NIGHT WHICH WOULD
PREVENT TEMPERATURES FROM DROPPING TO THEIR FULL POTENTIAL. AREAS TO
THE NORTH AROUND THE SAGINAW VALLEY WILL HAVE THE BEST CHANCE TO
DROP INTO THE LOW 40S AS THE HIGH WILL HAVE A LONGER RESIDENCE OVER
THAT AREA WHILE AREAS TO THE SOUTH WILL KEEP A TIGHTER PRESSURE
GRADIENT LONGER INTO THE NIGHT PREVENTING TEMPS FROM FALLING PAST
THE MID 40S. AS MENTIONED IN THE PREVIOUS DISCUSSION...THIS WILL
LIKELY LEAVE LOWS A DEGREE OR TWO SHY OF RECORD VALUES FOR
THE DATE AT BOTH MBS AND FNT /RECORD AT FNT 44...MBS 42/.
LONG TERM...WEDNESDAY THROUGH TUESDAY
A QUIET START TO THE EXTENDED FORECAST GIVES WAY TO INCREASINGLY
VOLATILE WEATHER THIS WEEKEND INTO EARLY NEXT WEEK. SURFACE HIGH
PRESSURE WILL BUILD SOUTHEAST THROUGH THE AREA WITHIN THE NORTHWEST
FLOW AROUND UPPER TROUGH AXIS OVER EASTERN CANADA. DRY WEATHER CAN
BE EXPECTED WEDNESDAY INTO THURSDAY AS THIS HIGH SHIFTS OVER AND
THEN JUST EAST OF THE AREA...MAINTAINING DRY...STABLE AIRMASS OVER
THE REGION. THIS CORE OF THIS CANADIAN AIRMASS WILL MAINTAIN COOL
READINGS THROUGH WEDNESDAY WITH HIGH TEMPERATURES OF 70-75. EXPECT
MODERATION INTO THURSDAY UNDER STRONG LATE JUNE SUNSHINE WITH THE
TEMPERATURES BACK TO AROUND 80.
THE PATTERN THEN UNDERGOES A NOTABLE TRANSITION OVER THE WEEKEND AS
AN UPPER RIDGE EXPANDS ACROSS THE EASTERN CONUS DOWNSTREAM OF AN
EVOLVING UPPER TROUGH OVER WESTERN NOAM. AS THIS TROUGH DEAMPLIFIES
AS AN UPPER LOW OPENS AND LIFTS FROM THE PACIFIC NORTHWEST INTO
WESTERN CANADA...UPPER FLOW PATTERN WILL SHIFT FROM SOUTHWESTERLY TO
ESSENTIALLY ZONAL WITH THE MAIN BELT OF STRONG WESTERLIES STREAMING
EAST THROUGH THE NORTHERN TIER OF THE CONUS.
NUMEROUS SHORTWAVES OF PACIFIC ORIGIN WILL RIDE THIS MAIN STORM
TRACK AND PROVIDE THE FORCING FOR A SERIES OF CONVECTIVE EPISODES.
IN ADDITION...THE AIRMASS FROM THE UPPER PLAINS/MISSISSIPPI WILL
WARM SIGNIFICANTLY OVER THE WEEKEND WITH A STEADY FEED OF GULF OF
MEXICO MOISTURE ALSO WORKING NORTH ON SOUTH/SOUTHWEST WINDS. THIS
BUILDING INSTABILITY WILL STEADILY SHIFT EAST INTO THE GREAT LAKES
AS UPPER FLOW BECOMES MORE ZONAL WITH TIME LATE THIS WEEKEND INTO
NEXT WEEK. THE JUXTAPOSITION OF THE BUILDING POOL INSTABILITY TO THE
BAND OF STRONGER WESTERLIES AND EMBEDDED UPPER IMPULSES WILL LEAD
TO MULTIPLE DAYS FROM SATURDAY INTO TUESDAY WHERE THE POTENTIAL FOR
CONVECTIVE COMPLEXES WILL BE ENHANCED.
WHILE THE BROAD SYNOPTIC PATTERN WOULD SUGGEST THAT THE POTENTIAL
FOR THUNDERSTORMS WILL INCREASE EVERY DAY FROM SATURDAY INTO TUESDAY
AS THE AIRMASS OVER THE CENTRAL GREAT LAKES BECOMES MORE AND MORE
UNSTABLE AND AS THE UPPER WESTERLIES SETTLE SOUTH CLOSER TO THE AREA
WITHIN ZONAL FLOW...THE EVENTUAL DAY-TO-DAY CHANCES FOR STORMS WILL
BE MODULATED AS LEAST AS MUCH BY THE MESOSCALE INFLUENCES OF THE
THUNDERSTORM COMPLEXES THEMSELVES. DURING THIS PERIOD OF ACTIVE
WEATHER...TEMPERATURES WILL BE MUCH MORE SUMMER-LIKE...WARMING WELL
INTO THE 80S TO AROUND 90 WITH MINIMUM TEMPERATURES OVERNIGHT AROUND
70.
MARINE...
CANADIAN HIGH PRESSURE SINKING INTO THE GREAT LAKES WILL ALLOW GUSTY
NE FLOW TO DECREASE TONIGHT WHILE BECOMING MORE EASTERLY. THIS WILL
RESULT IN LOWER WAVE HEIGHTS AS WELL FALLING TO LESS THAN 2 FEET BY
WEDNESDAY MORNING. CURRENTLY WAVES ALONG THE LAKE HURON SHORELINE
ARE SLIGHTLY ELEVATED TO AROUND 3-4 FEET WITH THE FAVORABLE
FETCH...BUT WILL FALL SHORT OF A SMALL CRAFT ADVISORY. THE SURFACE
HIGH...IN ADDITION TO MID LEVEL SUBSIDENCE NORTH OF A
SHORTWAVE...WILL LEAD TO FAVORABLE MARINE CONDITIONS INTO FRIDAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....RBP
SHORT TERM...DRK
LONG TERM....DG
MARINE.......DRK
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS
ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
000
FXUS63 KDTX 182257
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
657 PM EDT TUE JUN 18 2013
.AVIATION...
//DISCUSSION...
VFR CONDITIONS EXPECTED THROUGH THE NEXT 24 HOURS AND BEYOND. HIGH
PRESSURE LOCKED OVER THE GREAT LAKES WILL PRODUCE FAVORABLE AVIATION
CONDITIONS THROUGH WEDNESDAY. AFTERNOON CU IS DISSIPATING AND WILL
FORM AGAIN ON WEDNESDAY...BUT NO BETTER THAN FEW TO SCT. WINDS
GUSTING TO 20 MPH FROM THE NORTHEAST WILL DISSIPATE QUICKLY BY 01Z.
WINDS WILL VEER TO THE EAST AND REMAIN LIGHT OVERNIGHT AND WEDNESDAY
AS THE HIGH DROPS FURTHER SOUTH.
//DTW THRESHOLD THREATS...
* NONE
&&
.PREV DISCUSSION...ISSUED 344 PM EDT TUE JUN 18 2013
SHORT TERM...THROUGH TONIGHT
SURFACE HIGH PRESSURE SYSTEM IS DROPPING INTO THE STATE FROM CANADA
THIS EVENING. THIS LOWER MI WILL BECOME FIRMLY ENTRENCHED UNDER THIS
HIGH BY WEDNESDAY MORNING. IN ADDITION...AN AREA OF MID LEVEL
SUBSIDENCE NORTH OF A SHORTWAVE DIVING SE THROUGH THE OHIO VALLEY
WILL HELP PRODUCE A DEEP LAYER OF DRY AIR THROUGH THE MID LEVELS OF
THE ATMOSPHERE. THE MAIN ISSUE WITH THIS FORECAST WILL BE MINIMUM
TEMPERATURES OVERNIGHT. DECREASING WINDS...HIGH PRESSURE CENTERED
OVER THE AREA...DECREASING SFC DEWPOINTS...AND CLEAR SKIES WOULD ALL
LEAD TO FAVORABLE RADIATIONAL COOLING. LAST NIGHT TEMPERATURES
ACROSS NORTHERN MI DROPPED INTO THE MID/UPPER 30S WITH SOME FROST
DEVELOPMENT. MODELS ARE CONTINUING TO SUGGEST THE NE WINDS WILL
NOT DECOUPLE AND STAY SOMEWHAT ELEVATED INTO THE NIGHT WHICH WOULD
PREVENT TEMPERATURES FROM DROPPING TO THEIR FULL POTENTIAL. AREAS TO
THE NORTH AROUND THE SAGINAW VALLEY WILL HAVE THE BEST CHANCE TO
DROP INTO THE LOW 40S AS THE HIGH WILL HAVE A LONGER RESIDENCE OVER
THAT AREA WHILE AREAS TO THE SOUTH WILL KEEP A TIGHTER PRESSURE
GRADIENT LONGER INTO THE NIGHT PREVENTING TEMPS FROM FALLING PAST
THE MID 40S. AS MENTIONED IN THE PREVIOUS DISCUSSION...THIS WILL
LIKELY LEAVE LOWS A DEGREE OR TWO SHY OF RECORD VALUES FOR
THE DATE AT BOTH MBS AND FNT /RECORD AT FNT 44...MBS 42/.
LONG TERM...WEDNESDAY THROUGH TUESDAY
A QUIET START TO THE EXTENDED FORECAST GIVES WAY TO INCREASINGLY
VOLATILE WEATHER THIS WEEKEND INTO EARLY NEXT WEEK. SURFACE HIGH
PRESSURE WILL BUILD SOUTHEAST THROUGH THE AREA WITHIN THE NORTHWEST
FLOW AROUND UPPER TROUGH AXIS OVER EASTERN CANADA. DRY WEATHER CAN
BE EXPECTED WEDNESDAY INTO THURSDAY AS THIS HIGH SHIFTS OVER AND
THEN JUST EAST OF THE AREA...MAINTAINING DRY...STABLE AIRMASS OVER
THE REGION. THIS CORE OF THIS CANADIAN AIRMASS WILL MAINTAIN COOL
READINGS THROUGH WEDNESDAY WITH HIGH TEMPERATURES OF 70-75. EXPECT
MODERATION INTO THURSDAY UNDER STRONG LATE JUNE SUNSHINE WITH THE
TEMPERATURES BACK TO AROUND 80.
THE PATTERN THEN UNDERGOES A NOTABLE TRANSITION OVER THE WEEKEND AS
AN UPPER RIDGE EXPANDS ACROSS THE EASTERN CONUS DOWNSTREAM OF AN
EVOLVING UPPER TROUGH OVER WESTERN NOAM. AS THIS TROUGH DEAMPLIFIES
AS AN UPPER LOW OPENS AND LIFTS FROM THE PACIFIC NORTHWEST INTO
WESTERN CANADA...UPPER FLOW PATTERN WILL SHIFT FROM SOUTHWESTERLY TO
ESSENTIALLY ZONAL WITH THE MAIN BELT OF STRONG WESTERLIES STREAMING
EAST THROUGH THE NORTHERN TIER OF THE CONUS.
NUMEROUS SHORTWAVES OF PACIFIC ORIGIN WILL RIDE THIS MAIN STORM
TRACK AND PROVIDE THE FORCING FOR A SERIES OF CONVECTIVE EPISODES.
IN ADDITION...THE AIRMASS FROM THE UPPER PLAINS/MISSISSIPPI WILL
WARM SIGNIFICANTLY OVER THE WEEKEND WITH A STEADY FEED OF GULF OF
MEXICO MOISTURE ALSO WORKING NORTH ON SOUTH/SOUTHWEST WINDS. THIS
BUILDING INSTABILITY WILL STEADILY SHIFT EAST INTO THE GREAT LAKES
AS UPPER FLOW BECOMES MORE ZONAL WITH TIME LATE THIS WEEKEND INTO
NEXT WEEK. THE JUXTAPOSITION OF THE BUILDING POOL INSTABILITY TO THE
BAND OF STRONGER WESTERLIES AND EMBEDDED UPPER IMPULSES WILL LEAD
TO MULTIPLE DAYS FROM SATURDAY INTO TUESDAY WHERE THE POTENTIAL FOR
CONVECTIVE COMPLEXES WILL BE ENHANCED.
WHILE THE BROAD SYNOPTIC PATTERN WOULD SUGGEST THAT THE POTENTIAL
FOR THUNDERSTORMS WILL INCREASE EVERY DAY FROM SATURDAY INTO TUESDAY
AS THE AIRMASS OVER THE CENTRAL GREAT LAKES BECOMES MORE AND MORE
UNSTABLE AND AS THE UPPER WESTERLIES SETTLE SOUTH CLOSER TO THE AREA
WITHIN ZONAL FLOW...THE EVENTUAL DAY-TO-DAY CHANCES FOR STORMS WILL
BE MODULATED AS LEAST AS MUCH BY THE MESOSCALE INFLUENCES OF THE
THUNDERSTORM COMPLEXES THEMSELVES. DURING THIS PERIOD OF ACTIVE
WEATHER...TEMPERATURES WILL BE MUCH MORE SUMMER-LIKE...WARMING WELL
INTO THE 80S TO AROUND 90 WITH MINIMUM TEMPERATURES OVERNIGHT AROUND
70.
MARINE...
CANADIAN HIGH PRESSURE SINKING INTO THE GREAT LAKES WILL ALLOW GUSTY
NE FLOW TO DECREASE TONIGHT WHILE BECOMING MORE EASTERLY. THIS WILL
RESULT IN LOWER WAVE HEIGHTS AS WELL FALLING TO LESS THAN 2 FEET BY
WEDNESDAY MORNING. CURRENTLY WAVES ALONG THE LAKE HURON SHORELINE
ARE SLIGHTLY ELEVATED TO AROUND 3-4 FEET WITH THE FAVORABLE
FETCH...BUT WILL FALL SHORT OF A SMALL CRAFT ADVISORY. THE SURFACE
HIGH...IN ADDITION TO MID LEVEL SUBSIDENCE NORTH OF A
SHORTWAVE...WILL LEAD TO FAVORABLE MARINE CONDITIONS INTO FRIDAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....RBP
SHORT TERM...DRK
LONG TERM....DG
MARINE.......DRK
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
000
FXUS63 KDTX 181944
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
344 PM EDT TUE JUN 18 2013
.SHORT TERM...THROUGH TONIGHT
SURFACE HIGH PRESSURE SYSTEM IS DROPPING INTO THE STATE FROM CANADA
THIS EVENING. THIS LOWER MI WILL BECOME FIRMLY ENTRENCHED UNDER THIS
HIGH BY WEDNESDAY MORNING. IN ADDITION...AN AREA OF MID LEVEL
SUBSIDENCE NORTH OF A SHORTWAVE DIVING SE THROUGH THE OHIO VALLEY
WILL HELP PRODUCE A DEEP LAYER OF DRY AIR THROUGH THE MID LEVELS OF
THE ATMOSPHERE. THE MAIN ISSUE WITH THIS FORECAST WILL BE MINIMUM
TEMPERATURES OVERNIGHT. DECREASING WINDS...HIGH PRESSURE CENTERED
OVER THE AREA...DECREASING SFC DEWPOINTS...AND CLEAR SKIES WOULD ALL
LEAD TO FAVORABLE RADIATIONAL COOLING. LAST NIGHT TEMPERATURES
ACROSS NORTHERN MI DROPPED INTO THE MID/UPPER 30S WITH SOME FROST
DEVELOPMENT. MODELS ARE CONTINUING TO SUGGEST THE NE WINDS WILL
NOT DECOUPLE AND STAY SOMEWHAT ELEVATED INTO THE NIGHT WHICH WOULD
PREVENT TEMPERATURES FROM DROPPING TO THEIR FULL POTENTIAL. AREAS TO
THE NORTH AROUND THE SAGINAW VALLEY WILL HAVE THE BEST CHANCE TO
DROP INTO THE LOW 40S AS THE HIGH WILL HAVE A LONGER RESIDENCE OVER
THAT AREA WHILE AREAS TO THE SOUTH WILL KEEP A TIGHTER PRESSURE
GRADIENT LONGER INTO THE NIGHT PREVENTING TEMPS FROM FALLING PAST
THE MID 40S. AS MENTIONED IN THE PREVIOUS DISCUSSION...THIS WILL
LIKELY LEAVE LOWS A DEGREE OR TWO SHY OF RECORD VALUES FOR
THE DATE AT BOTH MBS AND FNT /RECORD AT FNT 44...MBS 42/.
&&
.LONG TERM...WEDNESDAY THROUGH TUESDAY
A QUIET START TO THE EXTENDED FORECAST GIVES WAY TO INCREASINGLY
VOLATILE WEATHER THIS WEEKEND INTO EARLY NEXT WEEK. SURFACE HIGH
PRESSURE WILL BUILD SOUTHEAST THROUGH THE AREA WITHIN THE NORTHWEST
FLOW AROUND UPPER TROUGH AXIS OVER EASTERN CANADA. DRY WEATHER CAN
BE EXPECTED WEDNESDAY INTO THURSDAY AS THIS HIGH SHIFTS OVER AND
THEN JUST EAST OF THE AREA...MAINTAINING DRY...STABLE AIRMASS OVER
THE REGION. THIS CORE OF THIS CANADIAN AIRMASS WILL MAINTAIN COOL
READINGS THROUGH WEDNESDAY WITH HIGH TEMPERATURES OF 70-75. EXPECT
MODERATION INTO THURSDAY UNDER STRONG LATE JUNE SUNSHINE WITH THE
TEMPERATURES BACK TO AROUND 80.
THE PATTERN THEN UNDERGOES A NOTABLE TRANSITION OVER THE WEEKEND AS
AN UPPER RIDGE EXPANDS ACROSS THE EASTERN CONUS DOWNSTREAM OF AN
EVOLVING UPPER TROUGH OVER WESTERN NOAM. AS THIS TROUGH DEAMPLIFIES
AS AN UPPER LOW OPENS AND LIFTS FROM THE PACIFIC NORTHWEST INTO
WESTERN CANADA...UPPER FLOW PATTERN WILL SHIFT FROM SOUTHWESTERLY TO
ESSENTIALLY ZONAL WITH THE MAIN BELT OF STRONG WESTERLIES STREAMING
EAST THROUGH THE NORTHERN TIER OF THE CONUS.
NUMEROUS SHORTWAVES OF PACIFIC ORIGIN WILL RIDE THIS MAIN STORM
TRACK AND PROVIDE THE FORCING FOR A SERIES OF CONVECTIVE EPISODES.
IN ADDITION...THE AIRMASS FROM THE UPPER PLAINS/MISSISSIPPI WILL
WARM SIGNIFICANTLY OVER THE WEEKEND WITH A STEADY FEED OF GULF OF
MEXICO MOISTURE ALSO WORKING NORTH ON SOUTH/SOUTHWEST WINDS. THIS
BUILDING INSTABILITY WILL STEADILY SHIFT EAST INTO THE GREAT LAKES
AS UPPER FLOW BECOMES MORE ZONAL WITH TIME LATE THIS WEEKEND INTO
NEXT WEEK. THE JUXTAPOSITION OF THE BUILDING POOL INSTABILITY TO THE
BAND OF STRONGER WESTERLIES AND EMBEDDED UPPER IMPULSES WILL LEAD
TO MULTIPLE DAYS FROM SATURDAY INTO TUESDAY WHERE THE POTENTIAL FOR
CONVECTIVE COMPLEXES WILL BE ENHANCED.
WHILE THE BROAD SYNOPTIC PATTERN WOULD SUGGEST THAT THE POTENTIAL
FOR THUNDERSTORMS WILL INCREASE EVERY DAY FROM SATURDAY INTO TUESDAY
AS THE AIRMASS OVER THE CENTRAL GREAT LAKES BECOMES MORE AND MORE
UNSTABLE AND AS THE UPPER WESTERLIES SETTLE SOUTH CLOSER TO THE AREA
WITHIN ZONAL FLOW...THE EVENTUAL DAY-TO-DAY CHANCES FOR STORMS WILL
BE MODULATED AS LEAST AS MUCH BY THE MESOSCALE INFLUENCES OF THE
THUNDERSTORM COMPLEXES THEMSELVES. DURING THIS PERIOD OF ACTIVE
WEATHER...TEMPERATURES WILL BE MUCH MORE SUMMER-LIKE...WARMING WELL
INTO THE 80S TO AROUND 90 WITH MINIMUM TEMPERATURES OVERNIGHT AROUND
70.
&&
.MARINE...
CANADIAN HIGH PRESSURE SINKING INTO THE GREAT LAKES WILL ALLOW GUSTY
NE FLOW TO DECREASE TONIGHT WHILE BECOMING MORE EASTERLY. THIS WILL
RESULT IN LOWER WAVE HEIGHTS AS WELL FALLING TO LESS THAN 2 FEET BY
WEDNESDAY MORNING. CURRENTLY WAVES ALONG THE LAKE HURON SHORELINE
ARE SLIGHTLY ELEVATED TO AROUND 3-4 FEET WITH THE FAVORABLE
FETCH...BUT WILL FALL SHORT OF A SMALL CRAFT ADVISORY. THE SURFACE
HIGH...IN ADDITION TO MID LEVEL SUBSIDENCE NORTH OF A
SHORTWAVE...WILL LEAD TO FAVORABLE MARINE CONDITIONS INTO FRIDAY.
&&
.AVIATION...ISSUED 144 PM EDT TUE JUN 18 2013
//DISCUSSION...
HIGH PRESSURE BUILDING INTO THE AREA FROM THE NORTH WILL PRODUCE
FAVORABLE AVIATION CONDITIONS THROUGH WEDNESDAY. AFTERNOON CU IS
CURRENTLY FORMING AND BETTER MIXING WILL PRODUCE WINDS GUSTING TO 20
MPH FROM THE NORTHEAST TIL SUNDOWN. WINDS WILL VEER TO THE EAST
OVERNIGHT AS THE HIGH DROPS FURTHER SOUTH AND REMAIN LIGHT ON
WEDNESDAY. A FEW CU MAY FORM ON WEDNESDAY BUT WITH LESS COVERAGE
THAN TODAY.
//DTW THRESHOLD THREATS...
* NONE
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...DRK
LONG TERM....DG
MARINE.......DRK
AVIATION.....DRK
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
000
FXUS63 KDTX 181744
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
144 PM EDT TUE JUN 18 2013
.AVIATION...
//DISCUSSION...
HIGH PRESSURE BUILDING INTO THE AREA FROM THE NORTH WILL PRODUCE
FAVORABLE AVIATION CONDITIONS THROUGH WEDNESDAY. AFTERNOON CU IS
CURRENTLY FORMING AND BETTER MIXING WILL PRODUCE WINDS GUSTING TO 20
MPH FROM THE NORTHEAST TIL SUNDOWN. WINDS WILL VEER TO THE EAST
OVERNIGHT AS THE HIGH DROPS FURTHER SOUTH AND REMAIN LIGHT ON
WEDNESDAY. A FEW CU MAY FORM ON WEDNESDAY BUT WITH LESS COVERAGE
THAN TODAY.
//DTW THRESHOLD THREATS...
* NONE
&&
.PREV DISCUSSION...ISSUED 257 AM EDT TUE JUN 18 2013
SHORT TERM...TODAY AND TONIGHT
WEAK MID LEVEL SUBSIDENCE WILL GRADUALLY TAKE HOLD THROUGH THE
LATTER HALF OF THE MORNING IN THE WAKE OF A SHEARING MID LEVEL WAVE
AND ATTENDANT ENTRANCE REGION UPPER JET DYNAMICS EXPECTED TO SLIDE
TO THE SOUTH. THIS WILL COMMENCE OVER INCREASING ANTICYCLONIC LOW
LEVEL FLOW DOWNSTREAM OF AN EXPANDING HIGH PRESSURE SYSTEM FILLING
INTO THE WESTERN GREAT LAKES. STEADY BUT WEAK COLD AIR ADVECTION
COMMENCING WITHIN A NORTHEAST POST-FRONTAL GRADIENT WILL LEAD TO
NOTICEABLY COOLER CONDITIONS FOR TODAY. SOME LINGERING EARLY DAY
CLOUD COVER WILL CONTRIBUTE TO THIS DOWNWARD THERMAL ADJUSTMENT.
A MODERATELY MIXED PROFILE INTO ROUGHLY 10C AT 850 MB TRANSLATES
INTO HIGHS OF MAINLY LOWER 70S...BUT WITH READINGS HELD MORE IN
CHECK /MID 60S/ ACROSS THE THUMB GIVEN THE COOLER LAKE INFLUENCE.
HIGH PRESSURE SETTLES INTO NORTHERN LOWER MI TONIGHT. DEEP
DRY MID LEVELS AND A CLEAR SKY WILL CERTAINLY ENHANCE THE
RADIATIONAL COOLING...ALTHOUGH THE NORTHEAST WIND MAY NOT COMPLETELY
DECOUPLE ESPECIALLY ACROSS THE SOUTH WITH THE HIGH CENTER TO THE
NORTH. REGARDLESS...THE STRENGTH OF THIS AIRMASS WILL SUPPORT
OVERNIGHT TEMPERATURES DROPPING INTO THE MIDDLE AND UPPER 40S
OUTSIDE OF THE DETROIT URBAN HEAT ISLAND. THIS WILL LIKELY LEAVE
LOWS A COUPLE DEGREES SHY OF RECORD VALUES FOR THE DATE AT BOTH MBS
AND FNT /RECORD AT FNT 44...MBS 42/.
LONG TERM...WEDNESDAY THROUGH MONDAY
CANADIAN HIGH PRESSURE ENHANCED BY A LAKE AGGREGATE COMPONENT WILL
REMAIN IN PLACE THROUGH THURSDAY AS LONGWAVE RIDGING BUILDS
UPSTREAM. DEEP LAYER SUBSIDENCE ACROSS THE GREAT LAKES REGION WILL
FAVOR MOSTLY CLEAR SKIES WITH LITTLE MORE THAN A PARTIAL COVERAGE OF
HIGH-BASED CU EXPECTED ON BOTH WED AND THURS. HOWEVER, LIGHT
SOUTHEAST FLOW BENEATH THE NOCTURNAL INVERSION DOES RAISE SOME
CONCERN FOR LAKE-ENHANCED CLOUD COVER OFF OF LAKE ERIE FOR SOUTHEAST
AREAS WEDNESDAY NIGHT INTO THE FIRST PART OF THURSDAY.
TEMPERATURE-WISE, ONLY SLIGHT AIRMASS MODIFICATION IS EXPECTED FOR
WEDNESDAY AS BOUNDARY LAYER FLOW REMAINS WEAK TO VARIABLE WITH
ADVECTIONS VIRTUALLY NIL. HOWEVER, AS THE UPPER PATTERN FORCES THE
SURFACE HIGH EAST BY THURSDAY, ORGANIZING SOUTHERLY RETURN FLOW WILL
ALLOW TEMPERATURES TO REBOUND INTO THE UPPER 70S ON THURS AFTERNOON
AND LOW 80S BY FRIDAY. ATTENTION THEN TURNS TO THE WEEKEND WHEN
ENERGY EMANATING FROM THE LARGE PAC NW LOW WILL TRIGGER CONVECTION
ACROSS THE HIGH PLAINS AROUND THE NORTHERN PERIPHERY OF THE RIDGE. A
DEVELOPING LOW-LEVEL JET WILL HELP MAINTAIN THIS ACTIVITY AS IT
PROPAGATES ALONG THE INSTABILITY GRADIENT NEAR THE EDGE OF THE
MID-LEVEL CAP AND POTENTIALLY INTO SOUTHEAST MICHIGAN BY LATE FRIDAY
NIGHT OR EARLY SATURDAY MORNING.
MARINE...
STEADY NORTHEAST FLOW IN THE 10 TO 15 KNOT RANGE TODAY IN THE WAKE
OF A COLD FRONT. THE ONSHORE FLOW WILL ALLOW WAVES TO BUILD ACROSS
SAGINAW BAY AND THE NEARSHORE WATERS OF LAKE HURON...BUT WITH WAVE
HEIGHTS LARGELY HOLDING WITHIN THE 2 TO 4 FOOT RANGE. THIS WILL
PRECLUDE THE ISSUANCE OF A SMALL CRAFT ADVISORY FOR TODAY. WINDS
WILL SLACKEN TONIGHT AS HIGH PRESSURE BUILDS INTO THE GREAT LAKES.
THIS HIGH WILL BRING A STRETCH OF FAVORABLE MARINE CONDITIONS WITH
LIGHT WINDS THROUGH THURSDAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....DRK
SHORT TERM...MR
LONG TERM....JVC
MARINE.......MR
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
000
FXUS63 KDTX 181114
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
713 AM EDT TUE JUN 18 2013
.AVIATION...
//DISCUSSION...
COOLER AND MORE STABLE CONDITIONS WILL EXIST TODAY IN THE WAKE OF
THE OVERNIGHT FRONTAL PASSAGE. ANY LINGERING EARLY DAY HIGH BASED
STRATOCU ACROSS THE NORTHERN TERMINALS WILL MIX OUT THROUGH LATE
MORNING...LEAVING CLEAR SKIES FOR THE REMAINDER OF THE TAF PERIOD.
NORTHEAST GRADIENT WILL STRENGTHEN SLIGHTLY DURING THE DAYTIME
PERIOD. THIS WILL RESULT IN SOME PEAK AFTERNOON GUSTS IN THE 20
KNOT RANGE.
//DTW THRESHOLD THREATS...
* NONE
&&
.PREV DISCUSSION...ISSUED 257 AM EDT TUE JUN 18 2013
SHORT TERM...TODAY AND TONIGHT
WEAK MID LEVEL SUBSIDENCE WILL GRADUALLY TAKE HOLD THROUGH THE
LATTER HALF OF THE MORNING IN THE WAKE OF A SHEARING MID LEVEL WAVE
AND ATTENDANT ENTRANCE REGION UPPER JET DYNAMICS EXPECTED TO SLIDE
TO THE SOUTH. THIS WILL COMMENCE OVER INCREASING ANTICYCLONIC LOW
LEVEL FLOW DOWNSTREAM OF AN EXPANDING HIGH PRESSURE SYSTEM FILLING
INTO THE WESTERN GREAT LAKES. STEADY BUT WEAK COLD AIR ADVECTION
COMMENCING WITHIN A NORTHEAST POST-FRONTAL GRADIENT WILL LEAD TO
NOTICEABLY COOLER CONDITIONS FOR TODAY. SOME LINGERING EARLY DAY
CLOUD COVER WILL CONTRIBUTE TO THIS DOWNWARD THERMAL ADJUSTMENT.
A MODERATELY MIXED PROFILE INTO ROUGHLY 10C AT 850 MB TRANSLATES
INTO HIGHS OF MAINLY LOWER 70S...BUT WITH READINGS HELD MORE IN
CHECK /MID 60S/ ACROSS THE THUMB GIVEN THE COOLER LAKE INFLUENCE.
HIGH PRESSURE SETTLES INTO NORTHERN LOWER MI TONIGHT. DEEP
DRY MID LEVELS AND A CLEAR SKY WILL CERTAINLY ENHANCE THE
RADIATIONAL COOLING...ALTHOUGH THE NORTHEAST WIND MAY NOT COMPLETELY
DECOUPLE ESPECIALLY ACROSS THE SOUTH WITH THE HIGH CENTER TO THE
NORTH. REGARDLESS...THE STRENGTH OF THIS AIRMASS WILL SUPPORT
OVERNIGHT TEMPERATURES DROPPING INTO THE MIDDLE AND UPPER 40S
OUTSIDE OF THE DETROIT URBAN HEAT ISLAND. THIS WILL LIKELY LEAVE
LOWS A COUPLE DEGREES SHY OF RECORD VALUES FOR THE DATE AT BOTH MBS
AND FNT /RECORD AT FNT 44...MBS 42/.
LONG TERM...WEDNESDAY THROUGH MONDAY
CANADIAN HIGH PRESSURE ENHANCED BY A LAKE AGGREGATE COMPONENT WILL
REMAIN IN PLACE THROUGH THURSDAY AS LONGWAVE RIDGING BUILDS
UPSTREAM. DEEP LAYER SUBSIDENCE ACROSS THE GREAT LAKES REGION WILL
FAVOR MOSTLY CLEAR SKIES WITH LITTLE MORE THAN A PARTIAL COVERAGE OF
HIGH-BASED CU EXPECTED ON BOTH WED AND THURS. HOWEVER, LIGHT
SOUTHEAST FLOW BENEATH THE NOCTURNAL INVERSION DOES RAISE SOME
CONCERN FOR LAKE-ENHANCED CLOUD COVER OFF OF LAKE ERIE FOR SOUTHEAST
AREAS WEDNESDAY NIGHT INTO THE FIRST PART OF THURSDAY.
TEMPERATURE-WISE, ONLY SLIGHT AIRMASS MODIFICATION IS EXPECTED FOR
WEDNESDAY AS BOUNDARY LAYER FLOW REMAINS WEAK TO VARIABLE WITH
ADVECTIONS VIRTUALLY NIL. HOWEVER, AS THE UPPER PATTERN FORCES THE
SURFACE HIGH EAST BY THURSDAY, ORGANIZING SOUTHERLY RETURN FLOW WILL
ALLOW TEMPERATURES TO REBOUND INTO THE UPPER 70S ON THURS AFTERNOON
AND LOW 80S BY FRIDAY. ATTENTION THEN TURNS TO THE WEEKEND WHEN
ENERGY EMANATING FROM THE LARGE PAC NW LOW WILL TRIGGER CONVECTION
ACROSS THE HIGH PLAINS AROUND THE NORTHERN PERIPHERY OF THE RIDGE. A
DEVELOPING LOW-LEVEL JET WILL HELP MAINTAIN THIS ACTIVITY AS IT
PROPAGATES ALONG THE INSTABILITY GRADIENT NEAR THE EDGE OF THE
MID-LEVEL CAP AND POTENTIALLY INTO SOUTHEAST MICHIGAN BY LATE FRIDAY
NIGHT OR EARLY SATURDAY MORNING.
MARINE...
STEADY NORTHEAST FLOW IN THE 10 TO 15 KNOT RANGE TODAY IN THE WAKE
OF A COLD FRONT. THE ONSHORE FLOW WILL ALLOW WAVES TO BUILD ACROSS
SAGINAW BAY AND THE NEARSHORE WATERS OF LAKE HURON...BUT WITH WAVE
HEIGHTS LARGELY HOLDING WITHIN THE 2 TO 4 FOOT RANGE. THIS WILL
PRECLUDE THE ISSUANCE OF A SMALL CRAFT ADVISORY FOR TODAY. WINDS
WILL SLACKEN TONIGHT AS HIGH PRESSURE BUILDS INTO THE GREAT LAKES.
THIS HIGH WILL BRING A STRETCH OF FAVORABLE MARINE CONDITIONS WITH
LIGHT WINDS THROUGH THURSDAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....MR
SHORT TERM...MR
LONG TERM....JVC
MARINE.......MR
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS
ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
000
FXUS63 KDTX 180657
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
257 AM EDT TUE JUN 18 2013
.SHORT TERM...TODAY AND TONIGHT
WEAK MID LEVEL SUBSIDENCE WILL GRADUALLY TAKE HOLD THROUGH THE
LATTER HALF OF THE MORNING IN THE WAKE OF A SHEARING MID LEVEL WAVE
AND ATTENDANT ENTRANCE REGION UPPER JET DYNAMICS EXPECTED TO SLIDE
TO THE SOUTH. THIS WILL COMMENCE OVER INCREASING ANTICYCLONIC LOW
LEVEL FLOW DOWNSTREAM OF AN EXPANDING HIGH PRESSURE SYSTEM FILLING
INTO THE WESTERN GREAT LAKES. STEADY BUT WEAK COLD AIR ADVECTION
COMMENCING WITHIN A NORTHEAST POST-FRONTAL GRADIENT WILL LEAD TO
NOTICEABLY COOLER CONDITIONS FOR TODAY. SOME LINGERING EARLY DAY
CLOUD COVER WILL CONTRIBUTE TO THIS DOWNWARD THERMAL ADJUSTMENT.
A MODERATELY MIXED PROFILE INTO ROUGHLY 10C AT 850 MB TRANSLATES
INTO HIGHS OF MAINLY LOWER 70S...BUT WITH READINGS HELD MORE IN
CHECK /MID 60S/ ACROSS THE THUMB GIVEN THE COOLER LAKE INFLUENCE.
HIGH PRESSURE SETTLES INTO NORTHERN LOWER MI TONIGHT. DEEP
DRY MID LEVELS AND A CLEAR SKY WILL CERTAINLY ENHANCE THE
RADIATIONAL COOLING...ALTHOUGH THE NORTHEAST WIND MAY NOT COMPLETELY
DECOUPLE ESPECIALLY ACROSS THE SOUTH WITH THE HIGH CENTER TO THE
NORTH. REGARDLESS...THE STRENGTH OF THIS AIRMASS WILL SUPPORT
OVERNIGHT TEMPERATURES DROPPING INTO THE MIDDLE AND UPPER 40S
OUTSIDE OF THE DETROIT URBAN HEAT ISLAND. THIS WILL LIKELY LEAVE
LOWS A COUPLE DEGREES SHY OF RECORD VALUES FOR THE DATE AT BOTH MBS
AND FNT /RECORD AT FNT 44...MBS 42/.
&&
.LONG TERM...WEDNESDAY THROUGH MONDAY
CANADIAN HIGH PRESSURE ENHANCED BY A LAKE AGGREGATE COMPONENT WILL
REMAIN IN PLACE THROUGH THURSDAY AS LONGWAVE RIDGING BUILDS
UPSTREAM. DEEP LAYER SUBSIDENCE ACROSS THE GREAT LAKES REGION WILL
FAVOR MOSTLY CLEAR SKIES WITH LITTLE MORE THAN A PARTIAL COVERAGE OF
HIGH-BASED CU EXPECTED ON BOTH WED AND THURS. HOWEVER, LIGHT
SOUTHEAST FLOW BENEATH THE NOCTURNAL INVERSION DOES RAISE SOME
CONCERN FOR LAKE-ENHANCED CLOUD COVER OFF OF LAKE ERIE FOR SOUTHEAST
AREAS WEDNESDAY NIGHT INTO THE FIRST PART OF THURSDAY.
TEMPERATURE-WISE, ONLY SLIGHT AIRMASS MODIFICATION IS EXPECTED FOR
WEDNESDAY AS BOUNDARY LAYER FLOW REMAINS WEAK TO VARIABLE WITH
ADVECTIONS VIRTUALLY NIL. HOWEVER, AS THE UPPER PATTERN FORCES THE
SURFACE HIGH EAST BY THURSDAY, ORGANIZING SOUTHERLY RETURN FLOW WILL
ALLOW TEMPERATURES TO REBOUND INTO THE UPPER 70S ON THURS AFTERNOON
AND LOW 80S BY FRIDAY. ATTENTION THEN TURNS TO THE WEEKEND WHEN
ENERGY EMANATING FROM THE LARGE PAC NW LOW WILL TRIGGER CONVECTION
ACROSS THE HIGH PLAINS AROUND THE NORTHERN PERIPHERY OF THE RIDGE. A
DEVELOPING LOW-LEVEL JET WILL HELP MAINTAIN THIS ACTIVITY AS IT
PROPAGATES ALONG THE INSTABILITY GRADIENT NEAR THE EDGE OF THE
MID-LEVEL CAP AND POTENTIALLY INTO SOUTHEAST MICHIGAN BY LATE FRIDAY
NIGHT OR EARLY SATURDAY MORNING.
&&
.MARINE...
STEADY NORTHEAST FLOW IN THE 10 TO 15 KNOT RANGE TODAY IN THE WAKE
OF A COLD FRONT. THE ONSHORE FLOW WILL ALLOW WAVES TO BUILD ACROSS
SAGINAW BAY AND THE NEARSHORE WATERS OF LAKE HURON...BUT WITH WAVE
HEIGHTS LARGELY HOLDING WITHIN THE 2 TO 4 FOOT RANGE. THIS WILL
PRECLUDE THE ISSUANCE OF A SMALL CRAFT ADVISORY FOR TODAY. WINDS
WILL SLACKEN TONIGHT AS HIGH PRESSURE BUILDS INTO THE GREAT LAKES.
THIS HIGH WILL BRING A STRETCH OF FAVORABLE MARINE CONDITIONS WITH
LIGHT WINDS THROUGH THURSDAY.
&&
.AVIATION...ISSUED 1145 PM EDT MON JUN 17 2013
//DISCUSSION...
SEVERAL THUNDERSTORMS HAVE PUSHED THE SURFACE COLD FRONT SOUTH OF
THE TAF SITES...HOWEVER THE MID LEVEL COLD FRONT CONTINUES TO
GENERATE SHOWERS AS IT SLOWLY SINKS SOUTH. SHOWERS MAY CONTINUE FOR
ANOTHER HOUR OR TWO BEFORE INSTABILITY COMPLETELY WANES AS THE FRONT
HEADS SOUTH. IT APPEARS INSTABILITY HAS FALLEN ENOUGH TO CREATE A
NEAR NIL THREAT FOR THUNDER AS THE REMAINING ACTIVITY TRACKS THROUGH
FROM FNT SOUTHWARD...WITH MBS CLEAR OF ANY SHOWER THREAT. COLD AND
DRY ADVECTION COUPLED WITH A TIGHT PRES GRADIENT LATER ON TUESDAY
WILL BRING WIND GUSTS OVER 20KT WITH VFR CONDITIONS EXPECTED.
FOR DTW...THE PROBABILITY FOR THUNDERSTORMS TO IMPACT THE TERMINAL
WITH THE COLD FRONTAL PASSAGE CONTINUES TO BE VERY LOW...WITH A
CONTINUED THREAT FOR SHOWERS THROUGH 09Z.
//DTW THRESHOLD THREATS...
* LOW CONFIDENCE IN CEILINGS BELOW 5000 FT THROUGH 09Z.
* LOW CONFIDENCE IN THUNDERSTORM POTENTIAL THROUGH 09Z.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...MR
LONG TERM....JVC
MARINE.......MR
AVIATION.....KURIMSKI
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
000
FXUS63 KDTX 180345
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1145 PM EDT MON JUN 17 2013
.AVIATION...
//DISCUSSION...
SEVERAL THUNDERSTORMS HAVE PUSHED THE SURFACE COLD FRONT SOUTH OF
THE TAF SITES...HOWEVER THE MID LEVEL COLD FRONT CONTINUES TO
GENERATE SHOWERS AS IT SLOWLY SINKS SOUTH. SHOWERS MAY CONTINUE FOR
ANOTHER HOUR OR TWO BEFORE INSTABILITY COMPLETELY WANES AS THE FRONT
HEADS SOUTH. IT APPEARS INSTABILITY HAS FALLEN ENOUGH TO CREATE A
NEAR NIL THREAT FOR THUNDER AS THE REMAINING ACTIVITY TRACKS THROUGH
FROM FNT SOUTHWARD...WITH MBS CLEAR OF ANY SHOWER THREAT. COLD AND
DRY ADVECTION COUPLED WITH A TIGHT PRES GRADIENT LATER ON TUESDAY
WILL BRING WIND GUSTS OVER 20KT WITH VFR CONDITIONS EXPECTED.
FOR DTW...THE PROBABILITY FOR THUNDERSTORMS TO IMPACT THE TERMINAL
WITH THE COLD FRONTAL PASSAGE CONTINUES TO BE VERY LOW...WITH A
CONTINUED THREAT FOR SHOWERS THROUGH 09Z.
//DTW THRESHOLD THREATS...
* LOW CONFIDENCE IN CEILINGS BELOW 5000 FT THROUGH 09Z.
* LOW CONFIDENCE IN THUNDERSTORM POTENTIAL THROUGH 09Z.
&&
.PREV DISCUSSION...ISSUED 401 PM EDT MON JUN 17 2013
SHORT TERM...THIS AFTERNOON AND TONIGHT
MAIN CONCERN FOR THE SHORT TERM WILL BE CONVECTION INITIATING THIS
AFTERNOON AND PERSISTING INTO EVENING AS LIFT/FORCING FROM SHORTWAVE
NOW SHIFTING INTO WESTERN GREAT LAKES PROVIDES SUPPORT FOR ACTIVITY
THAT FIRES ALONG SURFACE FRONT DRAPED FROM THE SAGINAW VALLEY INTO
THE THUMB REGION.
LEAD SURFACE TROUGH NEAR THE MICHIGAN/OHIO STATE LINE WILL CUT OFF
THE REGION FROM THE BEST BOUNDARY LAYER MOISTURE/INSTABILITY...BUT
STRONG SOLAR INSOLATION DURING THE REMAINDER OF THE AFTERNOON WILL
ALLOW FOR MODEST INSTABILITY EVEN IN AREAS WHERE SURFACE DEW POINTS
WILL BE LIMITED TO THE MID/UPPER 50S. GIVEN BULK WIND SHEAR VALUES
OF 45 KNOTS IN STRONG WEST/NORTHWEST FLOW REGIME...EXPECT SOME
DEGREE OF ORGANIZATION TO THE SHOWERS/THUNDERSTORMS THAT DEVELOP AS
THE INFLUENCE OF THE UPPER LEVEL WAVE INCREASES STEADILY DURING PEAK
HEATING/INSTABILITY OF THE AFTERNOON. THE ACTIVITY WILL ALSO BE
AIDED BY INCREASE LOW LEVEL CONVERGENCE AS NORTHEAST FLOW FROM
DEVELOPING LAKE BREEZE FROM LAKE HURON WILL AUGMENT THE PUSH OF THE
SYNOPTIC FRONTAL BOUNDARY SOUTHWARD THROUGH THE CWA.
STEEP LAPSE RATES THROUGH AT LEAST 650 MB IN WELL MIXED NORTHWEST
FLOW WILL PROVIDE A FAVORABLE ENVIRONMENT FOR GUSTY WINDS WITHIN
THUNDERSTORM DOWNDRAFTS. ALSO...RELATIVELY LOW FREEZING LEVEL WITH
LACK OF ANY SIGNIFICANT UPPER RIDGING OVER AREA WILL BE FAVORABLE
FOR SOME HAIL DEVELOPMENT.
SO...AS THE PREVIOUS FORECAST OUTLINED NICELY...THERE WILL BE A
CHANCE FOR SEVERAL SEVERE STORMS FROM THIS AFTERNOON INTO THE EARLY
EVENING AS ACTIVITY GRADUALLY EXPANDS AS INSTABILITY MAXES OUT WITH
LATE DAY HEATING. WHILE THE MAIN WINDOW FOR ACTIVE STORMS WILL EXIST
THROUGH 00Z-01Z...LINGERING CONVECTION WILL MOST LIKELY PERSIST OVER
SOME PARTS OF THE AREA INTO THE 04Z-06Z TIME FRAME AS LIFT FROM THE
TRAILING ENTRANCE REGION OF UPPER JET SHIFTS OVER THE AREA.
ANY REMAINING ACTIVITY WILL END QUICKLY AFTER MIDNIGHT AS FRONTAL
BOUNDARY PUSHES SOUTH OF THE AREA...AUGMENTED BY THE AGEOSTROPHIC
CIRCULATION ON THE TAIL END OF THE UPPER JET. BUILDING HIGH PRESSURE
WILL BRING RELATIVELY COOL TEMPERATURES INTO MUCH OF THE CWA...WITH
LOW TEMPERATURES NEAR 50 OVER THE NORTHERN CWA...AND MID 50S FOR A
GOOD PORTION OF THE AREA.
LONG TERM...TUESDAY THROUGH SUNDAY
AN ANTICYCLONE OF CANADIAN ORIGIN WILL BECOME ESTABLISHED OVER THE
GREAT LAKES IN WELL ORGANIZED CONFLUENCE ALOFT. THE SURFACE HIGH
WILL MAINTAIN A CENTERING OVER LAKE HURON THROUGH WEDNESDAY NIGHT.
AS THIS SURFACE HIGH PASSES EAST NWP SUGGESTS A STRONG SURFACE RIDGE
WILL THEN PERSIST OVER THE LAKE AGGREGATE THROUGH FRIDAY. A FINE
STRETCH OF EARLY SUMMER WEATHER IS EXPECTED WITH CONDITIONS THAT ARE
NOTABLY COOL. SURFACE TEMPERATURES TUESDAY SHOULD FAIL TO CLIMB OUT
OF THE 60S FOR THE THUMB...WITH READINGS IN THE HEAT ISLAND ABLE TO
REACH THE MID 70S DUE TO FULL JUNE INSOLATION. TUESDAY NIGHT WILL BE
DOWNRIGHT COOL WITH GUIDANCE SUGGESTING WIDESPREAD LOWER TO MIDDLE
40S WHICH WILL BE SOME 15 TO 17 DEGREES COOLER THAN NORMAL.
RETURN FLOW WILL EVENTUALLY COLLAPSE UPON THE REGION BY THIS
WEEKEND. CLEAN SHOWALTER INDICES ANALYSIS SUGGESTS THAT A
THERMODYNAMIC PROFILE CONDUCIVE FOR PRECIPITATION WILL ARRIVE ON
SATURDAY. IT IS AT THIS TIME THAT SOUTHEASTERN MICHIGAN MAY BECOME
IN LINE WITH POSSIBLE MCS TRACK THAT WILL BE CRESTING AN INBOUND MID
TO UPPER LEVEL RIDGE.
MARINE...
APPROACHING SHORTWAVE WILL INDUCE WEAK SURFACE LOW PRESSURE ALONG
FRONTAL BOUNDARY DRAPED THROUGH THE CENTRAL GREAT LAKES. SHOWER AND
THUNDERSTORM DEVELOPMENT WILL INCREASE AS THIS PROCESS TAKES PLACE
DURING PEAK HEATING LATE TODAY...WITH CONVECTION PERSISTING INTO
THIS EVENING AS JET SUPPORT SHIFTS OVERHEAD.
NORTHEAST FLOW WILL INCREASE OVERNIGHT INTO EARLY TUESDAY IN THE
WAKE OF THIS SYSTEM...BUT ONLY TOP OUT AROUND 15 KNOTS...SO WHILE
WAVES WILL BUILD OVER SOUTHERN LAKE HURON IN PARTICULAR...EXPECT
CONDITIONS TO REMAIN UNDER SMALL CRAFT ADVISORY CRITERION FOR THE
NEARSHORE ZONES...PEAKING AT 2-4 FEET OVER FAR SOUTHERN LAKE HURON.
ONCE THIS SLIGHTLY ENHANCED FLOW SUBSIDES BY MIDDAY TUESDAY...HIGH
PRESSURE WILL BRING FAVORABLE MARINE CONDITIONS FOR THE REMAINDER OF
THE WEEK AS WINDS BECOME LIGHT AND VARIABLE.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....KURIMSKI
SHORT TERM...DG
LONG TERM....CB
MARINE.......DG
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
000
FXUS63 KDTX 172258
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
658 PM EDT MON JUN 17 2013
.AVIATION...
//DISCUSSION...
A COLD FRONT CONTINUES TO TRACK THROUGH SOUTHEASTERN MICHIGAN EARLY
THIS EVENING. OUTFLOW FROM A SUPERCELL THAT TRACKED THROUGH THE
NORTHERN HALF OF THE CWA MAKES PLACING THE FRONTAL POSITION A BIT
DIFFICULT...HOWEVER IT APPEARS THE FRONT IS NORTH OF THE METRO
AIRPORTS AND SOUTH OF KPTK. WHILE THERE IS THE CHANCE FOR MORE
SHOWER DEVELOPMENT AS THE FRONT TRACKS SOUTH...HI-RES MODEL RUNS
SHOW THIS ACTIVITY SHOULD BE LIMITED AFTER 00Z WHICH IS REASONABLE
CONSIDERING SUNSET IS AROUND 01Z. THEREFORE WILL ONLY GO WITH A
TEMPO GROUP FOR SHOWERS DURING THE FIRST PART OF THE TAFS WITH
LINGERING SHOWER ACTIVITY...WITH DRY WEATHER AND VFR CONDITIONS
EXPECTED DURING THE REST OF THE OVERNIGHT HOURS. COLD AND DRY
ADVECTION COUPLED WITH A TIGHT PRES GRADIENT INTO TUESDAY WILL BRING
WIND GUSTS OVER 20KT.
FOR DTW...THE PROBABILITY FOR THUNDERSTORMS TO IMPACT THE TERMINAL
WITH THE COLD FRONTAL PASSAGE CURRENTLY REMAINS TOO LOW TO INCLUDE
IN THE TAFS. FROPA LOOKS TO OCCUR AROUND 00-01Z.
//DTW THRESHOLD THREATS...
* LOW CONFIDENCE IN CEILINGS BELOW 5000 FT THIS EVENING.
* LOW CONFIDENCE IN THUNDERSTORM POTENTIAL EARLY THIS EVENING.
&&
.PREV DISCUSSION...ISSUED 401 PM EDT MON JUN 17 2013
SHORT TERM...THIS AFTERNOON AND TONIGHT
MAIN CONCERN FOR THE SHORT TERM WILL BE CONVECTION INITIATING THIS
AFTERNOON AND PERSISTING INTO EVENING AS LIFT/FORCING FROM SHORTWAVE
NOW SHIFTING INTO WESTERN GREAT LAKES PROVIDES SUPPORT FOR ACTIVITY
THAT FIRES ALONG SURFACE FRONT DRAPED FROM THE SAGINAW VALLEY INTO
THE THUMB REGION.
LEAD SURFACE TROUGH NEAR THE MICHIGAN/OHIO STATE LINE WILL CUT OFF
THE REGION FROM THE BEST BOUNDARY LAYER MOISTURE/INSTABILITY...BUT
STRONG SOLAR INSOLATION DURING THE REMAINDER OF THE AFTERNOON WILL
ALLOW FOR MODEST INSTABILITY EVEN IN AREAS WHERE SURFACE DEW POINTS
WILL BE LIMITED TO THE MID/UPPER 50S. GIVEN BULK WIND SHEAR VALUES
OF 45 KNOTS IN STRONG WEST/NORTHWEST FLOW REGIME...EXPECT SOME
DEGREE OF ORGANIZATION TO THE SHOWERS/THUNDERSTORMS THAT DEVELOP AS
THE INFLUENCE OF THE UPPER LEVEL WAVE INCREASES STEADILY DURING PEAK
HEATING/INSTABILITY OF THE AFTERNOON. THE ACTIVITY WILL ALSO BE
AIDED BY INCREASE LOW LEVEL CONVERGENCE AS NORTHEAST FLOW FROM
DEVELOPING LAKE BREEZE FROM LAKE HURON WILL AUGMENT THE PUSH OF THE
SYNOPTIC FRONTAL BOUNDARY SOUTHWARD THROUGH THE CWA.
STEEP LAPSE RATES THROUGH AT LEAST 650 MB IN WELL MIXED NORTHWEST
FLOW WILL PROVIDE A FAVORABLE ENVIRONMENT FOR GUSTY WINDS WITHIN
THUNDERSTORM DOWNDRAFTS. ALSO...RELATIVELY LOW FREEZING LEVEL WITH
LACK OF ANY SIGNIFICANT UPPER RIDGING OVER AREA WILL BE FAVORABLE
FOR SOME HAIL DEVELOPMENT.
SO...AS THE PREVIOUS FORECAST OUTLINED NICELY...THERE WILL BE A
CHANCE FOR SEVERAL SEVERE STORMS FROM THIS AFTERNOON INTO THE EARLY
EVENING AS ACTIVITY GRADUALLY EXPANDS AS INSTABILITY MAXES OUT WITH
LATE DAY HEATING. WHILE THE MAIN WINDOW FOR ACTIVE STORMS WILL EXIST
THROUGH 00Z-01Z...LINGERING CONVECTION WILL MOST LIKELY PERSIST OVER
SOME PARTS OF THE AREA INTO THE 04Z-06Z TIME FRAME AS LIFT FROM THE
TRAILING ENTRANCE REGION OF UPPER JET SHIFTS OVER THE AREA.
ANY REMAINING ACTIVITY WILL END QUICKLY AFTER MIDNIGHT AS FRONTAL
BOUNDARY PUSHES SOUTH OF THE AREA...AUGMENTED BY THE AGEOSTROPHIC
CIRCULATION ON THE TAIL END OF THE UPPER JET. BUILDING HIGH PRESSURE
WILL BRING RELATIVELY COOL TEMPERATURES INTO MUCH OF THE CWA...WITH
LOW TEMPERATURES NEAR 50 OVER THE NORTHERN CWA...AND MID 50S FOR A
GOOD PORTION OF THE AREA.
LONG TERM...TUESDAY THROUGH SUNDAY
AN ANTICYCLONE OF CANADIAN ORIGIN WILL BECOME ESTABLISHED OVER THE
GREAT LAKES IN WELL ORGANIZED CONFLUENCE ALOFT. THE SURFACE HIGH
WILL MAINTAIN A CENTERING OVER LAKE HURON THROUGH WEDNESDAY NIGHT.
AS THIS SURFACE HIGH PASSES EAST NWP SUGGESTS A STRONG SURFACE RIDGE
WILL THEN PERSIST OVER THE LAKE AGGREGATE THROUGH FRIDAY. A FINE
STRETCH OF EARLY SUMMER WEATHER IS EXPECTED WITH CONDITIONS THAT ARE
NOTABLY COOL. SURFACE TEMPERATURES TUESDAY SHOULD FAIL TO CLIMB OUT
OF THE 60S FOR THE THUMB...WITH READINGS IN THE HEAT ISLAND ABLE TO
REACH THE MID 70S DUE TO FULL JUNE INSOLATION. TUESDAY NIGHT WILL BE
DOWNRIGHT COOL WITH GUIDANCE SUGGESTING WIDESPREAD LOWER TO MIDDLE
40S WHICH WILL BE SOME 15 TO 17 DEGREES COOLER THAN NORMAL.
RETURN FLOW WILL EVENTUALLY COLLAPSE UPON THE REGION BY THIS
WEEKEND. CLEAN SHOWALTER INDICES ANALYSIS SUGGESTS THAT A
THERMODYNAMIC PROFILE CONDUCIVE FOR PRECIPITATION WILL ARRIVE ON
SATURDAY. IT IS AT THIS TIME THAT SOUTHEASTERN MICHIGAN MAY BECOME
IN LINE WITH POSSIBLE MCS TRACK THAT WILL BE CRESTING AN INBOUND MID
TO UPPER LEVEL RIDGE.
MARINE...
APPROACHING SHORTWAVE WILL INDUCE WEAK SURFACE LOW PRESSURE ALONG
FRONTAL BOUNDARY DRAPED THROUGH THE CENTRAL GREAT LAKES. SHOWER AND
THUNDERSTORM DEVELOPMENT WILL INCREASE AS THIS PROCESS TAKES PLACE
DURING PEAK HEATING LATE TODAY...WITH CONVECTION PERSISTING INTO
THIS EVENING AS JET SUPPORT SHIFTS OVERHEAD.
NORTHEAST FLOW WILL INCREASE OVERNIGHT INTO EARLY TUESDAY IN THE
WAKE OF THIS SYSTEM...BUT ONLY TOP OUT AROUND 15 KNOTS...SO WHILE
WAVES WILL BUILD OVER SOUTHERN LAKE HURON IN PARTICULAR...EXPECT
CONDITIONS TO REMAIN UNDER SMALL CRAFT ADVISORY CRITERION FOR THE
NEARSHORE ZONES...PEAKING AT 2-4 FEET OVER FAR SOUTHERN LAKE HURON.
ONCE THIS SLIGHTLY ENHANCED FLOW SUBSIDES BY MIDDAY TUESDAY...HIGH
PRESSURE WILL BRING FAVORABLE MARINE CONDITIONS FOR THE REMAINDER OF
THE WEEK AS WINDS BECOME LIGHT AND VARIABLE.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....KURIMSKI
SHORT TERM...DG
LONG TERM....CB
MARINE.......DG
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
000
FXUS63 KDTX 172001
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
401 PM EDT MON JUN 17 2013
.SHORT TERM...THIS AFTERNOON AND TONIGHT
MAIN CONCERN FOR THE SHORT TERM WILL BE CONVECTION INITIATING THIS
AFTERNOON AND PERSISTING INTO EVENING AS LIFT/FORCING FROM SHORTWAVE
NOW SHIFTING INTO WESTERN GREAT LAKES PROVIDES SUPPORT FOR ACTIVITY
THAT FIRES ALONG SURFACE FRONT DRAPED FROM THE SAGINAW VALLEY INTO
THE THUMB REGION.
LEAD SURFACE TROUGH NEAR THE MICHIGAN/OHIO STATE LINE WILL CUT OFF
THE REGION FROM THE BEST BOUNDARY LAYER MOISTURE/INSTABILITY...BUT
STRONG SOLAR INSOLATION DURING THE REMAINDER OF THE AFTERNOON WILL
ALLOW FOR MODEST INSTABILITY EVEN IN AREAS WHERE SURFACE DEW POINTS
WILL BE LIMITED TO THE MID/UPPER 50S. GIVEN BULK WIND SHEAR VALUES
OF 45 KNOTS IN STRONG WEST/NORTHWEST FLOW REGIME...EXPECT SOME
DEGREE OF ORGANIZATION TO THE SHOWERS/THUNDERSTORMS THAT DEVELOP AS
THE INFLUENCE OF THE UPPER LEVEL WAVE INCREASES STEADILY DURING PEAK
HEATING/INSTABILITY OF THE AFTERNOON. THE ACTIVITY WILL ALSO BE
AIDED BY INCREASE LOW LEVEL CONVERGENCE AS NORTHEAST FLOW FROM
DEVELOPING LAKE BREEZE FROM LAKE HURON WILL AUGMENT THE PUSH OF THE
SYNOPTIC FRONTAL BOUNDARY SOUTHWARD THROUGH THE CWA.
STEEP LAPSE RATES THROUGH AT LEAST 650 MB IN WELL MIXED NORTHWEST
FLOW WILL PROVIDE A FAVORABLE ENVIRONMENT FOR GUSTY WINDS WITHIN
THUNDERSTORM DOWNDRAFTS. ALSO...RELATIVELY LOW FREEZING LEVEL WITH
LACK OF ANY SIGNIFICANT UPPER RIDGING OVER AREA WILL BE FAVORABLE
FOR SOME HAIL DEVELOPMENT.
SO...AS THE PREVIOUS FORECAST OUTLINED NICELY...THERE WILL BE A
CHANCE FOR SEVERAL SEVERE STORMS FROM THIS AFTERNOON INTO THE EARLY
EVENING AS ACTIVITY GRADUALLY EXPANDS AS INSTABILITY MAXES OUT WITH
LATE DAY HEATING. WHILE THE MAIN WINDOW FOR ACTIVE STORMS WILL EXIST
THROUGH 00Z-01Z...LINGERING CONVECTION WILL MOST LIKELY PERSIST OVER
SOME PARTS OF THE AREA INTO THE 04Z-06Z TIME FRAME AS LIFT FROM THE
TRAILING ENTRANCE REGION OF UPPER JET SHIFTS OVER THE AREA.
ANY REMAINING ACTIVITY WILL END QUICKLY AFTER MIDNIGHT AS FRONTAL
BOUNDARY PUSHES SOUTH OF THE AREA...AUGMENTED BY THE AGEOSTROPHIC
CIRCULATION ON THE TAIL END OF THE UPPER JET. BUILDING HIGH PRESSURE
WILL BRING RELATIVELY COOL TEMPERATURES INTO MUCH OF THE CWA...WITH
LOW TEMPERATURES NEAR 50 OVER THE NORTHERN CWA...AND MID 50S FOR A
GOOD PORTION OF THE AREA.
&&
.LONG TERM...TUESDAY THROUGH SUNDAY
AN ANTICYCLONE OF CANADIAN ORIGIN WILL BECOME ESTABLISHED OVER THE
GREAT LAKES IN WELL ORGANIZED CONFLUENCE ALOFT. THE SURFACE HIGH
WILL MAINTAIN A CENTERING OVER LAKE HURON THROUGH WEDNESDAY NIGHT.
AS THIS SURFACE HIGH PASSES EAST NWP SUGGESTS A STRONG SURFACE RIDGE
WILL THEN PERSIST OVER THE LAKE AGGREGATE THROUGH FRIDAY. A FINE
STRETCH OF EARLY SUMMER WEATHER IS EXPECTED WITH CONDITIONS THAT ARE
NOTABLY COOL. SURFACE TEMPERATURES TUESDAY SHOULD FAIL TO CLIMB OUT
OF THE 60S FOR THE THUMB...WITH READINGS IN THE HEAT ISLAND ABLE TO
REACH THE MID 70S DUE TO FULL JUNE INSOLATION. TUESDAY NIGHT WILL BE
DOWNRIGHT COOL WITH GUIDANCE SUGGESTING WIDESPREAD LOWER TO MIDDLE
40S WHICH WILL BE SOME 15 TO 17 DEGREES COOLER THAN NORMAL.
RETURN FLOW WILL EVENTUALLY COLLAPSE UPON THE REGION BY THIS
WEEKEND. CLEAN SHOWALTER INDICES ANALYSIS SUGGESTS THAT A
THERMODYNAMIC PROFILE CONDUCIVE FOR PRECIPITATION WILL ARRIVE ON
SATURDAY. IT IS AT THIS TIME THAT SOUTHEASTERN MICHIGAN MAY BECOME
IN LINE WITH POSSIBLE MCS TRACK THAT WILL BE CRESTING AN INBOUND MID
TO UPPER LEVEL RIDGE.
&&
.MARINE...
APPROACHING SHORTWAVE WILL INDUCE WEAK SURFACE LOW PRESSURE ALONG
FRONTAL BOUNDARY DRAPED THROUGH THE CENTRAL GREAT LAKES. SHOWER AND
THUNDERSTORM DEVELOPMENT WILL INCREASE AS THIS PROCESS TAKES PLACE
DURING PEAK HEATING LATE TODAY...WITH CONVECTION PERSISTING INTO
THIS EVENING AS JET SUPPORT SHIFTS OVERHEAD.
NORTHEAST FLOW WILL INCREASE OVERNIGHT INTO EARLY TUESDAY IN THE
WAKE OF THIS SYSTEM...BUT ONLY TOP OUT AROUND 15 KNOTS...SO WHILE
WAVES WILL BUILD OVER SOUTHERN LAKE HURON IN PARTICULAR...EXPECT
CONDITIONS TO REMAIN UNDER SMALL CRAFT ADVISORY CRITERION FOR THE
NEARSHORE ZONES...PEAKING AT 2-4 FEET OVER FAR SOUTHERN LAKE HURON.
ONCE THIS SLIGHTLY ENHANCED FLOW SUBSIDES BY MIDDAY TUESDAY...HIGH
PRESSURE WILL BRING FAVORABLE MARINE CONDITIONS FOR THE REMAINDER OF
THE WEEK AS WINDS BECOME LIGHT AND VARIABLE.
&&
.AVIATION...ISSUED 100 PM EDT MON JUN 17 2013
//DISCUSSION...
COLD FRONT DRAPED NEAR MBS TO LDM HAS STALLED OUT SOME WITH -TSRA
ORIENTED ALONG AND AHEAD OF THE FRONT. SURFACE OBS IN NORTHERN MI
HAVE CONFIRMED THAT INDICATE THE ACTIVITY IS HIGH-BASED WITH CLOUD
BASES NEAR 5-7.5K FEET. THIS WILL KEEP THE TAFS IN VFR MODE THROUGH
THE FORECAST...DESPITE THE POSSIBILITY FOR SHORT PERIODS OF VIS
DROPPING TO 5SM OR LESS WITHIN STRONGER STORMS. COLD AND DRY
ADVECTION COUPLED WITH A TIGHT PRES GRADIENT INTO TUES WILL BRING
WIND GUSTS OVER 20KT.
FOR DTW...THE PROBABILITY FOR THUNDERSTORMS TO IMPACT THE TERMINAL
WITH THE COLD FRONTAL PASSAGE CURRENTLY REMAINS TOO LOW TO INCLUDE
IN THE TAFS. FROPA LOOKS TO OCCUR AROUND 01-03Z.
//DTW THRESHOLD THREATS...
* LOW CONFIDENCE IN CEILINGS BELOW 5000 FT THIS AFTERNOON THROUGH
TONIGHT.
* LOW CONFIDENCE IN THUNDERSTORM POTENTIAL LATE THIS AFTERNOON
THROUGH TONIGHT.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...DG
LONG TERM....CB
MARINE.......DG
AVIATION.....MM
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
000
FXUS63 KDTX 171700
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
100 PM EDT MON JUN 17 2013
.AVIATION...
//DISCUSSION...
COLD FRONT DRAPED NEAR MBS TO LDM HAS STALLED OUT SOME WITH -TSRA
ORIENTED ALONG AND AHEAD OF THE FRONT. SURFACE OBS IN NORTHERN MI
HAVE CONFIRMED THAT INDICATE THE ACTIVITY IS HIGH-BASED WITH CLOUD
BASES NEAR 5-7.5K FEET. THIS WILL KEEP THE TAFS IN VFR MODE THROUGH
THE FORECAST...DESPITE THE POSSIBILITY FOR SHORT PERIODS OF VIS
DROPPING TO 5SM OR LESS WITHIN STRONGER STORMS. COLD AND DRY
ADVECTION COUPLED WITH A TIGHT PRES GRADIENT INTO TUES WILL BRING
WIND GUSTS OVER 20KT.
FOR DTW...THE PROBABILITY FOR THUNDERSTORMS TO IMPACT THE TERMINAL
WITH THE COLD FRONTAL PASSAGE CURRENTLY REMAINS TOO LOW TO INCLUDE
IN THE TAFS. FROPA LOOKS TO OCCUR AROUND 01-03Z.
//DTW THRESHOLD THREATS...
* LOW CONFIDENCE IN CEILINGS BELOW 5000 FT THIS AFTERNOON THROUGH
TONIGHT.
* LOW CONFIDENCE IN THUNDERSTORM POTENTIAL LATE THIS AFTERNOON
THROUGH TONIGHT.
&&
.PREV DISCUSSION...ISSUED 343 AM EDT MON JUN 17 2013
SHORT TERM...TODAY AND TONIGHT
GRADUAL HEIGHT FALLS SPREADING ACROSS THE UPPER GREAT LAKES EARLY
THIS MORNING...PROMPTED BY NUMEROUS WEAK PV FILAMENTS SHREDDING OFF
A PRIMARY SHORTWAVE NOTED ON WATER VAPOR EJECTING INTO NORTHERN
MINNESOTA. THIS PROCESS WILL ALLOW A COLD FRONTAL BOUNDARY
CURRENTLY ANALYZED DRIFTING ACROSS NORTHERN LOWER MICHIGAN TO
PROGRESSIVELY SETTLE SOUTHWARD ACROSS SE MICHIGAN OVER THE NEXT 24
HOURS. THESE WEAKER IMPULSES WORKING ACROSS A STEEPER MID LEVEL
LAPSE RATE ENVIRONMENT SEEMINGLY DRIVING THE ONGOING WIDELY
SCATTERED SHOWER ACTIVITY TRANSLATING FROM THE UPPER MS VALLEY INTO
NORTHERN/CENTRAL LOWER...AND WILL PROVIDE A LOWER END POTENTIAL FOR
POCKETS OF LIGHT PRECIPITATION TO IMPACT THE CORRIDOR NORTH OF I-69
DURING THE EARLY PART OF THE DAY.
GREATER PROSPECTS FOR SHOWER AND THUNDERSTORM DEVELOPMENT WILL FOCUS
INTO THE AFTERNOON AND EVENING PERIOD...AS THE ADVANCING FRONTAL
SLOPE ENTERS THE FORECAST AREA COINCIDENT WITH THE PEAK HEATING
CYCLE. SOLID WINDOW WILL EXIST TO CAPITALIZE ON DAYTIME HEATING
GIVEN THE FRONTAL TIMING...A HIGH DEGREE OF PRE-FRONTAL INSOLATION
WORKING INTO A WELL MIXED WEST-SOUTHWEST FLOW AND RELATIVELY DRY
BOUNDARY LAYER WILL BRING HIGHS INTO THE 80 TO 85 DEGREE RANGE
ACROSS ALL BUT THE FAR NORTH. THIS DEGREE OF WARMTH APPEARS
NECESSARY TO OVERCOME THE APPARENT LACK OF BETTER LOW LEVEL
MOISTURE /DEWPOINTS MID-UPPER 50S/. THIS SUGGESTS CONVECTIVE
INITIATION WILL REQUIRE A GOOD PORTION OF THE DAY...DEVELOPMENT/
EXPANSION MOST FAVORED AFTER 20Z AS MLCAPE VALUES APPROACH 1500 J/KG
INVOF INCREASING FRONTAL CONVERGENCE ACROSS NORTHERN SECTIONS OF THE
AREA. A SUPPRESSED HEIGHT FIELD WILL MAINTAIN STEEP MID LEVEL LAPSE
RATES THROUGH THIS TIME...PROVIDING A FAVORABLE ENVIRONMENT FOR
CONVECTION TO QUICKLY ATTAIN BETTER UPDRAFT STRENGTH WHERE THE LOW
LEVEL THERMODYNAMICS BECOME SUPPORTIVE. A STRONG AND LARGELY
UNIDIRECTIONAL MID LEVEL WIND FIELD WILL BE IN PLACE...YIELDING 0-6
KM BULK SHEAR PUSHING 45 KNOTS. AT THE VERY LEAST...GIVEN THIS WIND
FIELD AND LOWER FREEZING LEVELS...AN ISOLATED RISK FOR SEVERE WIND
GUSTS AND HAIL WILL EXIST. THERE IS CERTAINLY THE POTENTIAL WITHIN
THIS SETUP FOR A MORE ORGANIZED CONVECTIVE EPISODE TO EVOLVE AND
EXPAND SOUTH/EAST WITH TIME THROUGH THE LATE EVENING HOURS.
DESPITE THE GRADUAL EROSION OF THE INSTABILITY RESERVOIR UNDER
NOCTURNAL COOLING INFLUENCES...INFUSION OF SLIGHTLY BETTER MID LEVEL
DYNAMICS AS THE MAIN SHORTWAVE SHEARS ACROSS THE FRONTAL BOUNDARY
WILL MAINTAIN A CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS SOUTHERN
SECTIONS INTO TONIGHT. MODERATE POST-FRONTAL COOLING WITHIN
DEVELOPING NORTHEAST LOW LEVEL FLOW WILL PROVIDE A NOTICEABLE
DOWNWARD ADJUSTMENT TO TEMPERATURES TOWARD THE NORTH. LOWS RANGING
FROM LOWER 50S NORTH TO NEAR 60 NEAR THE OHIO BORDER.
LONG TERM...TUESDAY THROUGH SUNDAY
LONGWAVE FEEDBACK ASSOCIATED WITH THE LARGE CLOSED LOW ENCROACHING
ON THE PAC NW WILL RESULT IN A GENERAL PATTERN OF LARGE SCALE HEIGHT
RISES OVER THE CENTRAL US/GREAT LAKES THROUGH THE FIRST HALF OF THE
WEEK. THIS WILL MAINTAIN SURFACE HIGH PRESSURE AND NORMAL LATE JUNE
TEMPERATURES OF 75-80 DEGREES FOR A DECENT STRETCH OF WARM/DRY SE MI
SUMMER WEATHER. THE SHEAR MAX CURRENTLY NOTED OVER SOUTHERN
SASKATCHEWAN DIVING INTO THE NORTHERN PLAINS THIS MORNING WILL PASS
JUST SOUTH OF THE AREA ON TUESDAY, BUT SHOULD BE OF LITTLE
CONSEQUENCE, ASIDE FROM SOME MODULATION OF LOCAL CLOUD COVER, SINCE
MONDAY`S SFC BAROCLINIC ZONE WILL HAVE ALREADY EASED WELL SOUTH OF
THE AREA. LONGWAVE RIDGING ENTRENCHED OVER THE CENTRAL CONUS IS THEN
PROGGED TO GET A NOTEWORTHY BOOST FOR THE LATTER HALF OF THE WEEK AS
BROAD ANTICYLONIC NOTED INVOF 25N/130W EAST OF HAWAII IS ENTRAINED
INTO PREVAILING SW UPPER FLOW. H5 HEIGHTS ARE PROGGED BY THE 00Z
ECMWF TO BUILD TO 595DM OVER TX BY FRIDAY AFTERNOON AS A RESULT.
LOCALLY, CONTINUED NORTHWEST FLOW ALOFT AND DOMINANCE OF SURFACE
HIGH PRESSURE IS FORECAST TO MAINTAIN NEAR NORMAL TEMPERATURES INTO
THE WEEKEND, WHEN THE PATTERN WILL POTENTIALLY BECOME RIPE WITH
CONVECTIVE POTENTIAL GIVEN SOUTHEAST MICHIGAN`S FAVORABLE LOCATION
ALONG THE EDGE OF THE CAP & ALONG THE LOW-LEVEL INSTABILITY GRADIENT.
THEREFORE, NO CHANGES NECESSARY TO INHERITED CHANCE POPS SAT-MON.
MARINE...
FAVORABLE MARINE CONDITIONS WILL PERSIST ACROSS AREA WATERWAYS
THROUGH THE EARLY PORTION OF THE DAY. THE APPROACH OF A COLD FRONT
WILL BRING A CHANCE OF THUNDERSTORMS FROM MID AFTERNOON THROUGH
TONIGHT. WINDS WILL TURN TO NORTHEASTERLY WITH THE FRONTAL
PASSAGE. DRY AND STABLE CONDITIONS WITH HIGH PRESSURE TAKING
CONTROL TUESDAY AND WEDNESDAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....MM
SHORT TERM...MR
LONG TERM....JVC
MARINE.......MR
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
000
FXUS63 KDTX 171026
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
626 AM EDT MON JUN 17 2013
.AVIATION...
//DISCUSSION...
COLD FRONT CURRENTLY EXTENDING THROUGH NORTHERN LOWER MICHIGAN WILL
GRADUALLY SETTLE SOUTHWARD AND ACROSS SE MICHIGAN THIS AFTERNOON
INTO TONIGHT. RELATIVELY BENIGN CONDITIONS IN ADVANCE OF THIS FRONT
FOR A GOOD PORTION OF THE DAY...A SLOW EVOLVING HIGHER BASED VFR CU
FIELD INTO THE AFTERNOON WITH 10-12 KNOT WESTERLY WINDS. GREATEST
POTENTIAL FOR SHOWERS AND THUNDERSTORMS WILL EXIST ACROSS THE
NORTHERN TAF SITES FROM LATE AFTERNOON INTO THE EVENING...WITH THE
COLD FRONT ARRIVING COINCIDENT WITH PEAK HEATING/INSTABILITY. THIS
WILL SUPPORT A SPECIFIC MENTION AT THESE LOCALES.
FOR DTW...THE PROBABILITY FOR THUNDERSTORMS TO IMPACT THE TERMINAL
WITH THE COLD FRONTAL PASSAGE CURRENTLY REMAINS TOO LOW TO INCLUDE
AN EXPLICIT MENTION. COLD FRONT WILL MOVE THROUGH THE TERMINAL
DURING THE EARLY MORNING HOURS ON TUESDAY...WINDS SHIFTING TO
NORTHEASTERLY IN IT/S WAKE.
//DTW THRESHOLD THREATS...
* LOW CONFIDENCE IN CEILINGS BELOW 5000 FT THIS AFTERNOON THROUGH
TONIGHT.
* LOW CONFIDENCE IN THUNDERSTORM POTENTIAL LATE THIS AFTERNOON
THROUGH TONIGHT.
&&
.PREV DISCUSSION...ISSUED 343 AM EDT MON JUN 17 2013
SHORT TERM...TODAY AND TONIGHT
GRADUAL HEIGHT FALLS SPREADING ACROSS THE UPPER GREAT LAKES EARLY
THIS MORNING...PROMPTED BY NUMEROUS WEAK PV FILAMENTS SHREDDING OFF
A PRIMARY SHORTWAVE NOTED ON WATER VAPOR EJECTING INTO NORTHERN
MINNESOTA. THIS PROCESS WILL ALLOW A COLD FRONTAL BOUNDARY
CURRENTLY ANALYZED DRIFTING ACROSS NORTHERN LOWER MICHIGAN TO
PROGRESSIVELY SETTLE SOUTHWARD ACROSS SE MICHIGAN OVER THE NEXT 24
HOURS. THESE WEAKER IMPULSES WORKING ACROSS A STEEPER MID LEVEL
LAPSE RATE ENVIRONMENT SEEMINGLY DRIVING THE ONGOING WIDELY
SCATTERED SHOWER ACTIVITY TRANSLATING FROM THE UPPER MS VALLEY INTO
NORTHERN/CENTRAL LOWER...AND WILL PROVIDE A LOWER END POTENTIAL FOR
POCKETS OF LIGHT PRECIPITATION TO IMPACT THE CORRIDOR NORTH OF I-69
DURING THE EARLY PART OF THE DAY.
GREATER PROSPECTS FOR SHOWER AND THUNDERSTORM DEVELOPMENT WILL FOCUS
INTO THE AFTERNOON AND EVENING PERIOD...AS THE ADVANCING FRONTAL
SLOPE ENTERS THE FORECAST AREA COINCIDENT WITH THE PEAK HEATING
CYCLE. SOLID WINDOW WILL EXIST TO CAPITALIZE ON DAYTIME HEATING
GIVEN THE FRONTAL TIMING...A HIGH DEGREE OF PRE-FRONTAL INSOLATION
WORKING INTO A WELL MIXED WEST-SOUTHWEST FLOW AND RELATIVELY DRY
BOUNDARY LAYER WILL BRING HIGHS INTO THE 80 TO 85 DEGREE RANGE
ACROSS ALL BUT THE FAR NORTH. THIS DEGREE OF WARMTH APPEARS
NECESSARY TO OVERCOME THE APPARENT LACK OF BETTER LOW LEVEL
MOISTURE /DEWPOINTS MID-UPPER 50S/. THIS SUGGESTS CONVECTIVE
INITIATION WILL REQUIRE A GOOD PORTION OF THE DAY...DEVELOPMENT/
EXPANSION MOST FAVORED AFTER 20Z AS MLCAPE VALUES APPROACH 1500 J/KG
INVOF INCREASING FRONTAL CONVERGENCE ACROSS NORTHERN SECTIONS OF THE
AREA. A SUPPRESSED HEIGHT FIELD WILL MAINTAIN STEEP MID LEVEL LAPSE
RATES THROUGH THIS TIME...PROVIDING A FAVORABLE ENVIRONMENT FOR
CONVECTION TO QUICKLY ATTAIN BETTER UPDRAFT STRENGTH WHERE THE LOW
LEVEL THERMODYNAMICS BECOME SUPPORTIVE. A STRONG AND LARGELY
UNIDIRECTIONAL MID LEVEL WIND FIELD WILL BE IN PLACE...YIELDING 0-6
KM BULK SHEAR PUSHING 45 KNOTS. AT THE VERY LEAST...GIVEN THIS WIND
FIELD AND LOWER FREEZING LEVELS...AN ISOLATED RISK FOR SEVERE WIND
GUSTS AND HAIL WILL EXIST. THERE IS CERTAINLY THE POTENTIAL WITHIN
THIS SETUP FOR A MORE ORGANIZED CONVECTIVE EPISODE TO EVOLVE AND
EXPAND SOUTH/EAST WITH TIME THROUGH THE LATE EVENING HOURS.
DESPITE THE GRADUAL EROSION OF THE INSTABILITY RESERVOIR UNDER
NOCTURNAL COOLING INFLUENCES...INFUSION OF SLIGHTLY BETTER MID LEVEL
DYNAMICS AS THE MAIN SHORTWAVE SHEARS ACROSS THE FRONTAL BOUNDARY
WILL MAINTAIN A CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS SOUTHERN
SECTIONS INTO TONIGHT. MODERATE POST-FRONTAL COOLING WITHIN
DEVELOPING NORTHEAST LOW LEVEL FLOW WILL PROVIDE A NOTICEABLE
DOWNWARD ADJUSTMENT TO TEMPERATURES TOWARD THE NORTH. LOWS RANGING
FROM LOWER 50S NORTH TO NEAR 60 NEAR THE OHIO BORDER.
LONG TERM...TUESDAY THROUGH SUNDAY
LONGWAVE FEEDBACK ASSOCIATED WITH THE LARGE CLOSED LOW ENCROACHING
ON THE PAC NW WILL RESULT IN A GENERAL PATTERN OF LARGE SCALE HEIGHT
RISES OVER THE CENTRAL US/GREAT LAKES THROUGH THE FIRST HALF OF THE
WEEK. THIS WILL MAINTAIN SURFACE HIGH PRESSURE AND NORMAL LATE JUNE
TEMPERATURES OF 75-80 DEGREES FOR A DECENT STRETCH OF WARM/DRY SE MI
SUMMER WEATHER. THE SHEAR MAX CURRENTLY NOTED OVER SOUTHERN
SASKATCHEWAN DIVING INTO THE NORTHERN PLAINS THIS MORNING WILL PASS
JUST SOUTH OF THE AREA ON TUESDAY, BUT SHOULD BE OF LITTLE
CONSEQUENCE, ASIDE FROM SOME MODULATION OF LOCAL CLOUD COVER, SINCE
MONDAY`S SFC BAROCLINIC ZONE WILL HAVE ALREADY EASED WELL SOUTH OF
THE AREA. LONGWAVE RIDGING ENTRENCHED OVER THE CENTRAL CONUS IS THEN
PROGGED TO GET A NOTEWORTHY BOOST FOR THE LATTER HALF OF THE WEEK AS
BROAD ANTICYLONIC NOTED INVOF 25N/130W EAST OF HAWAII IS ENTRAINED
INTO PREVAILING SW UPPER FLOW. H5 HEIGHTS ARE PROGGED BY THE 00Z
ECMWF TO BUILD TO 595DM OVER TX BY FRIDAY AFTERNOON AS A RESULT.
LOCALLY, CONTINUED NORTHWEST FLOW ALOFT AND DOMINANCE OF SURFACE
HIGH PRESSURE IS FORECAST TO MAINTAIN NEAR NORMAL TEMPERATURES INTO
THE WEEKEND, WHEN THE PATTERN WILL POTENTIALLY BECOME RIPE WITH
CONVECTIVE POTENTIAL GIVEN SOUTHEAST MICHIGAN`S FAVORABLE LOCATION
ALONG THE EDGE OF THE CAP & ALONG THE LOW-LEVEL INSTABILITY GRADIENT.
THEREFORE, NO CHANGES NECESSARY TO INHERITED CHANCE POPS SAT-MON.
MARINE...
FAVORABLE MARINE CONDITIONS WILL PERSIST ACROSS AREA WATERWAYS
THROUGH THE EARLY PORTION OF THE DAY. THE APPROACH OF A COLD FRONT
WILL BRING A CHANCE OF THUNDERSTORMS FROM MID AFTERNOON THROUGH
TONIGHT. WINDS WILL TURN TO NORTHEASTERLY WITH THE FRONTAL
PASSAGE. DRY AND STABLE CONDITIONS WITH HIGH PRESSURE TAKING
CONTROL TUESDAY AND WEDNESDAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....MR
SHORT TERM...MR
LONG TERM....JVC
MARINE.......MR
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
000
FXUS63 KDTX 170743
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
343 AM EDT MON JUN 17 2013
.SHORT TERM...TODAY AND TONIGHT
GRADUAL HEIGHT FALLS SPREADING ACROSS THE UPPER GREAT LAKES EARLY
THIS MORNING...PROMPTED BY NUMEROUS WEAK PV FILAMENTS SHREDDING OFF
A PRIMARY SHORTWAVE NOTED ON WATER VAPOR EJECTING INTO NORTHERN
MINNESOTA. THIS PROCESS WILL ALLOW A COLD FRONTAL BOUNDARY
CURRENTLY ANALYZED DRIFTING ACROSS NORTHERN LOWER MICHIGAN TO
PROGRESSIVELY SETTLE SOUTHWARD ACROSS SE MICHIGAN OVER THE NEXT 24
HOURS. THESE WEAKER IMPULSES WORKING ACROSS A STEEPER MID LEVEL
LAPSE RATE ENVIRONMENT SEEMINGLY DRIVING THE ONGOING WIDELY
SCATTERED SHOWER ACTIVITY TRANSLATING FROM THE UPPER MS VALLEY INTO
NORTHERN/CENTRAL LOWER...AND WILL PROVIDE A LOWER END POTENTIAL FOR
POCKETS OF LIGHT PRECIPITATION TO IMPACT THE CORRIDOR NORTH OF I-69
DURING THE EARLY PART OF THE DAY.
GREATER PROSPECTS FOR SHOWER AND THUNDERSTORM DEVELOPMENT WILL FOCUS
INTO THE AFTERNOON AND EVENING PERIOD...AS THE ADVANCING FRONTAL
SLOPE ENTERS THE FORECAST AREA COINCIDENT WITH THE PEAK HEATING
CYCLE. SOLID WINDOW WILL EXIST TO CAPITALIZE ON DAYTIME HEATING
GIVEN THE FRONTAL TIMING...A HIGH DEGREE OF PRE-FRONTAL INSOLATION
WORKING INTO A WELL MIXED WEST-SOUTHWEST FLOW AND RELATIVELY DRY
BOUNDARY LAYER WILL BRING HIGHS INTO THE 80 TO 85 DEGREE RANGE
ACROSS ALL BUT THE FAR NORTH. THIS DEGREE OF WARMTH APPEARS
NECESSARY TO OVERCOME THE APPARENT LACK OF BETTER LOW LEVEL
MOISTURE /DEWPOINTS MID-UPPER 50S/. THIS SUGGESTS CONVECTIVE
INITIATION WILL REQUIRE A GOOD PORTION OF THE DAY...DEVELOPMENT/
EXPANSION MOST FAVORED AFTER 20Z AS MLCAPE VALUES APPROACH 1500 J/KG
INVOF INCREASING FRONTAL CONVERGENCE ACROSS NORTHERN SECTIONS OF THE
AREA. A SUPPRESSED HEIGHT FIELD WILL MAINTAIN STEEP MID LEVEL LAPSE
RATES THROUGH THIS TIME...PROVIDING A FAVORABLE ENVIRONMENT FOR
CONVECTION TO QUICKLY ATTAIN BETTER UPDRAFT STRENGTH WHERE THE LOW
LEVEL THERMODYNAMICS BECOME SUPPORTIVE. A STRONG AND LARGELY
UNIDIRECTIONAL MID LEVEL WIND FIELD WILL BE IN PLACE...YIELDING 0-6
KM BULK SHEAR PUSHING 45 KNOTS. AT THE VERY LEAST...GIVEN THIS WIND
FIELD AND LOWER FREEZING LEVELS...AN ISOLATED RISK FOR SEVERE WIND
GUSTS AND HAIL WILL EXIST. THERE IS CERTAINLY THE POTENTIAL WITHIN
THIS SETUP FOR A MORE ORGANIZED CONVECTIVE EPISODE TO EVOLVE AND
EXPAND SOUTH/EAST WITH TIME THROUGH THE LATE EVENING HOURS.
DESPITE THE GRADUAL EROSION OF THE INSTABILITY RESERVOIR UNDER
NOCTURNAL COOLING INFLUENCES...INFUSION OF SLIGHTLY BETTER MID LEVEL
DYNAMICS AS THE MAIN SHORTWAVE SHEARS ACROSS THE FRONTAL BOUNDARY
WILL MAINTAIN A CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS SOUTHERN
SECTIONS INTO TONIGHT. MODERATE POST-FRONTAL COOLING WITHIN
DEVELOPING NORTHEAST LOW LEVEL FLOW WILL PROVIDE A NOTICEABLE
DOWNWARD ADJUSTMENT TO TEMPERATURES TOWARD THE NORTH. LOWS RANGING
FROM LOWER 50S NORTH TO NEAR 60 NEAR THE OHIO BORDER.
&&
.LONG TERM...TUESDAY THROUGH SUNDAY
LONGWAVE FEEDBACK ASSOCIATED WITH THE LARGE CLOSED LOW ENCROACHING
ON THE PAC NW WILL RESULT IN A GENERAL PATTERN OF LARGE SCALE HEIGHT
RISES OVER THE CENTRAL US/GREAT LAKES THROUGH THE FIRST HALF OF THE
WEEK. THIS WILL MAINTAIN SURFACE HIGH PRESSURE AND NORMAL LATE JUNE
TEMPERATURES OF 75-80 DEGREES FOR A DECENT STRETCH OF WARM/DRY SE MI
SUMMER WEATHER. THE SHEAR MAX CURRENTLY NOTED OVER SOUTHERN
SASKATCHEWAN DIVING INTO THE NORTHERN PLAINS THIS MORNING WILL PASS
JUST SOUTH OF THE AREA ON TUESDAY, BUT SHOULD BE OF LITTLE
CONSEQUENCE, ASIDE FROM SOME MODULATION OF LOCAL CLOUD COVER, SINCE
MONDAY`S SFC BAROCLINIC ZONE WILL HAVE ALREADY EASED WELL SOUTH OF
THE AREA. LONGWAVE RIDGING ENTRENCHED OVER THE CENTRAL CONUS IS THEN
PROGGED TO GET A NOTEWORTHY BOOST FOR THE LATTER HALF OF THE WEEK AS
BROAD ANTICYLONIC NOTED INVOF 25N/130W EAST OF HAWAII IS ENTRAINED
INTO PREVAILING SW UPPER FLOW. H5 HEIGHTS ARE PROGGED BY THE 00Z
ECMWF TO BUILD TO 595DM OVER TX BY FRIDAY AFTERNOON AS A RESULT.
LOCALLY, CONTINUED NORTHWEST FLOW ALOFT AND DOMINANCE OF SURFACE
HIGH PRESSURE IS FORECAST TO MAINTAIN NEAR NORMAL TEMPERATURES INTO
THE WEEKEND, WHEN THE PATTERN WILL POTENTIALLY BECOME RIPE WITH
CONVECTIVE POTENTIAL GIVEN SOUTHEAST MICHIGAN`S FAVORABLE LOCATION
ALONG THE EDGE OF THE CAP & ALONG THE LOW-LEVEL INSTABILITY GRADIENT.
THEREFORE, NO CHANGES NECESSARY TO INHERITED CHANCE POPS SAT-MON.
&&
.MARINE...
FAVORABLE MARINE CONDITIONS WILL PERSIST ACROSS AREA WATERWAYS
THROUGH THE EARLY PORTION OF THE DAY. THE APPROACH OF A COLD FRONT
WILL BRING A CHANCE OF THUNDERSTORMS FROM MID AFTERNOON THROUGH
TONIGHT. WINDS WILL TURN TO NORTHEASTERLY WITH THE FRONTAL
PASSAGE. DRY AND STABLE CONDITIONS WITH HIGH PRESSURE TAKING
CONTROL TUESDAY AND WEDNESDAY.
&&
.AVIATION...ISSUED 1151 PM EDT SUN JUN 16 2013
//DISCUSSION...
ADVECTIONS WILL REMAIN WEAK THROUGH THE OVERNIGHT HOURS WITH ANY
BACKGROUND MIDLEVEL INVERSIONS NON-EXISTENT. SKIES WILL REMAIN
SKC-FEW COVERAGE THROUGH SUNRISE. CLOUDS WILL BE ON THE INCREASE
FROM NORTH TO SOUTH ON MONDAY AS A WEAK COLD FRONT TRACKS THROUGH
THE CENTRAL GREAT LAKES. RAIN CHANCES WILL BE BEST ACROSS THE NORTH
WITH THE BEST FORCING AND DYNAMICS...WITH LOWER POPS HEADING SOUTH.
WILL CONTINUE A PREVAILING GROUP FOR SHOWERS AT MBS...PROB30 AT FNT
AND INTRODUCE A PROB30 AT PTK...WHILE LEAVING THE REST OF THE
AIRPORTS DRY GIVEN THE LOW POPS. THUNDERSTORMS ARE STILL A
POSSIBILITY...HOWEVER COVERAGE AND TIMING ARE IN QUESTION TO LEAVE
OUT AT THIS TIME.
//DTW THRESHOLD THREATS...
* MEDIUM CONFIDENCE IN CEILINGS BELOW 5KFT MONDAY AFTERNOON.
* LOW CONFIDENCE IN THUNDERSTORM TIMING AND PROBABILITY MONDAY
AFTERNOON AND EVENING.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...MR
LONG TERM....JVC
MARINE.......MR
AVIATION.....KURIMSKI
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
000
FXUS63 KDTX 170351
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1151 PM EDT SUN JUN 16 2013
.AVIATION...
//DISCUSSION...
ADVECTIONS WILL REMAIN WEAK THROUGH THE OVERNIGHT HOURS WITH ANY
BACKGROUND MIDLEVEL INVERSIONS NON-EXISTENT. SKIES WILL REMAIN
SKC-FEW COVERAGE THROUGH SUNRISE. CLOUDS WILL BE ON THE INCREASE
FROM NORTH TO SOUTH ON MONDAY AS A WEAK COLD FRONT TRACKS THROUGH
THE CENTRAL GREAT LAKES. RAIN CHANCES WILL BE BEST ACROSS THE NORTH
WITH THE BEST FORCING AND DYNAMICS...WITH LOWER POPS HEADING SOUTH.
WILL CONTINUE A PREVAILING GROUP FOR SHOWERS AT MBS...PROB30 AT FNT
AND INTRODUCE A PROB30 AT PTK...WHILE LEAVING THE REST OF THE
AIRPORTS DRY GIVEN THE LOW POPS. THUNDERSTORMS ARE STILL A
POSSIBILITY...HOWEVER COVERAGE AND TIMING ARE IN QUESTION TO LEAVE
OUT AT THIS TIME.
//DTW THRESHOLD THREATS...
* MEDIUM CONFIDENCE IN CEILINGS BELOW 5KFT MONDAY AFTERNOON.
* LOW CONFIDENCE IN THUNDERSTORM TIMING AND PROBABILITY MONDAY
AFTERNOON AND EVENING.
&&
.PREV DISCUSSION...ISSUED 356 PM EDT SUN JUN 16 2013
SHORT TERM...REST OF TODAY AND TONIGHT
THE MAIN JET STREAM AXIS WILL REMAIN IN PLACE OVER THE GREAT LAKES
REGION RESULTING IN STATIC ADVECTIONS OR LITTLE AIRMASS TURNOVER.
THIS WILL BE REFLECTED AT THE SURFACE WITH NO SURFACE PRESSURE
TENDENCY AND A WEAK SURFACE TROUGH OR COL LIKE STRUCTURE. THE
NEUTRAL ADVECTION PATTERN HAS AN IMPACT HERE YET THIS AFTERNOON AS
THE LACK OF MIDLEVEL COOLING SHOULD KEEP A SUBTLE CAP IN PLACE
CENTERED AT 775MB. THERE STILL REMAINS SOME TIME FOR AN ISOLATED
CELL TO INITIATE IN SOME WEAKNESS OF THE CAPPING...POSSIBLY AIDED BY
SOME LAKE CONVERGENCE FORCING. HOWEVER...THE LIKELIHOOD OF THIS TO
OCCUR IS CERTAINLY 20 PERCENT OR LESS.
THE LACK OF ADVECTION OR POSITIVE SURFACE PRESSURE TENDENCY SHOULD
SIGNAL THE LACK OF ANY SIGNIFICANT LOW TO MIDLEVEL INVERSION
TONIGHT. THIS INCREASES CONFIDENCE THAT SKIES SHOULD BE
PREDOMINATELY CLEAR FOR THE DURATION OF THE NIGHT. THE ONE EXCEPTION
WILL BE OVER THE NORTHERN CWA LATE IN THE FORECAST PERIOD AS SOME
LEFTOVER CONVECTIVE DEBRIS AHEAD OF A WEAK SURFACE BOUNDARY MAY
SURVIVE THE TRIP SOUTHWARD. CONFIDENCE IN THIS OCCURRING REMAINS LOW.
LONG TERM... MONDAY THROUGH SUNDAY
AFTERNOON WATER VAPOR SATELLITE IMAGERY AND SURFACE ANALYSIS
INDICATE THE UPPER LEVEL TROUGH SHEARING SOUTHWARD FROM CENTRAL
CANADA AND CARRYING THE ASSOCIATED COLD FRONT INTO THE UPPER
MIDWEST. THIS SYSTEM WILL BE THE FOCUS OF CONDITIONS IN SE MICHIGAN
MONDAY AND MONDAY NIGHT AND PRESENTS A FAIRLY STRAIGHTFORWARD
FORECAST SCENARIO FOR SHOWERS AND THUNDERSTORMS. AT FIRST, IT LOOKED
LIKE BOUNDARY LAYER MOISTURE RETURN WOULD BE ONE OF THEM BUT PERHAPS
NOT CONSIDERING HOW CONVECTION IS DEVELOPING TODAY OVER THE NORTHERN
GREAT LAKES. LOWER 50S SURFACE DEWPOINT IS GOOD ENOUGH IN THAT
AREA WHERE TEMPERATURES ALOFT ARE ABOUT -16C AT 500 MB. THERE IS
GOOD AGREEMENT AMONG THE NEW MODEL OUTPUT SHOWING SOME OF THIS
COLD AIR ALOFT SETTLING OVER SOUTHERN LOWER MICHIGAN BY MONDAY
AFTERNOON TAKING 500 MB TEMPS DOWN TO BETWEEN -14 AND -16C. EXPECT
THIS WILL PERMIT LOWER TO MID 50S SURFACE DEWPOINT TO GENERATE
CAPE AROUND 1500 J/KG, GOOD ENOUGH FOR CONVECTION TO BECOME
ORGANIZED WITHIN A STRONG WIND FIELD FEATURING NEARLY 60 KNOTS OF
WESTERLY FLOW AT 500 MB AND 45 KNOTS OF 0-6KM BULK SHEAR. THE
STRONG UNIDIRECTIONAL NATURE OF THE SHEAR PROFILE INDICATES A
DISCRETE SUPERCELL MODE IS POSSIBLE EARLY WITH ENHANCED UPDRAFTS
CAPABLE OF LARGE HAIL DUE TO FREEZING LEVEL ON THE LOW SIDE,
ABOUT 10500 FEET, FOR THIS TIME OF YEAR. A QUICK EVOLUTION INTO A
LINEAR MODE COULD FOLLOW WITH A DAMAGING WIND COMPONENT.
WESTERLY UPPER LEVEL FLOW AND DAYTIME SURFACE HEATING SOUTH OF THE
FRONT WILL BUY SOME DRY CONDITIONS DURING MONDAY MORNING. THE MAIN
FORECAST ADJUSTMENT IS TO DELAY HIGHER POPS INTO THE AFTERNOON IN
THE TRI CITIES AND EXTEND TO THE SOUTH AND INTO MONDAY EVENING
TOWARD THE OHIO BORDER. MODEL CROSS SECTIONS ALSO INDICATE THE
SHALLOWNESS OF THE COLD FRONT WILL HAVE AN IMPACT ON SOUTHWARD
PROGRESSION AS SURFACE HEATING OVER INTERIOR LOWER ERODES THE
PRESSURE FIELD. NOT UNTIL MONDAY EVENING WILL THE FRONT RELEASE
THE REST OF THE WAY THROUGH LOWER MICHIGAN WITH A BOOST FROM LAKE
HURON AND LAKE MICHIGAN, AND ALSO WITH A BOOST FROM EXTRA HEIGHT
FALLS WITH THE SHARPENING UPPER TROUGH OVER NORTHERN ONTARIO AND
QUEBEC. EXPECT THEN A STEADY DECREASE IN POPS THROUGH THE NIGHT
AS THE LOW LEVEL BAROCLINIC ZONE MOVES FARTHER SOUTH OF THE REGION
TOWARD TUESDAY MORNING.
FRESH CANADIAN HIGH PRESSURE THEN REMAINS ON TRACK TO SETTLE OVER SE
MICHIGAN FOR THE MID WEEK PERIOD. THE NEW MODEL SOLUTIONS REMAIN
ROCK SOLID ON THE SCENARIO THROUGH THURSDAY WHEN HINTS OF A DRY
BACKDOOR COLD FRONT SHOW UP THURSDAY NIGHT INTO FRIDAY. THIS IS
SYMPTOMATIC OF NORTHWEST FLOW ALOFT PERSISTING LONGER OVER THE GREAT
LAKES AS THE UPPER LEVEL BLOCK MATURES OUT WEST. IT ALSO MEANS
CONDITIONS BECOMING MORE UNSETTLED FOR NEXT WEEKEND.
MARINE...
FAVORABLE MARINE CONDITIONS WILL PERSIST ACROSS AREA WATERWAYS WITH
A BENIGN PATTERN IN PLACE. WIND AND WAVE CONDITIONS WILL OTHERWISE
REMAIN FAVORABLE UNTIL MONDAY AFTERNOON WHEN THE NEXT COLD FRONT IS
DUE THROUGH THE REGION. WINDS ARE EXPECTED TO AGGRESSIVELY TURN TO
THE NORTHEAST BEHIND THE FRONTAL PASSAGE DURING THE LATE AFTERNOON
OR EARLY EVENING HOURS. SMALL CRAFT ADVISORIES MAY BE A POSSIBILITY
FOR THE NEARSHORE WATERS OF LAKE HURON INCLUDING SAGINAW BAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....KURIMSKI
SHORT TERM...CB
LONG TERM....BT
MARINE.......CB
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
000
FXUS63 KDTX 162317
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
717 PM EDT SUN JUN 16 2013
.AVIATION...
//DISCUSSION...
CONVECTIVE ACTIVITY THIS AFTERNOON HAS REMAINED EAST OF THE TAF
SITES AND EXPECTED TO STAY THERE FOR THE EVENING HOURS. ADVECTIONS
WILL REMAIN WEAK AGAIN TONIGHT WITH ANY BACKGROUND MIDLEVEL
INVERSIONS NON-EXISTENT. BELIEF IS THAT ONCE WE CAN MIX OUT CLOUDS
TOWARDS SUNDOWN...SKIES WILL REMAIN SKC FOR THE OVERNIGHT. CLOUDS
WILL BE ON THE INCREASE FROM NORTH TO SOUTH ON MONDAY AS A WEAK COLD
FRONT TRACKS THROUGH THE CENTRAL GREAT LAKES. RAIN CHANCES WILL BE
BEST ACROSS THE NORTH WITH THE BEST FORCING AND DYNAMICS...WITH
LOWER POPS HEADING SOUTH. WITH THIS TAF ISSUANCE WILL PUT A
PREVAILING GROUP FOR SHOWERS AT MBS...PROB30 AT FNT AND LEAVE THE
REST OF THE AIRPORTS DRY GIVEN THE LOW POPS. THUNDERSTORMS ARE A
POSSIBILITY...HOWEVER COVERAGE AND TIMING ARE IN QUESTION TO LEAVE
OUT AT THIS TIME.
//DTW THRESHOLD THREATS...
* MEDIUM CONFIDENCE IN CEILINGS BELOW 5KFT MONDAY AFTERNOON.
* LOW CONFIDENCE IN THUNDERSTORM TIMING AND PROBABILITY MONDAY
AFTERNOON AND EVENING.
&&
.PREV DISCUSSION...ISSUED 356 PM EDT SUN JUN 16 2013
SHORT TERM...REST OF TODAY AND TONIGHT
THE MAIN JET STREAM AXIS WILL REMAIN IN PLACE OVER THE GREAT LAKES
REGION RESULTING IN STATIC ADVECTIONS OR LITTLE AIRMASS TURNOVER.
THIS WILL BE REFLECTED AT THE SURFACE WITH NO SURFACE PRESSURE
TENDENCY AND A WEAK SURFACE TROUGH OR COL LIKE STRUCTURE. THE
NEUTRAL ADVECTION PATTERN HAS AN IMPACT HERE YET THIS AFTERNOON AS
THE LACK OF MIDLEVEL COOLING SHOULD KEEP A SUBTLE CAP IN PLACE
CENTERED AT 775MB. THERE STILL REMAINS SOME TIME FOR AN ISOLATED
CELL TO INITIATE IN SOME WEAKNESS OF THE CAPPING...POSSIBLY AIDED BY
SOME LAKE CONVERGENCE FORCING. HOWEVER...THE LIKELIHOOD OF THIS TO
OCCUR IS CERTAINLY 20 PERCENT OR LESS.
THE LACK OF ADVECTION OR POSITIVE SURFACE PRESSURE TENDENCY SHOULD
SIGNAL THE LACK OF ANY SIGNIFICANT LOW TO MIDLEVEL INVERSION
TONIGHT. THIS INCREASES CONFIDENCE THAT SKIES SHOULD BE
PREDOMINATELY CLEAR FOR THE DURATION OF THE NIGHT. THE ONE EXCEPTION
WILL BE OVER THE NORTHERN CWA LATE IN THE FORECAST PERIOD AS SOME
LEFTOVER CONVECTIVE DEBRIS AHEAD OF A WEAK SURFACE BOUNDARY MAY
SURVIVE THE TRIP SOUTHWARD. CONFIDENCE IN THIS OCCURRING REMAINS LOW.
LONG TERM... MONDAY THROUGH SUNDAY
AFTERNOON WATER VAPOR SATELLITE IMAGERY AND SURFACE ANALYSIS
INDICATE THE UPPER LEVEL TROUGH SHEARING SOUTHWARD FROM CENTRAL
CANADA AND CARRYING THE ASSOCIATED COLD FRONT INTO THE UPPER
MIDWEST. THIS SYSTEM WILL BE THE FOCUS OF CONDITIONS IN SE MICHIGAN
MONDAY AND MONDAY NIGHT AND PRESENTS A FAIRLY STRAIGHTFORWARD
FORECAST SCENARIO FOR SHOWERS AND THUNDERSTORMS. AT FIRST, IT LOOKED
LIKE BOUNDARY LAYER MOISTURE RETURN WOULD BE ONE OF THEM BUT PERHAPS
NOT CONSIDERING HOW CONVECTION IS DEVELOPING TODAY OVER THE NORTHERN
GREAT LAKES. LOWER 50S SURFACE DEWPOINT IS GOOD ENOUGH IN THAT
AREA WHERE TEMPERATURES ALOFT ARE ABOUT -16C AT 500 MB. THERE IS
GOOD AGREEMENT AMONG THE NEW MODEL OUTPUT SHOWING SOME OF THIS
COLD AIR ALOFT SETTLING OVER SOUTHERN LOWER MICHIGAN BY MONDAY
AFTERNOON TAKING 500 MB TEMPS DOWN TO BETWEEN -14 AND -16C. EXPECT
THIS WILL PERMIT LOWER TO MID 50S SURFACE DEWPOINT TO GENERATE
CAPE AROUND 1500 J/KG, GOOD ENOUGH FOR CONVECTION TO BECOME
ORGANIZED WITHIN A STRONG WIND FIELD FEATURING NEARLY 60 KNOTS OF
WESTERLY FLOW AT 500 MB AND 45 KNOTS OF 0-6KM BULK SHEAR. THE
STRONG UNIDIRECTIONAL NATURE OF THE SHEAR PROFILE INDICATES A
DISCRETE SUPERCELL MODE IS POSSIBLE EARLY WITH ENHANCED UPDRAFTS
CAPABLE OF LARGE HAIL DUE TO FREEZING LEVEL ON THE LOW SIDE,
ABOUT 10500 FEET, FOR THIS TIME OF YEAR. A QUICK EVOLUTION INTO A
LINEAR MODE COULD FOLLOW WITH A DAMAGING WIND COMPONENT.
WESTERLY UPPER LEVEL FLOW AND DAYTIME SURFACE HEATING SOUTH OF THE
FRONT WILL BUY SOME DRY CONDITIONS DURING MONDAY MORNING. THE MAIN
FORECAST ADJUSTMENT IS TO DELAY HIGHER POPS INTO THE AFTERNOON IN
THE TRI CITIES AND EXTEND TO THE SOUTH AND INTO MONDAY EVENING
TOWARD THE OHIO BORDER. MODEL CROSS SECTIONS ALSO INDICATE THE
SHALLOWNESS OF THE COLD FRONT WILL HAVE AN IMPACT ON SOUTHWARD
PROGRESSION AS SURFACE HEATING OVER INTERIOR LOWER ERODES THE
PRESSURE FIELD. NOT UNTIL MONDAY EVENING WILL THE FRONT RELEASE
THE REST OF THE WAY THROUGH LOWER MICHIGAN WITH A BOOST FROM LAKE
HURON AND LAKE MICHIGAN, AND ALSO WITH A BOOST FROM EXTRA HEIGHT
FALLS WITH THE SHARPENING UPPER TROUGH OVER NORTHERN ONTARIO AND
QUEBEC. EXPECT THEN A STEADY DECREASE IN POPS THROUGH THE NIGHT
AS THE LOW LEVEL BAROCLINIC ZONE MOVES FARTHER SOUTH OF THE REGION
TOWARD TUESDAY MORNING.
FRESH CANADIAN HIGH PRESSURE THEN REMAINS ON TRACK TO SETTLE OVER SE
MICHIGAN FOR THE MID WEEK PERIOD. THE NEW MODEL SOLUTIONS REMAIN
ROCK SOLID ON THE SCENARIO THROUGH THURSDAY WHEN HINTS OF A DRY
BACKDOOR COLD FRONT SHOW UP THURSDAY NIGHT INTO FRIDAY. THIS IS
SYMPTOMATIC OF NORTHWEST FLOW ALOFT PERSISTING LONGER OVER THE GREAT
LAKES AS THE UPPER LEVEL BLOCK MATURES OUT WEST. IT ALSO MEANS
CONDITIONS BECOMING MORE UNSETTLED FOR NEXT WEEKEND.
MARINE...
FAVORABLE MARINE CONDITIONS WILL PERSIST ACROSS AREA WATERWAYS WITH
A BENIGN PATTERN IN PLACE. WIND AND WAVE CONDITIONS WILL OTHERWISE
REMAIN FAVORABLE UNTIL MONDAY AFTERNOON WHEN THE NEXT COLD FRONT IS
DUE THROUGH THE REGION. WINDS ARE EXPECTED TO AGGRESSIVELY TURN TO
THE NORTHEAST BEHIND THE FRONTAL PASSAGE DURING THE LATE AFTERNOON
OR EARLY EVENING HOURS. SMALL CRAFT ADVISORIES MAY BE A POSSIBILITY
FOR THE NEARSHORE WATERS OF LAKE HURON INCLUDING SAGINAW BAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....KURIMSKI
SHORT TERM...CB
LONG TERM....BT
MARINE.......CB
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
000
FXUS63 KDTX 161956
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
356 PM EDT SUN JUN 16 2013
.SHORT TERM...REST OF TODAY AND TONIGHT
THE MAIN JET STREAM AXIS WILL REMAIN IN PLACE OVER THE GREAT LAKES
REGION RESULTING IN STATIC ADVECTIONS OR LITTLE AIRMASS TURNOVER.
THIS WILL BE REFLECTED AT THE SURFACE WITH NO SURFACE PRESSURE
TENDENCY AND A WEAK SURFACE TROUGH OR COL LIKE STRUCTURE. THE
NEUTRAL ADVECTION PATTERN HAS AN IMPACT HERE YET THIS AFTERNOON AS
THE LACK OF MIDLEVEL COOLING SHOULD KEEP A SUBTLE CAP IN PLACE
CENTERED AT 775MB. THERE STILL REMAINS SOME TIME FOR AN ISOLATED
CELL TO INITIATE IN SOME WEAKNESS OF THE CAPPING...POSSIBLY AIDED BY
SOME LAKE CONVERGENCE FORCING. HOWEVER...THE LIKELIHOOD OF THIS TO
OCCUR IS CERTAINLY 20 PERCENT OR LESS.
THE LACK OF ADVECTION OR POSITIVE SURFACE PRESSURE TENDENCY SHOULD
SIGNAL THE LACK OF ANY SIGNIFICANT LOW TO MIDLEVEL INVERSION
TONIGHT. THIS INCREASES CONFIDENCE THAT SKIES SHOULD BE
PREDOMINATELY CLEAR FOR THE DURATION OF THE NIGHT. THE ONE EXCEPTION
WILL BE OVER THE NORTHERN CWA LATE IN THE FORECAST PERIOD AS SOME
LEFTOVER CONVECTIVE DEBRIS AHEAD OF A WEAK SURFACE BOUNDARY MAY
SURVIVE THE TRIP SOUTHWARD. CONFIDENCE IN THIS OCCURRING REMAINS LOW.
&&
.LONG TERM... MONDAY THROUGH SUNDAY
AFTERNOON WATER VAPOR SATELLITE IMAGERY AND SURFACE ANALYSIS
INDICATE THE UPPER LEVEL TROUGH SHEARING SOUTHWARD FROM CENTRAL
CANADA AND CARRYING THE ASSOCIATED COLD FRONT INTO THE UPPER
MIDWEST. THIS SYSTEM WILL BE THE FOCUS OF CONDITIONS IN SE MICHIGAN
MONDAY AND MONDAY NIGHT AND PRESENTS A FAIRLY STRAIGHTFORWARD
FORECAST SCENARIO FOR SHOWERS AND THUNDERSTORMS. AT FIRST, IT LOOKED
LIKE BOUNDARY LAYER MOISTURE RETURN WOULD BE ONE OF THEM BUT PERHAPS
NOT CONSIDERING HOW CONVECTION IS DEVELOPING TODAY OVER THE NORTHERN
GREAT LAKES. LOWER 50S SURFACE DEWPOINT IS GOOD ENOUGH IN THAT
AREA WHERE TEMPERATURES ALOFT ARE ABOUT -16C AT 500 MB. THERE IS
GOOD AGREEMENT AMONG THE NEW MODEL OUTPUT SHOWING SOME OF THIS
COLD AIR ALOFT SETTLING OVER SOUTHERN LOWER MICHIGAN BY MONDAY
AFTERNOON TAKING 500 MB TEMPS DOWN TO BETWEEN -14 AND -16C. EXPECT
THIS WILL PERMIT LOWER TO MID 50S SURFACE DEWPOINT TO GENERATE
CAPE AROUND 1500 J/KG, GOOD ENOUGH FOR CONVECTION TO BECOME
ORGANIZED WITHIN A STRONG WIND FIELD FEATURING NEARLY 60 KNOTS OF
WESTERLY FLOW AT 500 MB AND 45 KNOTS OF 0-6KM BULK SHEAR. THE
STRONG UNIDIRECTIONAL NATURE OF THE SHEAR PROFILE INDICATES A
DISCRETE SUPERCELL MODE IS POSSIBLE EARLY WITH ENHANCED UPDRAFTS
CAPABLE OF LARGE HAIL DUE TO FREEZING LEVEL ON THE LOW SIDE,
ABOUT 10500 FEET, FOR THIS TIME OF YEAR. A QUICK EVOLUTION INTO A
LINEAR MODE COULD FOLLOW WITH A DAMAGING WIND COMPONENT.
WESTERLY UPPER LEVEL FLOW AND DAYTIME SURFACE HEATING SOUTH OF THE
FRONT WILL BUY SOME DRY CONDITIONS DURING MONDAY MORNING. THE MAIN
FORECAST ADJUSTMENT IS TO DELAY HIGHER POPS INTO THE AFTERNOON IN
THE TRI CITIES AND EXTEND TO THE SOUTH AND INTO MONDAY EVENING
TOWARD THE OHIO BORDER. MODEL CROSS SECTIONS ALSO INDICATE THE
SHALLOWNESS OF THE COLD FRONT WILL HAVE AN IMPACT ON SOUTHWARD
PROGRESSION AS SURFACE HEATING OVER INTERIOR LOWER ERODES THE
PRESSURE FIELD. NOT UNTIL MONDAY EVENING WILL THE FRONT RELEASE
THE REST OF THE WAY THROUGH LOWER MICHIGAN WITH A BOOST FROM LAKE
HURON AND LAKE MICHIGAN, AND ALSO WITH A BOOST FROM EXTRA HEIGHT
FALLS WITH THE SHARPENING UPPER TROUGH OVER NORTHERN ONTARIO AND
QUEBEC. EXPECT THEN A STEADY DECREASE IN POPS THROUGH THE NIGHT
AS THE LOW LEVEL BAROCLINIC ZONE MOVES FARTHER SOUTH OF THE REGION
TOWARD TUESDAY MORNING.
FRESH CANADIAN HIGH PRESSURE THEN REMAINS ON TRACK TO SETTLE OVER SE
MICHIGAN FOR THE MID WEEK PERIOD. THE NEW MODEL SOLUTIONS REMAIN
ROCK SOLID ON THE SCENARIO THROUGH THURSDAY WHEN HINTS OF A DRY
BACKDOOR COLD FRONT SHOW UP THURSDAY NIGHT INTO FRIDAY. THIS IS
SYMPTOMATIC OF NORTHWEST FLOW ALOFT PERSISTING LONGER OVER THE GREAT
LAKES AS THE UPPER LEVEL BLOCK MATURES OUT WEST. IT ALSO MEANS
CONDITIONS BECOMING MORE UNSETTLED FOR NEXT WEEKEND.
&&
.MARINE...
FAVORABLE MARINE CONDITIONS WILL PERSIST ACROSS AREA WATERWAYS WITH
A BENIGN PATTERN IN PLACE. WIND AND WAVE CONDITIONS WILL OTHERWISE
REMAIN FAVORABLE UNTIL MONDAY AFTERNOON WHEN THE NEXT COLD FRONT IS
DUE THROUGH THE REGION. WINDS ARE EXPECTED TO AGGRESSIVELY TURN TO
THE NORTHEAST BEHIND THE FRONTAL PASSAGE DURING THE LATE AFTERNOON
OR EARLY EVENING HOURS. SMALL CRAFT ADVISORIES MAY BE A POSSIBILITY
FOR THE NEARSHORE WATERS OF LAKE HURON INCLUDING SAGINAW BAY.
&&
.AVIATION...ISSUED 138 PM EDT SUN JUN 16 2013
//DISCUSSION...
THE JET STREAM AXIS WILL REMAIN IN A WEST TO EAST FASHION DIRECTLY
OVER THE GREAT LAKES REGION. THIS WILL MAKE DRY AIR ADVECTION A
STUBBORN PROCESS WITHIN THE LOW LEVELS. THERE REMAINS ENOUGH NEAR
SURFACE MOISTURE TO CARRY A SLIGHT CHANCE POP FOR A SHOWER OR
THUNDERSTORM THIS AFTERNOON BETWEEN 20-23Z. HOWEVER...THE
POTENTIAL REMAINS TOO LOW TO CARRY AN EXPLICIT MENTION. ADVECTIONS
WILL REMAIN WEAK AGAIN TONIGHT WITH ANY BACKGROUND MIDLEVEL
INVERSIONS NON-EXISTENT. BELIEF IS THAT ONCE WE CAN MIX OUT CLOUDS
TOWARDS SUNDOWN...SKIES WILL REMAIN SKC FOR THE OVERNIGHT.
//DTW THRESHOLD THREATS...
* HIGH CONFIDENCE THAT CEILINGS BELOW 5KFT WILL BREAK THIS
AFTERNOON.
* HIGH CONFIDENCE FOR A VERY LOW THUNDERSTORM PROBABILITY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...CB
LONG TERM....BT
MARINE.......CB
AVIATION.....CB
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
000
FXUS63 KDTX 161738
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
138 PM EDT SUN JUN 16 2013
.AVIATION...
//DISCUSSION...
THE JET STREAM AXIS WILL REMAIN IN A WEST TO EAST FASHION DIRECTLY
OVER THE GREAT LAKES REGION. THIS WILL MAKE DRY AIR ADVECTION A
STUBBORN PROCESS WITHIN THE LOW LEVELS. THERE REMAINS ENOUGH NEAR
SURFACE MOISTURE TO CARRY A SLIGHT CHANCE POP FOR A SHOWER OR
THUNDERSTORM THIS AFTERNOON BETWEEN 20-23Z. HOWEVER...THE
POTENTIAL REMAINS TOO LOW TO CARRY AN EXPLICIT MENTION. ADVECTIONS
WILL REMAIN WEAK AGAIN TONIGHT WITH ANY BACKGROUND MIDLEVEL
INVERSIONS NON-EXISTENT. BELIEF IS THAT ONCE WE CAN MIX OUT CLOUDS
TOWARDS SUNDOWN...SKIES WILL REMAIN SKC FOR THE OVERNIGHT.
//DTW THRESHOLD THREATS...
* HIGH CONFIDENCE THAT CEILINGS BELOW 5KFT WILL BREAK THIS
AFTERNOON.
* HIGH CONFIDENCE FOR A VERY LOW THUNDERSTORM PROBABILITY.
&&
.PREV DISCUSSION...ISSUED 324 AM EDT SUN JUN 16 2013
SHORT TERM...TODAY AND TONIGHT
EASTWARD PROGRESSION OF THE LOW-LEVEL JET AXIS WILL FACILITATE AN
EARLY EXIT OF ONGOING SHOWER AND THUNDERSTORM ACTIVITY THIS MORNING
WITH ORGANIZED PRECIP FORECAST TO CLEAR THE AREA BY 12Z. THE
REMAINDER OF THE DAY WILL BE CHARACTERIZED BY THE INFILTRATION OF
THE DEEP COLUMN OF DRY AIR NOTED OVER THE NORTHERN PLAINS THIS
MORNING AS THE SAGGING/DISTURBED MID-LEVEL HEIGHT FIELD AND
ASSOCIATED UPPER JET SHIFT SOUTH OF THE AREA. H7 PLANVIEWS OF
THETA-E DEPICT THE SOUTHEASTWARD PUSH OF DRY AIR WELL, WITH THE
THETA-E GRADIENT MAKING A QUICK PUSH THROUGH THE FORECAST AREA
BETWEEN 18Z AND 21Z. PRIOR TO THAT TIME, REMNANT MOISTURE AND
INCREASING DIURNAL HEATING IN THE PRESENCE OF WEAK MID-LEVEL
SHORTWAVE FORCING FOR ASCENT ARE SUFFICIENT JUSTIFICATION FOR
MENTION OF CHANCE POPS TO ACCOUNT FOR THE POTENTIAL FOR ISOLATED TO
SCATTERED ACTIVITY THROUGH THE FIRST HALF OF THE DAY.
EMERGENCE OF WELL-MIXED WESTERLY FLOW WILL COINCIDE WITH THE ARRIVAL
OF MAXIMUM MID-LEVEL DRYING AND THE PEAK IN DIURNAL HEATING. AS A
RESULT, BOUNDARY LAYER GROWTH TO 850MB WILL SUPPORT HIGH
TEMPERATURES NEARING 80 DEGREES THIS AFTERNOON DESPITE WHAT WILL
LIKELY BE A HEALTHY COVERAGE OF STRATOCU AND BREEZY WESTERLY WINDS.
AFTERNOON ARRIVAL OF DRY AIR WILL ALSO SUBSTANTIALLY LIMIT
THUNDERSTORM POTENTIAL DESPITE PROGGED SBCAPE VALUES AROUND 1500
J/KG. STILL, IT WILL NOT BE OUT OF THE QUESTION FOR A PERSISTENT
UPDRAFT OR TWO TO LOCALLY WORK OVER THEIR ENVIRONMENT AND SURVIVE
LONG ENOUGH TO PRODUCE SOME THUNDER AND A BRIEF HEAVY DOWNPOUR. AS A
RESULT, THE INHERITED LOW CHANCE POPS REMAIN IN PLACE SOUTH OF
INTERSTATE 69 THROUGH 00Z THIS EVENING. MILD BUT DRY CONDITIONS CAN
BE EXPECTED TONIGHT AS THE GRADIENT WINDS BACK TO SOUTHWESTERLY
AHEAD OF THE NEXT WAVE.
LONG TERM... MONDAY THROUGH SATURDAY
BROADER MID LEVEL TROUGHING ANCHORED ACROSS SOUTH-CENTRAL CANADA
WILL UNDERGO SOME STRENGTHENING WITH TIME OVER THE NEXT 48 HOURS
WITH A CLOSED LOW EVOLVING OVER HUDSON BAY. THIS WILL PROMPT THE
SOUTHERN EXTENSION OF THE MAIN HEIGHT FALL REGION TO SQUEEZE INTO
THE PREVAILING MID LEVEL WESTERLIES POSITIONED OVER THE GREAT
LAKES. THIS PROCESS WILL ALLOW A COLD FRONTAL BOUNDARY TO SETTLE
SOUTHWARD THROUGH LOWER MICHIGAN MONDAY AND MONDAY NIGHT. SOLID
WINDOW WILL EXIST TO CAPITALIZE ON DAYTIME HEATING WITH THE FRONTAL
PASSAGE CENTERED LOCALLY ON THE AFTERNOON/EVENING PERIOD. ASSUMING
SOME PESKY HIGHER LEVEL CLOUD DEBRIS DOES NOT DISRUPT THE DIABATIC
HEATING CONTRIBUTION...A STEADY LOW LEVEL WEST-SOUTHWEST GRADIENT
WILL SUPPORT HIGHS OF LOWER TO MIDDLE 80S ACROSS THE SOUTHERN
TWO-THIRDS OF THE AREA. THE DEGREE OF DESTABILIZATION WILL BE
LIMITED TO SOME EXTENT BY A RELATIVELY MODEST MOISTURE PROFILE...
ESPECIALLY WITHIN THE BOUNDARY LAYER WHERE A LACK OF BETTER
PRE-FRONTAL MOISTURE TRANSPORT WILL LEAVE DEWPOINTS HOVERING IN THE
MID/UPPER 50S. NONETHELESS THE INCREASING FRONTAL CONVERGENCE...
PERHAPS AIDED BY SOME FORM OF WEAK MID LEVEL ENERGY AND UPPER JET
FORCING...WILL SUPPORT SCATTERED SHOWER AND THUNDERSTORM DEVELOPMENT
GIVEN THE FAVORABLE FRONTAL TIMING. TREMENDOUS LARGELY
UNIDIRECTIONAL WIND FIELD WILL BE IN PLACE...0-6 KM BULK SHEAR IN
EXCESS OF 40 KNOTS. THEREFORE...POTENTIAL IS THERE FOR ANY STRONGER
UPDRAFTS TO QUICKLY ATTAIN BETTER ORGANIZATION...PRESENTING AT LEAST
AN ISOLATED RISK FOR SEVERE WIND GUSTS/HAIL.
STEADY BUT BRIEF TRANSITION TO MID LEVEL NORTHWEST FLOW ON THE EDGE
OF THE SOUTHERN CANADIAN TROUGH INTERFACE WILL EFFECTIVELY SHIFT THE
FRONT SOUTH OF THE REGION BY TUESDAY MORNING. LOW LEVEL
ANTICYCLONIC FLOW WILL THEN TAKE CONTROL FOR TUESDAY AS
STRENGTHENING HIGH PRESSURE FILLS SOUTHEAST TOWARD THE WESTERN GREAT
LAKES. THIS WILL USHER IN A COOLER AND LESS HUMID AIRMASS...
850-925 MB THERMAL LAYER DROPPING A GOOD 6-7 DEGREES. A HIGH DEGREE
OF SUNSHINE WILL BE THE SOURCE FOR THE DIURNAL RECOVERY...HIGHS
RANGING FROM MID 70S SOUTH TO MID 60S IN THE THUMB. HIGH PRESSURE
CENTER WORKS IN BY TUESDAY NIGHT...SETUP CERTAINLY POINTS TO A
FAVORABLE RADIATIONAL COOLING ENVIRONMENT. LOWS TUESDAY NIGHT MAY
ARRIVE JUST SHY OF RECORD TERRITORY /DTW 46...FNT 44...MBS 42/ BUT
THIS AIRMASS WOULD SUPPORT READINGS OF MIDDLE 40S IN THE COLDEST
LOCALES.
GENERAL SURFACE RIDGING TUCKED BENEATH WEAK WEST-NORTHWEST MID LEVEL
FLOW WILL MAINTAIN DRY AND STABLE CONDITIONS THROUGH THURSDAY. NO
REAL CHANGE TO OVERALL CONDITIONS ON WEDNESDAY WITH NEUTRAL
THERMAL/MOISTURE ADVECTION AND MINIMAL NOTED CHANGE IN THE UPPER
HEIGHT FIELD. A SLOW INCREASE IN MEAN THICKNESSES AS HEIGHTS SLOWLY
BUILD WILL INITIATE THE START OF A PROGRESSIVE WARMING TREND
BEGINNING ON THURSDAY. SOME DEGREE OF UPPER RIDGING WILL TAKE FORM
UPSTREAM BY THE END OF THE WEEK...WITH THIS HEIGHT FIELD ENTERING
THE PICTURE LOCALLY BY NEXT WEEKEND. THIS POINTS TOWARD A RETURN TO
MORE TYPICAL LATE JUNE WARMTH AND HUMIDITY DURING THIS TIME.
MARINE...
FAVORABLE MARINE CONDITIONS WILL PERSIST ACROSS AREA WATERWAYS WITH
A BENIGN PATTERN IN PLACE, ALTHOUGH SOME DISRUPTION WILL BE POSSIBLE
THROUGH EARLY THIS MORNING DUE TO THUNDERSTORM ACTIVITY. WIND AND
WAVE CONDITIONS WILL OTHERWISE REMAIN FAVORABLE UNTIL LATE MONDAY
WHEN THE NEXT COLD FRONT IS DUE THROUGH THE REGION.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....CB
SHORT TERM...JVC
LONG TERM....MR
MARINE.......JVC
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
000
FXUS63 KDTX 161109
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
709 AM EDT SUN JUN 16 2013
.AVIATION...
//DISCUSSION...
NOTHING MORE THAN A COUPLE OF LINGERING SHOWERS REMAINS FROM EARLY
MORNING ACTIVITY THAT PASSED THROUGH THE AREA. THE REMAINDER OF THE
DAY WILL FEATURE ONLY A LOW CHANCE FOR A SHOWER, NOTHING WORTH A
SPECIFIC MENTION IN THE 12Z TAF ISSUANCE, AND A SOLID COVERAGE OF
HIGH MVFR TO LOW VFR STRATOCU COURTESY OF DIURNAL MIXING AND
RESIDUAL LOW-LEVEL MOISTURE. WELL-MIXED WESTERLY FLOW WILL EMERGE BY
AFTERNOON WITH GUSTS APPROACHING 20 KNOTS DURING PEAK HEATING. AN
AGGRESSIVE PUSH OF DRY AIR AND LOSS OF DIURNAL HEATING WILL COMBINE
TO ERODE WHAT REMAINS OF LOW CLOUD COVER BY AROUND 00Z.
//DTW THRESHOLD THREATS...
* HIGH CONFIDENCE IN CEILINGS BELOW 5KFT
* LOW CONFIDENCE THAT A THUNDERSTORM WILL IMPACT KDTW AIRSPACE
&&
.PREV DISCUSSION...ISSUED 324 AM EDT SUN JUN 16 2013
SHORT TERM...TODAY AND TONIGHT
EASTWARD PROGRESSION OF THE LOW-LEVEL JET AXIS WILL FACILITATE AN
EARLY EXIT OF ONGOING SHOWER AND THUNDERSTORM ACTIVITY THIS MORNING
WITH ORGANIZED PRECIP FORECAST TO CLEAR THE AREA BY 12Z. THE
REMAINDER OF THE DAY WILL BE CHARACTERIZED BY THE INFILTRATION OF
THE DEEP COLUMN OF DRY AIR NOTED OVER THE NORTHERN PLAINS THIS
MORNING AS THE SAGGING/DISTURBED MID-LEVEL HEIGHT FIELD AND
ASSOCIATED UPPER JET SHIFT SOUTH OF THE AREA. H7 PLANVIEWS OF
THETA-E DEPICT THE SOUTHEASTWARD PUSH OF DRY AIR WELL, WITH THE
THETA-E GRADIENT MAKING A QUICK PUSH THROUGH THE FORECAST AREA
BETWEEN 18Z AND 21Z. PRIOR TO THAT TIME, REMNANT MOISTURE AND
INCREASING DIURNAL HEATING IN THE PRESENCE OF WEAK MID-LEVEL
SHORTWAVE FORCING FOR ASCENT ARE SUFFICIENT JUSTIFICATION FOR
MENTION OF CHANCE POPS TO ACCOUNT FOR THE POTENTIAL FOR ISOLATED TO
SCATTERED ACTIVITY THROUGH THE FIRST HALF OF THE DAY.
EMERGENCE OF WELL-MIXED WESTERLY FLOW WILL COINCIDE WITH THE ARRIVAL
OF MAXIMUM MID-LEVEL DRYING AND THE PEAK IN DIURNAL HEATING. AS A
RESULT, BOUNDARY LAYER GROWTH TO 850MB WILL SUPPORT HIGH
TEMPERATURES NEARING 80 DEGREES THIS AFTERNOON DESPITE WHAT WILL
LIKELY BE A HEALTHY COVERAGE OF STRATOCU AND BREEZY WESTERLY WINDS.
AFTERNOON ARRIVAL OF DRY AIR WILL ALSO SUBSTANTIALLY LIMIT
THUNDERSTORM POTENTIAL DESPITE PROGGED SBCAPE VALUES AROUND 1500
J/KG. STILL, IT WILL NOT BE OUT OF THE QUESTION FOR A PERSISTENT
UPDRAFT OR TWO TO LOCALLY WORK OVER THEIR ENVIRONMENT AND SURVIVE
LONG ENOUGH TO PRODUCE SOME THUNDER AND A BRIEF HEAVY DOWNPOUR. AS A
RESULT, THE INHERITED LOW CHANCE POPS REMAIN IN PLACE SOUTH OF
INTERSTATE 69 THROUGH 00Z THIS EVENING. MILD BUT DRY CONDITIONS CAN
BE EXPECTED TONIGHT AS THE GRADIENT WINDS BACK TO SOUTHWESTERLY
AHEAD OF THE NEXT WAVE.
LONG TERM... MONDAY THROUGH SATURDAY
BROADER MID LEVEL TROUGHING ANCHORED ACROSS SOUTH-CENTRAL CANADA
WILL UNDERGO SOME STRENGTHENING WITH TIME OVER THE NEXT 48 HOURS
WITH A CLOSED LOW EVOLVING OVER HUDSON BAY. THIS WILL PROMPT THE
SOUTHERN EXTENSION OF THE MAIN HEIGHT FALL REGION TO SQUEEZE INTO
THE PREVAILING MID LEVEL WESTERLIES POSITIONED OVER THE GREAT
LAKES. THIS PROCESS WILL ALLOW A COLD FRONTAL BOUNDARY TO SETTLE
SOUTHWARD THROUGH LOWER MICHIGAN MONDAY AND MONDAY NIGHT. SOLID
WINDOW WILL EXIST TO CAPITALIZE ON DAYTIME HEATING WITH THE FRONTAL
PASSAGE CENTERED LOCALLY ON THE AFTERNOON/EVENING PERIOD. ASSUMING
SOME PESKY HIGHER LEVEL CLOUD DEBRIS DOES NOT DISRUPT THE DIABATIC
HEATING CONTRIBUTION...A STEADY LOW LEVEL WEST-SOUTHWEST GRADIENT
WILL SUPPORT HIGHS OF LOWER TO MIDDLE 80S ACROSS THE SOUTHERN
TWO-THIRDS OF THE AREA. THE DEGREE OF DESTABILIZATION WILL BE
LIMITED TO SOME EXTENT BY A RELATIVELY MODEST MOISTURE PROFILE...
ESPECIALLY WITHIN THE BOUNDARY LAYER WHERE A LACK OF BETTER
PRE-FRONTAL MOISTURE TRANSPORT WILL LEAVE DEWPOINTS HOVERING IN THE
MID/UPPER 50S. NONETHELESS THE INCREASING FRONTAL CONVERGENCE...
PERHAPS AIDED BY SOME FORM OF WEAK MID LEVEL ENERGY AND UPPER JET
FORCING...WILL SUPPORT SCATTERED SHOWER AND THUNDERSTORM DEVELOPMENT
GIVEN THE FAVORABLE FRONTAL TIMING. TREMENDOUS LARGELY
UNIDIRECTIONAL WIND FIELD WILL BE IN PLACE...0-6 KM BULK SHEAR IN
EXCESS OF 40 KNOTS. THEREFORE...POTENTIAL IS THERE FOR ANY STRONGER
UPDRAFTS TO QUICKLY ATTAIN BETTER ORGANIZATION...PRESENTING AT LEAST
AN ISOLATED RISK FOR SEVERE WIND GUSTS/HAIL.
STEADY BUT BRIEF TRANSITION TO MID LEVEL NORTHWEST FLOW ON THE EDGE
OF THE SOUTHERN CANADIAN TROUGH INTERFACE WILL EFFECTIVELY SHIFT THE
FRONT SOUTH OF THE REGION BY TUESDAY MORNING. LOW LEVEL
ANTICYCLONIC FLOW WILL THEN TAKE CONTROL FOR TUESDAY AS
STRENGTHENING HIGH PRESSURE FILLS SOUTHEAST TOWARD THE WESTERN GREAT
LAKES. THIS WILL USHER IN A COOLER AND LESS HUMID AIRMASS...
850-925 MB THERMAL LAYER DROPPING A GOOD 6-7 DEGREES. A HIGH DEGREE
OF SUNSHINE WILL BE THE SOURCE FOR THE DIURNAL RECOVERY...HIGHS
RANGING FROM MID 70S SOUTH TO MID 60S IN THE THUMB. HIGH PRESSURE
CENTER WORKS IN BY TUESDAY NIGHT...SETUP CERTAINLY POINTS TO A
FAVORABLE RADIATIONAL COOLING ENVIRONMENT. LOWS TUESDAY NIGHT MAY
ARRIVE JUST SHY OF RECORD TERRITORY /DTW 46...FNT 44...MBS 42/ BUT
THIS AIRMASS WOULD SUPPORT READINGS OF MIDDLE 40S IN THE COLDEST
LOCALES.
GENERAL SURFACE RIDGING TUCKED BENEATH WEAK WEST-NORTHWEST MID LEVEL
FLOW WILL MAINTAIN DRY AND STABLE CONDITIONS THROUGH THURSDAY. NO
REAL CHANGE TO OVERALL CONDITIONS ON WEDNESDAY WITH NEUTRAL
THERMAL/MOISTURE ADVECTION AND MINIMAL NOTED CHANGE IN THE UPPER
HEIGHT FIELD. A SLOW INCREASE IN MEAN THICKNESSES AS HEIGHTS SLOWLY
BUILD WILL INITIATE THE START OF A PROGRESSIVE WARMING TREND
BEGINNING ON THURSDAY. SOME DEGREE OF UPPER RIDGING WILL TAKE FORM
UPSTREAM BY THE END OF THE WEEK...WITH THIS HEIGHT FIELD ENTERING
THE PICTURE LOCALLY BY NEXT WEEKEND. THIS POINTS TOWARD A RETURN TO
MORE TYPICAL LATE JUNE WARMTH AND HUMIDITY DURING THIS TIME.
MARINE...
FAVORABLE MARINE CONDITIONS WILL PERSIST ACROSS AREA WATERWAYS WITH
A BENIGN PATTERN IN PLACE, ALTHOUGH SOME DISRUPTION WILL BE POSSIBLE
THROUGH EARLY THIS MORNING DUE TO THUNDERSTORM ACTIVITY. WIND AND
WAVE CONDITIONS WILL OTHERWISE REMAIN FAVORABLE UNTIL LATE MONDAY
WHEN THE NEXT COLD FRONT IS DUE THROUGH THE REGION.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....JVC
SHORT TERM...JVC
LONG TERM....MR
MARINE.......JVC
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS
ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
| 
