Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 05/10/12
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
926 PM MDT WED MAY 9 2012
.AVIATION...SOUTHERLY DRAINAGE PATTERN IS SLIGHTLY STRONGER THAN
ORIGINALLY FORECAST. INCREASED WINDS SLIGHTLY FOR THE 03Z TAF
UPDATE. WINDS TO THEN SHIFT TO THE SOUTHEAST AFTER 18Z THURSDAY.
VFR CONDITIONS TO PREVAIL. SLIGHT CHANCE OF THUNDERSTORMS ALONG
FOOTHILLS AFTER 21Z...SHOULD NOT AFFECT AREA AIRPORTS.
&&
.PREV DISCUSSION... /ISSUED 303 PM MDT WED MAY 9 2012/
SHORT TERM...CUMULUS FINALLY DEVELOPING ACROSS MOUNTAINS OF PARK
SUMMIT AND GRAND COUNTIES. AIRMASS DRIER WITH LOW PRECIPITABLE
WATER. LAPS SURFACE ANALYSIS SHOWING CAPES AROUND 200 J/KG IN THIS
AREA. LATEST RUC INDICATES 200-300 J/KG OF CAPE ACROSS THE
MOUNTAINS THROUGH THE EARLY EVENING. STILL CAN`T RULE OUT A FEW
HIGH BASED STORMS...AND WILL MAINTAIN THE SLIGHT CHANCE THROUGH
THE EARLY EVENING. FORECAST SOUNDINGS INDICATE POTENTIAL FOR MORE
WIND THAN RAIN. OTHERWISE...DRY CONDITIONS TO PREVAIL WITH MAINLY
CLEAR SKIES. WITH LIGHT DRAINAGE WINDS EXPECTED OVERNIGHT...LOWS
TO DROP INTO THE 40S ACROSS THE PLAINS...WITH SOME MID AND UPPER
30S IN LOW LYING AREAS. ON THURSDAY...UPPER LEVEL RIDGE OVER AREA TO
SHIFT EAST WITH FLOW ALOFT BECOMING SOUTHWEST. THIS FLOW TO ALLOW
SOME INCREASE IN MOISTURE ACROSS THE MOUNTAINS BY THE AFTERNOON.
WITH FAIRLY STEEP LAPSE RATES EXPECTED AND FORECAST CAPES AROUND
500 J/KG...IT APPEARS THAT THERE WILL BE A BETTER CHANCE FOR
THUNDERSTORMS OVER THE HIGH COUNTRY. BUT WITHOUT HELP FROM AN
UPPER LEVEL FEATURE...SLIGHT CHANCE POPS SHOULD SUFFICE FOR NOW.
WILL ALSO ADD A SLIGHT CHANCE OF STORMS TO THE FOOTHILLS LATE IN
THE DAY AS A FEW OF THE STORMS COULD MOVE ACROSS AREA. FORECAST
SOUNDINGS STILL SHOWING POTENTIAL FOR MORE WIND THAN RAIN. ACROSS
PLAINS...AIRMASS TOO DRY FOR ANY CONVECTION DESPITE THE FAIRLY
DECENT LAPSE RATES. TEMPERATURE AND THICKNESS PROGS AS WELL AS
GUIDANCE SHOW HIGHS IN THE LOWER TO MID 80S ACROSS PLAINS. THIS
LOOKS REASONABLE GIVEN AMOUNT OF WARM AIR ADVECTION EXPECTED. CURRENT
TEMPERATURE GRIDS IN LINE WITH GUIDANCE AND LOOKS REASONABLE.
LONG TERM...UPPER LEVEL TROUGH WILL PASS WELL NORTH OF THE AREA
THURSDAY NIGHT...BUT IT WILL PUSH A COLD FRONT SOUTH THROUGH THE
AREA AROUND MIDNIGHT. MAY SEE A FEW HIGH BASED SHOWERS AND
THUNDERSTORMS AHEAD OF IT THURSDAY EVENING...THE BEST CHANCE BEING
OVER THE HIGHER TERRAIN. IT WILL BE MUCH COOLER BEHIND THE FRONT
ON FRIDAY WITH AREAS ALONG THE FRONT AND ACROSS THE EASTERN PLAINS
STRUGGLE TO CLIMB ABOVE 50 DEGREES. SHOULD BE ENOUGH MOISTURE AND
UPSLOPE FLOW TO KEEP CLOUDS OVER THE AREA FRIDAY. AIRMASS WILL BE
UNSTABLE OVER THE MOUNTAINS FRIDAY AFTERNOON. THIS COMBINED WITH
A SHORT WAVE WILL PRODUCE THUNDERSTORMS DURING THE AFTERNOON
HOURS. EAST OF THE CONTINENTAL DIVIDE...WINDS WILL TURN
EASTERLY...WHICH WILL ENHANCE THE UPSLOPE COMPONENT. EXPECT RAIN
AND SNOW TO BECOME WIDESPREAD BY FRIDAY EVENING OVER THE FRONT RANGE
AS THE UPPER LEVEL WAVE MOVES OVER. SNOW LEVEL WILL FALL TO 7000 TO
8000 FEET.
RAIN WILL LINGER INTO SATURDAY AS THE UPSLOPE FLOW CONTINUES.
HIGHS WILL AGAIN BE COOLER WITH READINGS AROUND 50 DEGREES. UPPER
LEVEL TROUGH WILL MOVE SOUTH ACROSS THE GREAT BASIN
SUNDAY. THIS SYSTEM WILL MAY BRING A ROUND OF AFTERNOON CONVECTION
TO THE HIGH COUNTRY. FOR THE PLAINS...IN ADDITION TO BEING TOO FAR
AWAY FROM THE UPPER LEVEL SYSTEM DRIER AIR WILL BE IN
PLACE. SO IF ANY SHOWERS FORM...THEY WILL BE LIGHT.
UPPER LEVEL RIDGE WILL MOVE OVER THE STATE EARLY NEXT WEEK.
CHANCES FOR CONVECTION WILL BE LOW UNDER THIS PATTERN.
TEMPERATURES WILL WARM TO SLIGHTLY ABOVE NORMAL BY TUESDAY.
AVIATION...LIGHT EASTERLY WINDS TO BECOME SOUTHWEST BY 02Z AS
DRAINAGE PATTERN DEVELOPS. WINDS TO THEN SHIFT TO THE SOUTHEAST
AFTER 18Z. VFR CONDITIONS TO PREVAIL. SLIGHT CHANCE OF
THUNDERSTORMS ALONG FOOTHILLS AFTER 21Z...SHOULD NOT AFFECT AREA
AIRPORTS.
HYDROLOGY...A FEW HIGH BASED STORMS POSSIBLE OVER THE MOUNTAINS
THIS EVENING WITH LIGHT RAINFALL EXPECTED. A SLIGHT CHANCE OF
THUNDERSTORMS MOUNTAINS AND FOOTHILLS AFTER 18Z WITH LIGHT RAIN.
NO HYDROLOGIC ISSUES ANTICIPATED.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....MEIER
AVIATION...KRIEDERMAN
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1221 AM EDT TUE MAY 8 2012
.SYNOPSIS...
HIGH PRESSURE OFF THE NORTHEAST COAST WILL DRIFT EAST. A WARM FRONT
WILL CROSS THE REGION LATE TONIGHT AND TUESDAY. A COLD FRONT WILL
SLOWLY APPROACH THE AREA TUESDAY NIGHT INTO WEDNESDAY AND CROSS THE
REGION LATE WEDNESDAY INTO WEDNESDAY NIGHT. LOW PRESSURE MAY FORM
ALONG THE FRONT AND PASS TO OUR EAST LATE WEDNESDAY NIGHT INTO
THURSDAY MORNING. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT
FOR THE END OF THE WEEK AND THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
NO BIG CHANGES HAVE BEEN MADE TO THE OVERNIGHT FORECAST. WE ARE
IN THE BREAK BETWEEN WAA SHOTS. HAVE CANCELLED THE CFA EARLY FOR
THE OCEAN FRONT AS THE HIGH TIDE HAS PASSED. AS IS NORMALLY THE
CASE WITH CONVECTION WHILE THE GENERAL THEME OF THE MODELS HAS
BEEN ALRIGHT, NO INDIVIDUAL MODEL IS HANDLING UPSTREAM CONVECTION
CLOSELY, ESPECIALLY THE ONGOING PCPN IN NORTHERN WEST VIRGINIA.
THUS WE HAVE MAINTAINED SOME CHANCE LATER TONIGHT AS FAR SOUTH AS
THE PHL SUBURBS. ONLY OTHER CHANGE WITH THE POPS BASED ON THE 18Z
AND HRRR MODEL DATA WAS TO PIVOT HIGHEST POPS ACROSS NORTHERN CWA
IN A MORE W TO E DIRECTION. OTHER THAN THE 18Z WRF- NMMB, NO OTHER
MODEL BRINGS THUNDER INTO OUR CWA. THE WRF-NMMB TENDS TO BE TOO
BULLISH WITH THUNDER, SO WITHOUT FURTHER MODEL CORROBORATION, IT
WAS NOT ADDED.
CLOUDS ARE STILL EXPANDING TO OUR SOUTH, SO NO ADJUSTMENTS HAVE
BEEN MADE TO SKY COVER. ALSO THIS SHOULD PRECLUDE MUCH FOG OUTSIDE
OF PCPN FROM OCCURRING. WITH THE SKY COVER AND SOME WIND
OVERNIGHT, TEMPERATURES SHOULD NOT MOVE MUCH FROM CURRENT LEVELS
AND THIS IS ALREADY REFLECTED IN THE GRIDS AND FORECAST.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/...
IT APPEARS THAT UNSETTLED WEATHER WILL BE STARTING DURING THIS TIME
FRAME. THIS IS COURTESY OF LOW PRESSURE MOVING FROM THE UPPER OHIO
VALLEY AND THE EASTERN GREAT LAKES INTO SOUTHEASTERN CANADA. AS THIS
OCCURS, A LOW-LEVEL JET WILL CONTINUE TO MOVE ACROSS OUR AREA AND
EVEN STRENGTHEN A BIT. THIS WILL GENERALLY DRIVE THE MAIN WAA PUSH
AND WARM FRONT TO OUR NORTH. HOWEVER, A COLD FRONT WILL BE ARRIVING
DURING THE AFTERNOON. IT APPEARS THAT AN INITIAL SURGE OF SHOWERS
WILL BE UP ACROSS OUR NORTHWEST ZONES AHEAD OF THE WARM FRONT. WE
THEN AWAIT FOR THE CONVECTION INDUCED BY THE COLD FRONT TO ARRIVE.
THE SURFACE DEW POINTS ARE NOT FORECAST TO RAPIDLY INCREASE DURING
THE DAY, THEREFORE NOT A LOT OF INSTABILITY IS FORECAST TO DEVELOP.
THE FORECAST SOUNDINGS DO IMPLY AT LEAST SOME ELEVATED INSTABILITY
OCCURRING, THEREFORE WE WILL CONTINUE WITH A MENTION OF AT LEAST
SOME THUNDER.
THE COLD FRONT ITSELF LOOKS TO BE FAIRLY SLOW TO ARRIVE, THEREFORE
WE SLOWLY DOWN THE POP INCREASE FROM WEST TO EAST AND TRIED TO SHOW
A TIGHTER GRADIENT AS WELL. THE EASTERN ZONES MAY END UP HAVING A
DRY DAY AS THE MAIN CONVECTION COULD TEND TO HANG BACK FOR AWHILE
WITH LITTLE OR NO DEVELOPMENT WELL IN ADVANCE. AS A RESULT, WE HELD
THE HIGHEST POPS ACROSS OUR FAR WESTERN ZONES.
THE PRESSURE GRADIENT IS FORECAST TO TIGHTEN IN ADVANCE OF THE COLD
FRONT AS HIGH PRESSURE IS TO OUR EAST. THIS ALONG WITH THE LOW-LEVEL
JET TO BE OVERHEAD WILL COMBINE WITH ENOUGH BOUNDARY LAYER HEATING
TO PROMOTE DEEPER VERTICAL MIXING. THIS IS EXPECTED TO RESULT IN A
BREEZE DAY DEVELOPING. THE BEST MIXING LOOKS TO OCCUR FARTHER
EASTWARD ACROSS THE CWA AS THESE LOCALES HAVE A BETTER CHC OF AT
LEAST SOME LONGER SURFACE HEATING. BASED ON THE FORECAST SOUNDINGS,
THE WIND GUSTS LOOK TO TOP OUT IN THE 25-30 MPH RANGE AT MOST
LOCALES. THE INCREASED WINDS MAY ALSO TRY AND LOWER THE SURFACE DEW
POINTS SOME, ESPECIALLY DURING PEAK MIXING.
AS FOR TEMPERATURES, WE STARTED WITH A MOS BLEND THE MADE SOME
TWEAKS ESPECIALLY ALONG THE COAST DUE TO THE SOUTHERLY FLOW AND ALSO
ACROSS THE NORTHWEST ZONES DUE TO THE IDEA OF MORE CLOUDS HERE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
THE 00Z NAM WAS MOST ROBUST WITH DEVELOPMENT OF LOW PRESSURE ALONG
THE FRONT DURING THE WEDNESDAY TO WEDNESDAY NIGHT TIME FRAME, BUT
THE 12Z RUN NOW RESEMBLES MORE THE 06Z AND 12Z GFS AND THE 00Z AND
12Z ECMWF. THEREFORE, ALTHOUGH THE FRONT MOVES SLOWLY, HAS DYNAMIC
SUPPORT AND HAS ACCESS TO GOOD MOISTURE, OUR CONCERN OVER FLOODING
HAS DIMINISHED A LITTLE. WE WILL CONTINUE TO CARRY THE MENTION OF
POSSIBLE HEAVY RAIN IN THE HWO FOR WEDNESDAY AND WEDNESDAY NIGHT.
TUESDAY NIGHT SHOULD SEE AN EXIT OF WARM-FRONTAL RAIN AS THE 300K
ISENTROPIC LIFT MOVES BY, BUT THEN WE START TO SEE THE COLD FRONT
APPROACH THE AREA WITH SUPPORT FROM AN UPPER JET, SOME MID LEVEL
Q-VECTOR CONVERGENCE AND ENERGY IN THE POSITIVELY TILTED MID LEVEL
TROUGH, SOME LOWER LEVEL FRONTOGENESIS, AND SOME SOLID LOW TO MID
LEVEL MOISTURE GIVEN H8 DEW POINTS AND H7 THETA E VALUES. THIS FRONT
PRESENTLY IS PROGGED TO MOVE ACROSS THE AREA LATE WEDNESDAY INTO
WEDNESDAY NIGHT. THAT THE NAM HAS TONED DOWN THE IMPULSE THAT MOVES
ALONG THE FRONT BY NO MEANS IS AN INDICATION THAT MID LEVEL ENERGY
WILL NOT GENERATE ANY IMPULSE WHATSOEVER ALONG IT. HENCE THE SLOW
MOVEMENT OF THE FRONT AND THE SIGNIFICANT RAINFALL FORECAST. IT
DOES, HOWEVER, SEEM THAT ALL FACTORS COME TOGETHER BEST ONCE THE
FRONT IS OFF THE COAST. REGARDING CONVECTION, THERE SHOULD BE ENOUGH
INSTABILITY AVAILABLE FOR THAT INTO WEDNESDAY EVENING. ALTHOUGH IT
LOOKS LIKE THE BEST CHANCE OF STRONG CONVECTION OCCURS TO OUR
SOUTHWEST, THERE ARE FAIR BULK SHEAR NUMBERS ON WEDNESDAY AFTERNOON
NORTHWEST (THE RIGHT REAR QUAD OF THE UPPER JET IS TO OUR NORTHWEST)
AND SOME INDICATION OF AT LEAST MARGINAL CAPES BEING AVAILABLE FOR
THAT SHEAR. SPC CONTINUES TO CARRY US IN A GENERAL TSTM OUTLOOK;
THERE IS AN OFF CHANCE THAT WILL BE ELEVATED WITH TIME.
ONCE THE MID LEVEL IMPULSE MOVES TO OUR EAST, THE MODELS AGREE ON
CUTTING IT OFF. THE CUTOFF MAY BE JUST FAR ENOUGH TO OUR NORTHEAST
TO RELIEVE US OF ANY CONCERN. WE`LL SEE ABOUT THAT, BUT WILL
MAINTAIN AN OPTIMISTIC FORECAST FOR NOW. AFTER THAT, THE NEXT
POTENTIAL FOR RAIN COMES WITH A COLD FRONT THAT APPROACHES LATE IN
THE WEEKEND. THE GFS MAY BE SUFFERING SOME CONVECTIVE FEEDBACK
ISSUES WITH THE FRONT, AND WE HAVE ELECTED TO KEEP THE FORECAST DRY
INTO MONDAY FOR NOW.
TEMPERATURES WILL START THE PERIOD ABOVE NORMAL AHEAD OF THE FRONT
(ESPECIALLY AT NIGHT), DROP TO SOMEWHAT BELOW NORMAL FOR A TIME
AFTER THE FRONT BEFORE GRADUALLY RISING BACK ABOVE NORMAL BY THE END
OF THE PERIOD.
&&
.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
GENERALLY VFR CONDITIONS ARE EXPECTED TO PREVAIL IN THIS TAF
PACKAGE FROM THE KPHL METRO AIRPORTS (I95 CORRIDOR) SEWD WITH
MVFR CONDITIONS AT TIMES AT TERMINALS AND AIRPORTS FARTHER TO THE
NORTHWEST.
FOR THIS EVENING THE FIRST SHOT OF LIGHT RAIN THAT AFFECTED MOSTLY
THE NORTHERN AIRPORTS IS THROUGH. VFR CIGS ARE EXPECTED TO
PREVAIL. HIGHEST CIGS AT KACY AND KMIV. LATER TONIGHT THE
REMNANTS OF ONGOING THUNDERSTORMS IN WESTERN PENNSYLVANIA SHOULD
AFFECT KRDG AND KABE WITH MVFR CIGS AND VSBYS AT TIMES. THEY ARE
GOING TO BE NEAR THE SOUTHERN EDGE OF THE SHOWERS (NO THUNDER BY
THE TIME THEY MOVE EAST) SO CONFIDENCE AS TO THEIR IMPACT IS LESS
THAN AVERAGE. HIGHEST CONFIDENCE ABOUT VFR CONDITIONS ARE AT KMIV
AND KACY.
ON TUESDAY DAY THE TERMINALS SHOULD SPEND A GOOD PART OF THE DAY
IN THE WARM SECTOR WITH CIGS STAYING OR RISING TO VFR LEVELS
DURING THE MORNING HOURS. FORECAST SOUNDINGS ARE SUPPORTING GUSTY
SOUTH WINDS RATHER QUICKLY DURING THE MORNING SHORTLY AFTER 12Z.
ON TUESDAY AFTERNOON CONDITIONS SHOULD DETERIORATE TO MVFR IN
SHOWERS AT KABE AND KRDG (CONFIDENCE IS TOO LOW TO INCLUDE THUNDER
PLUS THEIR COVERAGE IS NOT EXPECTED TO BE THAT WIDESPREAD), FASTER
AT AIRPORTS FARTHER TO THE NORTH, BUT SLOWER FOR THEM TO ARRIVE IN
THE KPHL AREA AIRPORTS WHERE VFR CONDITIONS ARE FORECAST. DITTO
FOR AIRPORTS AND TERMINALS FARTHER TO THE SOUTHEAST. GUSTY SOUTH
WINDS ARE FORECAST TO CONTINUE AND WOULD NOT BE THAT SURPRISED IF
SOME PEAK GUSTS EXCEED 30 KNOTS.
OUTLOOK...
TUESDAY NIGHT AND WEDNESDAY...MVFR CONDITIONS IN SHOWERS AND POSSIBLE
THUNDERSTORMS. LOCALIZED IFR CONDITIONS ARE POSSIBLE. CONFIDENCE IS
MODERATE. THERE IS A CHANCE OF LLWS ON TUESDAY NIGHT MORE SO
SOUTHEAST THAN NORTHWEST.
WEDNESDAY NIGHT...MVFR CONDITIONS IN SHOWERS AND POSSIBLE
THUNDERSTORMS. CONDITIONS MAY IMPROVE NORTHWEST OVERNIGHT.
CONFIDENCE IS LOW TO MODERATE.
THURSDAY AND THURSDAY NIGHT...MAINLY VFR. ISOLATED MVFR CONDITIONS
IN SHOWERS ARE POSSIBLE NORTH. A FRESH NORTHWEST BREEZE IS
ANTICIPATED FOR THURSDAY. CONFIDENCE IS MODERATE.
FRIDAY AND SATURDAY...VFR CONDITIONS ARE EXPECTED. CONFIDENCE IS
MODERATE.
&&
.MARINE...
HIGH PRESSURE DOWN THE MID ATLANTIC COAST TO START TONIGHT WILL
GRADUALLY SLIDE EASTWARD. THIS WILL ALLOW A WARM FRONT TO GRADUALLY
LIFT INTO OUR AREA THROUGH THE NIGHT. THE SOUTHEAST FLOW HAS TURNED
GUSTY ESPECIALLY IN DELAWARE BAY DUE TO THE WIND FUNNELING UP THE
BAY. THIS SHOULD CONTINUE INTO THIS EVENING, BUT GENERALLY REMAIN
UNDER 25 KNOTS. A LOW-LEVEL JET IS FORECAST TO ARRIVE, HOWEVER SOME
WARMING ALOFT MAY TEND TO KEEP THE MIXING TO A MINIMUM. THEREFORE, A
GRADUAL INCREASE IN THE SOUTHERLY FLOW TONIGHT. THE PRESSURE
GRADIENT TIGHTENS TUESDAY AS HIGH PRESSURE EASES TO THE EAST AND A
COLD FRONT SLOWLY APPROACHES FROM THE WEST. THE LOW-LEVEL JET IS
FORECAST TO INCREASE SOME THROUGH THE DAY, HOWEVER ENOUGH WARMING
JUST ABOVE THE SURFACE SHOULD TEND TO KNOCK DOWN THE MIXING TO SOME
EXTENT ESPECIALLY AWAY FROM THE COAST. HOWEVER, THE FORECAST
SOUNDINGS DO INDICATE THAT THE WINDS COULD NEAR 25 KNOTS TUESDAY AND
THE SOUTHERLY FLOW IS EXPECTED TO BUILD THE SEAS. THEREFORE, THE
SMALL CRAFT ADVISORY WILL GO INTO EFFECT AT 15Z TUESDAY.
OUTLOOK...
WITH A DECENT SOUTHERLY H925 JET PASSING OVERHEAD ON TUESDAY
NIGHT, WE`VE MAINTAINED THE ADVISORY LEVEL WINDS AND SEAS AHEAD OF
THE COLD FRONT. THERE ISN`T A VERY STRONG FLOW BEHIND THE COLD
FRONT UNTIL THAT FRONT STARTS TO PUT SOME DISTANCE BETWEEN ITSELF
AND OUR WATERS, SO WE MAY NOT SEE ADVISORY LEVEL WINDS IN ITS
WAKE. SEAS MAY TAKE LONGER TO SUBSIDE, AND WE MAY END UP EXTENDING
THE ADVISORY INTO WEDNESDAY. WE WON`T DO THAT NOW, HOWEVER, SINCE
THE FORECAST OF LOW PRESSURE ALONG THE FRONT IS NOT LOOKING QUITE
AS ROBUST AS IT ONCE DID. ONCE SEAS SUBSIDE, SUB-ADVISORY
CONDITIONS ARE EXPECTED INTO THE WEEKEND.
&&
.TIDES/COASTAL FLOODING...
WE ARE BEGINNING OUR DECLINE OFF THE PEAK OF THE ASTRONOMICAL HIGH
TIDES ASSOCIATED WITH THE PERIGEAN FULL MOON. NEVERTHELESS THERE
SHOULD BE SOME MINOR TIDAL FLOODING DURING THE OVERNIGHT INTO
TUESDAY MORNING (CHESAPEAKE BAY) HIGH TIDE CYCLE. WINDS ARE SLOWLY
VEERING MORE TO THE SOUTHEAST AND THIS ADDS OUR SIDE OF CHESAPEAKE
BAY TO THE LIST.
THE HIGHEST TIDAL DEPARTURES HAVE SHIFTED INTO UPPER DELAWARE BAY
AND CHESAPEAKE BAY THIS AFTERNOON (AROUND THREE QUARTERS OF A FOOT
ABOVE NORMAL) WITH LOWER DEPARTURES IN THE TIDAL DELAWARE RIVER AND
ALONG THE OCEAN (AROUND A THIRD OF A FOOT). THE LEAST AMOUNT OF
WIGGLE ROOM BETWEEN THE FORECAST ASTRONOMICAL HIGH TIDES AND ONGOING
DEPARTURES REMAIN ALONG THE OCEAN FRONT AND LOWER DELAWARE BAY WHERE
WE WILL KEEP THE ADVISORY GOING. IN THE UPPER HALF OF DELAWARE BAY
AS WELL AS THE TIDAL DELAWARE, WHERE THERE IS A LARGER GAP BETWEEN
THE NEEDED DEPARTURES AND PREDICTED ASTRONOMICAL TIDES, WE WILL KEEP
THE STATEMENT GOING. AFTER COORDINATING WITH WAKEFIELD, WE WILL
ISSUE A STATEMENT FOR CHESAPEAKE BAY FOR THE TUESDAY MORNING HIGH
TIDE CYCLE. WHILE CBOFS GUIDANCE TAKES BOTH CAMBRIDGE AND TOLCHESTER
TO THE MID LEVEL OF MINOR TIDAL FLOODING CATEGORIES, THE GUIDANCE
HAS BEEN TOO HOT BY AROUND HALF A FOOT. DOWNWARD ADJUSTING WE
SUSPECT TUESDAY MORNING`S HIGH TIDE WILL BE VERY CLOSE TO THE 3.5 FT
ABOVE MEAN LOWER LOW WATER INITIATION LEVEL FOR MINOR TIDAL
FLOODING.
OVERALL THE MDL STORM SURGE GUIDANCE HAS BEEN VERIFYING BETTER THAN
STEVENS OR THE SERIES OF OFS GUIDANCE WITH THIS SPRING TIDE CYCLE
SINCE SATURDAY.
ASTRONOMICAL TIDES STARTING DROPPING MORE ON TUESDAY AND BEYOND.
ALSO THE SOUTHERLY GRADIENT IS FORECAST TO WEAKEN. IF THIS TREND
CONTINUES, THIS WOULD DECREASE THE CHANCES FOR ADDITIONAL MINOR
TIDAL FLOODING WITH THE TUESDAY NIGHT INTO WEDNESDAY MORNING HIGH
TIDE CYCLE.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 5 AM EDT
WEDNESDAY FOR ANZ430-431-450>455.
&&
$$
SYNOPSIS...DELISI/HAYES
NEAR TERM...GIGI/NIERENBERG
SHORT TERM...GORSE
LONG TERM...DELISI
AVIATION...DELISI/GIGI
MARINE...DELISI/GORSE
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
214 PM EDT TUE MAY 8 2012
.PREV DISCUSSION...
UPDATE...
/ISSUED 1114 AM EDT TUE MAY 8 2012/
ALTHOUGH SHOWERS NEAR COLUMBUS HAVE DISSIPATED FOR THE MOST
PART...STARTING TO SEE DEVELOPMENT OVER EAST CENTRAL GEORGIA.
ALTHOUGH SO ISOLATED SHOWERS WILL BE POSSIBLE THROUGH EARLY
AFTERNOON...THE BEST CHANCE OF THUNDERSTORMS WILL BE AFTER 2PM.
THIS IS ALSO INLINE WITH THE HRRR /ALTHOUGH THE RUN IS A LITTLE
OUTDATED/ THAT SUGGESTS INCREASED ACTIVITY AFTER 2PM. CLOUD
COVERAGE THIS MORNING IS LIMITING THE HEATING...ONLY A FEW BREAKS
IN THE CLOUDS...SO WILL TAKE A WHILE TO REACH HIGHER INSTABILITY
VALUES...THUS THINK BEST CHANCE OF SEVERE WILL BE LATE AFTERNOON
INTO THE EVENING WHICH ALSO BETTER CORRESPONDS WITH THE FRONT
MOVING INTO GA.
FORECAST DEW POINTS WERE A LITTLE ON THE LOW SIDE SO MINOR
ADJUSTMENTS TO THOSE GRIDS.
11
SHORT TERM /TODAY THROUGH WEDNESDAY/...
/ISSUED 359 AM EDT TUE MAY 8 2012/
CURRENTLY HAVE SCATTERED SHOWERS DEVELOPING OVER NORTH GEORGIA
ASSOCIATED WITH A WEAK SHORT WAVE SWEEPING PAST THE REGION.
COVERAGE SHOULD REMAIN SCATTERED THROUGH THE MORNING HOURS. UPPER
LEVEL FLOW TRANSITIONING TO SOUTHWESTERLY TODAY AHEAD OF A TROUGH
DIGGING INTO THE EASTERN U.S. GFS...NAM AND ECMWF ALL SHOW A COLD
FRONT ENTERING NORTHWEST GEORGIA BY THIS AFTERNOON WHICH SHOULD
HELP TO ENHANCE THUNDERSTORM ACTIVITY. CURRENT PACE AND TIMING OF
THE FRONT PUSHES BEST PRECIPITATION CHANCES INTO CENTRAL GEORGIA
FOR WEDNESDAY.
MODELS SHOW MUCAPE AROUND 1500 J/KG ACROSS THE MAJORITY OF THE
FORECAST AREA BY THIS AFTERNOON...SLIGHTLY HIGHER THAN YESTERDAY.
WITH EXTENSIVE CLOUD COVER THROUGH THE MAJORITY OF THE DAY WE WILL
HAVE A SLOW TIME REACHING THESE VALUES. THIS SHOULD KEEP THE CHANCES
FOR SEVERE THUNDERSTORMS AT A MINIMUM FOR TODAY...ALTHOUGH A FEW
ISOLATED SEVERE STORMS ARE NOT IMPOSSIBLE BY LATE AFTERNOON...
ESPECIALLY IF WE CAN GET SOME SUNSHINE ACROSS THE AREA. SIMILAR
NUMBERS ARE INDICATED AHEAD OF THE FRONT WEDNESDAY ACROSS CENTRAL
GEORGIA...HOWEVER THE AREA WILL BE UNDER THE INFLUENCE OF THE TAIL
END OF A SLIGHTLY STRONGER UPPER LEVEL WAVE WHICH MAY HELP TO
INCREASE THE CHANCES FOR ISOLATED SEVERE STORMS.
20
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
/ISSUED 359 AM EDT TUE MAY 8 2012/
MODELS SIMILAR WITH THE FRONTAL BOUNDARY PUSHING INTO SOUTH
GEORGIA WEDNESDAY EVENING...THEN OFF THE GEORGIA COAST BY EARLY
THURSDAY. HIGH PRESSURE BUILDS INTO THE SOUTHEAST U.S. BEHIND THE
FRONT AND REMAIN DOMINANT OVER NORTH AND CENTRAL GEORGIA INTO THE
WEEKEND. EXTENDED PROGS CONTINUE TO SHOW SOME DEEPER MOISTURE
SPREADING BACK INTO OUR AREA SUNDAY INTO MONDAY AS A WEAK BOUNDARY
DRIFTS SOUTHWARD FROM THE OHIO/TENNESSEE VALLEY...AND A LOW
PRESSURE SYSTEM LIFTS NORTHEAST FROM THE GULF. WILL KEEP POPS IN
THE SLIGHT CHANCE RANGE ON SUNDAY AND MONDAY FOR NOW UNTIL WE CAN
GET A BETTER HANDLE ON THESE FEATURES. OVERALL...NEAR NORMAL
TEMPERATURES EXPECTED DURING THE PERIOD.
49
&&
.AVIATION...
18Z UPDATE...
SHOWERS HAVE ALREADY STARTED TO DEVELOP ACROSS THE AREA BUT THINK
BEST CHANCE OF CONVECTION AT THE TAF SITES WILL STILL BE LATER
THIS AFTERNOON /20-24Z/ THOUGH CHANCE OF THUNDER EXISTS THROUGH
02Z. ALTHOUGH PRECIP CHANCES WILL DECREASE OVERNIGHT...EXPECT AREA
OF SHRA TO SET UP OVER THE ATL AREA DURING THE LATE MORNING BUT
DECREASE FOR THE AFTERNOON AS THE FRONT MOVES INTO SOUTH GEORGIA.
CHANCE OF TSRA IN THE MORNING IS LOW. WINDS WILL BECOME MORE NW
AS THE FRONT MOVES THROUGH AND SHOULD STAY ON THE WEST SIDE
THROUGH THE TAF PERIOD. GUSTS WITH TSRA TODAY BUT BETTER CHANCE OF
STRONG PREDOMINATE WINDS ON WEDNESDAY.
//ATL CONFIDENCE...18Z UPDATE...
HIGH CONFIDENCE ON WINDS AND VSBYS. MEDIUM CONFIDENCE ON CIGS AND
MORNING VSBYS. HIGH CONFIDENCE ON OCCURRENCE OF TSRA AT THE
AIRPORT...BUT ONLY MEDIUM CONFIDENCE ON THE TIMING.
11
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 80 61 82 54 / 60 50 60 20
ATLANTA 81 64 80 56 / 60 50 60 10
BLAIRSVILLE 77 59 76 49 / 60 50 40 5
CARTERSVILLE 81 62 78 49 / 60 50 50 10
COLUMBUS 83 67 82 58 / 60 50 60 20
GAINESVILLE 79 61 79 54 / 60 50 50 10
MACON 83 65 84 56 / 60 50 60 30
ROME 81 60 77 50 / 60 50 40 5
PEACHTREE CITY 81 63 80 51 / 60 50 60 20
VIDALIA 84 67 86 62 / 60 50 70 60
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
1114 AM EDT TUE MAY 8 2012
.UPDATE...
ALTHOUGH SHOWERS NEAR COLUMBUS HAVE DISSIPATED FOR THE MOST
PART...STARTING TO SEE DEVELOPMENT OVER EAST CENTRAL GEORGIA.
ALTHOUGH SO ISOLATED SHOWERS WILL BE POSSIBLE THROUGH EARLY
AFTERNOON...THE BEST CHANCE OF THUNDERSTORMS WILL BE AFTER 2PM.
THIS IS ALSO INLINE WITH THE HRRR /ALTHOUGH THE RUN IS A LITTLE
OUTDATED/ THAT SUGGESTS INCREASED ACTIVITY AFTER 2PM. CLOUD
COVERAGE THIS MORNING IS LIMITING THE HEATING...ONLY A FEW BREAKS
IN THE CLOUDS...SO WILL TAKE A WHILE TO REACH HIGHER INSTABILITY
VALUES...THUS THINK BEST CHANCE OF SEVERE WILL BE LATE AFTERNOON
INTO THE EVENING WHICH ALSO BETTER CORRESPONDS WITH THE FRONT
MOVING INTO GA.
FORECAST DEW POINTS WERE A LITTLE ON THE LOW SIDE SO MINOR
ADJUSTMENTS TO THOSE GRIDS.
11
&&
.PREV DISCUSSION...
SHORT TERM /TODAY THROUGH WEDNESDAY/...
/ISSUED 359 AM EDT TUE MAY 8 2012/
CURRENTLY HAVE SCATTERED SHOWERS DEVELOPING OVER NORTH GEORGIA
ASSOCIATED WITH A WEAK SHORT WAVE SWEEPING PAST THE REGION.
COVERAGE SHOULD REMAIN SCATTERED THROUGH THE MORNING HOURS. UPPER
LEVEL FLOW TRANSITIONING TO SOUTHWESTERLY TODAY AHEAD OF A TROUGH
DIGGING INTO THE EASTERN U.S. GFS...NAM AND ECMWF ALL SHOW A COLD
FRONT ENTERING NORTHWEST GEORGIA BY THIS AFTERNOON WHICH SHOULD
HELP TO ENHANCE THUNDERSTORM ACTIVITY. CURRENT PACE AND TIMING OF
THE FRONT PUSHES BEST PRECIPITATION CHANCES INTO CENTRAL GEORGIA
FOR WEDNESDAY.
MODELS SHOW MUCAPE AROUND 1500 J/KG ACROSS THE MAJORITY OF THE
FORECAST AREA BY THIS AFTERNOON...SLIGHTLY HIGHER THAN YESTERDAY.
WITH EXTENSIVE CLOUD COVER THROUGH THE MAJORITY OF THE DAY WE WILL
HAVE A SLOW TIME REACHING THESE VALUES. THIS SHOULD KEEP THE CHANCES
FOR SEVERE THUNDERSTORMS AT A MINIMUM FOR TODAY...ALTHOUGH A FEW
ISOLATED SEVERE STORMS ARE NOT IMPOSSIBLE BY LATE AFTERNOON...
ESPECIALLY IF WE CAN GET SOME SUNSHINE ACROSS THE AREA. SIMILAR
NUMBERS ARE INDICATED AHEAD OF THE FRONT WEDNESDAY ACROSS CENTRAL
GEORGIA...HOWEVER THE AREA WILL BE UNDER THE INFLUENCE OF THE TAIL
END OF A SLIGHTLY STRONGER UPPER LEVEL WAVE WHICH MAY HELP TO
INCREASE THE CHANCES FOR ISOLATED SEVERE STORMS.
20
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
/ISSUED 359 AM EDT TUE MAY 8 2012/
MODELS SIMILAR WITH THE FRONTAL BOUNDARY PUSHING INTO SOUTH
GEORGIA WEDNESDAY EVENING...THEN OFF THE GEORGIA COAST BY EARLY
THURSDAY. HIGH PRESSURE BUILDS INTO THE SOUTHEAST U.S. BEHIND THE
FRONT AND REMAIN DOMINANT OVER NORTH AND CENTRAL GEORGIA INTO THE
WEEKEND. EXTENDED PROGS CONTINUE TO SHOW SOME DEEPER MOISTURE
SPREADING BACK INTO OUR AREA SUNDAY INTO MONDAY AS A WEAK BOUNDARY
DRIFTS SOUTHWARD FROM THE OHIO/TENNESSEE VALLEY...AND A LOW
PRESSURE SYSTEM LIFTS NORTHEAST FROM THE GULF. WILL KEEP POPS IN
THE SLIGHT CHANCE RANGE ON SUNDAY AND MONDAY FOR NOW UNTIL WE CAN
GET A BETTER HANDLE ON THESE FEATURES. OVERALL...NEAR NORMAL
TEMPERATURES EXPECTED DURING THE PERIOD.
49
AVIATION...
12Z UPDATE...
/ISSUED 730 AM EDT TUE MAY 8 2012/
MIXED MVFR/IFR CEILINGS AND VISIBILITIES CONTINUE ACROSS THE
MAJORITY OF NORTH AND CENTRAL GEORGIA AT THIS TIME...WILL BECOME
MAINLY MVFR BY 15Z AND VFR BY 18Z. ISOLATED TO SCATTERED SHOWERS AND
A FEW THUNDERSTORMS WILL CONTINUE TO BE POSSIBLE THROUGH 18Z...
BECOMING MORE WIDESPREAD BETWEEN 18Z AND 02Z. WINDS SOUTHEAST TO
SOUTHWEST 3-6KT WILL BECOME SOUTHWEST 6-10KT BY 15Z AND WEST TO
NORTHWEST BY 00Z.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM CONFIDENCE.
20
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 80 61 82 54 / 60 50 60 20
ATLANTA 81 64 80 56 / 60 50 60 10
BLAIRSVILLE 77 59 76 49 / 60 50 40 5
CARTERSVILLE 81 62 78 49 / 60 50 50 10
COLUMBUS 83 67 82 58 / 60 50 60 20
GAINESVILLE 79 61 79 54 / 60 50 50 10
MACON 83 65 84 56 / 60 50 60 30
ROME 81 60 77 50 / 60 50 40 5
PEACHTREE CITY 81 63 80 51 / 60 50 60 20
VIDALIA 84 67 86 62 / 60 50 70 60
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
200 AM EDT TUE MAY 8 2012
.UPDATE...
THE MAJORITY OF THE CONVECTIVE DEVELOPMENT HAS BEEN WANING ACROSS
THE FORECAST AREA TONIGHT... THOUGH THERE STILL HAS BEEN LINGERING
SHOWERS AND STORMS ALONG SOME CONVERGING OUTFLOW BOUNDARIES SOUTH
OF KFFC. HRRR STILL HOLDS ON TO SOME REDEVELOPMENT IN THE NORTH AFTER
06Z LIKELY DUE TO THE INFLUENCE OF AN UPPER LEVEL SHORTWAVE AHEAD
OF THE COLD FRONTAL PASSAGE. WILL NEED TO MONITOR THIS ON THE
OVERNIGHT. KEPT CHANCE POPS OVERNIGHT FOR MOST AREAS WITH LIKELY
POPS STARTING IN THE NORTHWEST DURING THE EARLY MORNING HOURS.
ALSO RAISED POPS EARLY WEDNESDAY MORNING BASED ON PROGGED
POSITIONING OF THE COLD FRONT SUGGESTED BY MAJORITY OF GUIDANCE.
TWEAKED WINDS SOME TO VEER A BIT EARLIER OUT OF THE SOUTHWEST
AHEAD OF THE FRONT. ALL ELSE SEEMED TO BE ON TRACK.
03
&&
.PREV DISCUSSION...
SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
/ISSUED 350 PM EDT MON MAY 7 2012/
AREA OF SHOWERS THAT DEVELOPED OVER EASTERN GEORGIA HAS DEVELOPED
INTO A LINE BETWEEN ATL AND AHN...STRETCHING SOUTHWARD AND EAST OF
MCN. CLOUD COVERAGE HAS HELPED TO LIMIT INSTABILITY ACROSS THAT AREA
BUT WITH SOME BREAKS IN THE CLOUDS...HAVE STARTED TO SEE INCREASED
THUNDER. AS THIS AREA DRIFTS TOWARD THE EAST...THE WESTERN HALF OF
THE CWA SHOULD BECOME MORE ACTIVE EARLY THIS EVENING AND CAN ALREADY
SEE SOME CELLS DEVELOPING ACROSS THAT AREA. THE WESTERN HALF OF THE
CWA WOULD ALSO BE THE FOCUS FOR THE STRONGER STORMS AS SLIGHTLY
LESSER CLOUD COVERAGE HAS ALLOWED FOR GREATER DESTABILIZATION.
OVERNIGHT...THE FOCUS WILL SHIFT TO THE NORTHWEST AS A SHORTWAVE
MOVES INTO NORTHWEST GEORGIA. BEFORE THIS SHIFTS ACROSS THE
MOUNTAINS AND WASHES OUT THOUGH IT WILL HELP TO ENHANCE THE CHANCE
OF PRECIPITATION ACROSS THE NORTH TONIGHT. FRONT MOVES INTO
NORTHWEST GEORGIA ON TUESDAY AND THIS WILL HELP TO ONCE AGAIN KEEP
THE FOCUS OF ACTIVITY ACROSS NORTH GEORGIA. WITH DECENT
INSTABILITY...MU CAPE VALUES OF 2000 J/KG...BUT WEAK SHEAR /BOTH 0-1
AND 0-6KM/...MAIN THREAT WITH STORMS WOULD BE DAMAGING WIND AND
HAIL. CANT RULE OUT A FEW SEVERE STORMS ON TUESDAY...BUT AT THIS
POINT NOT EXPECTING A WIDESPREAD SEVERE EVENT. FRONT WILL WEAKEN
OVERNIGHT ON TUESDAY AS IT DRIFTS INTO CENTRAL GEORGIA SO HAVE
SHOWED TREND OF DECREASING POPS.
MAX TEMPS ON TUESDAY ARE ON THE LOWER SIDE OF GUIDANCE DUE TO
EXPECTED CLOUD COVERAGE...OTHERWISE TEMPS ARE CLOSE TO GUIDANCE.
LONG TERM /WEDNESDAY THROUGH MONDAY/...
LATEST ROUND OF EXTENDED RANGE GUIDANCE INDICATES CONTINUED GOOD
AGREEMENT IN TIMING OF NEXT FRONTAL SYSTEM WITH THE GFS JUST
SLIGHTLY FASTER ALTHOUGH WX EFFECTS ARE NEGLIGIBLE. CONTINUED
THUNDERSTORM CHANCES INTO WEDNESDAY ALTHOUGH INSTABILITY AXIS RACES
EAST AHEAD OF FRONT AND OVERALL INSTABILITY LOOKS LESS THAN THAT
ON TUESDAY. CONTINUED LIMITED SHEAR PROFILE AND EXPECTED MAINLY
HAIL AND ISOLATED WIND THREAT.
HIGH PRESSURE AND A DRY FORECAST LOOK TO BE ON TAP BEHIND THE
FRONT THURSDAY THROUGH SATURDAY. THOUGH...BOTH GFS AD ECMWF SHOW
SOME INCREASE IN DEEPER MOISTURE SATURDAY NIGHT INTO SUNDAY AS A
WEAK LOW PRESSURE SYSTEM LIFTS NORTHEAST FROM THE GULF AND A COLD
FRONT DRIFTS SOUTHWARD FROM THE OH/TN VALLEY REGION. WILL KEEP
SATURDAY NIGHT DRY FOR NOW...BUT HAVE INTRODUCED SLIGHT CHANCE
POPS FOR MUCH OF THE AREA SUNDAY WITH THESE FEATURES POSSIBLY
BEGINNING TO AFFECT THE STATE.
COOLER BEHIND THE FRONT WITH MODELS ADVERTISING TEMPS BACK TO
MORE NORMAL LEVELS.
DEESE
&&
.AVIATION...
06Z UPDATE...
MIXED MVFR/IFR CONDITIONS EXPECTED ACROSS THE MAJORITY OF NORTH AND
CENTRAL GEORGIA BY 08Z... BECOMING MAINLY MVFR BY 15Z AND VFR BY
18Z. ISOLATED TO SCATTERED SHOWERS AND A FEW THUNDERSTORMS WILL
CONTINUE THROUGH 18Z...BECOMING MORE WIDESPREAD BETWEEN 18Z AND 02Z.
WINDS SOUTHEAST 3-6KT WILL BECOME SOUTHWEST 6-10KT BY 15Z AND WEST
TO NORTHWEST BY 00Z.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM CONFIDENCE.
20
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 63 79 63 83 / 30 60 50 60
ATLANTA 64 80 65 81 / 40 60 50 60
BLAIRSVILLE 61 75 59 74 / 60 60 60 70
CARTERSVILLE 64 80 60 79 / 50 60 50 70
COLUMBUS 66 86 67 86 / 40 60 50 60
GAINESVILLE 62 77 62 80 / 50 60 60 70
MACON 62 84 64 87 / 20 50 50 60
ROME 64 82 61 79 / 60 60 50 60
PEACHTREE CITY 62 81 62 81 / 40 60 50 60
VIDALIA 66 87 67 89 / 20 50 50 60
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...FIEUX/03
LONG TERM....DEESE
AVIATION...03
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1114 PM CDT MON MAY 7 2012
.DISCUSSION...
ISSUED 826 PM CDT MON MAY 7 2012
COLD FRONT HAS SHIFTED SOUTH OF THE FORECAST AREA EARLY THIS
EVENING WITH ONLY A FEW SHOWERS LEFT BEHIND OVER FAR SOUTHEAST IL.
HIGH PRESSURE ACRS THE PLAINS WILL SHIFT EAST INTO THE MIDWEST
OVERNIGHT BRINGING DRIER AIR EAST WITH IT. DEW POINTS ALREADY
HAVE DROPPED INTO THE UPPER 40S OVER PARTS OF WEST CENTRAL IL AND
EXPECT THAT TREND TO WORK ITS WAY EAST OVER THE REMAINDER OF THE
FORECAST AREA TONIGHT. THE DRIER AIR WILL NOT ARRIVE INTO THE
EAST UNTIL THE PRE-DAWN HOURS SO THE COMBINATION OF CLEARING
SKIES AND ABUNDANT LOW LEVEL MOISTURE LEFT OVER FROM THE RAINFALL
OF THE PAST SEVERAL DAYS WILL LEAD TO SOME PATCHY FOG MAINLY
EAST OF I-55. THE LAST FEW RUNS OF THE 3KM HRRR MODEL SUGGEST
AREAS ALONG AND EAST OF I-57 HAVE THE BETTER CHANCE OF SEEING
SOME FOG LATE TONIGHT SO WILL INCLUDE IN THE OVERNIGHT HOURS.
OTHERWISE...OTHER THAN THE USUAL ADJUSTMENTS IN THE EARLY EVE
TEMPERATURE TRENDS...THE REST OF THE FORECAST IS IN GOOD SHAPE.
SMITH
&&
.AVIATION...
ISSUED 1105 PM CDT MON MAY 7 2012
THREAT FOR FOG AND LOW CIGS FROM BMI TO DEC AND EAST A CONCERN
THRU 13Z TUESDAY. DRIER AIR CONTINUES TO SLOWLY EDGE EAST ACRS THE
STATE WITH TEMP-DEW POINT SPREADS RANGING FROM 10 DEGREES ACRS THE
WEST TO ZERO IN THE EAST WHERE SKIES HAVE JUST RECENTLY CLEARED.
WILL INCLUDE TEMPO GROUPS AT BMI...DEC AND CMI WHERE IT APPEARS
THE DRIER AIR WILL TAKE THE LONGEST TO GET TO OVERNIGHT. WINDS
HAVE DROPPED TO BELOW 7 KTS IN MOST OF THE FORECAST AREA SO THERE
MAY BE SOME LIGHT FOG IN AREAS TO THE WEST SUCH AS DEC AND BMI
OVERNIGHT AS WELL WITH THE LOWER DEW POINTS GETTING INTO PIA AND
SPI. WHAT FOG AND OR LOW CLOUDS WE SEE TONIGHT SHOULD BE GONE BY
13Z WITH VFR CONDITIONS EXPECTED FOR THE REMAINDER OF THE FORECAST
PERIOD. LIGHT MOSTLY NW WINDS TONIGHT WILL PICK UP IN SPEED FROM
THE WEST TO NORTHWEST AT 10 TO 15 KTS...WITH GUSTS AROUND 20
KTS...WHICH SHOULD DIMINISH TO LESS THAN 10 KTS BY 00Z.
SMITH
&&
.PREV DISCUSSION...
ISSUED 241 PM CDT MON MAY 7 2012
AFTER THE RECENT STRETCH OF ACTIVE WEATHER...A COOLER/DRIER
PATTERN WILL TAKE HOLD THROUGH THE REST OF THE WEEK.
SHORT TERM...TONIGHT THROUGH THURSDAY
SLOW-MOVING COLD FRONT CURRENTLY ALONG THE I-70 CORRIDOR WILL
SAG SOUTHWARD THIS EVENING...POTENTIALLY TRIGGERING A FEW SHOWERS
AND THUNDERSTORMS ACROSS THE E/SE KILX CWA. 18Z MESO-ANALYSIS SHOWS
MUCAPE VALUES OF 1500 TO 2000J/KG ACROSS SOUTHEAST ILLINOIS...WITH
EVEN HIGHER INSTABILITY PARAMETERS NOTED FURTHER EAST INTO THE OHIO
RIVER VALLEY. DESPITE DECENT INSTABILITY AND PRESENCE OF FORCING
MECHANISM...0-6KM BULK SHEAR REMAINS VERY WEAK. AS A RESULT...AM
ONLY EXPECTING SCATTERED THUNDERSTORM DEVELOPMENT ALONG/AHEAD OF
THE FRONT LATE THIS AFTERNOON INTO THE EVENING. WILL CARRY LOW
CHANCE POPS ALONG AND SOUTHEAST OF A CHAMPAIGN TO SHELBYVILLE LINE
THROUGH MIDNIGHT...THEN WILL GO DRY EVERYWHERE AFTER MIDNIGHT AS
THE BOUNDARY SINKS SOUTH OF THE OHIO RIVER. SKIES WILL INITIALLY
BE MOSTLY CLOUDY...BUT WILL GRADUALLY CLEAR FROM NORTHWEST TO
SOUTHEAST. OVERNIGHT LOWS WILL MAINLY BE IN THE LOWER TO MIDDLE
50S...BUT WILL REMAIN NEAR THE 60 DEGREE MARK ACROSS THE
CLOUD-COVERED FAR SE CWA.
CLOSED UPPER LOW CURRENTLY SPINNING OVER SOUTHERN MANITOBA WILL
WEAKEN INTO AN OPEN WAVE AS IT TRACKS E/SE INTO THE GREAT LAKES
OVER THE NEXT 24 TO 36 HOURS. AHEAD OF THIS FEATURE...MOSTLY SUNNY
AND WARM CONDITIONS WILL PREVAIL ON TUESDAY...WITH HIGHS REACHING
THE LOWER TO MIDDLE 70S. MAY SEE SOME INCREASE IN CLOUDINESS
ACROSS THE FAR NORTH LATE IN THE DAY...BUT ALL IN ALL...SHOULD BE
A MOSTLY SUNNY DAY. ALL MODELS TAKE WAVE INTO THE EASTERN GREAT
LAKES/OHIO RIVER VALLEY BY WEDNESDAY EVENING...WITH A FEW
SOLUTIONS HINTING AT SOME DIURNAL SHOWERS WEDNESDAY AFTERNOON. GFS
SEEMS TO BE THE MOST AGGRESSIVE WITH PRECIP ACROSS NEARLY THE
ENTIRE AREA...WHILE NAM IS COMPLETELY DRY. DESPITE WEAKENING
NATURE OF SYSTEM AND LACK OF DEEP MOISTURE...CYCLONIC FLOW ALOFT
AND MODERATELY STEEP LAPSE RATES WILL YIELD PARTLY SUNNY SKIES
ACROSS THE E/NE CWA...WITH PERHAPS A FEW ISOLATED SHOWERS. FURTHER
WEST...MOSTLY SUNNY AND DRY CONDITIONS WILL PERSIST.
UPPER WAVE WILL SHIFT TOWARD NEW ENGLAND ON THURSDAY...AS UPPER
RIDGING BEGINS TO BUILD INTO THE REGION FROM THE WEST. THANKS TO
RISING UPPER HEIGHTS AND THE PRESENCE OF SURFACE HIGH
PRESSURE...ABUNDANT SUNSHINE AND TEMPS IN THE 70S WILL BE THE RULE
FOR THURSDAY.
LONG TERM...FRIDAY THROUGH MONDAY
UPPER RIDGE WILL BUILD INTO THE MIDWEST FOR FRIDAY AND
SATURDAY...ENSURING THE CONTINUATION OF WARM AND DRY WEATHER INTO
THE FIRST HALF OF THE WEEKEND. STILL SOME MODEL DISAGREEMENT ON
HOW FAST RIDGE BREAKS DOWN AND NEXT COLD FRONT APPROACHES...WITH
THE GFS BEING FASTER THAN THE ECMWF. RECENT TREND HAS BEEN TO SLOW
THIS PROCESS...SO WILL TREND TOWARD THE ECMWF FOR THE WEEKEND
FORECAST. AS SUCH...WILL ONLY MENTION A LOW CHANCE POP ACROSS THE
FAR NORTH ON SATURDAY...WITH WARM AND DRY WEATHER ELSEWHERE AROUND
CENTRAL AND SOUTHEAST ILLINOIS. AFTER THAT...FRONT WILL SLOWLY
SETTLE SOUTHWARD...BRINGING A CHANCE FOR SCATTERED SHOWERS/STORMS
FOR SATURDAY NIGHT AND SUNDAY. RAIN CHANCES MAY EVEN LINGER INTO
MONDAY IF ECMWF VERIFIES...BUT HAVE MAINTAINED A DRY FORECAST FOR
MONDAY AT THIS TIME...UNTIL BETTER MODEL AGREEMENT IS ACHIEVED.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
314 PM EDT TUE MAY 8 2012
.SHORT TERM...
TONIGHT...WEDNESDAY...WEDNESDAY NIGHT...
WATER VAPOR IMAGERY AND LATEST RUC ANALYSIS CLEARLY DEPICTING THE
MAIN FEATURE OF CONCERN IN THE SHORT TERM...DEEP UPPER TROUGH OVER
MN THAT WILL BE DROPPING DOWN ACROSS THE GREAT LAKES REGION TONIGHT
AND WEDNESDAY. AHEAD OF THIS FEATURE WILL BE AN INCREASING SFC
GRADIENT ALONG WITH DRIER AIR IN THE BOUNDARY LAYER AND LOW LEVELS
WHICH SHOULD PRECLUDE ANY SIGNIFICANT FOG REDEVELOPMENT. 12Z RAOBS
SHOWING -25C COLD POOL TO ACCOMPANY TROUGH AND RESULT IN VERY STEEP
MID LEVEL LAPSE RATES BY THE LATE MORNING HOURS. EXPECT THE
DIURNALLY DRIVEN SHRA AND EVEN A FEW TSRA CURRENTLY SEEN OVER MN AND
WI WILL SPREAD OVER THE GREAT LAKES REGION AFTER MIDNIGHT TONIGHT
AND WEDNESDAY. WILL USE THE TRACK OF UPPER TROUGH AND COLD POOL IN
TIMING OF PRECIP CHANCES...BEGINNING IN THE NW CWA AFTER MIDNIGHT
TONIGHT AND CONTINUING IN THE EASTERN HALF THROUGH WEDNESDAY AFTN.
MAGNITUDE OF COLD POOL WILL ALSO FAVOR CONVECTIVE POTENTIAL BY THE
AFTERNOON HOURS...BUFKIT SOUNDINGS SHOWING TT GT 50...SO WILL ALSO
INCLUDE A MENTION OF THUNDER HERE. RESULTING TEMPS WILL BE
CONSIDERABLY COOLER IN THIS PATTERN...5-10F BELOW NORMAL BOTH
WEDNESDAY AND WEDNESDAY NIGHT.&&
.LONG TERM...
MEAN TROUGHING WILL REDVLP ACRS THE NE CONUS INTO THIS WEEKEND AS
WRN RIDGING AMPLIFIES. THUS W/PATTN REORIENTING TWD YET ANOTHER
PNA...XPC DRY WX TO CONT AS W/NW FLW ALOFT CONTS AND LL RIDGING
PERSISTS ACRS THE GOMEX W/LTL IN WAY OF SIG LL MSTR RTN UNTIL PSBLY
AT THE END OF THE PD ON DY8. TEMPS THROUGH THE PD GENERALLY NR
NORMAL.
&&
.AVIATION.../18Z TAFS/
LATEST VIS SAT SHOWING CU FIELD QUICKLY FILLING BACK IN OVER THE
KFWA AREA AND EXPECTED TO PERSIST REMAINDER OF THE AFTERNOON.
HOWEVER...KSBN IN LAKE SHADOW AREA ATTM WITH HIGHER BASED SCT CU
DECK MOVING ACROSS NE IL AND SOUTHERN LK MI...WILL HOLD&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...LOGSDON
LONG TERM...T
AVIATION...LOGSDON
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
138 AM EDT TUE MAY 8 2012
.AVIATION.../06Z TAFS/
WK SHRTWV MOVG EAST ACROSS THE AREA THIS EVE PROVIDING SUFFICIENT
LIFT COMBINED WITH LINGERING MOISTURE OVER NE INDIANA TO CAUSE
SHOWERS TO REDEVELOP ALONG AND A BIT TO THE NW OF SFC CDFNT OVER
NW OH INTO EAST CENTRAL INDIANA. THIS SHOULD BE SHORT LIVED AS
SHRTWV MOVES EAST WITH RAIN EXPECTED TO END BY 08Z AT FWA. TO THE
WEST... LIGHT WINDS/CLEARING ASSOCIATED WITH WK SFC RIDGE WAS
RESULTING IN DENSE FOG OVER NE IL. THIS SHOULD SPREAD EAST ACROSS
NRN INDIANA OVERNIGHT WITH CONDITIONS AT SBN EXPECTED TO LOWER TO
LIFR AND IFR AT FWA. DIURNAL HEATING SHOULD MIX OUT STRATUS/FOG BY
14-15Z WITH VFR CONDITIONS THEN EXPECTED FOR THE REMAINDER OF THE
DAY AND MONDAY EVE.
&&
.PREV DISCUSSION...
SHORT TERM...
TONIGHT...TUESDAY...TUESDAY NIGHT...
CONVECTIVE REDEVELOPMENT NOT FULLY MATERIALIZING YET AS AIRMASS
STRUGGLES TO RECOVER FROM EARLIER RAINS. KIWX RADAR SHOWING LONE
CONVECTIVE CELL JUST SOUTH OF THE CWA NEAR MUNCIE. KIND RADAR
INDICATING ADDL DEVELOPMENT NOW BEGINNING TO TAKE SHAPE FURTHER
SOUTH. WATER VAPOR IMAGERY AND LATEST RUC ANALYSIS SHOWING WEAK
SHORT WAVE APPROACHING THE AREA SO STILL HOLDING OUT HOPE FOR MORE
ORGANIZED PRECIP THIS EVENING AS SFC LOW AND FRONTAL BOUNDARY
CONTINUE TO MOVE EASTWARD...BUT HAVE DROPPED POPS OVER THE EASTERN
CWA AND OPTED FOR SCT WORDING. WILL KEEP MENTION OF THUNDER IN THE
SE CWA AS LATEST LAPS DATA ALONG WITH SPC MESO ANALYSIS HAS CAPES
NUDGING UP OVER 1000J/KG INTO JAY COUNTY. VIS SAT ALSO SHOWING
CLOUDS THINNING OUT FROM MARION TO LIMA SO FURTHER LATE AFTN
DESTABILIZATION EXPECTED. 12Z MODELS A LITTLE SLOWER IN MOVING
SYSTEM OUT SO WILL HANG ON TO SMALL CHANCE IN SE CWA TILL 12Z TUE.
REST OF THE SHORT TERM WILL FEATURE CAA PATTERN AS UPPER LOW DROPS
INTO THE NORTHERN GREAT LAKES. SHOULD STILL GET TO AROUND NORMAL FOR
HIGHS TUESDAY AS 850MB THERMAL TROUGH DELAYED UNTIL TUE NITE/WED AM.
EXPECT AN INCREASE IN CLOUD COVER TUE NITE AS UPPER TROUGH SINKS
FURTHER SOUTH ALONG WITH SECONDARY COLD FRONT.
LONG TERM...WEDNESDAY THROUGH MONDAY
AN UPPER LEVEL SPEED MAX DIGGING SOUTHWARD ACROSS THE UPPER MIDWEST
AND UPPER MS VALLEY WILL ALLOW UPPER TROUGH TO SHIFT SOUTHEAST INTO
THE GREAT LAKES REGION BY WEDNESDAY MORNING. MOISTURE WILL BE
RELATIVELY UNIMPRESSIVE WITH THIS SYSTEM AND THUS MAIN PRECIP CHANCE
IS EXPECTED TO BE CONFINED TO ASSOCIATED WEAK LOW LEVEL CONVERGENCE
AXIS THAT WILL BE DROPPING SOUTHWARD ACROSS THE AREA ON WEDNESDAY.
MID LEVEL COLD POOL IS EXPECTED TO SHIFT SOUTHEAST ACROSS LOWER
MICHIGAN INTO WEDNESDAY NIGHT. SOME WEAK SFC BASED INSTABILITY IS
POSSIBLE ON WEDNESDAY AFTERNOON ESPECIALLY ACROSS NORTHEAST PORTIONS
OF THE FORECAST AREA CLOSER TO THESE COOLER MID LEVEL PROFILES. WILL
HOLD OFF ON ANY TS INCLUSION AT THIS POINT WITH SOME CONCERN THAT IF
SOME DEEPER MIXING IS REALIZED...THIS COULD LIMIT ANY SFC BASED
INSTABILITY. CHANCE OF PRECIP TO COME TO AN END WEDNESDAY EVENING AS
THIS UPPER TROUGH SHIFTS EAST. BROAD LOW LEVEL ANTICYCLONE WILL THEN
OVERSPREAD THE REGION FOR THURSDAY AND FRIDAY SETTING UP A FEW QUIET
DAYS TO END THE WEEK.
LOW LEVEL ANTICYCLONE WILL BE VERY SLOW TO SHIFT EAST AS UPPER RIDGE
TO THE WEST AMPLIFIES AS IT APPROACHES THE GREAT LAKES REGION FRIDAY
IN RESPONSE TO NEXT PROGRESSIVE EASTERN PACIFIC TROUGH TRACKING INTO
THE NORTHERN PLAINS. MOISTURE RETURN IN ADVANCE OF THIS PACIFIC
TROUGH WILL BE SOMEWHAT ROUNDABOUT DUE TO PRESENCE OF DEPARTING
ANTICYCLONE TO THE SOUTHEAST. THIS SHOULD CONFINE ANY LOW LEVEL
MOISTURE RETURN OF CONSEQUENCE TO A FAIRLY NARROW CORRIDOR IN
ADVANCE OF ASSOCIATED COLD FRONTAL BOUNDARY. WHILE SOME SLIGHT
TIMING DIFFERENCES PERSIST WITH THIS FRONT...CHARACTERISTIC OF LARGE
SCALE FLOW AND GOOD AGREEMENT AMONGST MEDIUM RANGE MODELS HANDLING
THIS NEXT EASTERN PACIFIC TROUGH STILL LEND ENOUGH CONFIDENCE TO
MAINTAIN LOW CHANCE POPS FOR FRIDAY NIGHT INTO SUNDAY. ONCE FRONTAL
TIMING BECOMES BETTER RESOLVED WILL LIKELY BE ABLE TO CONTRACT THE
DURATION OF THESE POPS. HAVE OMITTED THUNDER AT THIS TIME GIVEN SOME
UNCERTAINTIES AS TO EXTENT OF LOW LEVEL MOISTURE RETURN BUT THIS
WILL ALSO NEED TO BE REASSESSED IN LATER FORECASTS. SOME SLIGHT
MODERATION IN TEMPERATURES EXPECTED FOR FRIDAY IN ADVANCE OF THIS
FRONT...BUT OVERALL TEMPERATURES NEAR SEASONABLE LEVELS ARE EXPECTED
THROUGH THE PERIOD. A RETURN TO DRY CONDITIONS EXPECTED FOR EARLY
NEXT WEEK AS THIS SYSTEM DEPARTS TO THE EAST.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...LOGSDON
LONG TERM...MARSILI
AVIATION...JT
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1043 PM EDT WED MAY 09 2012
.Forecast Update...
Issued at 1041 PM EDT Wed May 9 2012
One more quick update now that the showers have ended. The gusty
north winds should settle down over the next 1-2 hours.
Issued at 911 PM EDT Wed May 9 2012
Another update to follow radar trends, with big PoPs over small
areas where rain is currently falling. Also spread the PoPs farther
to the west since the western end of the area of scattered showers
has been holding together fairly well. This resulted in introducing
ISO/SCT showers to the Louisville metro roughly northeast of a line
from Palmyra to Shively to Mount Washington.
Issued at 827 PM EDT Wed May 9 2012
Have upped PoPs to 100% where it is currently raining from northern
Washington County through all of Jefferson County Indiana, with a
buffer zone around that of likelies. Still expecting the showers to
fade away as the sun sets.
Issued at 650 PM EDT Wed May 9 2012
Scattered showers in central Indiana have been holding their own as
they push quickly to the southeast, and there has even been some new
development between Indy and Bloomington along with an increase in
lightning production. The showers are only a couple counties away
from the LMK CWFA at this point, so a decision needed to be made
regarding PoPs this evening (which were dry). After looking at KIND
radar and HRRR progs, have decided to go ahead and insert SCT/ISO
PoPs into the north, basically north of a line from Paoli to
Louisville to Lexington. The showers should fizzle as they reach
the Blue Grass around mid-evening, and we have the PoPs stopping at
02Z.
.Short Term (Tonight through Thursday night)...
Issued at 245 PM EDT May 9 2012
A weak upper disturbance is rotating southeast across the lower
Great Lakes region, sparking off not only widespread, high-based
strato-cu, but also showers and even a few storms across IL/IN/OH.
Most of this activity will stay to our north, however our
northeastern CWA could see some sprinkles perhaps by early evening.
By that time, clouds/precip will start to dissipate with the loss of
afternoon heating, so will keep just the sprinkle wording in the
grids. Best time frame/location will be between 5-10pm northeast of
a line from Louisville to Lexington. Until that timeframe, expect
gusty northwest winds and partly cloudy skies.
Once that trough swings through by roughly midnight, we`ll have
clearing skies thereafter as surface high pressure starts to slide
in from the west. Winds will become light and will help overnight
lows drop into the low-mid 40s north to around 50 south.
The center of the surface high will still be to our west Thursday,
so a steady northerly wind will be in place. Even a few gusts to
about 15 knots or so will be possible especially east of I-65
tomorrow with good mixing. Although skies will be sunny, a steady
northerly wind will keep temps around the same highs as today, maybe
even a tad cooler. Look for highs in the mid-upper 60s north and
east, to the low 70s over the southwest.
Thursday night should be the coolest night with the surface high
directly overhead. Winds will be calm, and with excellent
radiational cooling, lows will plummet into the low 40s most places.
Wouldn`t be surprised to see a few sheltered, Bluegrass locations
drop into the upper 30s.
.Long Term (Friday through Wednesday)...
Issued at 318 PM EDT May 9 2012
Friday Through Sunday Night...
The Ohio Valley will start off in northwesterly flow on Friday as a
large trough exits in the northeast US and weak mid-level low moves
into the southern Plains. High pressure will remain in control of
the weather with dry conditions Friday/Friday night. Short term
shot of upper ridging ahead of the approaching southern Plains wave
will keep the region dry on Saturday, but we`ll likely see a quick
increase in cloud cover throughout the day. Combination of
southerly return flow and isentropic ascent will likely lead to some
isolated showers/storms develop Saturday night especially across
southern KY. Better moisture and synoptic scale lift look much
better on Sunday which looks to be rather dreary with extensive
cloud cover and scattered to numerous showers/storms dotting the
region as the upper wave moves across the region. Clouds and
convection are likely to continue Sunday night as the upper wave
slowly moves east and a surface low and cold front push through the
region. Basically have done an incremental update here as the
previous forecast has this well handled. Given the increasing
forecast convergence here, have raised PoPs a little during the
Sun/Sun night period.
Highs Friday and Saturday will generally be in the mid-upper 70s but
cool into the lower 70s for Sunday. Overnight temps look to remain
rather mild with readings in the upper 40s to the lower 50s.
Monday through Wednesday...
This afternoons long term deterministic and ensemble guidance is in
general agreement with the upper level flow across the CONUS in this
time frame. By and large, the models suggest that a large ridge
will build across the western US early in the period which will
force a downstream trough to develop across the eastern US. A
decent mid-level wave looks to crash into the western US coast by
late in the period which will likely knock down that western ridge.
Considerable spread exists in the height fields across the east
during the period with regards to whether we`ll see a closed low
develop. The 09/00Z and 09/12Z GFS offer the one extreme with a
very pronounced cut off low developing over the east and then
meandering slowly to the east as the flow becomes a bit more zonal.
The 09/00Z and 09/12Z GFS ensembles are not as robust with the upper
low development and actually have a little less spread when compared
with the 09/00Z and 09/12Z OP Euro and its ensembles. Suffice to
say, forecast confidence is average at the beginning of the period
with confidence dropping in the day 6/7 (Tue/Wed) timeframe as the
uncertainty with possible closed low develop complicate the
forecast. With this issuance, have leaned closer the 12Z GFS
Ensemble and Euro solutions which gives decent continuity to the
previous forecast.
This period of the forecast will likely be a rather unsettled one
with the upper trough being situated over the eastern US. Variable
cloudiness is likely with chances of rain throughout the period. It
does seem likely that the best chances of precipitation would be in
the Monday/Tuesday time frame as the trough moves over us with
lesser chances on Wednesday as the GEFS/Euro solutions are slightly
more progressive. For now, will keep slight to low chance PoPs
going with a drier trend for Wednesday. Depending on how the upper
level pattern evolves, future forecasts will likely need some
adjustments over the next few days. As for temperatures, readings
should generally be a little below average with daytime highs in the
upper 60s to lower 70s and overnight lows in the lower-middle 50s.
&&
.Aviation (00Z TAF Issuance)...
Updated at 650 PM EDT May 9 2012
Gusty winds at the terminals are expected through the next couple of
hours until the atmosphere decouples. The CU field has also already
begun to dissipate with clear skies expected overnight. Winds will
be fairly light out of the NNE through the overnight hours. Surface
high pressure will slide into the area tomorrow. Cloud cover will be
fairly limited, though some CU may develop. Winds will be out of the
north and lighter than today, in generally the 7-12 knot range, with
a few higher gusts. Winds will begin to shift to the east after 0Z
tomorrow at SDF as the high pressure shifts eastward.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........13
Short Term.......AL
Long Term........MJ
Aviation.........13
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
912 PM EDT WED MAY 09 2012
.Forecast Update...
Issued at 911 PM EDT Wed May 9 2012
Another update to follow radar trends, with big PoPs over small
areas where rain is currently falling. Also spread the PoPs farther
to the west since the western end of the area of scattered showers
has been holding together fairly well. This resulted in introducing
ISO/SCT showers to the Louisville metro roughly northeast of a line
from Palmyra to Shively to Mount Washington.
Issued at 827 PM EDT Wed May 9 2012
Have upped PoPs to 100% where it is currently raining from northern
Washington County through all of Jefferson County Indiana, with a
buffer zone around that of likelies. Still expecting the showers to
fade away as the sun sets.
Issued at 650 PM EDT Wed May 9 2012
Scattered showers in central Indiana have been holding their own as
they push quickly to the southeast, and there has even been some new
development between Indy and Bloomington along with an increase in
lightning production. The showers are only a couple counties away
from the LMK CWFA at this point, so a decision needed to be made
regarding PoPs this evening (which were dry). After looking at KIND
radar and HRRR progs, have decided to go ahead and insert SCT/ISO
PoPs into the north, basically north of a line from Paoli to
Louisville to Lexington. The showers should fizzle as they reach
the Blue Grass around mid-evening, and we have the PoPs stopping at
02Z.
.Short Term (Tonight through Thursday night)...
Issued at 245 PM EDT May 9 2012
A weak upper disturbance is rotating southeast across the lower
Great Lakes region, sparking off not only widespread, high-based
strato-cu, but also showers and even a few storms across IL/IN/OH.
Most of this activity will stay to our north, however our
northeastern CWA could see some sprinkles perhaps by early evening.
By that time, clouds/precip will start to dissipate with the loss of
afternoon heating, so will keep just the sprinkle wording in the
grids. Best time frame/location will be between 5-10pm northeast of
a line from Louisville to Lexington. Until that timeframe, expect
gusty northwest winds and partly cloudy skies.
Once that trough swings through by roughly midnight, we`ll have
clearing skies thereafter as surface high pressure starts to slide
in from the west. Winds will become light and will help overnight
lows drop into the low-mid 40s north to around 50 south.
The center of the surface high will still be to our west Thursday,
so a steady northerly wind will be in place. Even a few gusts to
about 15 knots or so will be possible especially east of I-65
tomorrow with good mixing. Although skies will be sunny, a steady
northerly wind will keep temps around the same highs as today, maybe
even a tad cooler. Look for highs in the mid-upper 60s north and
east, to the low 70s over the southwest.
Thursday night should be the coolest night with the surface high
directly overhead. Winds will be calm, and with excellent
radiational cooling, lows will plummet into the low 40s most places.
Wouldn`t be surprised to see a few sheltered, Bluegrass locations
drop into the upper 30s.
.Long Term (Friday through Wednesday)...
Issued at 318 PM EDT May 9 2012
Friday Through Sunday Night...
The Ohio Valley will start off in northwesterly flow on Friday as a
large trough exits in the northeast US and weak mid-level low moves
into the southern Plains. High pressure will remain in control of
the weather with dry conditions Friday/Friday night. Short term
shot of upper ridging ahead of the approaching southern Plains wave
will keep the region dry on Saturday, but we`ll likely see a quick
increase in cloud cover throughout the day. Combination of
southerly return flow and isentropic ascent will likely lead to some
isolated showers/storms develop Saturday night especially across
southern KY. Better moisture and synoptic scale lift look much
better on Sunday which looks to be rather dreary with extensive
cloud cover and scattered to numerous showers/storms dotting the
region as the upper wave moves across the region. Clouds and
convection are likely to continue Sunday night as the upper wave
slowly moves east and a surface low and cold front push through the
region. Basically have done an incremental update here as the
previous forecast has this well handled. Given the increasing
forecast convergence here, have raised PoPs a little during the
Sun/Sun night period.
Highs Friday and Saturday will generally be in the mid-upper 70s but
cool into the lower 70s for Sunday. Overnight temps look to remain
rather mild with readings in the upper 40s to the lower 50s.
Monday through Wednesday...
This afternoons long term deterministic and ensemble guidance is in
general agreement with the upper level flow across the CONUS in this
time frame. By and large, the models suggest that a large ridge
will build across the western US early in the period which will
force a downstream trough to develop across the eastern US. A
decent mid-level wave looks to crash into the western US coast by
late in the period which will likely knock down that western ridge.
Considerable spread exists in the height fields across the east
during the period with regards to whether we`ll see a closed low
develop. The 09/00Z and 09/12Z GFS offer the one extreme with a
very pronounced cut off low developing over the east and then
meandering slowly to the east as the flow becomes a bit more zonal.
The 09/00Z and 09/12Z GFS ensembles are not as robust with the upper
low development and actually have a little less spread when compared
with the 09/00Z and 09/12Z OP Euro and its ensembles. Suffice to
say, forecast confidence is average at the beginning of the period
with confidence dropping in the day 6/7 (Tue/Wed) timeframe as the
uncertainty with possible closed low develop complicate the
forecast. With this issuance, have leaned closer the 12Z GFS
Ensemble and Euro solutions which gives decent continuity to the
previous forecast.
This period of the forecast will likely be a rather unsettled one
with the upper trough being situated over the eastern US. Variable
cloudiness is likely with chances of rain throughout the period. It
does seem likely that the best chances of precipitation would be in
the Monday/Tuesday time frame as the trough moves over us with
lesser chances on Wednesday as the GEFS/Euro solutions are slightly
more progressive. For now, will keep slight to low chance PoPs
going with a drier trend for Wednesday. Depending on how the upper
level pattern evolves, future forecasts will likely need some
adjustments over the next few days. As for temperatures, readings
should generally be a little below average with daytime highs in the
upper 60s to lower 70s and overnight lows in the lower-middle 50s.
&&
.Aviation (00Z TAF Issuance)...
Updated at 650 PM EDT May 9 2012
Gusty winds at the terminals are expected through the next couple of
hours until the atmosphere decouples. The CU field has also already
begun to dissipate with clear skies expected overnight. Winds will
be fairly light out of the NNE through the overnight hours. Surface
high pressure will slide into the area tomorrow. Cloud cover will be
fairly limited, though some CU may develop. Winds will be out of the
north and lighter than today, in generally the 7-12 knot range, with
a few higher gusts. Winds will begin to shift to the east after 0Z
tomorrow at SDF as the high pressure shifts eastward.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........13
Short Term.......AL
Long Term........MJ
Aviation.........13
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
828 PM EDT WED MAY 09 2012
.Forecast Update...
Issued at 827 PM EDT Wed May 9 2012
Have upped PoPs to 100% where it is currently raining from northern
Washington County through all of Jefferson County Indiana, with a
buffer zone around that of likelies. Still expecting the showers to
fade away as the sun sets.
Issued at 650 PM EDT Wed May 9 2012
Scattered showers in central Indiana have been holding their own as
they push quickly to the southeast, and there has even been some new
development between Indy and Bloomington along with an increase in
lightning production. The showers are only a couple counties away
from the LMK CWFA at this point, so a decision needed to be made
regarding PoPs this evening (which were dry). After looking at KIND
radar and HRRR progs, have decided to go ahead and insert SCT/ISO
PoPs into the north, basically north of a line from Paoli to
Louisville to Lexington. The showers should fizzle as they reach
the Blue Grass around mid-evening, and we have the PoPs stopping at
02Z.
.Short Term (Tonight through Thursday night)...
Issued at 245 PM EDT May 9 2012
A weak upper disturbance is rotating southeast across the lower
Great Lakes region, sparking off not only widespread, high-based
strato-cu, but also showers and even a few storms across IL/IN/OH.
Most of this activity will stay to our north, however our
northeastern CWA could see some sprinkles perhaps by early evening.
By that time, clouds/precip will start to dissipate with the loss of
afternoon heating, so will keep just the sprinkle wording in the
grids. Best time frame/location will be between 5-10pm northeast of
a line from Louisville to Lexington. Until that timeframe, expect
gusty northwest winds and partly cloudy skies.
Once that trough swings through by roughly midnight, we`ll have
clearing skies thereafter as surface high pressure starts to slide
in from the west. Winds will become light and will help overnight
lows drop into the low-mid 40s north to around 50 south.
The center of the surface high will still be to our west Thursday,
so a steady northerly wind will be in place. Even a few gusts to
about 15 knots or so will be possible especially east of I-65
tomorrow with good mixing. Although skies will be sunny, a steady
northerly wind will keep temps around the same highs as today, maybe
even a tad cooler. Look for highs in the mid-upper 60s north and
east, to the low 70s over the southwest.
Thursday night should be the coolest night with the surface high
directly overhead. Winds will be calm, and with excellent
radiational cooling, lows will plummet into the low 40s most places.
Wouldn`t be surprised to see a few sheltered, Bluegrass locations
drop into the upper 30s.
.Long Term (Friday through Wednesday)...
Issued at 318 PM EDT May 9 2012
Friday Through Sunday Night...
The Ohio Valley will start off in northwesterly flow on Friday as a
large trough exits in the northeast US and weak mid-level low moves
into the southern Plains. High pressure will remain in control of
the weather with dry conditions Friday/Friday night. Short term
shot of upper ridging ahead of the approaching southern Plains wave
will keep the region dry on Saturday, but we`ll likely see a quick
increase in cloud cover throughout the day. Combination of
southerly return flow and isentropic ascent will likely lead to some
isolated showers/storms develop Saturday night especially across
southern KY. Better moisture and synoptic scale lift look much
better on Sunday which looks to be rather dreary with extensive
cloud cover and scattered to numerous showers/storms dotting the
region as the upper wave moves across the region. Clouds and
convection are likely to continue Sunday night as the upper wave
slowly moves east and a surface low and cold front push through the
region. Basically have done an incremental update here as the
previous forecast has this well handled. Given the increasing
forecast convergence here, have raised PoPs a little during the
Sun/Sun night period.
Highs Friday and Saturday will generally be in the mid-upper 70s but
cool into the lower 70s for Sunday. Overnight temps look to remain
rather mild with readings in the upper 40s to the lower 50s.
Monday through Wednesday...
This afternoons long term deterministic and ensemble guidance is in
general agreement with the upper level flow across the CONUS in this
time frame. By and large, the models suggest that a large ridge
will build across the western US early in the period which will
force a downstream trough to develop across the eastern US. A
decent mid-level wave looks to crash into the western US coast by
late in the period which will likely knock down that western ridge.
Considerable spread exists in the height fields across the east
during the period with regards to whether we`ll see a closed low
develop. The 09/00Z and 09/12Z GFS offer the one extreme with a
very pronounced cut off low developing over the east and then
meandering slowly to the east as the flow becomes a bit more zonal.
The 09/00Z and 09/12Z GFS ensembles are not as robust with the upper
low development and actually have a little less spread when compared
with the 09/00Z and 09/12Z OP Euro and its ensembles. Suffice to
say, forecast confidence is average at the beginning of the period
with confidence dropping in the day 6/7 (Tue/Wed) timeframe as the
uncertainty with possible closed low develop complicate the
forecast. With this issuance, have leaned closer the 12Z GFS
Ensemble and Euro solutions which gives decent continuity to the
previous forecast.
This period of the forecast will likely be a rather unsettled one
with the upper trough being situated over the eastern US. Variable
cloudiness is likely with chances of rain throughout the period. It
does seem likely that the best chances of precipitation would be in
the Monday/Tuesday time frame as the trough moves over us with
lesser chances on Wednesday as the GEFS/Euro solutions are slightly
more progressive. For now, will keep slight to low chance PoPs
going with a drier trend for Wednesday. Depending on how the upper
level pattern evolves, future forecasts will likely need some
adjustments over the next few days. As for temperatures, readings
should generally be a little below average with daytime highs in the
upper 60s to lower 70s and overnight lows in the lower-middle 50s.
&&
.Aviation (00Z TAF Issuance)...
Updated at 650 PM EDT May 9 2012
Gusty winds at the terminals are expected through the next couple of
hours until the atmosphere decouples. The CU field has also already
begun to dissipate with clear skies expected overnight. Winds will
be fairly light out of the NNE through the overnight hours. Surface
high pressure will slide into the area tomorrow. Cloud cover will be
fairly limited, though some CU may develop. Winds will be out of the
north and lighter than today, in generally the 7-12 knot range, with
a few higher gusts. Winds will begin to shift to the east after 0Z
tomorrow at SDF as the high pressure shifts eastward.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........13
Short Term.......AL
Long Term........MJ
Aviation.........13
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1127 PM CDT MON MAY 7 2012
.UPDATE...
ISSUED AT 1127 PM CDT MON MAY 7 2012
UPDATED THE AVIATION SECTION.
UPDATE ISSUED AT 641 PM CDT MON MAY 7 2012
AN INTERIM GRID REVISION WAS MADE TO BLEND CURRENT POP/WEATHER
WITH THE MODEL REFLECTIVITY FROM THE 3KM HRRR AND 4KM NMM VERSION
OF THE NAM-WRF GUIDANCE. THESE SETS OF HIGH RESOLUTION STORM
SCALE MODELS SUGGEST THAT THE MAIN BAND OF CONVECTION OVER THE
PENNYRILE REGION OF WEST KENTUCKY WILL SCOUR OUT THE DEEPEST
MOISTURE ALONG AND AHEAD OF THE COLD FRONT. THIS CONVECTION WAS
AIDED EARLIER IN THE AFTERNOON WITH A LOW/MIDDLE LEVEL CIRCULATION
RIDING NORTHEAST ALONG AND AHEAD OF THE FRONTAL BOUNDARY.
THE SECONDARY LINE OF DISORGANIZED CONVECTION MAY BE SUGGESTIVE OF
POST-FRONTAL ZONE OF LIFT IN THE 925-850 MB FRONTAL ZONE. THIS MAY
PERSIST INTO THE EVENING HOURS ACROSS THE WFO PAH FORECAST AREA.
GIVEN THE LIMITED INSTABILITY EXPECTED TONIGHT...MAY NEED TO RE-EVALUATE
THE MENTION OF THUNDERSTORMS IN THE GRIDDED FORECAST...WITH A
HIGHER POP ASSOCIATED WITH SHOWERS VERSUS THUNDERSTORMS.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 152 PM CDT MON MAY 7 2012
THIS MORNING`S SHOWERS/STORMS REALLY WORKED THE ATMOSPHERE OVER
AND CAPPED IT OFF WITH A NICE LAYERED DECK OF CLOUDINESS. THIS WAS
INHIBITING CONVECTION FROM REFIRING THUS FAR...AND LED TO THE SPC
DOWNGRADE FROM SLGT RISK TO SEE TEXT FOR OUR AREA.
EVEN SO...SATELLITE IS STARTING TO SHOW SOME HINTS AT THINNING OF
THIS MORNING`S COMPLEX CLOUDINESS. SURFACE OBS REVEAL THE ACTUAL
FRONTAL BOUNDARY STILL PERCHED JUST TO THE NORTH AND WEST OF THE
FA...AND RADAR MOSAIC DOES SHOW SOME ACTIVITY TRYING TO DEVELOP
ALONG IT. AS THE BOUNDARY MOVES IN THIS PM...WE WILL MONITOR FOR
STRONG STORM POTENTIAL. WHILE WE`VE BACKED OFF THE PREVIOUSLY
INHERITED LIKELY AND BETTER POPS...WE STILL WANT TO MAINTAIN AT
LEAST HIGH CHANCE CAT GOING UNTIL THE FRONT MAKES ITS PASS.
12Z MODELS INDICATE THE PASSAGE OF THE FRONT AND THE ASSOCIATED
UPPER WAVE WILL BE THIS EVENING...WITH PCPN ALL BUT THRU BY 06Z.
SOME LATE NIGHT LINGERING OF A SMALL POP IS POSSIBLE IN THE FARTHEST
SERN PTNS FA...BUT ALL SHOULD BE PCPN FREE BY 12Z TUESDAY...SO WE`LL
MAKE THAT MODIFICATION TO THE FORECAST AS WELL.
TUESDAY-WEDNESDAY NIGHT WILL SEE POST FRONTAL COOLING/DRYING AIRMASS
BRINGING PLEASANT RELIEF TO THE SUMMER-LIKE HEAT/HUMIDITY OF RECENT
DAYS PAST. UPPER TROF PASSAGE WED LOOKS FOR NOW TO KEEP PCPN CHANCES
NORTH AND EAST OF US...BUT SOMETHING TO KEEP AN EYE UPON.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 152 PM CDT MON MAY 7 2012
SURFACE HIGH PRESSURE AND RISING HEIGHTS ALOFT SHOULD KEEP THE
REGION DRY WITH SEASONAL TEMPERATURES THROUGH SATURDAY. MODELS
DRAG A FRONT ACROSS OUR CWA ON SATURDAY BUT DONT GENERATE ANY
PRECIP IN THE PROCESS. THEY DO HOWEVER INDICATE POST FRONTAL
PRECIP CHANCES SATURDAY NIGHT AND SUNDAY.
BEYOND THAT DRY CONDITIONS SHOULD RETURN THROUGH THE END OF THE
FORECAST CYCLE WITH SLIGHTLY MODERATING TEMPERATURES. THE ECMWF
SHOWS A WEAKNESS IN THE SURFACE AND UPPER LEVELS OVER SOUTHEAST
MISSOURI NEXT MONDAY AND GENERATES A BIT OF PRECIP THERE. SINCE
THE OTHER LONG RANGE MODELS KEEP THE SURFACE HIGH STRONGER AND
GENERATE NO PRECIP...WILL KEEP IT DRY FOR NOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1127 PM CDT MON MAY 7 2012
VARIABLE VFR DECK MOVING SOUTH ACROSS THE REGION WITH HIGH CLOUDS
HEADING EAST. WINDS SHOULD REMAIN LIGHT NORTHWEST THROUGH THE
NIGHT IN THE WAKE OF A COOL FRONT. SOME CU POSSIBLE TOMORROW WITH
SOME HIGH CLOUDS RETURNING. NORTHWEST WINDS UP TO 10 KTS WILL BE
POSSIBLE...DIMINISHING TO LIGHT NORTHWEST AFTER 00Z.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
431 PM EDT TUE MAY 8 2012
.SYNOPSIS...
ISSUED AT 429 PM EDT TUE MAY 8 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH AXIS
FROM JAMES BAY THROUGH WRN LAKE SUPERIOR TO ERN MN. AT THE SFC...A
TROUGH EXTENDED FROM SE LAKE SUPERIOR THROUGH CNTRL UPPER MI INTO
WRN WI. THE COMBINATION OF DIURNAL HEATING...STEEP MID LEVEL LAPSE
RATES AND WEAK TO MODERATE QVECTOR CONV ASSOCIATED WITH THE MID
LEVEL TROUGH HAS SUPPORTED SCT/NMRS SHRA OVER MOST OF INLAND UPPER
MI. IN ADDITION...SOME ISOLD TSRA WITH SMALL HAIL HAVE ALSO
DEVELOPED. THE GREATEST SHRA COVERAGE AND HEAVIEST RAIN WAS OVER THE SE
CWA WHERE LOW LEVEL CONV WITH THE TROUGH AND LAKE BREEZE WAS MOST
PROMINENT.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 429 PM EDT TUE MAY 8 2012
AS THE MID LEVEL AND SFC TROUGH SHIFTS TO THE SOUTHEAST AND DIURNAL
HEATING SUBSIDES...EXPECT THE AREA OF SHOWERS TO DIMINISH AND SAG TO
THE SOUTH. SHOWERS MAY STILL BE NMRS/WIDESPREAD LATE THIS AFTERNOON
20Z-24Z BUT BY 00Z-03Z...THE REMAINING PCPN SHOULD BECOME SCT/ISOLD
AND END BY AROUND MIDNIGHT. HOWEVER...WITH ABUNDANT LOW LEVEL
MOISTURE REMAINING INCREASING CYCLONIC NE TO N FLOW (9505-850 MB N
WINDS OF 20-30 KT) INTO N CNTRL UPPER MI...HIGHER RES MODELS SUGGEST
LIGHT PCPN WILL DEVELOP IN LINE WITH PREVIOUS FCST.
MODELS SUGGEST THAT THE SHARP BACK EDGE OF THE LOW LEVEL
MOISTURE...PER VIS IMAGERY...WILL MOVE N-S THROUGH THE AREA BTWN
09Z-15Z. SO...ANY PCPN SHOULD END BY EARLY WED WITH PARTLY TO MOSTLY
SUNNY SKIES BY MIDDAY. SUNSHINE/MIXING SHOULD ALLOW INLAND TEMPS TO
CLIMB TO NEAR 60 BUT ONSHORE FLOW NORTH WILL KEEP READINGS IN THE
UPPER 40S TO LOWER 50S NEAR LAKE SUPERIOR.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 429 PM EDT TUE MAY 8 2012
A RIDGE OF HIGH PRESSURE...CENTERED FROM WY TO N MANITOBA WILL BE
PUSHING ACROSS THE UPPER GREAT LAKES WEDNESDAY NIGHT THROUGH FRIDAY
MORNING. WE CONTINUE TO LOOK INTO WEDNESDAY NIGHT/THURSDAY MORNING
AS BEING THE COLDEST TIME PERIOD...WITH LIGHT WINDS AND RELATIVELY
LOW PW VALUES. INCLUDED THE MENTION OF FREEZING TEMPS FOR THE
INTERIOR WEST IN THE HWO.
THE MAIN FEATURE OF INTEREST PRECIPITATION WISE WILL BE THE STACKED
LOW OVER N CENTRAL CANADA FOR THE LATTER HALF OF THE WORK WEEK. THE
LOW ITSELF WILL SLOWLY SHIFT ACROSS HUDSON BAY BY SATURDAY
NIGHT...WHERE IT WILL LIKELY LINGER THROUGH THE REMAINDER OF THE
PERIOD. WAVES ROTATING AROUND THE LOW SHOULD BRING THE INITIAL SFC
TROUGH/COLD FRONT TO FAR W LAKE SUPERIOR AT 18Z FRIDAY...CENTRAL
UPPER MI BY 00Z SATURDAY...AND EAST OF ALL UPPER MI BY 12Z SATURDAY.
TIMING DIFFERS BY 3-5HRS BETWEEN THE VARIOUS MODELS...WITH THE
08/00Z CANADIAN ON THE SLOW END...AND THE 08/00Z ECMWF AND 08/12Z
BEING ON THE QUICKER SOLUTIONS. THE 08/06Z GFS RUNS THE MIDDLE
GROUND BETWEEN THESE VARYING SOLUTIONS. ADDED THE MENTION OF
ISOLATED TS OVER THE WITH SB/MU CAPE VALUES OF 300 TO 600J/KG.
GIVEN THE STRENGTHENING SOUTHERLY WINDS AHEAD OF THE COLD FRONT
FRIDAY AFTERNOON WITH THE PEAK OF DAYTIME HEATING...FIRE WX CONCERNS
MAY INCREASE...PARTICULARLY OVER THE E HALF WHERE MORE LIMITED
HUMIDITY VALUES WILL LIKELY EXIST. WILL ALSO CONTINUE TO HIGHLIGHT
DOWNSLOPE AREAS FOR SOME OF THE WARMER TEMPS ACROSS THE CWA. SOME
GUIDANCE IS HINTING AT THE POTENTIAL OF 80 DEGREES OVER THE BARAGA
PLAINS FRIDAY.
EXPECT SHOWERS TO COME TO AN END SATURDAY MORNING...WITH DRY WEATHER
THEN TAKING HOLD THROUGH TUESDAY. GIVEN W TO NW FLOW ALOFT...THERE
COULD BE A SMALLER CHANCE OF SHOWERS...BUT WILL NOT INCLUDE AT THIS
TIME GIVEN THE LOW PROBABILITY...WITH HIGH PRESSURE SLIDING IN FROM
THE N/CENTRAL PLAINS. MODELS ARE NOT DOING THE BEST AT COMING
TOGETHER ON A SOLUTION FOR MONDAY...WITH THE POTENTIAL OF ANOTHER
COLD FRONT MOVING NW TO SE OVER THE CWA /LIKE THE 08/12Z ECMWF/.
THIS MAY BE ONE AREA OF THE FCST THAT CHANGES MORE THAN ANY OTHER
OVER THE NEXT SEVERAL DAYS. OTHERWISE...HIGHS IN THE 60S INLAND FROM
THE GREAT LAKES LOOK TO BE THE RULE FROM SUNDAY THROUGH NEXT TUESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 144 PM EDT TUE MAY 8 2012
AN UPPER LEVEL DISTURBANCE AND SFC TROUGH WILL RESULT IN SCT SHRA
OVER INLAND PORTIOS OF UPPER MI WITH THE BEST CHANCES WILL BE SOUTH
OF ALL OF THE TAF SITES. MVFR CIGS ARE POSSIBLE BY LATE AFTERNOON AT
KSAW AS INCREASING NORTH WINDS FAVOR UPSLOPE LOW CLOUDS.
SECONDARY SURGE OF MOISTURE ARRIVES THIS EVENING FOR ALL SITES AND
SHOULD LEAD TO ANOTHER PERIOD OF IFR OR LOWER CIGS. BEST CHANCE FOR
LOWER VSBYS WILL BE AT KSAW...WHERE UPSLOPE FLOW COULD LEAD TO
-DZ/FOG. THINK WINDS WILL BE STRONG ENOUGH FOR HIGHER VSBYS...BUT
IF CLOUDS ARE LOW ENOUGH COULD STILL SEE VSBYS FALLING TOWARDS ALT
LANDING MINS LIKE THE CIGS. DRIER AIR MOVING IN FROM THE NORTH WILL
LEAD TO QUICKLY IMPROVING CONDITIONS TO VFR BY MID WED MORNING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 429 PM EDT TUE MAY 8 2012
ABUNDANT LOW-LEVEL MOISTURE AND LIGHT CONVERGENT WIND FLOW HAS LEAD
TO AREAS OF FOG (DENSE AT TIMES) ACROSS LAKE SUPERIOR. THUS DENSE
FOG ADVY CONTINUES FOR MUCH OF THE LAKE. FOG WILL LIFT TONIGHT AS
DRIER AIR ARRIVES FROM THE N.
LACK OF SIGNIFICANT WEATHER FEATURES WILL RESULT IN WINDS MOSTLY
UNDER 20KT ACROSS LAKE SUPERIOR THRU THE END OF THE WEEK. THE
STRONGER WINDS THIS WEEK WILL OCCUR THIS EVENING INTO WED OVER
ERN LAKE SUPERIOR AS A LOW PRES TROF EXITS THE AREA...AND ALSO FRI
AS ANOTHER LOW PRES TROF MOVES ACROSS THE UPPER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LSZ249>251-
266-267.
DENSE FOG ADVISORY UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING FOR
LSZ162-248-263-265.
DENSE FOG ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR LSZ242>247-
264.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...KF
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS DULUTH MN
342 PM CDT TUE MAY 8 2012
SFC/MID LVL LOW COLLAPSING SOUTHWARD THIS AFTERNOON AS PROGRESSIVE
FLOW ALOFT CONTINUES. ELONGATED SFC TROUGH/CONVERGENCE ZONE HAS BEEN
A RESERVOIR OF LOW LVL INSTABILITY TODAY AS DEPICTED BY RUC13 THETAE
FIELDS IN LOWEST 3/4K FT. UPPER COLD POOL HAS PROVIDED OPPORTUNITY
FOR STEEP LAPSE RATES AND AREAS OF CONVECTION HAVE DEVELOPED. MOST
PERSISTENT PRECIP HAS BEEN LOCATED ALONG/NORTH OF DEEP SHEAR AXIS
ACROSS IRON RANGE...SLOWLY MOVING SOUTH. A FEW REPORTS OF SMALL HAIL
WERE RECEIVED ACROSS WISCONSIN ZONES EARLY THIS AFTERNOON.
TONIGHT...OTHER THAN EARLY EVENING CONVECTION POTENTIAL...CONDITIONS
SHOULD TREND TOWARDS LESS PRECIP AND DECREASING CLOUD COVER FROM
NORTH TO SOUTH. CONFIDENCE NOT HIGH ON BR/FG DEVELOPMENT SO HAVE
LEFT OUT OF GRIDS/ZFP FOR NOW. LOWEST TEMPS SHOULD OCCUR IN
ARROWHEAD WHERE CLEARING OCCURS FIRST.
TOMORROW/TOMORROW NIGHT...SFC/MID LVL RIDGING WILL DOMINATE
WEDNESDAY. EXPECT DECENT WARMING WITH MAX TEMPS NEAR/ABOVE CLIMO.
EXPECT AN AREA OF INCREASING HIGH CLOUDS TO PUSH ACROSS RIDGE AXIS INTO CWA
DURING THE AFTN/EVENING HOURS. TIMING IS A BIT OF A CHALLENGE AS
MDLS DIFFER ON EXTENT/SPEED OF HIGH LVL COND PRESS DEFICITS.
LONG TERM...THURSDAY THROUGH TUESDAY.
MAIN FORECAST CONCERN FOR THE EXTENDED FORECAST PERIOD IS A STRONG
COLD FRONT THAT IS PROGGED TO TRACK ACROSS THE UPPER MIDWEST
FRIDAY/FRIDAY NIGHT. AHEAD OF THE FRONT...A WARM-UP IS EXPECTED FOR
THURSDAY WITH HIGHS IN THE 70S. THE FRONT WILL TAP THIS WARMTH ALONG
WITH INCREASING MOISTURE TO PRODUCE A CHANCE OF SHOWERS AND STORMS
ACROSS THE NORTHLAND FRIDAY AND FRIDAY NIGHT. THE PRECIPITATION WILL
END BY SATURDAY...WITH MAINLY DRY CONDITIONS EXPECTED THROUGH EARLY
NEXT WEEK.
.AVIATION.../18Z TAF ISSUANCE/
STRATOCU WITH MVFR CIGS AND SCTD SHOWERS/ISOLD STORMS ASSOCTD
WITH AN UPPER LEVEL TROUGH MOVING ACROSS THE UPPER MIDWEST WILL
CONTINUE TO AFFECT MOST OF THE NORTHLAND THROUGH THE EARLY EVENING
HOURS. THE SHOWERS SHOULD QUICKLY END AROUND OR AFTER SUNSET AND
THE CLOUD COVER SHOULD SCTR OUT FOR MOST AREAS AFTER MIDNIGHT.
WITH LINGERING MOISTURE AND SOME NIGHTTIME COOLING...AREAS OF FOG
MAY DEVELOP TONIGHT.
.POINT TEMPS/POPS...
DLH 38 62 42 69 / 20 0 0 0
INL 34 65 41 73 / 10 0 10 0
BRD 40 65 43 75 / 10 0 10 0
HYR 36 64 38 72 / 30 0 0 0
ASX 36 63 39 71 / 20 0 0 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...CANNON
LONG TERM....BERDES
AREA FORECAST DISCUSSION...UPDATED
NWS GLASGOW MT
913 PM MDT WED MAY 9 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH FRIDAY...
HAVE NOT SEEN A LICK OF LIGHTNING TONIGHT. ISOLATED VIRGA SHOWERS
AT BEST. REDUCED THUNDERSTORM WORDING IN THE FORECAST MORE TO AN
ISOLATED NATURE. SENT AN UPDATE TO BACK OFF ON POPS ESPECIALLY
BETWEEN MIDNIGHT AND 6 AM AS EACH UPDATE OF THE HRRR MODEL KEEPS
PRECIPITATION AWAY UNTIL AFTER 12Z. TRIED TO FOLLOW THIS TREND
WITH SOME SILENT POPS AS WELL. ALSO MADE SOME SMALL ADJUSTMENTS
TO TEMPS AND WINDS. BMICKELSON
PREVIOUS SHORT TERM DISCUSSION...SYNOPTIC SET UP... A RIDGE RUNS
FROM UTAH THROUGH EASTERN MONTANA AND UP INTO NORTHERN MANITOBA
WHILE A LARGE TROUGH EXTENDS FROM OFF THE COAST OF THE PACIFIC
NORTHWEST THROUGH BRITISH COLUMBIA AND UP INTO NUNAVUT. BETWEEN
THESE TWO FEATURES A SOUTHWEST FLOW WITH A STRONG PACIFIC MOISTURE
FETCH HAS FORMED WITH A JET EXITING THE FRONT RANGE OF MONTANA.
FURTHER WEST A RIDGE IS STARTING TO BUILD INTO THE GULF OF ALASKA.
TONIGHT THROUGH THURSDAY... SOUTHWEST FLOW WILL CONTINUE TO PUMP
PACIFIC MOISTURE INTO THE REGION AS COLD AIR PROGRESSES DOWN FROM
ALBERTA. ALL OF THESE SHOULD MEET TOGETHER OVER THE HIGH PLAINS OF
MONTANA DURING THE MORNING HOURS. THE COLD FRONT SHOULD BE THROUGH
THE CWA BY THE AFTERNOON WITH POST FRONTAL SHOWERS BECOMING
INCREASINGLY LIKELY. AT THIS TIME TOTAL QPF AMOUNTS ARE LOOKING TO
BE BETWEEN A COUPLE HUNDREDTHS AND A TENTH OF AN INCH FOR AREAS
NORTH OF THE MISSOURI RIVER WITH UP TO A QUARTER INCH POSSIBLE FOR
ISOLATED LOCATIONS. AS MODEL PROFILE SOUNDINGS ARE HAVING A HARD
TIME GETTING CAPE INTO THE -10*C LAYER... LET ALONE THE -20*C LEVEL...
THUNDER SHOULD NOT BE A PROBLEM WITH THIS FRONTAL PASSAGE. BUT
LIFT FROM THE FRONT ITSELF OR ANY SHORTWAVES TRAVELING ALONG THE
FRONT MAY STILL BE SUFFICIENT TO GENERATE A BOLT OR TWO DURING THE
AFTERNOON.
THURSDAY NIGHT THROUGH FRIDAY... COOLER AIR WILL SETTLE INTO THE
REGION AND STABILIZE IT ALONG THE BACKSIDE OF THE TROUGH. MODELS
ARE PROJECTING MAJORITY OF SHOWER ACTIVITY TO EXIT THE AREA BY
FRIDAY MORNING WITH RAPIDLY CLEARING SKIES. THURSDAY NIGHT/FRIDAY
MORNING WILL BE RATHER COOL ONE WITH TEMPERATURES APPROACHING
FREEZING BEFORE SUN UP.
.LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY...
NO SIGNIFICANT CHANGES TO THE EXTENDED FORECAST AS IT WILL BE
DOMINATED BY RIDGE OVER THE NORTHERN ROCKIES/PLAINS. WITH THE
RIDGE STRENGTHENING AND THE DRY AIR MASS IN PLACE...DID RAISE
TEMPERATURES A FEW DEGREES FOR EARLY NEXT WEEK. EBERT
PREVIOUS EXTENDED DISCUSSION...LONG TERM FORECAST PERIOD BEGINS
AS THE DEPARTING UPPER LEVEL TROUGH GIVES WAY TO A CALM AND
DIFFUSE WEATHER PATTERN UNDER A PERSISTENT UPPER LEVEL
RIDGE...WHICH WILL DOMINATE THE NORTHERN ROCKIES AND NORTHERN HIGH
PLAINS REGIONS THROUGH MOST OF THE EXTENDED FORECAST PERIOD.
DROPPED POPS TO ZERO OR NEAR ZERO FROM FRIDAY NIGHT THROUGH MONDAY
MORNING. FORCING FOR ASCENT PROGGED TO REMAIN COMPLETELY NEUTRAL
THROUGH THE WEEKEND.
BEGINNING TUESDAY...THE UPPER RIDGE BEGINS TO BREAK DOWN AHEAD OF AN
APPROACHING STORM SYSTEM FROM THE NORTHWEST WHICH WILL TURN THE
UPPER LEVEL FLOW FROM THE SOUTHWEST BY NEXT WEDNESDAY NIGHT.
PRECIPITATION FOR THIS TIME FRAME LOOKS BE MORE ISOLATED WITH
LITTLE MOISTURE AVAILABLE...ALTHOUGH SIGNIFICANT FORCING FOR
ASCENT IS PROGGED BY THE GFS IN THE ADVANCE FLANK OF THIS SYSTEM
NEXT WEEK. INTRODUCED SOME SLIGHT CHANCE POPS TO SHOWCASE THIS NEXT
SYSTEM. BMICKELSON
&&
.AVIATION...
VFR. A COLD FRONT WILL MOVE THROUGH THE REGION THURSDAY MORNING
WITH WINDS SHIFTING TO THE NORTHWEST AND INCREASING. CLOUDS WILL
BE INCREASING AND LOWERING WITH SHOWERS POSSIBLE...BUT MAINLY
AFFECTING KGGW. RAE
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY FROM 9 AM TO 8 PM MDT THURSDAY FOR FORT PECK
LAKE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
905 PM MDT WED MAY 9 2012
.DISCUSSION...
UPDATE FORTHCOMING. HAVE LOWERED POPS ACROSS THE NORTHERN PORTION OF
THE COUNTY WARNING AREA UNTIL MIDNIGHT. APPROACHING COLD FRONT HAS
SLOWED A LITTLE AND THE AIRMASS OVER THE COUNTY WARNING AREA IS VERY
DRY. EXPECT LITTLE DEVELOPMENT THE REMAINDER OF THE EVENING. THE
COLD FRONT SHOULD PUSH THROUGH THE GREAT FALLS AREA AFTER MIDNIGHT.
SHOWERS LIKELY TO DEVELOP WITH FRONTAL PASSAGE BUT MODELS ARE
BEGINNING TO SCALE BACK QPF NUMBERS. HRRR RADAR PROJECTIONS HAVE A
NARROW BAND OF PRECIPITATION ASSOCIATED WITH THE COLD FRONT AND
LATEST NAM QPF VALUES HAVE NO PRECIPITATION FOR GREAT FALLS AND
POINTS FURTHER NORTH. MIDNIGHT SHIFT WILL HAVE THE COMPLETE 00Z RUNS
TO DETERMINE IF POPS NEED TO BE SCALED BACK THURSDAY MORNING.
EMANUEL
&&
.AVIATION...
UPDATED 0000Z.
A PACIFIC COLD FRONT WILL MOVE THROUGH THE REGION TONIGHT. EXPECT
SCATTERED SHOWERS TO DEVELOP OVER THE REGION...WITH THE SHOWERS
BECOMING MORE WIDESPREAD AFTER 12Z THURSDAY. RAIN AND MOUNTAIN SNOW
WILL BE LIKELY OVER CENTRAL MONTANA ON THURSDAY MORNING. SOME
MOUNTAINS WILL BE OBSCURED AT TIMES...WITH IFR CEILINGS POSSIBLE AT
THE TAF SITES. EXPECT GRADUALLY IMPROVING CONDITIONS DURING THE
AFTERNOON HOURS. BRUSDA
&&
.PREV DISCUSSION...ISSUED 241 PM MDT WED MAY 9 2012
TONIGHT THROUGH FRIDAY EVENING...CONTINUED GOOD AGREEMENT AMONG
MODELS WITH A PACIFIC TROF BRINGING A SURFACE COLD FRONT EAST OF
THE CONTINENTAL DIVIDE THIS EVENING. THE FRONT SHOULD PUSH
THROUGH CENTRAL AND SOUTHWEST MT TONIGHT AND DURING THE OVERNIGHT
HOURS. AN ISOLATED SHOWER OR TWO MAY POP UP AHEAD OF THE FRONT BUT
NOTHING MAJOR IS EXPECTED. PROBABILITY FOR PRECIP WILL INCREASE
BEHIND THE FRONT AS ADDITIONAL MOISTURE ARRIVES ALONG WITH COOLER
TEMPERATURES. FREEZING LEVELS WILL FALL THROUGH THE DAY THURSDAY
CREATING FAVORABLE CONDITIONS FOR LIGHT SNOW IN THE MTNS AND FOR
SOME LOCATIONS TO SEE GRAUPEL/SMALL HAIL WITH RAIN SHOWERS THURS
AFTERNOON. PRECIP SHOULD TAPER OFF THURS NIGHT AS THE TROF
CONTINUES EAST ACROSS MONTANA. AN UPPER LEVEL RIDGE BEGINS TO
BUILD BACK IN OVER THE REGION FRI BRINGING A RETURN OF WARM AND
DRY CONDITIONS. AS FOR TEMPERATURES...THE COLDER AIRMASS
ASSOCIATED WITH THE INCOMING FRONT WILL DROP OVERNIGHT LOW TEMPS
TONIGHT INTO THE 20S IN THE MOUNTAINS AND 30S TO LOW 40S ACROSS
THE PLAINS AND VALLEYS. HIGHS IN THE MID 40S TO LOW 50S ON
THURSDAY SHOULD RETURN TO THE UPPER 50S TO LOW 60S ON FRIDAY.
FRIDAY NIGHT THROUGH WEDNESDAY...AN UPPER LEVEL RIDGE OF HIGH
PRESSURE BECOMES ESTABLISHED OVER THE NORTHERN ROCKIES FRIDAY NIGHT
AND STRENGTHENS OVER MUCH OF THE WESTERN U.S. THIS WEEKEND THROUGH
AT LEAST THE FIRST HALF OF NEXT WEEK. THIS WILL BRING AN EXTENDED
PERIOD OF MAINLY DRY WEATHER TO THE FORECAST AREA WITH AFTERNOON
TEMPERATURES INITIALLY NEAR SEASONAL AVERAGES ON SATURDAY...RISING
TO 10-15 DEGREES ABOVE AVERAGE FROM SUNDAY THROUGH THE FIRST HALF OF
NEXT WEEK. OVERNIGHT LOW TEMPERATURES FRIDAY NIGHT/SATURDAY MORNING
WILL LIKELY FALL TO NEAR FREEZING IN MANY AREAS AGAIN WITH WARMING
MINIMUM TEMPS THEREAFTER. SURFACE PRESSURE GRADIENTS AND WINDS ALOFT
ARE RELATIVELY WEAK THROUGH THE PERIOD...WITH SURFACE WINDS EXPECTED
TO BE RELATIVELY LIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 41 52 31 59 / 30 60 20 0
CTB 34 47 27 60 / 10 50 20 0
HLN 41 55 31 63 / 40 60 20 0
BZN 37 54 26 61 / 20 60 10 0
WEY 31 53 24 57 / 10 30 20 0
DLN 39 54 25 61 / 30 40 10 0
HVR 40 50 30 60 / 20 70 30 0
LWT 37 48 29 56 / 30 70 30 0
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
WEATHER.GOV/GREATFALLS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
125 PM CDT TUE MAY 8 2012
.UPDATE...MORNING UPPER AIR ANALYSIS AND WATER VAPOR
IMAGERY INDICATES A MID LEVEL SHORT WAVE OVER THE NORTHERN PLAINS AND
UPPER MISSISSIPPI VALLEY...AS WELL AS A MID LEVEL LOW OVER THE
SOUTHWESTERN CONUS. LONG WAVE RIDGING EXISTS OVER THE EASTERN CONUS
AS WELL AS THE NORTHWESTERN CONUS. UPPER LEVEL JET ENERGY EXTENDS
FROM NEAR NEW MEXICO AND WEST-TEXAS...NORTHEASTWARD ACROSS THE
CENTRAL PLAINS AND ON INTO THE GREAT LAKES REGION...AND THEN
EASTWARD TOWARDS THE NORTHEASTERN CONUS. A ~110KT UPPER LEVEL JET
STREAK IS ALSO NOTED EXTENDING FROM THE GREAT LAKES REGION INTO
SOUTHERN ONTARIO AND SOUTHERN QUEBEC...AS WELL AS THE NORTHEASTERN
CONUS. VISIBLE SATELLITE IMAGERY SHOWS AN EXPANSIVE CU FIELD OVER
NORTHEASTERN NEBRASKA INCLUDING NORTHEASTERN PORTIONS OF OUR CWA...WITH
SUNNY SKIES NOTED ELSEWHERE ACROSS OUR CWA. AT THE SURFACE AN AREA OF
HIGH PRESSURE IS NOTED MOVING INTO THE CENTRAL PLAINS FROM THE
MIDDLE ROCKY MOUNTAIN RANGE...WITH THE LOW LEVEL WIND FIELD ACROSS
OUR AREA REMAINING FROM THE WEST/NORTHWEST FOR THE MOST PART.
INCREASING MID LEVEL LAPS RATES ALONG THE AXIS OF THE MID LEVEL
SHORT WAVE WILL CONTINUE PROMOTING AN EXPANSIVE BUT WEAK CU FIELD ACROSS
THE NORTHEASTERN HALF OF THE CWA THIS AFTERNOON. DESPITE THE
INCREASING CLOUD COVER...DRY CONDITIONS ARE EXPECTED THIS
AFTERNOON WITH UPDRAFT STRENGTH REMAINING WEAK AND FORECAST
PROXIMITY SOUNDINGS SUGGESTING THE TROPOSPHERE WILL REMAIN VERY
DRY BELOW 700MB. FORECAST PROXIMITY SOUNDINGS ALSO SUGGEST
AFTERNOON BOUNDARY LAYER MIXING WILL INCREASE TO NEAR 700MB THIS
AFTERNOON...THUS RESULTING IN A SIGNIFICANT DROP-OFF IN AFTERNOON
DEW POINTS. DEW POINTS HAVE ALREADY FALLEN INTO THE UPPER 20S AND
LOWER 30S AS OF 18Z...A TREND WHICH IS EXPECTED TO CONTINUE
THROUGH THE REMAINDER OF THE AFTERNOON. THESE LOW VALUES OF
HUMIDITY...ALONG WITH A STIFF NORTHWESTERLY WIND IN THE 15-20KT
RANGE ACROSS MUCH OF THE CWA...WOULD PRESENT A FIRE WEATHER
CONCERN TODAY BUT WITH FUEL STATUS REMAINING NEGATIVE FOR
EXPLOSIVE FIRE GROWTH ACROSS THE ENTIRE CWA...RFW ISSUANCE WILL NOT
BE REQUIRED TODAY.
&&
.PREV DISCUSSION... /ISSUED 1220 PM CDT TUE MAY 8 2012/
AVIATION...18Z KGRI TAF. VFR CONDITIONS EXPECTED THROUGH THE NEXT
24 HOURS. AFTERNOON CU NEAR 7000FT AGL WILL BE OBSERVED THROUGH
MUCH OF THE AFTERNOON...WITH CLEAR SKIES EXPECTED AFTER 01Z.
SURFACE WINDS WILL REMAIN FROM THE NORTHWEST AT AROUND
14KTS...GUSTING TO NEAR 23KTS...BEFORE BECOMING LIGHT AND VARIABLE
AFTER 01Z. VISIBILITY RESTRICTIONS ARE NOT EXPECTED THROUGH THE
NEXT 24 HOURS.
PREV DISCUSSION... /ISSUED 722 AM CDT TUE MAY 8 2012/
UPDATE...JUST COMPLETED A QUICK UPDATE TO PURGE ISOLATED SPRINKLE
WORDING FROM KS ZONES...AS RADAR RETURNS EXITED STAGE SOUTH A BIT
FASTER THAN PREVIOUSLY EXPECTED WITHIN THE NARROW MID LEVEL
FRONTOGENETIC ZONE...AND AREN/T EXPECTED TO COME BACK. NEVER
ACTUALLY HAD CONFIRMED GROUND TRUTH THAT THIS LIGHT PRECIP REACHED
THE GROUND ANYWAY WITHIN THE CWA...BUT CHANCES ARE A FEW SPRINKLES
MANAGED TO. NO OTHER NOTABLE CHANGES MADE...OTHER THAN BRINGING
HOURLY TEMPS/DEWPOINTS/SKY COVER MORE IN LINE WITH LATEST OBS.
PREV DISCUSSION... /ISSUED 349 AM CDT TUE MAY 8 2012/
SHORT TERM...THROUGH THURSDAY NIGHT. WITH VERY LIMITED TO NO RISK
OF PRECIPITATION THROUGH THESE 72 HOURS...PRIMARY CHALLENGES BOIL
DOWN TO TEMPS/DEWPOINTS/WINDS...INCLUDING JUST HOW WARM THURSDAY
WILL ULTIMATELY GET.
STARTING OFF EARLY THIS MORNING...07Z OBJECTIVE SURFACE ANALYSIS
PLACES A BROAD HIGH PRESSURE AXIS CENTERED ALONG THE HIGH
PLAINS/FRONT RANGE FROM EASTERN MT THROUGH CENTRAL CO...WHILE A
WEAK LOW IS NOTED OVER FAR NORTHERN MN. WITH THE DOMINANT HIGH OFF
TO THE WEST...NEAR CALM TO LIGHT WESTERLY BREEZES DOMINATE THE
CWA. ALOFT...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA
INDICATE THE CENTRAL PLAINS ALONG THE SOUTHWESTERN FRINGES OF A
POSITIVELY TILTED TROUGH AXIS EXTENDING NORTHEASTWARD TO A CLOSED
500MB CIRCULATION SINKING SOUTHWARD INTO MN. MEANWHILE...ANOTHER
COMPACT CLOSED LOW IS EVIDENT ALONG THE AZ/SOUTHERN CALI
BORDER...WHILE A POSITIVELY TILTED RIDGE AXIS IS CENTERED FROM
CENTRAL CALI TO SOUTHWEST CANADA. ALONG THE SOUTHEASTERN PERIPHERY
OF THE GREAT LAKES REGION TROUGH AXIS...A MODEST 80+KT 300MB JET
STREAK IS CENTERED FROM CENTRAL NEB TO NORTH OF THE GREAT LAKES.
AS IS OH-SO COMMON IN THE ENTRANCE REGION OF SUCH A JET STREAK...A
NARROW BAND OF MID LEVEL FRONTOGENESIS EVIDENT NEAR THE 600MB
LEVEL IS FORCING A SNEAKY GENERALLY EAST-WEST BAND OF SPRINKLES
EXTENDING FROM EAST CENTRAL CO THROUGH AREAS ALONG AND MAINLY
SOUTH OF THE NEB-KS BORDER IN THE LOCAL AREA. WITH CLOUD CEILINGS
GENERALLY IN EXCESS OF 9K FEET...THIS WEAKLY FORCED PRECIPITATION
IS NOT EXPECTED TO MEASURE...BUT AS HINTED BY THE LATEST HRRR
RUNS...IT AT LEAST WARRANTS AN ISOLATED/SLIGHT CHANCE SPRINKLE
MENTION ACROSS PARTS OF THE SOUTHERN CWA DURING THE PRE-DAWN
HOURS. TURNING TO TEMPS...THE FAIRLY EXTENSIVE COVERAGE OF MID-
HIGH LEVEL CLOUDS SO FAR TONIGHT HAS HELD TEMPS WELL INTO THE
UPPER 40S/LOW 50S IN SOUTHERN ZONES...WITH NORTHERN AREAS JUST
NOW STARTING TO REALIZE SOME UPPER 30S/LOW 40S. LEANING ON THE 00Z
NAM 600MB RH FIELDS...THE THICKER BATCH OF MID CLOUDS/SPRINKLES
SHOULD GRADUALLY SINK SOUTHWARD THROUGH THE NEXT SEVERAL
HOURS...LIKELY ALLOWING A MORE PRONOUNCED TEMP DROP TOWARD
SUNRISE. THIS SHOULD ALLOW THE MAJORITY OF THE CWA TO AT LEAST
REALIZE LOW-MID 40S FOR LOWS...WITH SOME MID-UPPER 30S STILL
EXPECTED MAINLY WEST OF A GREELEY-LEXINGTON LINE. ALTHOUGH
CONFIDENCE IS LOW ON ANY AREAS TOUCHING THE 36-DEGREE RANGE LONG
ENOUGH TO FORM FROST...WITH NONETHELESS HANG ONTO SOME PATCHY
FROST WORDING EARLY THIS MORNING ONLY FOR PARTS OF DAWSON AND
NORTHWEST GOSPER COUNTIES...WITH MINIMAL IMPACT ANTICIPATED.
GETTING INTO THE DAYTIME HOURS POST-12Z...WILL CONTINUE TO FOLLOW
THE NAM 600MB RELATIVE HUMIDITY MAXIMUM FAIRLY CLOSELY TO
DELINEATE THE NORTHERN EDGE OF MORNING SPRINKLE POTENTIAL...AND
WILL LINGER THIS MENTION ONLY IN KS ZONES THROUGH 15Z...AND
HOPEFULLY THIS IS LONG ENOUGH AS LATEST HRRR TRIES SUGGESTING SOME
SPRINKLES COULD STICK AROUND EVEN THROUGH 17Z OR SO...BUT THIS
LOOKS A BIT OVERDONE AS LIFT IN THE ENTRANCE REGION OF THE UPPER
JET AND RESULTANT MID LEVEL SATURATION SINKS SOUTH OF THE AREA
WITH TIME. MAY HAVE TO DEBATE ADDING A SLIGHT MEASURABLE POP AS
WELL...BUT FEEL THAT MEASURABLE RAIN WILL BE THE EXCEPTION OUT OF
THIS ACTIVITY UNLESS RADAR TRENDS DICTATE OTHERWISE DURING NEXT
FEW HOURS. HAVE NO MENTION OF RAIN WHATSOEVER ANYWHERE IN THE CWA
BEYOND 15Z...AS THE MAIN GREAT LAKES REGION VORT MAX DROPS SOUTH
INTO NORTHERN IA BY 00Z. ALTHOUGH THE COLD POCKET ALOFT WITH THIS
WAVE WILL SURELY SPARK SCATTERED SHOWERS/MAYBE A FEW WEAK STORMS
THIS AFTERNOON AS CLOSE AS NORTHEAST NEB...WILL ASSUME FOR NOW
THAT THIS ACTIVITY WILL REMAIN OUTSIDE THE CWA. HOWEVER...PER THE
LATEST 00Z 4KM WRF-NMM REFLECTIVITY PROG...SOME OF THIS SHOWER
ACTIVITY COULD GET FAIRLY CLOSE TO BRUSHING THE FAR NORTHEAST CWA
IN THE NANCE/POLK COUNTY AREA AND NEXT SHIFTS WILL HAVE TO KEEP AN
EYE ON THIS ESPECIALLY BETWEEN 20Z-00Z. AS HAS ALREADY BEEN PROVEN
IN THE PAST 24 HOURS...SETUPS LIKE THIS CAN GO FROM LOOKING
COMPLETELY DRY 2 DAYS PRIOR...TO ULTIMATELY PRODUCING AT LEAST
NUISANCE SPRINKLES/LIGHT SHOWERS WITH LITTLE ADVANCE NOTICE.
TURNING TO OTHER FACETS OF TODAY/S FORECAST...DEEP MIXING TO NEAR
700MB PER NAM SOUNDINGS WILL PROMOTE ANOTHER BREEZY DAY...WITH
SUSTAINED SPEEDS EASILY 15-20 MPH WITH GUSTS TO AROUND 25 MPH
ESPECIALLY ACROSS THE NORTHEAST 1/2 OF THE CWA. TEMP-WISE...ALTHOUGH
COULD EASILY SEE A FAIR AMOUNT OF HIGH-BASED CUMULUS THIS
AFTERNOON...FORESEE NO WORSE THAN PARTLY CLOUDY SKIES OVERALL. AS
A RESULT...KEPT HIGHS SIMILAR TO PREVIOUS FORECAST...WITH MOST
AREAS IN THE UPPER 60S-LOW 70S. PER A NAM-BASED MIXING TOOL...DID
LOWER DEWPOINTS AT LEAST 5 DEGREES DURING THE DAY MOST AREAS.
ALTHOUGH THIS WOULD DROP SURFACE RH VALUES DOWN TO AROUND 20 PERCENT
OR SO...ANY FIRE WEATHER THREAT SHOULD BE QUITE MINIMAL GIVEN
RECENT RAINFALL AND CONTINUED GREEN-UP.
TONIGHT...SHORTWAVE RIDGING OVERTAKES THE CWA IN THE WAKE OF THE
DEPARTING TROUGH AXIS...WHICH WILL REACH ALONG A LINE FROM
SOUTHERN KS UP THROUGH THE EASTERN GREAT LAKES BY 12Z. ASSUMING
THAT NO SPRINKLES/LIGHT SHOWERS ARE AFFECTING THE NORTHEAST CWA
RIGHT AWAY IN THE EARLY EVENING...HAVE HIGH CONFIDENCE IN A DRY
OVERNIGHT PERIOD AS A ROUGHLY 1022MB SURFACE HIGH SETTLES
DIRECTLY OVER THE CWA. WITH MOSTLY CLEAR SKIES AND LIGHT/VARIABLE
BREEZES...SHOULD SEE A MORE EFFICIENT TEMP DROP TONIGHT...AND
NUDGED DOWN LOWS AT LEAST 2-3 DEGREES FROM PREVIOUS
FORECAST...PUTTING MOST OF THE CWA DOWN INTO THE 38-41 RANGE FOR
LOWS. AS FOR FROST POTENTIAL...ONLY HAVE FAR WESTERN AREAS SUCH AS
DAWSON AND GOSPER COUNTIES REACHING AS LOW AS 36...AND THUS
CONFINED PATCHY FROST MENTION TO ONLY THIS LIMITED AREA FOR
NOW...WITH NO FROST HEADLINE PLANNED.
WEDNESDAY...RIDGING CONTINUES TO DOMINATE THE CWA BOTH AT THE
SURFACE AND ALOFT...WITH HIGH CONFIDENCE IN A DRY DAY WITH AT
LEAST MOSTLY SUNNY SKIES. ALTHOUGH THE SURFACE RIDGE AXIS WILL
INHIBIT EFFICIENT MIXING MOST OF THE DAY...A GRADUAL RETURN TO
SOUTHERLY BREEZES WILL DEVELOP. CHANGED HIGHS LITTLE...WITH MOST
AREAS BETWEEN 71-74.
WEDNESDAY NIGHT...STEADY LIGHT SOUTHERLY BREEZES CONTINUE AS AN
EXPANSIVE MID/UPPER RIDGE RETAINS CONTROL AHEAD OF THE NEXT LARGE
SCALE SHORTWAVE TROUGH MOVING INTO THE PACIFIC NORTHWEST. THE
SOUTHERLY FLOW WILL HELP KEEP LOWS WARMER...AND STAYED CLOSE TO
GUIDANCE AND PREVIOUS FORECAST WITH UPPER 40S-NEAR 50 CWA-WIDE.
THURSDAY...THIS STILL LOOKS TO BE THE HANDS-DOWN WARMEST DAY OF
THE FORECAST PERIOD...AS HIGH PLAINS SURFACE PRESSURE FALLS AHEAD
OF THE INCOMING TROUGH INDUCES INCREASING SOUTHERLY BREEZES WITH
SUSTAINED SPEEDS EASILY 15-20 MPH. DEEPER MIXING...IN CONCERT WITH
WARMER TEMPS EVIDENT AT 850MB AND PLENTY OF SUNSHINE SHOULD REALLY
GIVE TEMPS A BOOST...AND RAISED HIGHS AT LEAST 2-3 DEGREES FROM
PREVIOUS FORECAST...NOW RANGING FROM LOW 80S EAST TO MID 80S WEST.
NUMERICAL MET/MAV GUIDANCE JUST LOOKS TO BE SEVERAL DEGREES TOO
COOL AT THIS TIME.
THURSDAY NIGHT...MAIN CHANGE WAS TO PULL THE TOKEN 20 PERCENT
CHANCE OF SHOWERS/STORMS THAT HAD BEEN ADVERTISED IN FAR NORTHWEST
COUNTIES THE PAST FEW FORECAST CYCLES. ALTHOUGH BOTH THE NAM/ECMWF
ARE IN GOOD AGREEMENT THAT A WELL-DEFINED COLD FRONT WILL ENTER
NORTHWEST PORTIONS OF THE CWA BETWEEN 06Z-12Z...WHAT MEAGER
ELEVATED INSTABILITY THERE IS SHOULD HANG BACK IN WEST CENTRAL/NORTH
CENTRAL NEB THROUGH THE ENTIRE NIGHT AS THE PARENT MID LEVEL
TROUGH AXIS MIGRATES ACROSS THE NORTHERN ROCKIES. WANT TO NOTE
THAT THE NAM/ECMWF ARE BOTH FASTER THAN THE GFS IN BRINGING THE
COLD FRONT AND INCREASING NORTHWEST WINDS INTO THE CWA...SO THERE
ARE STILL SOME TIMING ISSUE TO WORK OUT HERE.
LONG TERM...FRIDAY THROUGH MONDAY. DURING THIS FORECAST PERIOD WE
START ANOTHER COOL DOWN WITH A COLD FRONTAL PASSAGE EARLY FRIDAY.
MOISTURE IS MEAGER ALONG THE BOUNDARY...BUT WE WILL NOTICE COOLING
TEMPERATURES BACK TO SEASONAL NUMBERS DURING THE DAY FRIDAY.
GLANCING BLOW OF UPPER LEVEL ENERGY AND TAIL END OF 250MB JET STREAK
COULD BE ENOUGH TO SPARK SOME SHOWERS...MAYBE A THUNDERSTORM OR TWO
BEHIND THE FRONT. ALL MODEL FORECAST HAVE THIS TREND. PRETTY STRONG
SURFACE HIGH PRESSURE SPREADS INTO THE REGION LATE FRIDAY AND
SATURDAY. EXPERIENCE WITH PRECIPITATION TRENDS AND BUILDING FRONT
RANGE SURFACE HIGH PRESSURES IN MODEL WORLD...IS THE MODELS TEND TO
OVERDO THE PRECIPITATION TOO FAR EAST AND WITH TOO MUCH OF IT. A
CONSERVATIVE APPROACH IS BEST AT THIS POINT...AS WE ARE LIABLE TO
SEE MORE CLOUDS THAN ANYTHING...ESPECIALLY THE FURTHER NORTH/EAST
YOU GO ACROSS OUR FORECAST AREA. THEREFORE...ONLY 20 TO 30 PERCENT
CHANCE FOR MEASURABLE PRECIPITATION AREA IN THE FORECAST. MID LEVEL
LAPSE RATES SUGGEST THUNDER RISK IF MARGINAL AT BEST AND ONLY AN
ISOLATED STORM IS EXPECTED. TEMPERATURES WILL DROP BACK INTO THE 60S
FOR A TIME...BUT START TO REBOUND LATE SUNDAY AND MONDAY. HARDLY A
RAINOUT BY ANY MEANS...BUT SOME SHOWERS WILL BE FLOATING AROUND ON
THIS MOTHERS DAY WEEKEND.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
1825Z UPDATE/AVIATION...BRYANT
1222Z UPDATE/SHORT TERM...PFANNKUCH
LONG TERM...MORITZ
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1220 PM CDT TUE MAY 8 2012
.AVIATION...18Z KGRI TAF. VFR CONDITIONS EXPECTED THROUGH THE NEXT
24 HOURS. AFTERNOON CU NEAR 7000FT AGL WILL BE OBSERVED THROUGH
MUCH OF THE AFTERNOON...WITH CLEAR SKIES EXPECTED AFTER 01Z.
SURFACE WINDS WILL REMAIN FROM THE NORTHWEST AT AROUND
14KTS...GUSTING TO NEAR 23KTS...BEFORE BECOMING LIGHT AND VARIABLE
AFTER 01Z. VISIBILITY RESTRICTIONS ARE NOT EXPECTED THROUGH THE
NEXT 24 HOURS.
&&
.PREV DISCUSSION... /ISSUED 722 AM CDT TUE MAY 8 2012/
UPDATE...JUST COMPLETED A QUICK UPDATE TO PURGE ISOLATED SPRINKLE
WORDING FROM KS ZONES...AS RADAR RETURNS EXITED STAGE SOUTH A BIT
FASTER THAN PREVIOUSLY EXPECTED WITHIN THE NARROW MID LEVEL
FRONTOGENETIC ZONE...AND AREN/T EXPECTED TO COME BACK. NEVER
ACTUALLY HAD CONFIRMED GROUND TRUTH THAT THIS LIGHT PRECIP REACHED
THE GROUND ANYWAY WITHIN THE CWA...BUT CHANCES ARE A FEW SPRINKLES
MANAGED TO. NO OTHER NOTABLE CHANGES MADE...OTHER THAN BRINGING
HOURLY TEMPS/DEWPOINTS/SKY COVER MORE IN LINE WITH LATEST OBS.
PREV DISCUSSION... /ISSUED 349 AM CDT TUE MAY 8 2012/
SHORT TERM...THROUGH THURSDAY NIGHT. WITH VERY LIMITED TO NO RISK
OF PRECIPITATION THROUGH THESE 72 HOURS...PRIMARY CHALLENGES BOIL
DOWN TO TEMPS/DEWPOINTS/WINDS...INCLUDING JUST HOW WARM THURSDAY
WILL ULTIMATELY GET.
STARTING OFF EARLY THIS MORNING...07Z OBJECTIVE SURFACE ANALYSIS
PLACES A BROAD HIGH PRESSURE AXIS CENTERED ALONG THE HIGH
PLAINS/FRONT RANGE FROM EASTERN MT THROUGH CENTRAL CO...WHILE A
WEAK LOW IS NOTED OVER FAR NORTHERN MN. WITH THE DOMINANT HIGH OFF
TO THE WEST...NEAR CALM TO LIGHT WESTERLY BREEZES DOMINATE THE
CWA. ALOFT...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA
INDICATE THE CENTRAL PLAINS ALONG THE SOUTHWESTERN FRINGES OF A
POSITIVELY TILTED TROUGH AXIS EXTENDING NORTHEASTWARD TO A CLOSED
500MB CIRCULATION SINKING SOUTHWARD INTO MN. MEANWHILE...ANOTHER
COMPACT CLOSED LOW IS EVIDENT ALONG THE AZ/SOUTHERN CALI
BORDER...WHILE A POSITIVELY TILTED RIDGE AXIS IS CENTERED FROM
CENTRAL CALI TO SOUTHWEST CANADA. ALONG THE SOUTHEASTERN PERIPHERY
OF THE GREAT LAKES REGION TROUGH AXIS...A MODEST 80+KT 300MB JET
STREAK IS CENTERED FROM CENTRAL NEB TO NORTH OF THE GREAT LAKES.
AS IS OH-SO COMMON IN THE ENTRANCE REGION OF SUCH A JET STREAK...A
NARROW BAND OF MID LEVEL FRONTOGENESIS EVIDENT NEAR THE 600MB
LEVEL IS FORCING A SNEAKY GENERALLY EAST-WEST BAND OF SPRINKLES
EXTENDING FROM EAST CENTRAL CO THROUGH AREAS ALONG AND MAINLY
SOUTH OF THE NEB-KS BORDER IN THE LOCAL AREA. WITH CLOUD CEILINGS
GENERALLY IN EXCESS OF 9K FEET...THIS WEAKLY FORCED PRECIPITATION
IS NOT EXPECTED TO MEASURE...BUT AS HINTED BY THE LATEST HRRR
RUNS...IT AT LEAST WARRANTS AN ISOLATED/SLIGHT CHANCE SPRINKLE
MENTION ACROSS PARTS OF THE SOUTHERN CWA DURING THE PRE-DAWN
HOURS. TURNING TO TEMPS...THE FAIRLY EXTENSIVE COVERAGE OF MID-
HIGH LEVEL CLOUDS SO FAR TONIGHT HAS HELD TEMPS WELL INTO THE
UPPER 40S/LOW 50S IN SOUTHERN ZONES...WITH NORTHERN AREAS JUST
NOW STARTING TO REALIZE SOME UPPER 30S/LOW 40S. LEANING ON THE 00Z
NAM 600MB RH FIELDS...THE THICKER BATCH OF MID CLOUDS/SPRINKLES
SHOULD GRADUALLY SINK SOUTHWARD THROUGH THE NEXT SEVERAL
HOURS...LIKELY ALLOWING A MORE PRONOUNCED TEMP DROP TOWARD
SUNRISE. THIS SHOULD ALLOW THE MAJORITY OF THE CWA TO AT LEAST
REALIZE LOW-MID 40S FOR LOWS...WITH SOME MID-UPPER 30S STILL
EXPECTED MAINLY WEST OF A GREELEY-LEXINGTON LINE. ALTHOUGH
CONFIDENCE IS LOW ON ANY AREAS TOUCHING THE 36-DEGREE RANGE LONG
ENOUGH TO FORM FROST...WITH NONETHELESS HANG ONTO SOME PATCHY
FROST WORDING EARLY THIS MORNING ONLY FOR PARTS OF DAWSON AND
NORTHWEST GOSPER COUNTIES...WITH MINIMAL IMPACT ANTICIPATED.
GETTING INTO THE DAYTIME HOURS POST-12Z...WILL CONTINUE TO FOLLOW
THE NAM 600MB RELATIVE HUMIDITY MAXIMUM FAIRLY CLOSELY TO
DELINEATE THE NORTHERN EDGE OF MORNING SPRINKLE POTENTIAL...AND
WILL LINGER THIS MENTION ONLY IN KS ZONES THROUGH 15Z...AND
HOPEFULLY THIS IS LONG ENOUGH AS LATEST HRRR TRIES SUGGESTING SOME
SPRINKLES COULD STICK AROUND EVEN THROUGH 17Z OR SO...BUT THIS
LOOKS A BIT OVERDONE AS LIFT IN THE ENTRANCE REGION OF THE UPPER
JET AND RESULTANT MID LEVEL SATURATION SINKS SOUTH OF THE AREA
WITH TIME. MAY HAVE TO DEBATE ADDING A SLIGHT MEASURABLE POP AS
WELL...BUT FEEL THAT MEASURABLE RAIN WILL BE THE EXCEPTION OUT OF
THIS ACTIVITY UNLESS RADAR TRENDS DICTATE OTHERWISE DURING NEXT
FEW HOURS. HAVE NO MENTION OF RAIN WHATSOEVER ANYWHERE IN THE CWA
BEYOND 15Z...AS THE MAIN GREAT LAKES REGION VORT MAX DROPS SOUTH
INTO NORTHERN IA BY 00Z. ALTHOUGH THE COLD POCKET ALOFT WITH THIS
WAVE WILL SURELY SPARK SCATTERED SHOWERS/MAYBE A FEW WEAK STORMS
THIS AFTERNOON AS CLOSE AS NORTHEAST NEB...WILL ASSUME FOR NOW
THAT THIS ACTIVITY WILL REMAIN OUTSIDE THE CWA. HOWEVER...PER THE
LATEST 00Z 4KM WRF-NMM REFLECTIVITY PROG...SOME OF THIS SHOWER
ACTIVITY COULD GET FAIRLY CLOSE TO BRUSHING THE FAR NORTHEAST CWA
IN THE NANCE/POLK COUNTY AREA AND NEXT SHIFTS WILL HAVE TO KEEP AN
EYE ON THIS ESPECIALLY BETWEEN 20Z-00Z. AS HAS ALREADY BEEN PROVEN
IN THE PAST 24 HOURS...SETUPS LIKE THIS CAN GO FROM LOOKING
COMPLETELY DRY 2 DAYS PRIOR...TO ULTIMATELY PRODUCING AT LEAST
NUISANCE SPRINKLES/LIGHT SHOWERS WITH LITTLE ADVANCE NOTICE.
TURNING TO OTHER FACETS OF TODAY/S FORECAST...DEEP MIXING TO NEAR
700MB PER NAM SOUNDINGS WILL PROMOTE ANOTHER BREEZY DAY...WITH
SUSTAINED SPEEDS EASILY 15-20 MPH WITH GUSTS TO AROUND 25 MPH
ESPECIALLY ACROSS THE NORTHEAST 1/2 OF THE CWA. TEMP-WISE...ALTHOUGH
COULD EASILY SEE A FAIR AMOUNT OF HIGH-BASED CUMULUS THIS
AFTERNOON...FORESEE NO WORSE THAN PARTLY CLOUDY SKIES OVERALL. AS
A RESULT...KEPT HIGHS SIMILAR TO PREVIOUS FORECAST...WITH MOST
AREAS IN THE UPPER 60S-LOW 70S. PER A NAM-BASED MIXING TOOL...DID
LOWER DEWPOINTS AT LEAST 5 DEGREES DURING THE DAY MOST AREAS.
ALTHOUGH THIS WOULD DROP SURFACE RH VALUES DOWN TO AROUND 20 PERCENT
OR SO...ANY FIRE WEATHER THREAT SHOULD BE QUITE MINIMAL GIVEN
RECENT RAINFALL AND CONTINUED GREEN-UP.
TONIGHT...SHORTWAVE RIDGING OVERTAKES THE CWA IN THE WAKE OF THE
DEPARTING TROUGH AXIS...WHICH WILL REACH ALONG A LINE FROM
SOUTHERN KS UP THROUGH THE EASTERN GREAT LAKES BY 12Z. ASSUMING
THAT NO SPRINKLES/LIGHT SHOWERS ARE AFFECTING THE NORTHEAST CWA
RIGHT AWAY IN THE EARLY EVENING...HAVE HIGH CONFIDENCE IN A DRY
OVERNIGHT PERIOD AS A ROUGHLY 1022MB SURFACE HIGH SETTLES
DIRECTLY OVER THE CWA. WITH MOSTLY CLEAR SKIES AND LIGHT/VARIABLE
BREEZES...SHOULD SEE A MORE EFFICIENT TEMP DROP TONIGHT...AND
NUDGED DOWN LOWS AT LEAST 2-3 DEGREES FROM PREVIOUS
FORECAST...PUTTING MOST OF THE CWA DOWN INTO THE 38-41 RANGE FOR
LOWS. AS FOR FROST POTENTIAL...ONLY HAVE FAR WESTERN AREAS SUCH AS
DAWSON AND GOSPER COUNTIES REACHING AS LOW AS 36...AND THUS
CONFINED PATCHY FROST MENTION TO ONLY THIS LIMITED AREA FOR
NOW...WITH NO FROST HEADLINE PLANNED.
WEDNESDAY...RIDGING CONTINUES TO DOMINATE THE CWA BOTH AT THE
SURFACE AND ALOFT...WITH HIGH CONFIDENCE IN A DRY DAY WITH AT
LEAST MOSTLY SUNNY SKIES. ALTHOUGH THE SURFACE RIDGE AXIS WILL
INHIBIT EFFICIENT MIXING MOST OF THE DAY...A GRADUAL RETURN TO
SOUTHERLY BREEZES WILL DEVELOP. CHANGED HIGHS LITTLE...WITH MOST
AREAS BETWEEN 71-74.
WEDNESDAY NIGHT...STEADY LIGHT SOUTHERLY BREEZES CONTINUE AS AN
EXPANSIVE MID/UPPER RIDGE RETAINS CONTROL AHEAD OF THE NEXT LARGE
SCALE SHORTWAVE TROUGH MOVING INTO THE PACIFIC NORTHWEST. THE
SOUTHERLY FLOW WILL HELP KEEP LOWS WARMER...AND STAYED CLOSE TO
GUIDANCE AND PREVIOUS FORECAST WITH UPPER 40S-NEAR 50 CWA-WIDE.
THURSDAY...THIS STILL LOOKS TO BE THE HANDS-DOWN WARMEST DAY OF
THE FORECAST PERIOD...AS HIGH PLAINS SURFACE PRESSURE FALLS AHEAD
OF THE INCOMING TROUGH INDUCES INCREASING SOUTHERLY BREEZES WITH
SUSTAINED SPEEDS EASILY 15-20 MPH. DEEPER MIXING...IN CONCERT WITH
WARMER TEMPS EVIDENT AT 850MB AND PLENTY OF SUNSHINE SHOULD REALLY
GIVE TEMPS A BOOST...AND RAISED HIGHS AT LEAST 2-3 DEGREES FROM
PREVIOUS FORECAST...NOW RANGING FROM LOW 80S EAST TO MID 80S WEST.
NUMERICAL MET/MAV GUIDANCE JUST LOOKS TO BE SEVERAL DEGREES TOO
COOL AT THIS TIME.
THURSDAY NIGHT...MAIN CHANGE WAS TO PULL THE TOKEN 20 PERCENT
CHANCE OF SHOWERS/STORMS THAT HAD BEEN ADVERTISED IN FAR NORTHWEST
COUNTIES THE PAST FEW FORECAST CYCLES. ALTHOUGH BOTH THE NAM/ECMWF
ARE IN GOOD AGREEMENT THAT A WELL-DEFINED COLD FRONT WILL ENTER
NORTHWEST PORTIONS OF THE CWA BETWEEN 06Z-12Z...WHAT MEAGER
ELEVATED INSTABILITY THERE IS SHOULD HANG BACK IN WEST CENTRAL/NORTH
CENTRAL NEB THROUGH THE ENTIRE NIGHT AS THE PARENT MID LEVEL
TROUGH AXIS MIGRATES ACROSS THE NORTHERN ROCKIES. WANT TO NOTE
THAT THE NAM/ECMWF ARE BOTH FASTER THAN THE GFS IN BRINGING THE
COLD FRONT AND INCREASING NORTHWEST WINDS INTO THE CWA...SO THERE
ARE STILL SOME TIMING ISSUE TO WORK OUT HERE.
LONG TERM...FRIDAY THROUGH MONDAY. DURING THIS FORECAST PERIOD WE
START ANOTHER COOL DOWN WITH A COLD FRONTAL PASSAGE EARLY FRIDAY.
MOISTURE IS MEAGER ALONG THE BOUNDARY...BUT WE WILL NOTICE COOLING
TEMPERATURES BACK TO SEASONAL NUMBERS DURING THE DAY FRIDAY.
GLANCING BLOW OF UPPER LEVEL ENERGY AND TAIL END OF 250MB JET STREAK
COULD BE ENOUGH TO SPARK SOME SHOWERS...MAYBE A THUNDERSTORM OR TWO
BEHIND THE FRONT. ALL MODEL FORECAST HAVE THIS TREND. PRETTY STRONG
SURFACE HIGH PRESSURE SPREADS INTO THE REGION LATE FRIDAY AND
SATURDAY. EXPERIENCE WITH PRECIPITATION TRENDS AND BUILDING FRONT
RANGE SURFACE HIGH PRESSURES IN MODEL WORLD...IS THE MODELS TEND TO
OVERDO THE PRECIPITATION TOO FAR EAST AND WITH TOO MUCH OF IT. A
CONSERVATIVE APPROACH IS BEST AT THIS POINT...AS WE ARE LIABLE TO
SEE MORE CLOUDS THAN ANYTHING...ESPECIALLY THE FURTHER NORTH/EAST
YOU GO ACROSS OUR FORECAST AREA. THEREFORE...ONLY 20 TO 30 PERCENT
CHANCE FOR MEASURABLE PRECIPITATION AREA IN THE FORECAST. MID LEVEL
LAPSE RATES SUGGEST THUNDER RISK IF MARGINAL AT BEST AND ONLY AN
ISOLATED STORM IS EXPECTED. TEMPERATURES WILL DROP BACK INTO THE 60S
FOR A TIME...BUT START TO REBOUND LATE SUNDAY AND MONDAY. HARDLY A
RAINOUT BY ANY MEANS...BUT SOME SHOWERS WILL BE FLOATING AROUND ON
THIS MOTHERS DAY WEEKEND.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AVIATION...BRYANT
UPDATE/SHORT TERM...PFANNKUCH
LONG TERM...MORITZ
AREA FORECAST DISCUSSION
NWS HASTINGS NE
722 AM CDT TUE MAY 8 2012
.UPDATE...JUST COMPLETED A QUICK UPDATE TO PURGE ISOLATED SPRINKLE
WORDING FROM KS ZONES...AS RADAR RETURNS EXITED STAGE SOUTH A BIT
FASTER THAN PREVIOUSLY EXPECTED WITHIN THE NARROW MID LEVEL
FRONTOGENETIC ZONE...AND AREN/T EXPECTED TO COME BACK. NEVER
ACTUALLY HAD CONFIRMED GROUND TRUTH THAT THIS LIGHT PRECIP REACHED
THE GROUND ANYWAY WITHIN THE CWA...BUT CHANCES ARE A FEW SPRINKLES
MANAGED TO. NO OTHER NOTABLE CHANGES MADE...OTHER THAN BRINGING
HOURLY TEMPS/DEWPOINTS/SKY COVER MORE IN LINE WITH LATEST OBS.
&&
.PREV DISCUSSION... /ISSUED 602 AM CDT TUE MAY 8 2012/
AVIATION...12Z TAF. VFR CONDITIONS ARE FORECAST FOR THE TAF
PERIOD. SOME LOW/MID CLOUDS WILL WRAP AROUND AN UPPER LOW INTO
THE AREA THIS AFTERNOON...ALONG WITH SOME CONVECTIVE CUMULUS
DEVELOPMENT. WINDS WILL PICK UP BY LATE MORNING AND GUST OVER
20KTS IN THE AFTERNOON. SKIES WILL CLEAR AND WIND DIMINISH
QUICKLY THIS EVENING.
PREV DISCUSSION... /ISSUED 349 AM CDT TUE MAY 8 2012/
SHORT TERM...THROUGH THURSDAY NIGHT. WITH VERY LIMITED TO NO RISK
OF PRECIPITATION THROUGH THESE 72 HOURS...PRIMARY CHALLENGES BOIL
DOWN TO TEMPS/DEWPOINTS/WINDS...INCLUDING JUST HOW WARM THURSDAY
WILL ULTIMATELY GET.
STARTING OFF EARLY THIS MORNING...07Z OBJECTIVE SURFACE ANALYSIS
PLACES A BROAD HIGH PRESSURE AXIS CENTERED ALONG THE HIGH
PLAINS/FRONT RANGE FROM EASTERN MT THROUGH CENTRAL CO...WHILE A
WEAK LOW IS NOTED OVER FAR NORTHERN MN. WITH THE DOMINANT HIGH OFF
TO THE WEST...NEAR CALM TO LIGHT WESTERLY BREEZES DOMINATE THE
CWA. ALOFT...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA
INDICATE THE CENTRAL PLAINS ALONG THE SOUTHWESTERN FRINGES OF A
POSITIVELY TILTED TROUGH AXIS EXTENDING NORTHEASTWARD TO A CLOSED
500MB CIRCULATION SINKING SOUTHWARD INTO MN. MEANWHILE...ANOTHER
COMPACT CLOSED LOW IS EVIDENT ALONG THE AZ/SOUTHERN CALI
BORDER...WHILE A POSITIVELY TILTED RIDGE AXIS IS CENTERED FROM
CENTRAL CALI TO SOUTHWEST CANADA. ALONG THE SOUTHEASTERN PERIPHERY
OF THE GREAT LAKES REGION TROUGH AXIS...A MODEST 80+KT 300MB JET
STREAK IS CENTERED FROM CENTRAL NEB TO NORTH OF THE GREAT LAKES.
AS IS OH-SO COMMON IN THE ENTRANCE REGION OF SUCH A JET STREAK...A
NARROW BAND OF MID LEVEL FRONTOGENESIS EVIDENT NEAR THE 600MB
LEVEL IS FORCING A SNEAKY GENERALLY EAST-WEST BAND OF SPRINKLES
EXTENDING FROM EAST CENTRAL CO THROUGH AREAS ALONG AND MAINLY
SOUTH OF THE NEB-KS BORDER IN THE LOCAL AREA. WITH CLOUD CEILINGS
GENERALLY IN EXCESS OF 9K FEET...THIS WEAKLY FORCED PRECIPITATION
IS NOT EXPECTED TO MEASURE...BUT AS HINTED BY THE LATEST HRRR
RUNS...IT AT LEAST WARRANTS AN ISOLATED/SLIGHT CHANCE SPRINKLE
MENTION ACROSS PARTS OF THE SOUTHERN CWA DURING THE PRE-DAWN
HOURS. TURNING TO TEMPS...THE FAIRLY EXTENSIVE COVERAGE OF MID-
HIGH LEVEL CLOUDS SO FAR TONIGHT HAS HELD TEMPS WELL INTO THE
UPPER 40S/LOW 50S IN SOUTHERN ZONES...WITH NORTHERN AREAS JUST
NOW STARTING TO REALIZE SOME UPPER 30S/LOW 40S. LEANING ON THE 00Z
NAM 600MB RH FIELDS...THE THICKER BATCH OF MID CLOUDS/SPRINKLES
SHOULD GRADUALLY SINK SOUTHWARD THROUGH THE NEXT SEVERAL
HOURS...LIKELY ALLOWING A MORE PRONOUNCED TEMP DROP TOWARD
SUNRISE. THIS SHOULD ALLOW THE MAJORITY OF THE CWA TO AT LEAST
REALIZE LOW-MID 40S FOR LOWS...WITH SOME MID-UPPER 30S STILL
EXPECTED MAINLY WEST OF A GREELEY-LEXINGTON LINE. ALTHOUGH
CONFIDENCE IS LOW ON ANY AREAS TOUCHING THE 36-DEGREE RANGE LONG
ENOUGH TO FORM FROST...WITH NONETHELESS HANG ONTO SOME PATCHY
FROST WORDING EARLY THIS MORNING ONLY FOR PARTS OF DAWSON AND
NORTHWEST GOSPER COUNTIES...WITH MINIMAL IMPACT ANTICIPATED.
GETTING INTO THE DAYTIME HOURS POST-12Z...WILL CONTINUE TO FOLLOW
THE NAM 600MB RELATIVE HUMIDITY MAXIMUM FAIRLY CLOSELY TO
DELINEATE THE NORTHERN EDGE OF MORNING SPRINKLE POTENTIAL...AND
WILL LINGER THIS MENTION ONLY IN KS ZONES THROUGH 15Z...AND
HOPEFULLY THIS IS LONG ENOUGH AS LATEST HRRR TRIES SUGGESTING SOME
SPRINKLES COULD STICK AROUND EVEN THROUGH 17Z OR SO...BUT THIS
LOOKS A BIT OVERDONE AS LIFT IN THE ENTRANCE REGION OF THE UPPER
JET AND RESULTANT MID LEVEL SATURATION SINKS SOUTH OF THE AREA
WITH TIME. MAY HAVE TO DEBATE ADDING A SLIGHT MEASURABLE POP AS
WELL...BUT FEEL THAT MEASURABLE RAIN WILL BE THE EXCEPTION OUT OF
THIS ACTIVITY UNLESS RADAR TRENDS DICTATE OTHERWISE DURING NEXT
FEW HOURS. HAVE NO MENTION OF RAIN WHATSOEVER ANYWHERE IN THE CWA
BEYOND 15Z...AS THE MAIN GREAT LAKES REGION VORT MAX DROPS SOUTH
INTO NORTHERN IA BY 00Z. ALTHOUGH THE COLD POCKET ALOFT WITH THIS
WAVE WILL SURELY SPARK SCATTERED SHOWERS/MAYBE A FEW WEAK STORMS
THIS AFTERNOON AS CLOSE AS NORTHEAST NEB...WILL ASSUME FOR NOW
THAT THIS ACTIVITY WILL REMAIN OUTSIDE THE CWA. HOWEVER...PER THE
LATEST 00Z 4KM WRF-NMM REFLECTIVITY PROG...SOME OF THIS SHOWER
ACTIVITY COULD GET FAIRLY CLOSE TO BRUSHING THE FAR NORTHEAST CWA
IN THE NANCE/POLK COUNTY AREA AND NEXT SHIFTS WILL HAVE TO KEEP AN
EYE ON THIS ESPECIALLY BETWEEN 20Z-00Z. AS HAS ALREADY BEEN PROVEN
IN THE PAST 24 HOURS...SETUPS LIKE THIS CAN GO FROM LOOKING
COMPLETELY DRY 2 DAYS PRIOR...TO ULTIMATELY PRODUCING AT LEAST
NUISANCE SPRINKLES/LIGHT SHOWERS WITH LITTLE ADVANCE NOTICE.
TURNING TO OTHER FACETS OF TODAY/S FORECAST...DEEP MIXING TO NEAR
700MB PER NAM SOUNDINGS WILL PROMOTE ANOTHER BREEZY DAY...WITH
SUSTAINED SPEEDS EASILY 15-20 MPH WITH GUSTS TO AROUND 25 MPH
ESPECIALLY ACROSS THE NORTHEAST 1/2 OF THE CWA. TEMP-WISE...ALTHOUGH
COULD EASILY SEE A FAIR AMOUNT OF HIGH-BASED CUMULUS THIS
AFTERNOON...FORESEE NO WORSE THAN PARTLY CLOUDY SKIES OVERALL. AS
A RESULT...KEPT HIGHS SIMILAR TO PREVIOUS FORECAST...WITH MOST
AREAS IN THE UPPER 60S-LOW 70S. PER A NAM-BASED MIXING TOOL...DID
LOWER DEWPOINTS AT LEAST 5 DEGREES DURING THE DAY MOST AREAS.
ALTHOUGH THIS WOULD DROP SURFACE RH VALUES DOWN TO AROUND 20 PERCENT
OR SO...ANY FIRE WEATHER THREAT SHOULD BE QUITE MINIMAL GIVEN
RECENT RAINFALL AND CONTINUED GREEN-UP.
TONIGHT...SHORTWAVE RIDGING OVERTAKES THE CWA IN THE WAKE OF THE
DEPARTING TROUGH AXIS...WHICH WILL REACH ALONG A LINE FROM
SOUTHERN KS UP THROUGH THE EASTERN GREAT LAKES BY 12Z. ASSUMING
THAT NO SPRINKLES/LIGHT SHOWERS ARE AFFECTING THE NORTHEAST CWA
RIGHT AWAY IN THE EARLY EVENING...HAVE HIGH CONFIDENCE IN A DRY
OVERNIGHT PERIOD AS A ROUGHLY 1022MB SURFACE HIGH SETTLES
DIRECTLY OVER THE CWA. WITH MOSTLY CLEAR SKIES AND LIGHT/VARIABLE
BREEZES...SHOULD SEE A MORE EFFICIENT TEMP DROP TONIGHT...AND
NUDGED DOWN LOWS AT LEAST 2-3 DEGREES FROM PREVIOUS
FORECAST...PUTTING MOST OF THE CWA DOWN INTO THE 38-41 RANGE FOR
LOWS. AS FOR FROST POTENTIAL...ONLY HAVE FAR WESTERN AREAS SUCH AS
DAWSON AND GOSPER COUNTIES REACHING AS LOW AS 36...AND THUS
CONFINED PATCHY FROST MENTION TO ONLY THIS LIMITED AREA FOR
NOW...WITH NO FROST HEADLINE PLANNED.
WEDNESDAY...RIDGING CONTINUES TO DOMINATE THE CWA BOTH AT THE
SURFACE AND ALOFT...WITH HIGH CONFIDENCE IN A DRY DAY WITH AT
LEAST MOSTLY SUNNY SKIES. ALTHOUGH THE SURFACE RIDGE AXIS WILL
INHIBIT EFFICIENT MIXING MOST OF THE DAY...A GRADUAL RETURN TO
SOUTHERLY BREEZES WILL DEVELOP. CHANGED HIGHS LITTLE...WITH MOST
AREAS BETWEEN 71-74.
WEDNESDAY NIGHT...STEADY LIGHT SOUTHERLY BREEZES CONTINUE AS AN
EXPANSIVE MID/UPPER RIDGE RETAINS CONTROL AHEAD OF THE NEXT LARGE
SCALE SHORTWAVE TROUGH MOVING INTO THE PACIFIC NORTHWEST. THE
SOUTHERLY FLOW WILL HELP KEEP LOWS WARMER...AND STAYED CLOSE TO
GUIDANCE AND PREVIOUS FORECAST WITH UPPER 40S-NEAR 50 CWA-WIDE.
THURSDAY...THIS STILL LOOKS TO BE THE HANDS-DOWN WARMEST DAY OF
THE FORECAST PERIOD...AS HIGH PLAINS SURFACE PRESSURE FALLS AHEAD
OF THE INCOMING TROUGH INDUCES INCREASING SOUTHERLY BREEZES WITH
SUSTAINED SPEEDS EASILY 15-20 MPH. DEEPER MIXING...IN CONCERT WITH
WARMER TEMPS EVIDENT AT 850MB AND PLENTY OF SUNSHINE SHOULD REALLY
GIVE TEMPS A BOOST...AND RAISED HIGHS AT LEAST 2-3 DEGREES FROM
PREVIOUS FORECAST...NOW RANGING FROM LOW 80S EAST TO MID 80S WEST.
NUMERICAL MET/MAV GUIDANCE JUST LOOKS TO BE SEVERAL DEGREES TOO
COOL AT THIS TIME.
THURSDAY NIGHT...MAIN CHANGE WAS TO PULL THE TOKEN 20 PERCENT
CHANCE OF SHOWERS/STORMS THAT HAD BEEN ADVERTISED IN FAR NORTHWEST
COUNTIES THE PAST FEW FORECAST CYCLES. ALTHOUGH BOTH THE NAM/ECMWF
ARE IN GOOD AGREEMENT THAT A WELL-DEFINED COLD FRONT WILL ENTER
NORTHWEST PORTIONS OF THE CWA BETWEEN 06Z-12Z...WHAT MEAGER
ELEVATED INSTABILITY THERE IS SHOULD HANG BACK IN WEST CENTRAL/NORTH
CENTRAL NEB THROUGH THE ENTIRE NIGHT AS THE PARENT MID LEVEL
TROUGH AXIS MIGRATES ACROSS THE NORTHERN ROCKIES. WANT TO NOTE
THAT THE NAM/ECMWF ARE BOTH FASTER THAN THE GFS IN BRINGING THE
COLD FRONT AND INCREASING NORTHWEST WINDS INTO THE CWA...SO THERE
ARE STILL SOME TIMING ISSUE TO WORK OUT HERE.
LONG TERM...FRIDAY THROUGH MONDAY. DURING THIS FORECAST PERIOD WE
START ANOTHER COOL DOWN WITH A COLD FRONTAL PASSAGE EARLY FRIDAY.
MOISTURE IS MEAGER ALONG THE BOUNDARY...BUT WE WILL NOTICE COOLING
TEMPERATURES BACK TO SEASONAL NUMBERS DURING THE DAY FRIDAY.
GLANCING BLOW OF UPPER LEVEL ENERGY AND TAIL END OF 250MB JET STREAK
COULD BE ENOUGH TO SPARK SOME SHOWERS...MAYBE A THUNDERSTORM OR TWO
BEHIND THE FRONT. ALL MODEL FORECAST HAVE THIS TREND. PRETTY STRONG
SURFACE HIGH PRESSURE SPREADS INTO THE REGION LATE FRIDAY AND
SATURDAY. EXPERIENCE WITH PRECIPITATION TRENDS AND BUILDING FRONT
RANGE SURFACE HIGH PRESSURES IN MODEL WORLD...IS THE MODELS TEND TO
OVERDO THE PRECIPITATION TOO FAR EAST AND WITH TOO MUCH OF IT. A
CONSERVATIVE APPROACH IS BEST AT THIS POINT...AS WE ARE LIABLE TO
SEE MORE CLOUDS THAN ANYTHING...ESPECIALLY THE FURTHER NORTH/EAST
YOU GO ACROSS OUR FORECAST AREA. THEREFORE...ONLY 20 TO 30 PERCENT
CHANCE FOR MEASURABLE PRECIPITATION AREA IN THE FORECAST. MID LEVEL
LAPSE RATES SUGGEST THUNDER RISK IF MARGINAL AT BEST AND ONLY AN
ISOLATED STORM IS EXPECTED. TEMPERATURES WILL DROP BACK INTO THE 60S
FOR A TIME...BUT START TO REBOUND LATE SUNDAY AND MONDAY. HARDLY A
RAINOUT BY ANY MEANS...BUT SOME SHOWERS WILL BE FLOATING AROUND ON
THIS MOTHERS DAY WEEKEND.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE/SHORT TERM...PFANNKUCH
LONG TERM/AVIATION...MORITZ
AREA FORECAST DISCUSSION
NWS HASTINGS NE
602 AM CDT TUE MAY 8 2012
.AVIATION...12Z TAF. VFR CONDITIONS ARE FORECAST FOR THE TAF
PERIOD. SOME LOW/MID CLOUDS WILL WRAP AROUND AN UPPER LOW INTO
THE AREA THIS AFTERNOON...ALONG WITH SOME CONVECTIVE CUMULUS
DEVELOPMENT. WINDS WILL PICK UP BY LATE MORNING AND GUST OVER
20KTS IN THE AFTERNOON. SKIES WILL CLEAR AND WIND DIMINISH
QUICKLY THIS EVENING.
&&
.PREV DISCUSSION... /ISSUED 349 AM CDT TUE MAY 8 2012/
SHORT TERM...THROUGH THURSDAY NIGHT. WITH VERY LIMITED TO NO RISK
OF PRECIPITATION THROUGH THESE 72 HOURS...PRIMARY CHALLENGES BOIL
DOWN TO TEMPS/DEWPOINTS/WINDS...INCLUDING JUST HOW WARM THURSDAY
WILL ULTIMATELY GET.
STARTING OFF EARLY THIS MORNING...07Z OBJECTIVE SURFACE ANALYSIS
PLACES A BROAD HIGH PRESSURE AXIS CENTERED ALONG THE HIGH
PLAINS/FRONT RANGE FROM EASTERN MT THROUGH CENTRAL CO...WHILE A
WEAK LOW IS NOTED OVER FAR NORTHERN MN. WITH THE DOMINANT HIGH OFF
TO THE WEST...NEAR CALM TO LIGHT WESTERLY BREEZES DOMINATE THE
CWA. ALOFT...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA
INDICATE THE CENTRAL PLAINS ALONG THE SOUTHWESTERN FRINGES OF A
POSITIVELY TILTED TROUGH AXIS EXTENDING NORTHEASTWARD TO A CLOSED
500MB CIRCULATION SINKING SOUTHWARD INTO MN. MEANWHILE...ANOTHER
COMPACT CLOSED LOW IS EVIDENT ALONG THE AZ/SOUTHERN CALI
BORDER...WHILE A POSITIVELY TILTED RIDGE AXIS IS CENTERED FROM
CENTRAL CALI TO SOUTHWEST CANADA. ALONG THE SOUTHEASTERN PERIPHERY
OF THE GREAT LAKES REGION TROUGH AXIS...A MODEST 80+KT 300MB JET
STREAK IS CENTERED FROM CENTRAL NEB TO NORTH OF THE GREAT LAKES.
AS IS OH-SO COMMON IN THE ENTRANCE REGION OF SUCH A JET STREAK...A
NARROW BAND OF MID LEVEL FRONTOGENESIS EVIDENT NEAR THE 600MB
LEVEL IS FORCING A SNEAKY GENERALLY EAST-WEST BAND OF SPRINKLES
EXTENDING FROM EAST CENTRAL CO THROUGH AREAS ALONG AND MAINLY
SOUTH OF THE NEB-KS BORDER IN THE LOCAL AREA. WITH CLOUD CEILINGS
GENERALLY IN EXCESS OF 9K FEET...THIS WEAKLY FORCED PRECIPITATION
IS NOT EXPECTED TO MEASURE...BUT AS HINTED BY THE LATEST HRRR
RUNS...IT AT LEAST WARRANTS AN ISOLATED/SLIGHT CHANCE SPRINKLE
MENTION ACROSS PARTS OF THE SOUTHERN CWA DURING THE PRE-DAWN
HOURS. TURNING TO TEMPS...THE FAIRLY EXTENSIVE COVERAGE OF MID-
HIGH LEVEL CLOUDS SO FAR TONIGHT HAS HELD TEMPS WELL INTO THE
UPPER 40S/LOW 50S IN SOUTHERN ZONES...WITH NORTHERN AREAS JUST
NOW STARTING TO REALIZE SOME UPPER 30S/LOW 40S. LEANING ON THE 00Z
NAM 600MB RH FIELDS...THE THICKER BATCH OF MID CLOUDS/SPRINKLES
SHOULD GRADUALLY SINK SOUTHWARD THROUGH THE NEXT SEVERAL
HOURS...LIKELY ALLOWING A MORE PRONOUNCED TEMP DROP TOWARD
SUNRISE. THIS SHOULD ALLOW THE MAJORITY OF THE CWA TO AT LEAST
REALIZE LOW-MID 40S FOR LOWS...WITH SOME MID-UPPER 30S STILL
EXPECTED MAINLY WEST OF A GREELEY-LEXINGTON LINE. ALTHOUGH
CONFIDENCE IS LOW ON ANY AREAS TOUCHING THE 36-DEGREE RANGE LONG
ENOUGH TO FORM FROST...WITH NONETHELESS HANG ONTO SOME PATCHY
FROST WORDING EARLY THIS MORNING ONLY FOR PARTS OF DAWSON AND
NORTHWEST GOSPER COUNTIES...WITH MINIMAL IMPACT ANTICIPATED.
GETTING INTO THE DAYTIME HOURS POST-12Z...WILL CONTINUE TO FOLLOW
THE NAM 600MB RELATIVE HUMIDITY MAXIMUM FAIRLY CLOSELY TO
DELINEATE THE NORTHERN EDGE OF MORNING SPRINKLE POTENTIAL...AND
WILL LINGER THIS MENTION ONLY IN KS ZONES THROUGH 15Z...AND
HOPEFULLY THIS IS LONG ENOUGH AS LATEST HRRR TRIES SUGGESTING SOME
SPRINKLES COULD STICK AROUND EVEN THROUGH 17Z OR SO...BUT THIS
LOOKS A BIT OVERDONE AS LIFT IN THE ENTRANCE REGION OF THE UPPER
JET AND RESULTANT MID LEVEL SATURATION SINKS SOUTH OF THE AREA
WITH TIME. MAY HAVE TO DEBATE ADDING A SLIGHT MEASURABLE POP AS
WELL...BUT FEEL THAT MEASURABLE RAIN WILL BE THE EXCEPTION OUT OF
THIS ACTIVITY UNLESS RADAR TRENDS DICTATE OTHERWISE DURING NEXT
FEW HOURS. HAVE NO MENTION OF RAIN WHATSOEVER ANYWHERE IN THE CWA
BEYOND 15Z...AS THE MAIN GREAT LAKES REGION VORT MAX DROPS SOUTH
INTO NORTHERN IA BY 00Z. ALTHOUGH THE COLD POCKET ALOFT WITH THIS
WAVE WILL SURELY SPARK SCATTERED SHOWERS/MAYBE A FEW WEAK STORMS
THIS AFTERNOON AS CLOSE AS NORTHEAST NEB...WILL ASSUME FOR NOW
THAT THIS ACTIVITY WILL REMAIN OUTSIDE THE CWA. HOWEVER...PER THE
LATEST 00Z 4KM WRF-NMM REFLECTIVITY PROG...SOME OF THIS SHOWER
ACTIVITY COULD GET FAIRLY CLOSE TO BRUSHING THE FAR NORTHEAST CWA
IN THE NANCE/POLK COUNTY AREA AND NEXT SHIFTS WILL HAVE TO KEEP AN
EYE ON THIS ESPECIALLY BETWEEN 20Z-00Z. AS HAS ALREADY BEEN PROVEN
IN THE PAST 24 HOURS...SETUPS LIKE THIS CAN GO FROM LOOKING
COMPLETELY DRY 2 DAYS PRIOR...TO ULTIMATELY PRODUCING AT LEAST
NUISANCE SPRINKLES/LIGHT SHOWERS WITH LITTLE ADVANCE NOTICE.
TURNING TO OTHER FACETS OF TODAY/S FORECAST...DEEP MIXING TO NEAR
700MB PER NAM SOUNDINGS WILL PROMOTE ANOTHER BREEZY DAY...WITH
SUSTAINED SPEEDS EASILY 15-20 MPH WITH GUSTS TO AROUND 25 MPH
ESPECIALLY ACROSS THE NORTHEAST 1/2 OF THE CWA. TEMP-WISE...ALTHOUGH
COULD EASILY SEE A FAIR AMOUNT OF HIGH-BASED CUMULUS THIS
AFTERNOON...FORESEE NO WORSE THAN PARTLY CLOUDY SKIES OVERALL. AS
A RESULT...KEPT HIGHS SIMILAR TO PREVIOUS FORECAST...WITH MOST
AREAS IN THE UPPER 60S-LOW 70S. PER A NAM-BASED MIXING TOOL...DID
LOWER DEWPOINTS AT LEAST 5 DEGREES DURING THE DAY MOST AREAS.
ALTHOUGH THIS WOULD DROP SURFACE RH VALUES DOWN TO AROUND 20 PERCENT
OR SO...ANY FIRE WEATHER THREAT SHOULD BE QUITE MINIMAL GIVEN
RECENT RAINFALL AND CONTINUED GREEN-UP.
TONIGHT...SHORTWAVE RIDGING OVERTAKES THE CWA IN THE WAKE OF THE
DEPARTING TROUGH AXIS...WHICH WILL REACH ALONG A LINE FROM
SOUTHERN KS UP THROUGH THE EASTERN GREAT LAKES BY 12Z. ASSUMING
THAT NO SPRINKLES/LIGHT SHOWERS ARE AFFECTING THE NORTHEAST CWA
RIGHT AWAY IN THE EARLY EVENING...HAVE HIGH CONFIDENCE IN A DRY
OVERNIGHT PERIOD AS A ROUGHLY 1022MB SURFACE HIGH SETTLES
DIRECTLY OVER THE CWA. WITH MOSTLY CLEAR SKIES AND LIGHT/VARIABLE
BREEZES...SHOULD SEE A MORE EFFICIENT TEMP DROP TONIGHT...AND
NUDGED DOWN LOWS AT LEAST 2-3 DEGREES FROM PREVIOUS
FORECAST...PUTTING MOST OF THE CWA DOWN INTO THE 38-41 RANGE FOR
LOWS. AS FOR FROST POTENTIAL...ONLY HAVE FAR WESTERN AREAS SUCH AS
DAWSON AND GOSPER COUNTIES REACHING AS LOW AS 36...AND THUS
CONFINED PATCHY FROST MENTION TO ONLY THIS LIMITED AREA FOR
NOW...WITH NO FROST HEADLINE PLANNED.
WEDNESDAY...RIDGING CONTINUES TO DOMINATE THE CWA BOTH AT THE
SURFACE AND ALOFT...WITH HIGH CONFIDENCE IN A DRY DAY WITH AT
LEAST MOSTLY SUNNY SKIES. ALTHOUGH THE SURFACE RIDGE AXIS WILL
INHIBIT EFFICIENT MIXING MOST OF THE DAY...A GRADUAL RETURN TO
SOUTHERLY BREEZES WILL DEVELOP. CHANGED HIGHS LITTLE...WITH MOST
AREAS BETWEEN 71-74.
WEDNESDAY NIGHT...STEADY LIGHT SOUTHERLY BREEZES CONTINUE AS AN
EXPANSIVE MID/UPPER RIDGE RETAINS CONTROL AHEAD OF THE NEXT LARGE
SCALE SHORTWAVE TROUGH MOVING INTO THE PACIFIC NORTHWEST. THE
SOUTHERLY FLOW WILL HELP KEEP LOWS WARMER...AND STAYED CLOSE TO
GUIDANCE AND PREVIOUS FORECAST WITH UPPER 40S-NEAR 50 CWA-WIDE.
THURSDAY...THIS STILL LOOKS TO BE THE HANDS-DOWN WARMEST DAY OF
THE FORECAST PERIOD...AS HIGH PLAINS SURFACE PRESSURE FALLS AHEAD
OF THE INCOMING TROUGH INDUCES INCREASING SOUTHERLY BREEZES WITH
SUSTAINED SPEEDS EASILY 15-20 MPH. DEEPER MIXING...IN CONCERT WITH
WARMER TEMPS EVIDENT AT 850MB AND PLENTY OF SUNSHINE SHOULD REALLY
GIVE TEMPS A BOOST...AND RAISED HIGHS AT LEAST 2-3 DEGREES FROM
PREVIOUS FORECAST...NOW RANGING FROM LOW 80S EAST TO MID 80S WEST.
NUMERICAL MET/MAV GUIDANCE JUST LOOKS TO BE SEVERAL DEGREES TOO
COOL AT THIS TIME.
THURSDAY NIGHT...MAIN CHANGE WAS TO PULL THE TOKEN 20 PERCENT
CHANCE OF SHOWERS/STORMS THAT HAD BEEN ADVERTISED IN FAR NORTHWEST
COUNTIES THE PAST FEW FORECAST CYCLES. ALTHOUGH BOTH THE NAM/ECMWF
ARE IN GOOD AGREEMENT THAT A WELL-DEFINED COLD FRONT WILL ENTER
NORTHWEST PORTIONS OF THE CWA BETWEEN 06Z-12Z...WHAT MEAGER
ELEVATED INSTABILITY THERE IS SHOULD HANG BACK IN WEST CENTRAL/NORTH
CENTRAL NEB THROUGH THE ENTIRE NIGHT AS THE PARENT MID LEVEL
TROUGH AXIS MIGRATES ACROSS THE NORTHERN ROCKIES. WANT TO NOTE
THAT THE NAM/ECMWF ARE BOTH FASTER THAN THE GFS IN BRINGING THE
COLD FRONT AND INCREASING NORTHWEST WINDS INTO THE CWA...SO THERE
ARE STILL SOME TIMING ISSUE TO WORK OUT HERE.
LONG TERM...FRIDAY THROUGH MONDAY. DURING THIS FORECAST PERIOD WE
START ANOTHER COOL DOWN WITH A COLD FRONTAL PASSAGE EARLY FRIDAY.
MOISTURE IS MEAGER ALONG THE BOUNDARY...BUT WE WILL NOTICE COOLING
TEMPERATURES BACK TO SEASONAL NUMBERS DURING THE DAY FRIDAY.
GLANCING BLOW OF UPPER LEVEL ENERGY AND TAIL END OF 250MB JET STREAK
COULD BE ENOUGH TO SPARK SOME SHOWERS...MAYBE A THUNDERSTORM OR TWO
BEHIND THE FRONT. ALL MODEL FORECAST HAVE THIS TREND. PRETTY STRONG
SURFACE HIGH PRESSURE SPREADS INTO THE REGION LATE FRIDAY AND
SATURDAY. EXPERIENCE WITH PRECIPITATION TRENDS AND BUILDING FRONT
RANGE SURFACE HIGH PRESSURES IN MODEL WORLD...IS THE MODELS TEND TO
OVERDO THE PRECIPITATION TOO FAR EAST AND WITH TOO MUCH OF IT. A
CONSERVATIVE APPROACH IS BEST AT THIS POINT...AS WE ARE LIABLE TO
SEE MORE CLOUDS THAN ANYTHING...ESPECIALLY THE FURTHER NORTH/EAST
YOU GO ACROSS OUR FORECAST AREA. THEREFORE...ONLY 20 TO 30 PERCENT
CHANCE FOR MEASURABLE PRECIPITATION AREA IN THE FORECAST. MID LEVEL
LAPSE RATES SUGGEST THUNDER RISK IF MARGINAL AT BEST AND ONLY AN
ISOLATED STORM IS EXPECTED. TEMPERATURES WILL DROP BACK INTO THE 60S
FOR A TIME...BUT START TO REBOUND LATE SUNDAY AND MONDAY. HARDLY A
RAINOUT BY ANY MEANS...BUT SOME SHOWERS WILL BE FLOATING AROUND ON
THIS MOTHERS DAY WEEKEND.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
349 AM CDT TUE MAY 8 2012
.SHORT TERM...THROUGH THURSDAY NIGHT. WITH VERY LIMITED TO NO RISK
OF PRECIPITATION THROUGH THESE 72 HOURS...PRIMARY CHALLENGES BOIL
DOWN TO TEMPS/DEWPOINTS/WINDS...INCLUDING JUST HOW WARM THURSDAY
WILL ULTIMATELY GET.
STARTING OFF EARLY THIS MORNING...07Z OBJECTIVE SURFACE ANALYSIS
PLACES A BROAD HIGH PRESSURE AXIS CENTERED ALONG THE HIGH
PLAINS/FRONT RANGE FROM EASTERN MT THROUGH CENTRAL CO...WHILE A
WEAK LOW IS NOTED OVER FAR NORTHERN MN. WITH THE DOMINANT HIGH OFF
TO THE WEST...NEAR CALM TO LIGHT WESTERLY BREEZES DOMINATE THE
CWA. ALOFT...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA
INDICATE THE CENTRAL PLAINS ALONG THE SOUTHWESTERN FRINGES OF A
POSITIVELY TILTED TROUGH AXIS EXTENDING NORTHEASTWARD TO A CLOSED
500MB CIRCULATION SINKING SOUTHWARD INTO MN. MEANWHILE...ANOTHER
COMPACT CLOSED LOW IS EVIDENT ALONG THE AZ/SOUTHERN CALI
BORDER...WHILE A POSITIVELY TILTED RIDGE AXIS IS CENTERED FROM
CENTRAL CALI TO SOUTHWEST CANADA. ALONG THE SOUTHEASTERN PERIPHERY
OF THE GREAT LAKES REGION TROUGH AXIS...A MODEST 80+KT 300MB JET
STREAK IS CENTERED FROM CENTRAL NEB TO NORTH OF THE GREAT LAKES.
AS IS OH-SO COMMON IN THE ENTRANCE REGION OF SUCH A JET STREAK...A
NARROW BAND OF MID LEVEL FRONTOGENESIS EVIDENT NEAR THE 600MB
LEVEL IS FORCING A SNEAKY GENERALLY EAST-WEST BAND OF SPRINKLES
EXTENDING FROM EAST CENTRAL CO THROUGH AREAS ALONG AND MAINLY
SOUTH OF THE NEB-KS BORDER IN THE LOCAL AREA. WITH CLOUD CEILINGS
GENERALLY IN EXCESS OF 9K FEET...THIS WEAKLY FORCED PRECIPITATION
IS NOT EXPECTED TO MEASURE...BUT AS HINTED BY THE LATEST HRRR
RUNS...IT AT LEAST WARRANTS AN ISOLATED/SLIGHT CHANCE SPRINKLE
MENTION ACROSS PARTS OF THE SOUTHERN CWA DURING THE PRE-DAWN
HOURS. TURNING TO TEMPS...THE FAIRLY EXTENSIVE COVERAGE OF MID-
HIGH LEVEL CLOUDS SO FAR TONIGHT HAS HELD TEMPS WELL INTO THE
UPPER 40S/LOW 50S IN SOUTHERN ZONES...WITH NORTHERN AREAS JUST
NOW STARTING TO REALIZE SOME UPPER 30S/LOW 40S. LEANING ON THE 00Z
NAM 600MB RH FIELDS...THE THICKER BATCH OF MID CLOUDS/SPRINKLES
SHOULD GRADUALLY SINK SOUTHWARD THROUGH THE NEXT SEVERAL
HOURS...LIKELY ALLOWING A MORE PRONOUNCED TEMP DROP TOWARD
SUNRISE. THIS SHOULD ALLOW THE MAJORITY OF THE CWA TO AT LEAST
REALIZE LOW-MID 40S FOR LOWS...WITH SOME MID-UPPER 30S STILL
EXPECTED MAINLY WEST OF A GREELEY-LEXINGTON LINE. ALTHOUGH
CONFIDENCE IS LOW ON ANY AREAS TOUCHING THE 36-DEGREE RANGE LONG
ENOUGH TO FORM FROST...WITH NONETHELESS HANG ONTO SOME PATCHY
FROST WORDING EARLY THIS MORNING ONLY FOR PARTS OF DAWSON AND
NORTHWEST GOSPER COUNTIES...WITH MINIMAL IMPACT ANTICIPATED.
GETTING INTO THE DAYTIME HOURS POST-12Z...WILL CONTINUE TO FOLLOW
THE NAM 600MB RELATIVE HUMIDITY MAXIMUM FAIRLY CLOSELY TO
DELINEATE THE NORTHERN EDGE OF MORNING SPRINKLE POTENTIAL...AND
WILL LINGER THIS MENTION ONLY IN KS ZONES THROUGH 15Z...AND
HOPEFULLY THIS IS LONG ENOUGH AS LATEST HRRR TRIES SUGGESTING SOME
SPRINKLES COULD STICK AROUND EVEN THROUGH 17Z OR SO...BUT THIS
LOOKS A BIT OVERDONE AS LIFT IN THE ENTRANCE REGION OF THE UPPER
JET AND RESULTANT MID LEVEL SATURATION SINKS SOUTH OF THE AREA
WITH TIME. MAY HAVE TO DEBATE ADDING A SLIGHT MEASURABLE POP AS
WELL...BUT FEEL THAT MEASURABLE RAIN WILL BE THE EXCEPTION OUT OF
THIS ACTIVITY UNLESS RADAR TRENDS DICTATE OTHERWISE DURING NEXT
FEW HOURS. HAVE NO MENTION OF RAIN WHATSOEVER ANYWHERE IN THE CWA
BEYOND 15Z...AS THE MAIN GREAT LAKES REGION VORT MAX DROPS SOUTH
INTO NORTHERN IA BY 00Z. ALTHOUGH THE COLD POCKET ALOFT WITH THIS
WAVE WILL SURELY SPARK SCATTERED SHOWERS/MAYBE A FEW WEAK STORMS
THIS AFTERNOON AS CLOSE AS NORTHEAST NEB...WILL ASSUME FOR NOW
THAT THIS ACTIVITY WILL REMAIN OUTSIDE THE CWA. HOWEVER...PER THE
LATEST 00Z 4KM WRF-NMM REFLECTIVITY PROG...SOME OF THIS SHOWER
ACTIVITY COULD GET FAIRLY CLOSE TO BRUSHING THE FAR NORTHEAST CWA
IN THE NANCE/POLK COUNTY AREA AND NEXT SHIFTS WILL HAVE TO KEEP AN
EYE ON THIS ESPECIALLY BETWEEN 20Z-00Z. AS HAS ALREADY BEEN PROVEN
IN THE PAST 24 HOURS...SETUPS LIKE THIS CAN GO FROM LOOKING
COMPLETELY DRY 2 DAYS PRIOR...TO ULTIMATELY PRODUCING AT LEAST
NUISANCE SPRINKLES/LIGHT SHOWERS WITH LITTLE ADVANCE NOTICE.
TURNING TO OTHER FACETS OF TODAY/S FORECAST...DEEP MIXING TO NEAR
700MB PER NAM SOUNDINGS WILL PROMOTE ANOTHER BREEZY DAY...WITH
SUSTAINED SPEEDS EASILY 15-20 MPH WITH GUSTS TO AROUND 25 MPH
ESPECIALLY ACROSS THE NORTHEAST 1/2 OF THE CWA. TEMP-WISE...ALTHOUGH
COULD EASILY SEE A FAIR AMOUNT OF HIGH-BASED CUMULUS THIS
AFTERNOON...FORESEE NO WORSE THAN PARTLY CLOUDY SKIES OVERALL. AS
A RESULT...KEPT HIGHS SIMILAR TO PREVIOUS FORECAST...WITH MOST
AREAS IN THE UPPER 60S-LOW 70S. PER A NAM-BASED MIXING TOOL...DID
LOWER DEWPOINTS AT LEAST 5 DEGREES DURING THE DAY MOST AREAS.
ALTHOUGH THIS WOULD DROP SURFACE RH VALUES DOWN TO AROUND 20 PERCENT
OR SO...ANY FIRE WEATHER THREAT SHOULD BE QUITE MINIMAL GIVEN
RECENT RAINFALL AND CONTINUED GREEN-UP.
TONIGHT...SHORTWAVE RIDGING OVERTAKES THE CWA IN THE WAKE OF THE
DEPARTING TROUGH AXIS...WHICH WILL REACH ALONG A LINE FROM
SOUTHERN KS UP THROUGH THE EASTERN GREAT LAKES BY 12Z. ASSUMING
THAT NO SPRINKLES/LIGHT SHOWERS ARE AFFECTING THE NORTHEAST CWA
RIGHT AWAY IN THE EARLY EVENING...HAVE HIGH CONFIDENCE IN A DRY
OVERNIGHT PERIOD AS A ROUGHLY 1022MB SURFACE HIGH SETTLES
DIRECTLY OVER THE CWA. WITH MOSTLY CLEAR SKIES AND LIGHT/VARIABLE
BREEZES...SHOULD SEE A MORE EFFICIENT TEMP DROP TONIGHT...AND
NUDGED DOWN LOWS AT LEAST 2-3 DEGREES FROM PREVIOUS
FORECAST...PUTTING MOST OF THE CWA DOWN INTO THE 38-41 RANGE FOR
LOWS. AS FOR FROST POTENTIAL...ONLY HAVE FAR WESTERN AREAS SUCH AS
DAWSON AND GOSPER COUNTIES REACHING AS LOW AS 36...AND THUS
CONFINED PATCHY FROST MENTION TO ONLY THIS LIMITED AREA FOR
NOW...WITH NO FROST HEADLINE PLANNED.
WEDNESDAY...RIDGING CONTINUES TO DOMINATE THE CWA BOTH AT THE
SURFACE AND ALOFT...WITH HIGH CONFIDENCE IN A DRY DAY WITH AT
LEAST MOSTLY SUNNY SKIES. ALTHOUGH THE SURFACE RIDGE AXIS WILL
INHIBIT EFFICIENT MIXING MOST OF THE DAY...A GRADUAL RETURN TO
SOUTHERLY BREEZES WILL DEVELOP. CHANGED HIGHS LITTLE...WITH MOST
AREAS BETWEEN 71-74.
WEDNESDAY NIGHT...STEADY LIGHT SOUTHERLY BREEZES CONTINUE AS AN
EXPANSIVE MID/UPPER RIDGE RETAINS CONTROL AHEAD OF THE NEXT LARGE
SCALE SHORTWAVE TROUGH MOVING INTO THE PACIFIC NORTHWEST. THE
SOUTHERLY FLOW WILL HELP KEEP LOWS WARMER...AND STAYED CLOSE TO
GUIDANCE AND PREVIOUS FORECAST WITH UPPER 40S-NEAR 50 CWA-WIDE.
THURSDAY...THIS STILL LOOKS TO BE THE HANDS-DOWN WARMEST DAY OF
THE FORECAST PERIOD...AS HIGH PLAINS SURFACE PRESSURE FALLS AHEAD
OF THE INCOMING TROUGH INDUCES INCREASING SOUTHERLY BREEZES WITH
SUSTAINED SPEEDS EASILY 15-20 MPH. DEEPER MIXING...IN CONCERT WITH
WARMER TEMPS EVIDENT AT 850MB AND PLENTY OF SUNSHINE SHOULD REALLY
GIVE TEMPS A BOOST...AND RAISED HIGHS AT LEAST 2-3 DEGREES FROM
PREVIOUS FORECAST...NOW RANGING FROM LOW 80S EAST TO MID 80S WEST.
NUMERICAL MET/MAV GUIDANCE JUST LOOKS TO BE SEVERAL DEGREES TOO
COOL AT THIS TIME.
THURSDAY NIGHT...MAIN CHANGE WAS TO PULL THE TOKEN 20 PERCENT
CHANCE OF SHOWERS/STORMS THAT HAD BEEN ADVERTISED IN FAR NORTHWEST
COUNTIES THE PAST FEW FORECAST CYCLES. ALTHOUGH BOTH THE NAM/ECMWF
ARE IN GOOD AGREEMENT THAT A WELL-DEFINED COLD FRONT WILL ENTER
NORTHWEST PORTIONS OF THE CWA BETWEEN 06Z-12Z...WHAT MEAGER
ELEVATED INSTABILITY THERE IS SHOULD HANG BACK IN WEST CENTRAL/NORTH
CENTRAL NEB THROUGH THE ENTIRE NIGHT AS THE PARENT MID LEVEL
TROUGH AXIS MIGRATES ACROSS THE NORTHERN ROCKIES. WANT TO NOTE
THAT THE NAM/ECMWF ARE BOTH FASTER THAN THE GFS IN BRINGING THE
COLD FRONT AND INCREASING NORTHWEST WINDS INTO THE CWA...SO THERE
ARE STILL SOME TIMING ISSUE TO WORK OUT HERE.
.LONG TERM...FRIDAY THROUGH MONDAY. DURING THIS FORECAST PERIOD WE
START ANOTHER COOL DOWN WITH A COLD FRONTAL PASSAGE EARLY FRIDAY.
MOISTURE IS MEAGER ALONG THE BOUNDARY...BUT WE WILL NOTICE COOLING
TEMPERATURES BACK TO SEASONAL NUMBERS DURING THE DAY FRIDAY.
GLANCING BLOW OF UPPER LEVEL ENERGY AND TAIL END OF 250MB JET STREAK
COULD BE ENOUGH TO SPARK SOME SHOWERS...MAYBE A THUNDERSTORM OR TWO
BEHIND THE FRONT. ALL MODEL FORECAST HAVE THIS TREND. PRETTY STRONG
SURFACE HIGH PRESSURE SPREADS INTO THE REGION LATE FRIDAY AND
SATURDAY. EXPERIENCE WITH PRECIPITATION TRENDS AND BUILDING FRONT
RANGE SURFACE HIGH PRESSURES IN MODEL WORLD...IS THE MODELS TEND TO
OVERDO THE PRECIPITATION TOO FAR EAST AND WITH TOO MUCH OF IT. A
CONSERVATIVE APPROACH IS BEST AT THIS POINT...AS WE ARE LIABLE TO
SEE MORE CLOUDS THAN ANYTHING...ESPECIALLY THE FURTHER NORTH/EAST
YOU GO ACROSS OUR FORECAST AREA. THEREFORE...ONLY 20 TO 30 PERCENT
CHANCE FOR MEASURABLE PRECIPITATION AREA IN THE FORECAST. MID LEVEL
LAPSE RATES SUGGEST THUNDER RISK IF MARGINAL AT BEST AND ONLY AN
ISOLATED STORM IS EXPECTED. TEMPERATURES WILL DROP BACK INTO THE 60S
FOR A TIME...BUT START TO REBOUND LATE SUNDAY AND MONDAY. HARDLY A
RAINOUT BY ANY MEANS...BUT SOME SHOWERS WILL BE FLOATING AROUND ON
THIS MOTHERS DAY WEEKEND.
&&
.PREV DISCUSSION... /ISSUED 1036 PM CDT MON MAY 7 2012/
AVIATION...06Z TAF. VFR CONDITIONS ARE FORECAST THROUGH THE PERIOD
WITH NO VISIBILITY RESTRICTIONS AND ONLY OCCASIONAL MID LEVEL CLOUDS
BRUSHING BY THE AREA DURING THE DAY TUESDAY. WINDS WILL INCREASE
AGAIN AND GUST ABOVE 20KTS FOR MUCH OF THE DAY...BEFORE DROPPING
OFF EARLY IN THE EVENING AS HIGH PRESSURE MOVES INTO CENTRAL
NEBRASKA.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM/AVIATION...MORITZ
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1029 PM EDT WED MAY 9 2012
.SYNOPSIS...
AN UPPER LEVEL TROUGH WILL DIG ACROSS THE AREA TODAY GENERATING A
FEW SHOWERS AND THUNDERSTORMS THIS AFTERNOON. HIGH PRESSURE WILL
THEN GRADUALLY BUILD ACROSS THE REGION DURING THE REMAINDER OF THE
WEEK BRINGING IMPROVING CONDITIONS ON THURSDAY AND DRY WEATHER FOR
FRIDAY AND SATURDAY.
&&
.NEAR TERM /THROUGH THURSDAY/...
AN UPPER LEVEL TROF WILL VERY SLOWLY APPROACH FROM THE WEST
OVERNIGHT...EVENTUALLY SETTLING ACROSS WESTERN NEW YORK BY DAYBREAK.
DESPITE THE APPROACH OF THIS FEATURE...THE LOSS OF DAYTIME HEATING
HAS KEYED THE DEMISE OF SHOWERS ACROSS WESTERN NEW YORK.
CONSENSUS QPF OF THE NAM12/RGEM BOTH SHOW LIGHT QPF IN UPSLOPE
REGIONS...BUT LOOKING AT THE OMEGA FIELD...NEARLY ALL THE LIFT IS
GENERATED IN THE LOWEST 3000 FT. THIS WILL PROBABLY NOT BE DEEP
ENOUGH TO PRODUCE SHOWERS. THE HRRR TENDS TO SUPPORT THIS
CONCLUSION...FORECASTING MINIMAL QPF OVERNIGHT. WITH THE UPPER
TROF...AND A LIMITED CHANCE FOR DRIZZLE...WILL HANG ONTO 20 SLIGHT
CHANCE POPS...BUT OUTSIDE OF SOME LINGERING SHOWERS...EXPECT A
MAINLY DRY NIGHT. THERE IS QUITE A BIT OF CLOUD COVER ASSOCIATED
WITH THE UPPER LOW...SO THIS WILL LIMIT RADIATIONAL
COOLING...THOUGHT HE NORTHERLY FLOW WILL ADVECT SLIGHTLY COLDER
TEMPERATURES IN. LOWS SHOULD MAINLY BE IN THE 40S ACROSS THE
REGION.
THURSDAY...UPPER TROUGH AXIS WILL BE LOCATED OVER WESTERN NEW YORK
SHIFTING EASTWARD AND CUTTING OFF THROUGH THE DAY. 543 DM LOW
CENTERED OVER SOUTHERN QUEBEC WILL PROVIDE COLD AIR ALOFT YIELDING
INSTABILITY CLOUDS ACROSS THE FORECAST AREA WITH A CHANCE FOR
INSTABILITY SHOWERS FOCUSED MAINLY ACROSS THE COUNTIES EAST OF LAKE
ONTARIO CLOSER TO THE UPPER LOW. MANY LOCATIONS WILL ONLY TOP OUT IN
THE MID TO UPPER 50S WITH THE CLOUD COVER AND COLD AIR ALOFT...850MB
TEMPS NEAR 0C. A FEW AREAS COULD SEE 60. BREEZY WEST TO NORTHWEST
WINDS WILL ALSO DEVELOP IN THE AFTERNOON AS THE SURFACE LOW NEAR
OTTAWA CANADA SHIFTS EAST OVER MAINE AND DEEPENS. A COOL...CLOUDY
AND BREEZY DAY TO SUM IT UP.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
A HIGH AMPLITUDE RIDGE WILL FORCE A BROAD SURFACE RIDGE INTO THE
EASTERN GREAT LAKES REGION THURSDAY NIGHT. THIS WILL BRING A
CLEARING TREND AND THE RISK FOR FROST...ESPECIALLY TO INTERIOR
SECTIONS OF THE SOUTHERN TIER WHERE TEMPERATURES WILL FALL TO THE
MID 30S IN SPOTS...POSSIBLY TO NEAR FREEZING IN THE GENESEE VALLEY.
FRIDAY SHOULD SEE PLENTY OF SUNSHINE...ALTHOUGH THERE MAY BE SOME
DIURNALLY DRIVEN CUMULUS WITH DEPARTING COLD POOL. WITH THE
ADDITIONAL SUNSHINE HIGHS WILL BE A SOLID 5 TO 10 DEGREES WARMER
THAN THURSDAY...MAINLY IN THE MID TO UPPER 60S.
SKIES WILL REMAIN CLEAR DURING FRIDAY NIGHT AND THE APPROACH OF A
WEAK COLD FRONT WILL INCREASE THE SOUTHWESTERLY BREEZE OVERNIGHT...
MIXING THE BOUNDARY LAYER AND HOLDING TEMPS LOWER TO MID 40S...
ALLEVIATING THE RISK OF FROST.
SATURDAY WILL ALSO BE A SUNNY DAY FOR THE MOST PART...SOME HIGH
CLOUDS STREAMING IN AND THICKENING THROUGH THE AFTERNOON. WILL SEE
HIGH TEMPS IN THE MID/UPR 60S EAST OF LAKE ONTARIO WITH LOWER 70S
ELSEWHERE AS 850MB TEMPS RISE TO THE +6C TO +8C RANGE PRECEDING A
WEAKENING TROUGH TO THE WEST. SAID TROUGH WILL CROSS THE REGION
SATURDAY NIGHT WITH LITTLE FANFARE...EXPECT THE COOL FRONT
ASSOCIATED WITH THE TROUGH TO WASH OUT ALMOST COMPLETELY. MID AND
HIGH CLOUDS ACCOMPANYING THE TROUGH/FRONT WILL KEEP OVERNIGHT TEMPS
UP INTO THE MID TO UPPER 40S ACROSS THE FORECAST AREA. GFS HAS COME
IN LINE WITH THE LONG STANDING ECMWF CONCEPT OF HAVING VERY LOW POPS
AND QPF ASSOCIATED WITH THE FRONT...SLIGHT CHANCE ACROSS MOST OF THE
FORECAST AREA WITH LOW CHANCE POPS FOR THE SAINT LAWRENCE VALLEY AND
TUG HILL/ WESTERN ADIRONDACKS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
ON SUNDAY...HIGH PRESSURE CENTERED OVER THE CENTRAL PLAINS WILL
RIDGE EASTWARD FOLLOWING THE PASSAGE OF THE DYING SURFACE TROUGH.
THE THERMAL BOUNDARY WILL REMAIN JUST SOUTH OF THE FORECAST AREA
WITH LOW CHANCE POPS ACROSS THE SOUTHERN TIER AND NIL POPS
ELSEWHERE. CLOUDS WILL LINGER ALONG THE NORTH OF THIS THERMAL
BOUNDARY WITH AFTERNOON TEMPS REACHING THE MID TO UPPER 60S.
HIGH PRESSURE FROM THE PLAINS TO THE MID GREAT LAKES AND ONWARD TO
WESTERN QUEBEC WILL HOLD A BROAD REGION OF LOW PRESSURE TO THE SOUTH
OF THE FORECAST AREA... ACROSS THE SOUTHEASTERN STATES. THE HIGH
PRESSURE SHOULD SUPPRESS ANY CHANCE OF PRECIP MONDAY THROUGH
WEDNESDAY WITH HIGH TEMPS GENERALLY IN THE MID 60S TO THE LOWER 70S.
LOWS WILL BE IN THE MID 40S TO LOW 50S.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
EXPECT THE REMAINDER OF THE OVERNIGHT PERIOD TO REMAIN DRY...WITH
LOWERING CIGS THE MAIN CONCERN. EXPECT BKN-OVC LOW CLOUDS TO
DEVELOP ACROSS THE REGION...GENERALLY HOVERING AROUND 3000 FT AT
BUF/IAG/ROC/ART...A BIT LOWER AT JHW. THE TREND SHOULD GENERALLY
BE DOWNWARD OVERNIGHT AS THE UPPER TROF APPROACHES...AND THE
INVERSION LOWERS.
THURSDAY...CIGS IMPROVE AFTER 14Z/15Z AND WIND GUSTS DEVELOP WITH
DAYTIME MIXING. BKN VFR SKIES WILL PREVAIL WITH COOL AIR ALOFT
PROVIDED BY UPPER LEVEL TROUGH OVER NY. SCATTERED SHOWERS HAVE
HIGHEST CHANCES EAST OF LAKE ONTARIO WHERE BEST INSTABILITY AND
HIGHER MOISTURE RESIDE.
OUTLOOK...
FRIDAY AND SATURDAY...VFR.
SUNDAY...VFR WITH A CHANCE OF SHOWERS.
&&
.MARINE...
A MODEST WEST TO OCCASIONALLY NORTHWESTERLY FLOW WILL PREVAIL ACROSS
THE LOWER GREAT LAKES THROUGH FRIDAY...WITH WINDS AND WAVES EXPECTED
TO REMAIN BELOW ADVISORY CRITERIA. MINIMAL SMALL CRAFT ADVISORY
CONDITIONS NEED TO BE WATCHED ALONG THE SOUTH SHORE OF LK ONTARIO
FOR THURSDAY AFTERNOON THROUGH THURSDAY NIGHT WITH ONSHORE NW
WINDS NEAR 20 KTS.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SMITH
NEAR TERM...APFFEL/SMITH
SHORT TERM...WCH
LONG TERM...WCH
AVIATION...APFFEL
MARINE...APFFEL/SMITH
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1058 PM EDT WED MAY 9 2012
.SYNOPSIS...
A COLD FRONT APPROACHING FROM THE WEST...MAY BRING A FEW STRONG TO
SEVERE THUNDERSTORMS TONIGHT. AFTER ITS PASSAGE LATE TONIGHT... MUCH
DRIER AIR WILL OVERSPREAD THE AREA AS HIGH PRESSURE RIDGES ACROSS
THE AREA THROUGH THE UPCOMING WEEKEND. THE HIGH WILL SLIP OFFSHORE
FROM THE COAST LATE SUNDAY. A COLD FRONT WILL APPROACH THE REGION
FROM THE NORTH MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 PM WEDNESDAY...LARGE AMPLIFIED UPPER TROF IN CONTROL OF
THE EAST COAST THIS NEAR TERM. AT THE SFC...A COLD FRONT ORIENTED
NE-SW ACROSS THE EASTERN CAROLINAS AT THE MOMENT...WILL TRACK
EASTWARD OVERNIGHT...MOVING OFF THE ILM CWA MAINLAND BETWEEN
MIDNIGHT AND 2 AM THURSDAY. LATEST HRRR MODEL RUNS ALSO INDICATE THE
WELL DEFINED COLD FRONT TO MOVE OFF THE CAROLINA COASTS BY EARLY THU
MORNING. PROGGED SFC WIND FIELDS VIA HRRR LOOKS LIKE THE BEST WAY TO
GO. EXPECT EXCELLENT POST FRONTAL CAA AFTER FROPA...WITH 850 TEMPS
DROPPING FROM ROUGHLY 14C TO 7C AND ALSO 1K-8H THICKNESS DROPPING
FROM ROUGHLY 1396M TO 1366M BY DAYBREAK THURSDAY. MAIN AREA OF
CONVECTION VIA KLTX AND SURROUNDING 88DOS...INDICATE THE MAIN AND
STRONGER AREAS OF CONVECTION LIE ACROSS THE ADJACENT ATLANTIC
WATERS. COULD OBSERVE SCATTERED -SHRA PRIOR TO THE CFP. WILL NEED TO
FURTHER ADJUST POPS ESPECIALLY WITH THE MAIN AREA NOW OFF THE COAST.
MIN TEMP GUIDANCE TRICKY DUE TO POST FRONTAL POSSIBLE LOW STRATUS
AND FOG. THE LATTER LIKELY NOT TO OCCUR DUE TO LOW LEVEL WINDS TO
INCREASE ENOUGH TO PREVENT FOG
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...BY THURSDAY DAYBREAK THE BULK OF COLUMN
MOISTURE ASSOCIATED WITH A DEPARTING FRONTAL SYSTEM WILL RESIDE
OFFSHORE. STRONG MID AND UPPER LEVEL DRYING COUPLED WITH MODERATE
NORTH WINDS WILL ALREADY BE OVERSPREADING THE AREA. MAXIMUM TEMPS
THU MAINLY MID/UPPER 70S WITH A FEW LOCATIONS OVER THE SC INTERIOR
APT TO REACH 80. MAINLY CLEAR UNDER LOW-LEVEL NORTH WIND FLOW THU
NIGHT SHOULD YIELD LOW/MID 50S INTO EARLY FRIDAY. NORTH FLOW WILL
ENDURE MUCH OF FRIDAY DELAYING A SIGNIFICANT DAYTIME WARMING TREND
WITH MAXIMUMS VERY SIMILAR TO THURSDAY. UNDER IDEAL RADIATIONAL
COOLING...UPPER 40S INLAND LOOKS PROBABLE WITH LOWER 50S ALONG THE
COASTAL ZONES...AND SURFACE HIGH PRESSURE NEARLY OVERHEAD.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 3 PM WEDNESDAY...SURFACE AND UPPER RIDGE AXIS OVERHEAD SAT
WILL SHIFT OFFSHORE SUN AS BROAD 5H TROUGH STARTS TO DEVELOP OVER
THE EASTERN HALF OF THE COUNTRY. SAT INTO SUN LOOKS DRY BUT
WEAKENING INFLUENCE OF THE UPPER RIDGE AND MOISTURE RETURN IN DEEP
SOUTHWEST FLOW COULD PRODUCE SOME ISOLATED CONVECTION SUN AFTERNOON.
INHERITED SLIGHT CHANCE POP LOOKS GOOD AT THIS POINT. FOR THE
REMAINDER OF THE PERIOD WEATHER WILL REMAIN UNSETTLED WITH 5H TROUGH
AXIS TO THE WEST AND DEEP SOUTHWEST FLOW ADVECTING PLENTY OF
MOISTURE INTO THE REGION. ANY PASSING SHORTWAVE WILL ENHANCE DIURNAL
CONVECTION MON AFTERNOON WHICH WARRANTS A SMALL POP INCREASE...NOW
LOW CHANCE. TUE/WED REMAINS UNCERTAIN WITH THE 12Z GFS MUCH MORE
PROGRESSIVE THAN ITS PREVIOUS RUNS. MEDIUM RANGE GUIDANCE AGREES ON
WEAK LOW PRESSURE DEVELOPING ALONG THE GULF COAST WHICH THEN MOVES
ACROSS NORTHERN FL AND UP THE SE COAST. SIGNIFICANT TIMING
DIFFERENCES BETWEEN THE 12Z GFS...12Z CANADIAN...00Z ECMWF AND LACK
OF CONTINUITY BETWEEN THEIR RESPECTIVE RUNS IS KEEPING CONFIDENCE
LOW LATE IN THE PERIOD. THE MAIN ISSUE IS HOW THE GUIDANCE IS
HANDLING THE COLLAPSE OF THE UPPER RIDGE OUT WEST AND THE IMPACT
THIS HAS ON THE TROUGHING OVER THE EAST. WILL CONTINUE TO CARRY A
CHANCE POP TUE/TUE NIGHT WHICH WILL EXTEND INTO WED AD MUCH OF THE
GUIDANCE...SAVE THE GFS...IS SUGGESTING A SLOWER/WETTER SOLUTION.
HIGHS WILL REMAIN SLIGHTLY BELOW CLIMO THROUGH THE PERIOD WITH LOWS
STARTING OUT SLIGHTLY BELOW CLIMO BUT ENDING UP NEAR TO SLIGHTLY
ABOVE CLIMO.
&&
.AVIATION /00Z THURSDAY THROUGH TUESDAY/...
AS OF 00Z...MVFR/IFR THROUGH THE EARLY OVERNIGHT HOURS...BECOMING
VFR FOR THE REMAINDER OF THE PERIOD AFTER MIDNIGHT.
WITH THE STRONGEST STORMS OUT OF THE AREA...ANOTHER ROUND OF SHOWERS
IS EXPECTED TO PROGRESS ACROSS THE AREA OVER THE NEXT COUPLE OF
HOURS AS SEEN ON CURRENT RADAR IMAGERY. WITH MVFR/IFR ALREADY IN
PLACE DUE TO LOW CIGS AND LOWERED VISIBILITIES FROM RAIN AND
FOG...EXPECT THIS TO CONTINUE THROUGH THE EARLY OVERNIGHT
HOURS...THOUGH A BRIEF LULL IN IMPROVED CONDITIONS MAY OCCUR BETWEEN
BANDS OF RAIN. AS THE COLD FRONT CONTINUES TO PUSH EASTWARD...EXPECT
SCT MID TO HIGH CLOUDS BEHIND THE BOUNDARY WITH NORTH-NORTHWEST
WINDS AOB 10 KTS. AFTER DAYBREAK...ANTICIPATE NEARLY CLEAR SKIES
WITH NORTH-NORTHWEST WINDS AOB 12 KTS. SCT MID LEVEL CLOUDS AROUND
6KFT WILL DEVELOP IN THE AFTERNOON...WITH GUSTS NEAR 20 KTS
POSSIBLE.
EXTENDED OUTLOOK...ISOLATED CONVECTION LATE FRIDAY
EVENING...BECOMING SCATTERED TO NUMEROUS SATURDAY. ISOLATED
CONVECTION POSSIBLE SUNDAY. VFR MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 PM WEDNESDAY...FOLLOWING THE HRRR MODEL SFC WIND
FIELDS...WITH THE CFP SLATED BETWEEN 1 AND 3 AM THURSDAY. A
PRONOUNCED WIND SHIFT WILL OCCUR...WITH SW 10 TO OCCASIONALLY 15
KT...VEERING TO THE NW 15 TO 20 KT OVERNIGHT. THE LATTER MAY BE A
BIT UNDERDONE GIVEN THE TIGHTENED POST FRONTAL SFC PRESSURE GRADIENT
AND COOL/COLD SURGE RESULTING WITH HIGH. SIG SEAS WILL RUN BASICALLY
2 TO 4 FT. INITIALLY THE EASTERLY 2 TO 3 FT GROUND SWELL WILL
DOMINATE SIG SEAS. IT WILL GIVE WAY TO AN INCREASING SHORT PERIOD
LOCALLY PRODUCED WIND WAVES EXHIBITING 3 TO 5 SECOND PERIODS. THIS
WIND DRIVEN VARIETY WILL BECOME THE DOMINATE PLAYER WITH REGARD TO
SIG. SEAS LATE TONIGHT.
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
AS OF 3 PM WEDNESDAY...A COLD FRONT MAY BRING LIMITED VISIBILITIES
IN RAIN AND ISOLATED TSTMS...ALONG WITH LOCALLY GUSTY WINDS AND
LOCALLY HIGHER WIND-WAVES TONIGHT. MARINERS SHOULD CONSULT RADAR
BEFORE HEADING OUT LATE THIS AFTERNOON OR EVENING. THE FRONT WILL
BRING A WIND-SHIFT IN THE VERY LATE EVENING AROUND MIDNIGHT. THIS
COULD BRING N WIND GUSTS TO 20 KT THROUGH THURSDAY MORNING...BEFORE
EASING IN THE AFTERNOON. REINFORCING HIGH PRESSURE WILL SUSTAIN N
WINDS THROUGH MOST OF FRIDAY...WITH THE HIGH MOVING OVERHEAD FRIDAY
NIGHT. SEAS MAY APPROACH 5 FEET ACROSS THE OUTER PORTION AND THE
NORTH END OF FRYING PAN SHOALS THURSDAY MORNING.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 PM WEDNESDAY...WEAK GRADIENT SAT INTO SUN WILL KEEP WINDS
LIGHT AND HIGHLY VARIABLE. THERE WILL BE A GENERAL NORTHEAST TO
EAST FLOW WITH SPEEDS 10 KT OR LESS. GRADIENT BECOMES A LITTLE
MORE DEFINED SUN AS HIGH MOVES FARTHER OF THE COAST AND SOUTHEAST
FLOW DEVELOPS. SOME GUIDANCE HINTING AT WEAK COASTAL TROUGH ALONG
THE GA/SOUTHERN SC COAST WHICH MAY ENHANCE FLOW ACROSS SC ZONES.
HOWEVER SPEEDS SHOULD REMAIN UNDER 15 KT INTO MON. SURFACE HIGH
EAST OF THE WATERS AND LACK OF ANY SIGNIFICANT SURFACE FEATURES TO
THE WEST MEANS SOUTHEAST FLOW WILL CONTINUE ON MON. OVERALL LITTLE
CHANGE TO THE SURFACE GRADIENT BETWEEN SUN AND MON SO SPEEDS
SHOULD BE SIMILAR...10 TO 15 KT. SEAS WILL RUN 2 TO 4 FT THROUGH
THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...DCH
SHORT TERM...MJC
LONG TERM...III
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
815 PM EDT WED MAY 9 2012
.SYNOPSIS...
A COLD FRONT APPROACHING FROM THE WEST...MAY BRING A FEW STRONG TO
SEVERE THUNDERSTORMS TONIGHT. AFTER ITS PASSAGE LATE TONIGHT... MUCH
DRIER AIR WILL OVERSPREAD THE AREA AS HIGH PRESSURE RIDGES ACROSS
THE AREA THROUGH THE UPCOMING WEEKEND. THE HIGH WILL SLIP OFFSHORE
FROM THE COAST LATE SUNDAY. A COLD FRONT WILL APPROACH THE REGION
FROM THE NORTH MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 800 PM WEDNESDAY...LARGE AMPLIFIED UPPER TROF IN CONTROL OF
THE EAST COAST THIS NEAR TERM. AT THE SFC...A COLD FRONT ORIENTED
NE-SW ACROSS THE CENTRAL CAROLINAS...WILL TRACK EASTWARD
OVERNIGHT...MOVING OFF THE ILM CWA LAND AREAS BETWEEN MIDNIGHT
THROUGH 2 AM THURSDAY. LATEST HRRR MODEL RUNS INDICATE THE WELL
DEFINED COLD FRONT TO MOVE OFF THE CAROLINA COASTS BY EARLY THU
MORNING HRS. HRRR SFC NW-N WIND FIELDS. EXPECT EXCELLENT POST
FRONTAL CAA AFTER FROPA...WITH 850 TEMPS DROPPING FROM ROUGHLY
14C TO 7C AND ALSO 1K-8H THICKNESSES DROPPING FROM ROUGHLY 1396M TO
1392M BY DAYBREAK THURSDAY. MAIN AREA OF CONVECTION VIA 88DS...NOW
MAINLY AFFECTING THE ADJACENT ATLANTIC WATERS. COULD OBSERVE
SCATTERED -SHRA PRIOR TO THE CFP. WILL NEED TO FURTHER ADJUST POPS
ESPECIALLY WITH THE MAIN AREA OF STRONG-SEVERE CONVECTION NOW OFF
THE COAST. MIN TEMP GUIDANCE TRICKY DUE TO POST FRONTAL POSSIBLE LOW
STRATUS AND POSSIBLY FOG. THE LATTER LIKELY NOT DUE TO LOW LEVEL
WINDS HAVING INCREASED ENOUGH TO PREVENT FOG FORMATION.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...BY THURSDAY DAYBREAK THE BULK OF COLUMN
MOISTURE ASSOCIATED WITH A DEPARTING FRONTAL SYSTEM WILL RESIDE
OFFSHORE. STRONG MID AND UPPER LEVEL DRYING COUPLED WITH MODERATE
NORTH WINDS WILL ALREADY BE OVERSPREADING THE AREA. MAXIMUM TEMPS
THU MAINLY MID/UPPER 70S WITH A FEW LOCATIONS OVER THE SC INTERIOR
APT TO REACH 80. MAINLY CLEAR UNDER LOW-LEVEL NORTH WIND FLOW THU
NIGHT SHOULD YIELD LOW/MID 50S INTO EARLY FRIDAY. NORTH FLOW WILL
ENDURE MUCH OF FRIDAY DELAYING A SIGNIFICANT DAYTIME WARMING TREND
WITH MAXIMUMS VERY SIMILAR TO THURSDAY. UNDER IDEAL RADIATIONAL
COOLING...UPPER 40S INLAND LOOKS PROBABLE WITH LOWER 50S ALONG THE
COASTAL ZONES...AND SURFACE HIGH PRESSURE NEARLY OVERHEAD.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 3 PM WEDNESDAY...SURFACE AND UPPER RIDGE AXIS OVERHEAD SAT
WILL SHIFT OFFSHORE SUN AS BROAD 5H TROUGH STARTS TO DEVELOP OVER
THE EASTERN HALF OF THE COUNTRY. SAT INTO SUN LOOKS DRY BUT
WEAKENING INFLUENCE OF THE UPPER RIDGE AND MOISTURE RETURN IN DEEP
SOUTHWEST FLOW COULD PRODUCE SOME ISOLATED CONVECTION SUN AFTERNOON.
INHERITED SLIGHT CHANCE POP LOOKS GOOD AT THIS POINT. FOR THE
REMAINDER OF THE PERIOD WEATHER WILL REMAIN UNSETTLED WITH 5H TROUGH
AXIS TO THE WEST AND DEEP SOUTHWEST FLOW ADVECTING PLENTY OF
MOISTURE INTO THE REGION. ANY PASSING SHORTWAVE WILL ENHANCE DIURNAL
CONVECTION MON AFTERNOON WHICH WARRANTS A SMALL POP INCREASE...NOW
LOW CHANCE. TUE/WED REMAINS UNCERTAIN WITH THE 12Z GFS MUCH MORE
PROGRESSIVE THAN ITS PREVIOUS RUNS. MEDIUM RANGE GUIDANCE AGREES ON
WEAK LOW PRESSURE DEVELOPING ALONG THE GULF COAST WHICH THEN MOVES
ACROSS NORTHERN FL AND UP THE SE COAST. SIGNIFICANT TIMING
DIFFERENCES BETWEEN THE 12Z GFS...12Z CANADIAN...00Z ECMWF AND LACK
OF CONTINUITY BETWEEN THEIR RESPECTIVE RUNS IS KEEPING CONFIDENCE
LOW LATE IN THE PERIOD. THE MAIN ISSUE IS HOW THE GUIDANCE IS
HANDLING THE COLLAPSE OF THE UPPER RIDGE OUT WEST AND THE IMPACT
THIS HAS ON THE TROUGHING OVER THE EAST. WILL CONTINUE TO CARRY A
CHANCE POP TUE/TUE NIGHT WHICH WILL EXTEND INTO WED AD MUCH OF THE
GUIDANCE...SAVE THE GFS...IS SUGGESTING A SLOWER/WETTER SOLUTION.
HIGHS WILL REMAIN SLIGHTLY BELOW CLIMO THROUGH THE PERIOD WITH LOWS
STARTING OUT SLIGHTLY BELOW CLIMO BUT ENDING UP NEAR TO SLIGHTLY
ABOVE CLIMO.
&&
.AVIATION /00Z THURSDAY THROUGH TUESDAY/...
AS OF 00Z...MVFR/IFR THROUGH THE EARLY OVERNIGHT HOURS...BECOMING
VFR FOR THE REMAINDER OF THE PERIOD AFTER MIDNIGHT.
WITH THE STRONGEST STORMS OUT OF THE AREA...ANOTHER ROUND OF SHOWERS
IS EXPECTED TO PROGRESS ACROSS THE AREA OVER THE NEXT COUPLE OF
HOURS AS SEEN ON CURRENT RADAR IMAGERY. WITH MVFR/IFR ALREADY IN
PLACE DUE TO LOW CIGS AND LOWERED VISIBILITIES FROM RAIN AND
FOG...EXPECT THIS TO CONTINUE THROUGH THE EARLY OVERNIGHT
HOURS...THOUGH A BRIEF LULL IN IMPROVED CONDITIONS MAY OCCUR BETWEEN
BANDS OF RAIN. AS THE COLD FRONT CONTINUES TO PUSH EASTWARD...EXPECT
SCT MID TO HIGH CLOUDS BEHIND THE BOUNDARY WITH NORTH-NORTHWEST
WINDS AOB 10 KTS. AFTER DAYBREAK...ANTICIPATE NEARLY CLEAR SKIES
WITH NORTH-NORTHWEST WINDS AOB 12 KTS. SCT MID LEVEL CLOUDS AROUND
6KFT WILL DEVELOP IN THE AFTERNOON...WITH GUSTS NEAR 20 KTS
POSSIBLE.
EXTENDED OUTLOOK...ISOLATED CONVECTION LATE FRIDAY
EVENING...BECOMING SCATTERED TO NUMEROUS SATURDAY. ISOLATED
CONVECTION POSSIBLE SUNDAY. VFR MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 800 PM WEDNESDAY...FOLLOWING THE HRRR MODEL SFC WIND
FIELDS...THE CFP WILL OCCUR BETWEEN 1 AND 3 AM THURSDAY.
A PRONOUNCED WIND SHIFT WILL OCCUR...WITH SW 10 TO OCCASIONALLY 15
KT...VEERING TO THE NW 15 TO 20 KT OVERNIGHT. THE LATTER MAY BE A
BIT UNDERDONE GIVEN THE TIGHTENED POST FRONTAL GRADIENT AND
COOL/COLD WX CONDITIONS. SIG SEAS WILL RUN BASICALLY 2 TO 4 FT.
INITIALLY THE EASTERLY 2 TO 3 FT GROUND SWELL WILL DOMINATE SIG
SEAS...BUT THEN GIVE WAY TO AN INCREASING AND SOON TO DOMINATE SIG
SEAS...THE BUILDING LOW PERIOD 3 TO 5 SECOND PERIOD LOCALLY PRODUCED
WIND DRIVEN WAVES.
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
AS OF 3 PM WEDNESDAY...A COLD FRONT MAY BRING LIMITED VISIBILITIES
IN RAIN AND ISOLATED TSTMS...ALONG WITH LOCALLY GUSTY WINDS AND
LOCALLY HIGHER WIND-WAVES TONIGHT. MARINERS SHOULD CONSULT RADAR
BEFORE HEADING OUT LATE THIS AFTERNOON OR EVENING. THE FRONT WILL
BRING A WIND-SHIFT IN THE VERY LATE EVENING AROUND MIDNIGHT. THIS
COULD BRING N WIND GUSTS TO 20 KT THROUGH THURSDAY MORNING...BEFORE
EASING IN THE AFTERNOON. REINFORCING HIGH PRESSURE WILL SUSTAIN N
WINDS THROUGH MOST OF FRIDAY...WITH THE HIGH MOVING OVERHEAD FRIDAY
NIGHT. SEAS MAY APPROACH 5 FEET ACROSS THE OUTER PORTION AND THE
NORTH END OF FRYING PAN SHOALS THURSDAY MORNING.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 PM WEDNESDAY...WEAK GRADIENT SAT INTO SUN WILL KEEP WINDS
LIGHT AND HIGHLY VARIABLE. THERE WILL BE A GENERAL NORTHEAST TO
EAST FLOW WITH SPEEDS 10 KT OR LESS. GRADIENT BECOMES A LITTLE
MORE DEFINED SUN AS HIGH MOVES FARTHER OF THE COAST AND SOUTHEAST
FLOW DEVELOPS. SOME GUIDANCE HINTING AT WEAK COASTAL TROUGH ALONG
THE GA/SOUTHERN SC COAST WHICH MAY ENHANCE FLOW ACROSS SC ZONES.
HOWEVER SPEEDS SHOULD REMAIN UNDER 15 KT INTO MON. SURFACE HIGH
EAST OF THE WATERS AND LACK OF ANY SIGNIFICANT SURFACE FEATURES TO
THE WEST MEANS SOUTHEAST FLOW WILL CONTINUE ON MON. OVERALL LITTLE
CHANGE TO THE SURFACE GRADIENT BETWEEN SUN AND MON SO SPEEDS
SHOULD BE SIMILAR...10 TO 15 KT. SEAS WILL RUN 2 TO 4 FT THROUGH
THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...DCH
SHORT TERM...MJC
LONG TERM...III
AVIATION...SGL
AREA FORECAST DISCUSSION...CORRECTED
NWS RALEIGH NC
335 PM EDT TUE MAY 8 2012
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE WEST TONIGHT...THEN SLOWLY
PROGRESS EAST THROUGH THE CAROLINAS WEDNESDAY AND WEDNESDAY NIGHT.
HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT ON THURSDAY AND
FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 315 PM TUESDAY...
LATEST SFC ANALYSIS SHOWS A COLD FRONT EXTENDING SOUTHWESTERLY
ACROSS THE OH AND TN VALLEYS. MULTIPLE WEAK SFC TROUGHS WERE NOTED
ACROSS THE SOUTHERN APPALACHIANS AND GA/SC. LATEST SPC MESOANALYSIS
INDICATES A WEAKLY UNSTABLE AIRMASS ACROSS FAR WESTERN NC AND SC
WITH MLCAPE VALUES OF AROUND 250-500 J/KG IN A REGION OF ENHANCED
SFC DEW POINTS IN THE LOW/MID 60S. FURTHER EAST ACROSS THE PIEDMONT
AND COASTAL PLAIN THE AIR MASS IS MORE STABLE WITH LITTLE OR NO
SBCAPE/MLCAPE IN A REGION OF DEW POINTS IN THE MID 50S TO AROUND 60.
SCT SHOWERS CONTINUE TO MOVE NORTHEAST AT AROUND 20KTS. MUCH OF
CENTRAL NC UNDER A BKN CLOUD DECK WITH CIGS RANGING FROM 3-5KFT.
RECENT SIMULATIONS FROM THE WRF HIRESW AND HRRR SUGGEST THAT THE SCT
CONVECTION WILL PERSIST INTO THE EVENING HOURS AND CONTINUE TO SHIFT
EASTWARD. IN FACT SOME SIMULATION SUGGEST THAT THE CONVECTION ACROSS
THE FOOTHILLS WILL INTENSIFY A BIT AND GROW INTO A BROKEN LINE AND
MOVE ACROSS THE WESTERN PIEDMONT INTO THE EASTERN PIEDMONT BUT
LIKELY WEAKEN OR HOLD WEST OF THE COASTAL PLAIN. THREAT OF SEVERE
CONVECTION THIS AFTN/EVE IS LIMITED WITH A WEAKLY UNSTABLE AIRMASS
THIS AFTN CHARACTERIZED BY MLCAPE VALUES LESS THAN 500 J/KG...MODEST
0-6KM BULK SHEAR OF 15 KTS OR LESS AND WEAK MID LEVEL LAPSE RATES.
GIVEN AN INCREASE IN PW VALUES NOW APPROACHING 1.7 INCHES IN THE
SOUTHERN PIEDMONT...SOME LOCATIONS COULD SEE HEAVY RAIN THIS
EVENING. THREAT OF PRECIPITATION OVERNIGHT DECREASES SOMEWHAT WITH
LIMITED FORCING FOR ASCENT BUT WILL MAINTAIN AT LEAST A SLIGHT CHC
POP OVERNIGHT. GIVEN WIDESPREAD CLOUDINESS...A LIGHT SOUTHERLY WIND
TRANSPORTING SLIGHTLY HIGHER DEW POINTS INTO THE REGION...HAVE EDGED
TOWARD THE WARMER END OF THE GUIDANCE ENVELOPE WITH LOWS IN THE
62-66 RANGE. -BLAES
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 315 PM TUESDAY...
THE NORTHERN STREAM SHORTWAVE WILL DIVE INTO THE OH VALLEY TOWARD
DAYBREAK ON WED. BOTH THE NAM/GFS HAVE TRENDED A LITTLE SHARPER WITH
THIS FEATURE AS IT PIVOTS EAST AND BECOMES NEUTRAL OR EVEN BRIEFLY
NEGATIVELY TILTED WEDNESDAY NIGHT. THE BEST FORCING FOR ASCENT WITH
THE WAVE WILL REMAIN IN WV/VA NORTHWARD. THE POLAR JET STRENGTHENS
ACROSS PA/NY AND EXTEND SOUTHWEST TO THE OH VALLEY WED AFTERNOON BUT
WILL LIKELY ONLY PROVIDE LIMITED FORCING FOR ASCENT OVER NC. WHILE
THE BEST FORCING WILL REMAIN NORTH OF NC...SFC DEW POINTS RECOVER
INTO THE LOWER TO MID 60S WHICH MAY BE SUFFICIENT FOR PERHAPS A
MODERATELY UNSTABLE AIRMASS WITH MLCAPE VALUES CLIMBING TO AROUND
1000 J/KG IN THE COASTAL PLAIN WITH REDUCED MLCAPE VALUES IN THE
PIEDMONT GIVEN A SHALLOWER BOUNDARY LAYER. NAM/GFS FORECAST
SOUNDINGS BOTH DEPICT A MOIST ENVIRONMENT WITH THIN CAPE AND LIMITED
DRY AIR ALOFT. BULK SHEAR VALUES INCREASE DURING THE AFTERNOON AND
REACH THE 25-30KT RANGE IN THE EAST AND AROUND 35KTS ACROSS THE
WEST. WHILE THE SHEAR IS SUFFICIENT TO SUPPORT SOME
ORGANIZATION...THE MOIST PROFILES SUGGEST THE SEVERE WEATHER THREAT
MAY BE SOMEWHAT LIMITED. WITH A GENERALLY LINEAR WIND PROFILE AND
THE MEAN WIND PARALLEL TO THE APPROACHING COLD FRONT...THE
CONVECTION WILL LIKELY TAKE ON A MORE LINEAR ORIENTATION. ANY
DISCRETE STORM WILL HAVE AN INCREASED SEVERE WEATHER THREAT GIVEN
THE MARGINAL POTENTIAL FOR SUPERCELLS AND SEMI STRAIGHT HODOGRAPHS
WHICH SUGGEST POSSIBLE SPLITTING SUPERCELLS. PW VALUES CLIMB TO
AROUND 1.75 INCHES AND THE CONVECTION WILL LIKELY BECOME ORIENTED
PARALLEL TO THE THE NORTHEAST MOTION...SUGGESTING THAT STORMS WILL
HAVE THE POTENTIAL TO DUMP HEAVY RAIN OVER A GIVEN LOCATION FOR A
PROLONGED PERIOD OF TIME. GIVEN THIS...THE PRIMARY SEVERE THREAT ON
WEDNESDAY AND WEDNESDAY EVENING WILL BE FLOODING AND WET DOWNBURSTS.
WILL RAMP UP POPS INTO THE LIKELY RANGE ON WEDNESDAY AFTERNOON AND
EARLY EVENING AND THEN QUICKLY DIMINISH POPS FROM WEST TO EAST AFTER
MIDNIGHT. HIGH TEMPERATURES ON WEDNESDAY WILL RANGE IN THE MID 70S
WEST TO THE UPPER 70S TO AROUND 80 EAST. WILL KEEP LOWS ON WEDNESDAY
NIGHT TOWARD THE HIGHER END OF THE GUIDANCE RANGE GIVEN THE CLOUD
COVER AND TENDENCY FOR OVERNIGHT LOWS TO REMAIN ELEVATED WITH COLD
FRONTAL PASSAGES LATE AT NIGHT. LOWS IN THE MID 50S NORTHWEST TO
AROUND 60 SOUTHEAST. -BLAES
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS OF 300 PM TUESDAY...
THURSDAY THROUGH FRIDAY...THE UPPER TROUGH AXIS PUSHES EAST OF
CENTRAL NORTH CAROLINA QUICKLY DURING THE MORNING...WITH THE JET
ALOFT ALSO MOVING EAST. GOOD SUBSIDENCE TAKES PLACE AS HIGH PRESSURE
BUILDS IN...WITH BUFR SOUNDINGS AT 12Z STABLE TO DEEP CONVECTION
THROUGHOUT CENTRAL NORTH CAROLINA ON BOTH THE NAM AND THE GFS.
PRECIPITABLE WATER VALUES THAT FALL TO AROUND 0.75 INCH AROUND 12Z
THURSDAY FALL FURTHER TO AROUND 0.5 INCH BY 18Z THURSDAY...WHERE
THEY REMAIN THROUGH THE DAY ON FRIDAY. EXCEPT FOR VERY EARLY
THURSDAY...K INDICES ARE NEGATIVE...WELL NEGATIVE FOR FRIDAY.
WHILE IT WILL BE CLOSE TO THE INTERSTATE 95 CORRIDOR...EXPECT
PRECIPITATION TO BE JUST EAST OF CENTRAL NORTH CAROLINA BY 12Z
THURSDAY. FROM THERE...SKIES SHOULD CLEAR...BUT A RELATIVE MAXIMUM
OF 850MB THETA-E IN THE COASTAL PLAIN COULD YIELD SOME SHALLOW
AFTERNOON CU. IN ADDITION...A FEW CLOUDS COULD DRIFT FROM THE
MOUNTAINS...WHERE COOL AIR ALOFT WILL MAKE CONDITIONS THERE
RELATIVELY UNSTABLE...TOWARD THE TRIAD...BUT THE AIR SHOULD BE SO
STABLE THAT ONLY FEW SHOULD MAKE IT TO NEAR KINT AND KGSO. THE
SURFACE GRADIENT BEHIND THE FRONT WILL BE TIGHT TO START THE DAY...
RESULTING IN WIND GUSTS WITH MIXING AS HIGH AS THE LOWER 20S MPH
BEFORE 925MB WINDS FALL TO AROUND 15KT IN THE AFTERNOON...LESSENING
THE WIND GUSTS. UNDER OVERALL 850MB THETA-E TROUGHINESS FRIDAY...AND
AMPLE SUBSIDENCE AND DRY AIR...UNDER A SLACK GRADIENT AS WELL...
EXPECT PLENTY OF SUNSHINE AND CALM CONDITIONS FOR THE DAY...POSSIBLY
A BRIEF NOTICEABLE WIND GUST TO AROUND 10KT WITH MIXING EARLY.
BASED ON A COMBINATION OF 1000-850MB THICKNESSES...MOS GUIDANCE...
AND EXPECTED MIXING BASED ON BUFR SOUNDINGS...FORECAST HIGHS NEAR
THE HIGHER MAV MOS ON THURSDAY. WITH A FORECAST NEARER THE COOLER
GUIDANCE THURSDAY NIGHT UNDER A CLEAR SKY AND DIMINISHING WIND...
TEMPERATURES IN CENTRAL NORTH CAROLINA FRIDAY SHOULD BE SIMILAR TO
THURSDAY WITH A THICKNESS DIFFERENCE OF ONLY ABOUT 5M. FOR
NOW...WENT ABOUT A DEGREE COOLER FRIDAY COMPARED TO THURSDAY DUE TO
THE LIGHT...GENERALLY NORTHERLY LOW-LEVEL FLOW.
HEIGHTS ALOFT RISE NOTICEABLY FRIDAY NIGHT INTO SATURDAY...BEFORE
HEIGHTS START TO FALL AGAIN AS A WEAKENING UPPER-LEVEL LOW THAT
MOVES FROM THE SOUTHWEST STATES INTO THE SOUTH PLAINS SLOWLY PUSHES
FARTHER EAST. THE SOUTHEAST CONUS FALLS ON THE DOWNSTREAM SIDE OF
THE UPPER REMNANT TROUGH BY THE END OF THE WEEKEND...AND WHILE A
MID-LEVEL SHORTWAVE OF SOME STRENGTH SHOULD REACH CENTRAL NORTH
CAROLINA BY LATE SUNDAY...THE UPPER FLOW IS INITIALLY CONFLUENT AND
THE SURFACE RIDGE AXIS REMAINS OVERHEAD. DRY CONDITIONS SHOULD EXIST
FRIDAY NIGHT THROUGH SATURDAY IN HIGH PRESSURE SURFACE AND
ALOFT...AND WILL CONTINUE A DRY FORECAST FOR NOW THROUGH SUNDAY DUE
TO THE PRESENCE OF SURFACE HIGH PRESSURE AND THE CONFLUENT FLOW
ALOFT. LATE SUNDAY AND SUNDAY NIGHT...IT IS POSSIBLE THAT THE
SURFACE RIDGE AXIS STARTS TO MOVE NORTH OF THE AREA RESULTING IN
INCREASING ATLANTIC MOISTURE...AND WHILE AN ISOLATED SHOWER OR
THUNDERSTORM IS POSSIBLE...WILL LEAVE IT OUT OF THE FORECAST FOR NOW
THAT FAR OUT IN TIME. MOST OF THE GUIDANCE IS DRY OR TRENDING DRIER
FOR SUNDAY.
WHILE THE EVOLUTION OF SURFACE AND UPPER-LEVEL FEATURES ARE IN
QUESTION EARLY NEXT WEEK...CURRENTLY THE PREPONDERANCE OF THE
EVIDENCE SUGGESTS A MOISTENING AIR MASS WITH INCREASING LIFT. AT A
MINIMUM...ATLANTIC MOISTURE SHOULD BE ABLE TO SPREAD INTO CENTRAL
NORTH CAROLINA...AND THE UPPER-LEVEL FLOW...PERSISTENTLY
SOUTHWEST...BECOMES LESS CONFLUENT. AT LEAST SLIGHT CHANCES FOR
SHOWERS AND THUNDERSTORMS WILL BE FORECAST MONDAY...WITH SLIGHTLY
HIGHER CHANCES IN THAT CATEGORY OVER THE WESTERN PIEDMONT DUE TO
GREATER INSTABILITY AND CONVERGENCE EXPECTED TOWARD THE MOUNTAINS...
ALONG WITH A MORE FAVORABLE UPSLOPE FLOW FOR DEEPER CONVECTION WHICH
MAY THEN MOVE INTO THE TRIAD AND AREAS NEAR THE YADKIN RIVER ON THE
WESTERLY THERMAL WIND AS CURRENTLY FORECAST. BY TUESDAY...MOISTENING
CONTINUES...AND WITH A SLIGHTLY MORE DIFFLUENT FLOW ALOFT UNDER A
SERIES OF MID-LEVEL WAVES MOVING THROUGH ON THE SOUTHWEST FLOW...
AT LEAST CHANCES FOR SHOWERS AND THUNDERSTORMS ARE EXPECTED. GFSX
MOS ENSEMBLE GUIDANCE POPS ARE VIRTUALLY ALL ABOVE CLIMATOLOGY
MONDAY AND TUESDAY...AND IT IS POSSIBLE OVER TIME THAT CHANCES FOR
PRECIPITATION WILL INCREASE DURING PART OR ALL OF THOSE TWO DAYS...
WITH THAT INCREASE SEEMINGLY MORE LIKELY FOR TUESDAY.
1000-850MB THICKNESSES SUPPORT TEMPERATURES EACH DAY FROM THE MID
70S TO NEAR 80 DEGREES...BASICALLY AROUND NORMAL. HIGHEST
THICKNESSES ARE SATURDAY...BUT THE DAY TO DAY VARIATION IS ON THE
ORDER OF 5 TO 10M ON BOTH THE GFS AND ECMWF. LEANED TOWARD COOLER
VALUES TUESDAY DUE TO THE INCREASING POTENTIAL FOR CLOUDS AND
PRECIPITATION...BUT STILL SLIGHTLY ABOVE THE HPC GUIDANCE VALUES FOR
NOW BASED ON EXPECTED WARMER OVERNIGHT LOWS AS A RESULT OF CLOUD
COVER...AND SOME WARMING POTENTIAL ANTICIPATED DUE TO THE TIME OF
YEAR.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
AS OF 205 PM TUESDAY...
GOOD CONFIDENCE OF VFR/MVFR CIGS AND VSBY THIS AFTN/EVE...IFR/LIFR
CIGS EXPECTED LATE TONIGHT WITH STRATUS...PERIODS OF MVFR/IFR
CONDITIONS LIKELY AT TIMES WED WITH SCT THUNDERSTORMS.
STRATUS AND WIDELY SCT SHOWERS SHOULD CONTINUE NEAR KINT/KGSO
THROUGH THE LATE AFTN WITH PERIODS OF MVFR CONDITIONS WHILE
KRDU/KRWI/KFAY WILL LARGELY EXPERIENCE VFR CONDITIONS THROUGH LATE
AFTN. SCT SHOWERS AND POSSIBLY A THUNDERSTORM ACROSS THE WESTERN
PIEDMONT WILL MOVE EAST AND WEAKEN THIS EVENING PERHAPS PRODUCING A
BRIEF PERIOD OF MVFR CONDITIONS. FORECAST SOUNDINGS INDICATED LOW
STRATUS AND POSSIBLY SOME FOG WILL DEVELOP DURING THE PREDAWN HOURS.
NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP AHEAD OF
A COLD FRONT DURING THE LATE MORNING AND EARLY AFTERNOON WED AND
THEN MOVE EASTWARD. THE BEST CHANCE WILL OCCUR AFTER THE CURRENT TAF
PERIOD AND HAVE OMITTED THE MENTION OF THUNDER FOR NOW. SOUTHERLY
SURFACE WINDS WITH A FEW GUSTS TO AROUND 15KT THIS AFTERNOON WILL
DIMINISH TO LIGHT SOUTHERLY TONIGHT AND THEN SOUTHWEST AT AROUND
10KTS ON WEDNESDAY.
LOOKING FURTHER AHEAD...THE COLD FRONT WILL MOVE OFFSHORE AROUND
MIDNIGHT THURSDAY WITH LINGERING SHOWERS AND LOW CIGS DISSIPATING BY
DAYBREAK THURSDAY. HIGH PRESSURE BUILDS INTO THE REGION ON THURSDAY
AND PERSISTS WITH FAIR WEATHER FROM FRIDAY THROUGH SUNDAY. -BLAES
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLAES
NEAR TERM...BLAES
SHORT TERM...BLAES
LONG TERM...DJF
AVIATION...BLAES
AREA FORECAST DISCUSSION
NWS RALEIGH NC
318 PM EDT TUE MAY 8 2012
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE WEST TONIGHT...THEN SLOWLY
PROGRESS EAST THROUGH THE CAROLINAS WEDNESDAY AND WEDNESDAY NIGHT.
HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT ON THURSDAY AND
FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 315 PM TUESDAY...
LATEST SFC ANALYSIS SHOWS A COLD FRONT EXTENDING SOUTHWESTERLY
ACROSS THE OH AND TN VALLEYS. MULTIPLE WEAK SFC TROUGHS WERE NOTED
ACROSS THE SOUTHERN APPALACHIANS AND GA/SC. LATEST SPC MESOANALYSIS
INDICATES A WEAKLY UNSTABLE AIRMASS ACROSS FAR WESTERN NC AND SC
WITH MLCAPE VALUES OF AROUND 250-500 J/KG IN A REGION OF ENHANCED
SFC DEW POINTS IN THE LOW/MID 60S. FURTHER EAST ACROSS THE PIEDMONT
AND COASTAL PLAIN THE AIRMASS IS MORE STABLE WITH LITTLE OR NO
SBCAPE/MLCAPE IN A REGION OF DEW POINTS IN THE MID 50S TO AROUND 60.
SCT SHOWERS CONTINUE TO MOVE NORTHEAST AT AROUND 20KTS. MUCH OF
CENTRAL NC UNDER A BKN CLOUD DECK WITH CIGS RANGING FROM 3-5KFT.
RECENT SIMULATIONS FROM THE WRF HIRESW AND HRRR SUGGEST THAT THE SCT
CONVECTION WILL PERSIST INTO THE EVENING HOURS AND CONTINUE TO SHIFT
EASTWARD. IN FACT SOME SIMULATION SUGGEST THAT THE CONVECTION ACROSS
THE FOOTHILLS WILL INTENSIFY A BIT AND GROW INTO A BROKEN LINE AND
MOVE ACROSS THE WESTERN PIEDMONT INTO THE EASTERN PIEDMONT BUT
LIKELY WEAKEN OR HOLD WEST OF THE COASTAL PLAIN. THREAT OF SEVERE
CONVECTION THIS AFTN/EVE IS LIMITED WITH A WEAKLY UNSTABLE AIRMASS
THIS AFTN CHARACTERIZED BY MLCAPE VALUES LESS THAN 500 J/KG...MODEST
0-6KM BULK SHEAR OF 15 KTS OR LESS AND WEAK MID LEVEL LAPSE RATES.
GIVEN AN INCREASE IN PW VALUES NOW APPROACHING 1.7 INCHES IN THE
SOUTHERN PIEDMONT...SOME LOCATIONS COULD SEE HEAVY RAIN THIS
EVENING. THREAT OF PRECIPITATION OVERNIGHT DECREASES SOMEWHAT WITH
LIMITED FORCING FOR ASCENT BUT WILL MAINTAIN AT LEAST A SLIGHT CHC
POP OVERNIGHT. GIVEN WIDESPREAD CLOUDINESS...A LIGHT SOUTHERLY WIND
TRANSPORTING SLIGHTLY HIGHER DEW POINTS INTO THE REGION...HAVE EDGED
TOWARD THE WARMER END OF THE GUIDANCE ENVELOPE WITH LOWS IN THE
62-66 RANGE. -BLAES
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 315 PM TUESDAY...
NORTHERN STREAM SHORTWAVE WILL DIVE INTO THE OH VALLEY TOWARD
DAYBREAK ON WED. BOTH THE NAM/GFS HAVE TRENDED A LITTLE SHARPER WITH
THIS FEATURE AS IT PIVOTS EAST AND BECOMES NEUTRAL OR EVEN BRIEFLY
NEGATIVELY TILTED WEDNESDAY NIGHT. THE BEST FORCING FOR ASCENT WITH
THE WAVE WILL REMAIN IN WV/VA NORTHWARD. THE POLAR JET STRENGTHENS
ACROSS PA/NY AND EXTEND SOUTHWEST TO THE OH VALLEY WED AFTERNOON
WILL LIKELY ONLY PROVIDE LIMITED FORCING FOR ASCENT OVER NC. WHILE
THE BEST FORCING WILL REMAIN NORTH OF NC...SFC DEW POINTS RECOVER
INTO THE LOWER TO MID 60S WHICH MAY BE SUFFICIENT FOR A MARGINALLY
UNSTABLE AIRMASS WITH MLCAPE VALUES CLIMBING TO AROUND 1000 J/KG IN
THE COASTAL PLAIN WITH SLIGHTLY REDUCED MLCAPE VALUES IN THE
PIEDMONT. NAM/GFS FORECAST SOUNDINGS BOTH DEPICT A MOIST ENVIRONMENT
WITH THIN CAPE AND LIMITED DRY AIR ALOFT. BULK SHEAR VALUES INCREASE
DURING THE AFTERNOON AND REACH THE 25-30KT RANGE IN THE EAST AND
AROUND 35KTS ACROSS THE WEST. WHILE THE SHEAR IS SUFFICIENT TO
SUPPORT SOME ORGANIZATION THE MOST PROFILES SUGGEST THE SEVERE
WEATHER THREAT MAY BE SOMEWHAT LIMITED. WITH THE MEAN WIND PARALLEL
TO THE APPROACHING COLD FRONT...THE CONVECTION WILL LIKELY TAKE ON A
MORE LINEAR ORIENTATION BUT ANY DISCRETE STORM WILL HAVE AN
INCREASED SEVERE WEATHER THREAT. PW VALUES CLIMB TO AROUND 1.75
INCHES
AND THE CONVECTION WILL LIKELY BECOME ORIENTED PARALLEL TO THE
THE NORTHEAST MOTION...SUGGESTING THAT STORMS WILL HAVE THE
POTENTIAL TO DUMP HEAVY RAIN OVER A GIVEN LOCATION FOR A PROLONGED
PERIOD OF TIME. GIVEN THIS...THE PRIMARY SEVERE THREAT ON WEDNESDAY
AND WEDNESDAY EVENING WILL BE FLOODING AND WET DOWNBURSTS. WILL RAMP
UP POPS INTO THE LIKELY RANGE ON WEDNESDAY AFTERNOON AND EARLY
EVENING AND THEN QUICKLY DIMINISH POPS FROM WEST TO EAST AFTER
MIDNIGHT. HIGH TEMPERATURES ON WEDNESDAY WILL RANGE IN THE MID 70S
WEST TO THE UPPER 70S TO AROUND 80 EAST. WILL KEEP LOWS ON WEDNESDAY
NIGHT TOWARD THE HIGHER END OF THE GUIDANCE RANGE GIVEN THE CLOUD
COVER AND TENDENCY FOR OVERNIGHT LOWS TO REMAIN ELEVATED WITH COLD
FRONTAL PASSAGES LATE AT NIGHT. LOWS IN THE MID 50S NORTHWEST TO
AROUND 60 SOUTHEAST. -BLAES
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS OF 300 PM TUESDAY...
THURSDAY THROUGH FRIDAY...THE UPPER TROUGH AXIS PUSHES EAST OF
CENTRAL NORTH CAROLINA QUICKLY DURING THE MORNING...WITH THE JET
ALOFT ALSO MOVING EAST. GOOD SUBSIDENCE TAKES PLACE AS HIGH PRESSURE
BUILDS IN...WITH BUFR SOUNDINGS AT 12Z STABLE TO DEEP CONVECTION
THROUGHOUT CENTRAL NORTH CAROLINA ON BOTH THE NAM AND THE GFS.
PRECIPITABLE WATER VALUES THAT FALL TO AROUND 0.75 INCH AROUND 12Z
THURSDAY FALL FURTHER TO AROUND 0.5 INCH BY 18Z THURSDAY...WHERE
THEY REMAIN THROUGH THE DAY ON FRIDAY. EXCEPT FOR VERY EARLY
THURSDAY...K INDICES ARE NEGATIVE...WELL NEGATIVE FOR FRIDAY.
WHILE IT WILL BE CLOSE TO THE INTERSTATE 95 CORRIDOR...EXPECT
PRECIPITATION TO BE JUST EAST OF CENTRAL NORTH CAROLINA BY 12Z
THURSDAY. FROM THERE...SKIES SHOULD CLEAR...BUT A RELATIVE MAXIMUM
OF 850MB THETA-E IN THE COASTAL PLAIN COULD YIELD SOME SHALLOW
AFTERNOON CU. IN ADDITION...A FEW CLOUDS COULD DRIFT FROM THE
MOUNTAINS...WHERE COOL AIR ALOFT WILL MAKE CONDITIONS THERE
RELATIVELY UNSTABLE...TOWARD THE TRIAD...BUT THE AIR SHOULD BE SO
STABLE THAT ONLY FEW SHOULD MAKE IT TO NEAR KINT AND KGSO. THE
SURFACE GRADIENT BEHIND THE FRONT WILL BE TIGHT TO START THE DAY...
RESULTING IN WIND GUSTS WITH MIXING AS HIGH AS THE LOWER 20S MPH
BEFORE 925MB WINDS FALL TO AROUND 15KT IN THE AFTERNOON...LESSENING
THE WIND GUSTS. UNDER OVERALL 850MB THETA-E TROUGHINESS FRIDAY...AND
AMPLE SUBSIDENCE AND DRY AIR...UNDER A SLACK GRADIENT AS WELL...
EXPECT PLENTY OF SUNSHINE AND CALM CONDITIONS FOR THE DAY...POSSIBLY
A BRIEF NOTICEABLE WIND GUST TO AROUND 10KT WITH MIXING EARLY.
BASED ON A COMBINATION OF 1000-850MB THICKNESSES...MOS GUIDANCE...
AND EXPECTED MIXING BASED ON BUFR SOUNDINGS...FORECAST HIGHS NEAR
THE HIGHER MAV MOS ON THURSDAY. WITH A FORECAST NEARER THE COOLER
GUIDANCE THURSDAY NIGHT UNDER A CLEAR SKY AND DIMINISHING WIND...
TEMPERATURES IN CENTRAL NORTH CAROLINA FRIDAY SHOULD BE SIMILAR TO
THURSDAY WITH A THICKNESS DIFFERENCE OF ONLY ABOUT 5M. FOR
NOW...WENT ABOUT A DEGREE COOLER FRIDAY COMPARED TO THURSDAY DUE TO
THE LIGHT...GENERALLY NORTHERLY LOW-LEVEL FLOW.
HEIGHTS ALOFT RISE NOTICEABLY FRIDAY NIGHT INTO SATURDAY...BEFORE
HEIGHTS START TO FALL AGAIN AS A WEAKENING UPPER-LEVEL LOW THAT
MOVES FROM THE SOUTHWEST STATES INTO THE SOUTH PLAINS SLOWLY PUSHES
FARTHER EAST. THE SOUTHEAST CONUS FALLS ON THE DOWNSTREAM SIDE OF
THE UPPER REMNANT TROUGH BY THE END OF THE WEEKEND...AND WHILE A
MID-LEVEL SHORTWAVE OF SOME STRENGTH SHOULD REACH CENTRAL NORTH
CAROLINA BY LATE SUNDAY...THE UPPER FLOW IS INITIALLY CONFLUENT AND
THE SURFACE RIDGE AXIS REMAINS OVERHEAD. DRY CONDITIONS SHOULD EXIST
FRIDAY NIGHT THROUGH SATURDAY IN HIGH PRESSURE SURFACE AND
ALOFT...AND WILL CONTINUE A DRY FORECAST FOR NOW THROUGH SUNDAY DUE
TO THE PRESENCE OF SURFACE HIGH PRESSURE AND THE CONFLUENT FLOW
ALOFT. LATE SUNDAY AND SUNDAY NIGHT...IT IS POSSIBLE THAT THE
SURFACE RIDGE AXIS STARTS TO MOVE NORTH OF THE AREA RESULTING IN
INCREASING ATLANTIC MOISTURE...AND WHILE AN ISOLATED SHOWER OR
THUNDERSTORM IS POSSIBLE...WILL LEAVE IT OUT OF THE FORECAST FOR NOW
THAT FAR OUT IN TIME. MOST OF THE GUIDANCE IS DRY OR TRENDING DRIER
FOR SUNDAY.
WHILE THE EVOLUTION OF SURFACE AND UPPER-LEVEL FEATURES ARE IN
QUESTION EARLY NEXT WEEK...CURRENTLY THE PREPONDERANCE OF THE
EVIDENCE SUGGESTS A MOISTENING AIR MASS WITH INCREASING LIFT. AT A
MINIMUM...ATLANTIC MOISTURE SHOULD BE ABLE TO SPREAD INTO CENTRAL
NORTH CAROLINA...AND THE UPPER-LEVEL FLOW...PERSISTENTLY
SOUTHWEST...BECOMES LESS CONFLUENT. AT LEAST SLIGHT CHANCES FOR
SHOWERS AND THUNDERSTORMS WILL BE FORECAST MONDAY...WITH SLIGHTLY
HIGHER CHANCES IN THAT CATEGORY OVER THE WESTERN PIEDMONT DUE TO
GREATER INSTABILITY AND CONVERGENCE EXPECTED TOWARD THE MOUNTAINS...
ALONG WITH A MORE FAVORABLE UPSLOPE FLOW FOR DEEPER CONVECTION WHICH
MAY THEN MOVE INTO THE TRIAD AND AREAS NEAR THE YADKIN RIVER ON THE
WESTERLY THERMAL WIND AS CURRENTLY FORECAST. BY TUESDAY...MOISTENING
CONTINUES...AND WITH A SLIGHTLY MORE DIFFLUENT FLOW ALOFT UNDER A
SERIES OF MID-LEVEL WAVES MOVING THROUGH ON THE SOUTHWEST FLOW...
AT LEAST CHANCES FOR SHOWERS AND THUNDERSTORMS ARE EXPECTED. GFSX
MOS ENSEMBLE GUIDANCE POPS ARE VIRTUALLY ALL ABOVE CLIMATOLOGY
MONDAY AND TUESDAY...AND IT IS POSSIBLE OVER TIME THAT CHANCES FOR
PRECIPITATION WILL INCREASE DURING PART OR ALL OF THOSE TWO DAYS...
WITH THAT INCREASE SEEMINGLY MORE LIKELY FOR TUESDAY.
1000-850MB THICKNESSES SUPPORT TEMPERATURES EACH DAY FROM THE MID
70S TO NEAR 80 DEGREES...BASICALLY AROUND NORMAL. HIGHEST
THICKNESSES ARE SATURDAY...BUT THE DAY TO DAY VARIATION IS ON THE
ORDER OF 5 TO 10M ON BOTH THE GFS AND ECMWF. LEANED TOWARD COOLER
VALUES TUESDAY DUE TO THE INCREASING POTENTIAL FOR CLOUDS AND
PRECIPITATION...BUT STILL SLIGHTLY ABOVE THE HPC GUIDANCE VALUES FOR
NOW BASED ON EXPECTED WARMER OVERNIGHT LOWS AS A RESULT OF CLOUD
COVER...AND SOME WARMING POTENTIAL ANTICIPATED DUE TO THE TIME OF
YEAR.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
AS OF 205 PM TUESDAY...
GOOD CONFIDENCE OF VFR/MVFR CIGS AND VSBY THIS AFTN/EVE...IFR/LIFR
CIGS EXPECTED LATE TONIGHT WITH STRATUS...PERIODS OF MVFR/IFR
CONDITIONS LIKELY AT TIMES WED WITH SCT THUNDERSTORMS.
STRATUS AND WIDELY SCT SHOWERS SHOULD CONTINUE NEAR KINT/KGSO
THROUGH THE LATE AFTN WITH PERIODS OF MVFR CONDITIONS WHILE
KRDU/KRWI/KFAY WILL LARGELY EXPERIENCE VFR CONDITIONS THROUGH LATE
AFTN. SCT SHOWERS AND POSSIBLY A THUNDERSTORM ACROSS THE WESTERN
PIEDMONT WILL MOVE EAST AND WEAKEN THIS EVENING PERHAPS PRODUCING A
BRIEF PERIOD OF MVFR CONDITIONS. FORECAST SOUNDINGS INDICATED LOW
STRATUS AND POSSIBLY SOME FOG WILL DEVELOP DURING THE PREDAWN HOURS.
NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP AHEAD OF
A COLD FRONT DURING THE LATE MORNING AND EARLY AFTERNOON WED AND
THEN MOVE EASTWARD. THE BEST CHANCE WILL OCCUR AFTER THE CURRENT TAF
PERIOD AND HAVE OMITTED THE MENTION OF THUNDER FOR NOW. SOUTHERLY
SURFACE WINDS WITH A FEW GUSTS TO AROUND 15KT THIS AFTERNOON WILL
DIMINISH TO LIGHT SOUTHERLY TONIGHT AND THEN SOUTHWEST AT AROUND
10KTS ON WEDNESDAY.
LOOKING FURTHER AHEAD...THE COLD FRONT WILL MOVE OFFSHORE AROUND
MIDNIGHT THURSDAY WITH LINGERING SHOWERS AND LOW CIGS DISSIPATING BY
DAYBREAK THURSDAY. HIGH PRESSURE BUILDS INTO THE REGION ON THURSDAY
AND PERSISTS WITH FAIR WEATHER FROM FRIDAY THROUGH SUNDAY. -BLAES
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLAES
NEAR TERM...BLAES
SHORT TERM...BLAES
LONG TERM...DJF
AVIATION...BLAES
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
251 PM EDT TUE MAY 8 2012
.SYNOPSIS...
A STRONG COLD FRONT WILL APPROACH FROM THE WEST TONIGHT AND BRING
SHOWERS AND THUNDERSTORMS TO THE AREA WEDNESDAY AND WEDNESDAY NIGHT.
COOL AND DRY HIGH PRESSURE WILL BUILD INTO THE AREA THURSDAY AND
PERSIST THROUGH THE WEEKEND. THE HIGH WILL SLIP OFF THE COAST BY
LATE SUNDAY MOVING FARTHER OFFSHORE AS NEXT FRONT APPROACHES LATE
MONDAY INTO TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 245 PM TUESDAY...LARGE SCALE GUIDANCE AS WELL AS LOCAL
MESOSCALE WRF/HRRR SHOW LINE OF CONVECTION DEVELOPING BY 20Z A FEW
COUNTIES WEST OF THE CWA BUT LARGELY FIZZLING OUT DUE TO LOSS OF
HEATING BEFORE REACHING OUR WESTERN ZONES. THIS SEEMS PLAUSIBLE AS
CU FIELD HAS NOT SHOWN SIGNIFICANT AGITATION/VERTICAL DEVELOPMENT
OVER ANY OF THE ILM COUNTIES AND RUC ANALYSIS SHOWS VIRTUALLY NO
CAPE OVER THE REGION. HAVE TRIMMED POPS ONCE AGAIN FOR THE REST OF
THE AFTERNOON AND EVENING TO BE CAPPED AT SLIGHT CHANCE AND CONFINED
EVEN FURTHER WEST THAN THE PREVIOUS/MID MORNING TRIMMING. SUSPECT
THAT THE OVERNIGHT HOURS REMAIN LARGELY RAIN-FREE AS WELL BUT IN
VERY WEAK WAA THE SLIGHT CHANCE POPS FROM CONTINUITY ARE HARD TO
ARGUE WITH AS OVERALL MOISTURE GROWS DEEPER.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 245 PM TUESDAY...MAIN FORECAST CHALLENGE IS THE POTENTIAL FOR
SEVERE WEATHER WITH A COLD FRONT MOVING THROUGH THE AREA WEDNESDAY
AND WEDNESDAY NIGHT. AMPLE CLOUD COVER AHEAD OF THE FRONT WILL
IMPACT THE INSTABILITY...HOWEVER RRQ OF AN H3 JET WILL ADD LIFT TO
THE REGION RESULTING IN DECENT CONVECTIVE COVERAGE. IN THE END...MAY
NEED TO DEAL WITH A FEW SEVERE TSTMS WITH DAMAGING WINDS AS THE
PRIMARY THREAT. SPC CONTINUES TO HIGHLIGHT NEARLY THE ENTIRE ILM
FORECAST AREA IN A SLIGHT RISK.
ONCE THE FRONT MOVES THROUGH MUCH DRIER CONDITIONS WILL PREVAIL WITH
NEAR SEASONABLE TEMPERATURES ON TAP. PRECIPITABLE WATER VALUES OF
1.7 INCHES WEDNESDAY AFTERNOON/EVE WILL DROP BELOW 0.75 INCHES
THURSDAY. TIME HEIGHT CROSS SECTIONS INDICATE A VERY DRY COLUMN
ABOVE H8 WHICH WILL LEAD TO MOSTLY SUNNY SKIES BY THURSDAY MORNING.
HIGHS ON THURSDAY WILL BE AROUND 80 MOST LOCATIONS AND LOWS WILL BE
A COUPLE CATEGORIES BELOW NORMAL THURSDAY NIGHT (LOWER 50S PEE DEE
AND LBT AREAS TO THE MID 50S INLAND COASTAL AREAS). LASTLY...UNTIL
THE LOW-LEVEL WIND FIELD WEAKENS COULD SEE 20-25 MPH GUSTS IN
NORTHWEST FLOW THURSDAY MORNING.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 245 PM TUESDAY...PERIOD STARTS OFF DRY WITH TEMPERATURES NEAR
TO SLIGHTLY CLIMO AS 5H TROUGH AXIS MOVES OFF THE COAST AND SURFACE
HIGH SETTLES IN FROM THE NORTH. COMBINATION OF SURFACE HIGH AND WEAK
5H RIDGE AXIS OVER THE WEEKEND SHOULD KEEP THE AREA DRY FOR MUCH OF
THE WEEKEND. LATE SUN AFTERNOON RETURN FLOW AROUND EXITING HIGH AND
DEEPER SOUTHWEST FLOW ON THE WEST SIDE OF EXITING RIDGE ALOFT MAY
LEAD TO SOME CONVECTION ACROSS WESTERN AREAS. WILL CARRY SILENT POP
FOR SUN AFTERNOON AT THIS POINT. PRECIP CHANCES INCREASE DURING THE
MON/TUE TIMEFRAME. MEDIUM RANGE GUIDANCE IS SHOWING BROAD 5H TROUGH
DEVELOPING OVER THE EASTERN US NEXT WEEK...THOUGH MANY OF THE
PARTICULARS REMAIN IN QUESTION. IT DOES APPEAR THERE WILL BE PLENTY
OF MOISTURE IN THE AREA...GIVEN THE DEEP SOUTHWEST FLOW. SETUP MON
LOOK FAVORABLE AS FAR AS DIURNAL CONVECTION IS CONCERNED. TUE LOOKS
A LITTLE MORE SYNOPTIC WITH A WEAK COASTAL TROUGH OR WARM FRONT IN
THE VICINITY AND LOW PRESSURE MOVING UP THE COAST. AT THIS POINT
WILL CONTINUE WITH SLIGHT CHANCE MON/MON NIGHT INCREASING TO LOW
CHANCE FOR TUE/TUE NIGHT. TEMPERATURES WILL REMAIN NEAR TO SLIGHTLY
BELOW CLIMO THROUGH THE PERIOD.
&&
.AVIATION /18Z TUESDAY THROUGH SATURDAY/...
AS OF 18Z...VISIBLE SATELLITE IMAGES AND SURFACE OBSERVATIONS THIS
AFTERNOON DEPICT WIDESPREAD SCATTERED TO BROKEN LOW CLOUDS FROM 3-5K
JUST INLAND OF THE COAST. NO PRECIPITATION IS CURRENTLY OCCURRING.
BERMUDA HIGH PRESSURE WILL CONTINUE TO ADVECT LOW LEVEL MOISTURE
INLAND THIS TAF VALID PERIOD ON SOUTHEAST TO SOUTH WINDS. CONFIDENCE
THAT PERIODS OF MVFR CEILINGS WILL OCCUR THIS TAF VALID PERIOD IS
HIGH...BUT CONFIDENCE IN THE EXACT TIMING IS LOW. IN GENERAL...MVFR
CEILINGS AND/OR MVFR VISIBILITIES WILL BE POSSIBLE LATE THIS
AFTERNOON INTO THE EARLY EVENING AT FLO AS SHOWERS AND POSSIBLY AN
ISOLATED THUNDERSTORM MAINLY WEST OF THE TERMINAL SPREAD EAST. SOME
OF THIS PRECIPITATION WILL REACH THE LBT TERMINAL BUT EXPECT VFR TO
CONTINUE AT THAT TERMINAL. MVFR CEILINGS WILL BECOME MORE LIKELY
AFTER 07-10Z.
MVFR CEILINGS WILL CONTINUE AFTER SUNRISE THROUGH THE MORNING HOURS
AS PRECIPITATION CHANCES INCREASE AHEAD OF AN APPROACHING COLD
FRONT. WINDS WILL BE SOUTH TO SOUTHWEST 5 TO 10 KNOTS.
EXTENDED OUTLOOK...MODERATE CONFIDENCE FOR SCATTERED TO POSSIBLE
NUMEROUS SHOWERS AND THUNDERSTORMS WEDNESDAY AFTERNOON THROUGH
WEDNESDAY NIGHT...WITH INTERMITTENT IFR POSSIBLE. BECOMING VFR
THURSDAY AND CONTINUING THROUGH SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 245 PM TUESDAY...S TO SE WINDS OVERNIGHT NO HIGHER THAN IN THE
10 TO 15 KT RANGE AND EVEN THIS MAY BE A LITTLE PESSIMISTIC AS HIGH
PRESSURE REMAINS WELL DISPLACED OFF THE NE AND MID ATLANTIC COAST.
LOCAL SWAN INITIALIZED ABOUT 0.5 FT TOO HIGH BUT OTHERWISE SHOWED
DECENT GRADIENTS AND WAS FOLLOWED CLOSELY WITH AFOREMENTIONED VALUE
SUBTRACTED FROM BASE VALUES. AS SUCH SEAS WILL GENERALLY BE IN THE 2
T 3 FT RANGE AND COMPRISED MOSTLY OF 7 SECOND WIND CHOP AND
DIMINISHING 10-11 SECOND SWELL.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 245 PM TUESDAY...SOUTHERLY WINDS WEDNESDAY AHEAD OF THE COLD
FRONT WILL VEER TO A WEST-NORTHWEST DIRECTION IN ITS WAKE WEDNESDAY
NIGHT. ADDITIONAL VEERING TO A NORTHERLY DIRECTION EXPECTED THURSDAY
AS HIGH PRESSURE BUILDS ACROSS THE WATERS. SPEEDS WILL INCREASE
10-15 KTS AHEAD OF THE FRONT THEN PEAK AROUND 15 KNOTS IN ITS WAKE.
COULD SEE A MINOR SURGE ARRIVE OVER THE WATERS LATE THURSDAY WITH
SPEEDS PICKING UP OVER THE WATERS AWAY FROM THE COAST. SEAS WILL
RANGE FROM 2-3 FT ACROSS LONG BAY AND 2-4 FT ACROSS ONSLOW BAY
WEDNESDAY...THEN NEARLY A SOLID 4 FT OFF CAPE FEAR AND 3 FT OVER
LONG BAY WED NIGHT. SEAS WILL BE AROUND 3 FT THURSDAY THEN SLIGHTLY
INCREASE AWAY FROM THE COAST LATE THURSDAY NIGHT WITH THE
AFOREMENTIONED MINOR SURGE. OTHERWISE...SCATTERED TO NUMEROUS
SHOWERS AND TSTMS WILL LOCALLY ENHANCE WINDS...ESPECIALLY WEDNESDAY
NIGHT.
LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 245 PM TUESDAY...NORTHERLY FLOW AT THE START OF THE PERIOD
WILL BE DECREASING AND VEER TO NORTHEAST THROUGHOUT THE DAY AS
SURFACE HIGH SETTLES SOUTH. RELAXED GRADIENT WILL SEE SPEEDS DROP TO
10 KT OR LESS BY AFTERNOON. WEAK SEA BREEZE DEVELOPS IN THE
AFTERNOON...BUT COOLER NORTHEAST FLOW WILL HELP LIMIT THE STRENGTH
OF THE NEAR SHORE CIRCULATION. LIGHT NORTHEAST FLOW CONTINUE TO VEER
FRI NIGHT INTO SAT AS CENTER OF THE HIGH MOVES OFF THE COAST JUST
NORTH OF THE WATERS. EAST TO SOUTHEAST FLOW AROUND 10 KT SAT BECOMES
SOUTHEAST SAT NIGHT AND SUN. SPEEDS START TO PICK UP SUN INTO SUN
NIGHT AS GRADIENT BECOMES A LITTLE MORE DEFINED. WINDS UNDER 15 KT
THROUGH THE PERIOD WILL KEEP SEAS 2 TO 3 FT.
&&
.TIDES/COASTAL FLOODING...
AS OF 245 PM TUESDAY...DESPITE SOME OF THE APPRECIABLE DEVIATIONS OF
RECENT HIGH TIDES THE WANING MOON IS HAVING LESS OF AN EFFECT NOW
WITH EACH CYCLE. AFTER MONITORING THIS EARLY AFTERNOON`S HIGH TIDE
(THE LOWER OF THE TWO) THE ET SURGE MODEL APPEARED TO DO QUITE WELL.
SAID MODEL STILL BRINGS EAST FACING BEACHES AND CAPE FEAR RIVER TO
THE VERY CUSP OF MINOR FLOOD...WHICH IS QUITE TYPICAL/QUITE COMMON.
HAVE MADE NO CHANGES TO THE CURRENT ADVISORY. A LITTLE LESS CERTAIN
ABOUT BRUNSWICK COUNTY BEACHES WITH TIDE GAGE NOT WORKING BUT THERE
WERE SEVERAL REPORTS TODAY OF FLOODING OCEAN ISLE BEACH...WOULD
PREFER TO LEAVE ADVISORY UNCHANGED THERE AS WELL AT THIS TIME.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...COASTAL FLOOD ADVISORY FROM 8 PM THIS EVENING TO MIDNIGHT EDT
TONIGHT FOR NCZ106-108-110.
COASTAL FLOOD ADVISORY FROM 11 PM THIS EVENING TO 3 AM EDT
WEDNESDAY FOR NCZ107.
MARINE...NONE.
&&
$$
NEAR TERM...MBB
SHORT TERM...SRP
LONG TERM...III
AVIATION...MRR
TIDES/COASTAL FLOODING...MBB
AREA FORECAST DISCUSSION
NWS PORTLAND OR
845 AM PDT TUE MAY 8 2012
.SYNOPSIS...AN UPPER LEVEL RIDGE THAT HAS BEEN OVER THE PACIFIC
NORTHWEST THE LAST COUPLE OF DAYS WILL CONTINUE TO MOVE EAST TODAY AS
AN UPPER LEVEL LOW NEAR THE GULF OF ALASKA APPROACHES WESTERN BRITISH
COLUMBIA. ONSHORE FLOW WILL INCREASE TODAY...WITH A WEAKENING COLD
FRONT MOVING ONSHORE THIS AFTERNOON AND THROUGH THE FORECAST AREA
THIS EVENING. A TRAILING UPPER TROUGH WILL MOVE THROUGH THE PACIFIC
NORTHWEST WEDNESDAY AND EARLY WEDNESDAY NIGHT FOR CONTINUED STRONG
ONSHORE FLOW...CLOUDS...AND MUCH COOLER TEMPERATURES...AND A CHANCE
OF SOME SPOTTY LIGHT PRECIPITATION. AN UPPER RIDGE WILL BEGIN
BUILDING AND MOVING INTO THE PACIFIC NORTHWEST THURSDAY AND CONTINUE
TO STRENGTHEN THROUGH THE WEEKEND. THIS WILL BRING DRY WEATHER AND
ABOVE NORMAL TEMPERATURES THAT MAY LAST WELL INTO NEXT WEEK.
&&
.SHORT TERM...SATELLITE SHOWING WEAKENING FRONT FROM THE NORTH WA
COAST...SW TO ABOUT 80 MILES OFF THE CENTRAL OREGON COAST. THE FRONT
HAS BEEN WEAKENING THIS FEATURE OVER THE LAST SEVERAL HOURS BASED ON
SURFACE ANALYSIS. THE FRONT PUSHES ASHORE THIS AFTERNOON. PRECIPITATION
LOOKS TO BE SPOTTY AND LIGHT WITH THIS FRONT...ESPECIALLY NEAR THE
COAST AND OVER THE HIGHER TERRAIN IN THE NORTHERN ZONES. THE BAND
WILL MOVE THROUGH THE NORTHERN WILLAMETTE VALLEY AND CLARK COUNTY
DURING THE EVENING COMMUTE WITH MAINLY CLOUDS...THOUGH A FEW
SPRINKLES OR A LITTLE DRIZZLE IS NOT OUT OF THE QUESTION. EXPECT
CLOUDS BUT LITTLE OR NO PRECIPITATION FARTHER SOUTH IN THE
WILLAMETTE VALLEY THIS EVENING. THE BAND WILL PUSH EAST OF THE
CASCADES BY MIDNIGHT.
THE ONSHORE FLOW ASSOCIATED WITH THE FRONT WILL LIKELY GIVE SOME
BREEZY WEST WINDS MUCH OF OUR FORECAST AREA LATER TODAY AND THIS
EVENING...ESPECIALLY THROUGH THE COAST RANGE AND THE GORGE AND OVER
THE CASCADES...BUT SOME IN THE INTERIOR VALLEYS AS WELL.
DESPITE THE RATHER STRONG ONSHORE FLOW CONTINUING OVERNIGHT TONIGHT
AND ON WEDNESDAY...THE LOW LEVEL CLOUDS MAY BREAK UP SOME AT TIMES
ESPECIALLY AFTER THE FRONTAL BAND THIS EVENING AND ON WEDNESDAY. A
TRAILING UPPER TROUGH WILL PUSH THROUGH WEDNESDAY AFTERNOON AND
EVENING AND COULD PRODUCE A FEW SHOWERS ACROSS OUR NORTHERN ZONES AS
IT MOVES THROUGH...ESPECIALLY NEAR THE COAST AND OVER THE HIGHER
TERRAIN. EXPECTED BREEZY WEST WINDS TO CONTINUE. LOOK FOR TEMPS
WEDNESDAY TO FALL BELOW NORMAL...CLOSE TO 60 DEGREES INLAND.
THE UPPER TROUGH WILL MOVE EAST OF THE AREA BY THURSDAY MORNING WITH
PRECIPITATION GENERALLY ENDING. THERE WILL LIKELY BE AREAS OF LOW
CLOUDS AND PATCHY FOG THURSDAY MORNING...THEN CLEARING IN THE
AFTERNOON AS AN UPPER RIDGE BEGINS TO SPREAD ONSHORE. TEMPS WILL
BEGIN TO RECOVER BUT STILL BE A BIT BELOW NORMAL...IN THE LOWER TO
MID 60S. TOLLESON/MH
.LONG TERM...THE UPPER RIDGE FROM THURSDAY IS FORECAST TO AMPLIFY
OVER THE PACIFIC NORTHWEST THROUGH THIS WEEKEND INTO EARLY NEXT
WEEK...GIVING SOUTHWEST WASHINGTON AND NORTHWEST OREGON ITS MOST
PROLONGED WARM AND DRY WEATHER OF THE SPRING SO FAR. WE COULD SEE
SOME 80S THIS WEEKEND INTO NEXT WEEK IN THE INLAND AREAS. THE NEXT
CHANCE OF ANY PRECIPITATION IS LOOKING TO BE THE MIDDLE OR LATTER
PART OF NEXT WEEK. TOLLESON
&&
.AVIATION...MINIMAL CHANGES. PREVIOUS DISCUSSION FOLLOWS...IFR/LOW
MVFR CEILINGS ARE EXPANDING ALONG THE COAST AS A WEAKENING COLD
FRONT APPROACHES THE REGION. ONCE MORE EXPANSIVE IFR/MVFR CIGS DO
DEVELOP ALONG THE COAST TONIGHT...EXPECT THEM TO LAST INTO TUESDAY
MORNING BEFORE LIFTING AND DISSIPATING TUESDAY EARLY TO MID
AFTERNOON ALONG THE NORTH COAST...AND LATE AFTERNOON TO EARLY
EVENING ALONG THE CENTRAL COAST AS THE FRONT WILL TAKE LONGER TO
MOVE INLAND FARTHER SOUTH.
THE LOW STRATUS IS HAVING A HARD TIME GETTING THROUGH THE COASTAL
GAPS THIS MORNING. LATEST NAM IS STILL TRYING TO BRING LOW CLOUDS
INTO THE SOUTH AND CENTRAL VALLEY AND ALONG THE COLUMBIA RIVER TO
KELSO...WHEREAS THE LATEST HI RESOLUTION MODELS...NAMELY THE WRF/ARW
AND HRRR ARE KEEPING THINGS OUT...AS ARE ALL MOS GUIDANCE
BULLETINS. WE WILL MONITOR SATELLITE TRENDS DURING THE EARLY
MORNING TO SEE IF ANY LOW CLOUDS CAN MAKE IT THROUGH...THOUGH AT
THIS TIME WE STILL EXPECT INLAND TERMINALS SHOULD REMAIN VFR
THROUGH THE PERIOD...THOUGH THERE COULD BE A BRIEF PERIOD OF VERY
LIGHT RAIN/DRIZZLE DURING THE 0Z-6Z TIME FRAME WITH A WEAK FRONT
MOVING THROUGH. KMD
KPDX AND APPROACHES...VFR CONDITIONS GENERALLY EXPECTED. EXPECT
BREEZY NW WINDS IN THE 10-15 KT RANGE DURING THE AFTERNOON AND
EARLY EVENING. WE STILL EXPECT THAT BROKEN LOW CLOUDS WILL REMAIN
AWAY FROM THE TERMINAL THIS MORNING...THOUGH THERE IS A CHANCE
THAT THEY MAY MAKE TO KELSO AND A SMALL CHANCE OF GETTING FURTHER
DOWN THE COLUMBIA. KMD
&&
.MARINE...MINIMAL CHANGES. PREVIOUS DISCUSSION FOLLOWS...A
WEAKENING COLD FRONT WILL BRUSH THE COASTAL WATERS LATE TONIGHT
INTO TUESDAY MORNING...FOLLOWED BY ENHANCED NORTHWEST FLOW...AS
HIGH PRESSURE BUILDS IN BEHIND THE FRONT TUESDAY. SMALL CRAFT
ADVISORY WINDS IN EXCESS OF 21 KT APPEAR LIKELY BY TUE AFTERNOON.
AFTER A BREAK TONIGHT...EXPECT SEVERAL PERIODS OF WIND GUSTS
GREATER IN THE 20-25 KT RANGE IN THE AFTERNOON AND EVENING
PERIODS...ESPECIALLY FOR THE CENTRAL OREGON WATERS...BUT THE NORTH
OREGON WATERS MAY GET IN ON THE ACTION AS WELL. WEST SWELL
ASSOCIATED WITH THE PARENT LOW SHOULD ARRIVE EARLY WED...WILL
SNEAK INTO THE LOW TEENS...THEN QUICKLY DROP BACK BELOW 10 FT THU
AFTERNOON.
DESPITE MINIMAL SWELL TODAY AND TUESDAY...THE STRONGEST EBBS OF
THE YEAR ARE STILL CAUSING ROUGH CONDITIONS FOR THE COLUMBIA RIVER
BAR...THUS A SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR
REMAINS FOR THE VERY STRONG EBB EXPECTED THIS MORNING. KMD
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS FROM NOON TODAY TO MIDNIGHT PDT
TONIGHT FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
CASCADE HEAD OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR WINDS FROM NOON TODAY TO 5 AM PDT
WEDNESDAY FOR COASTAL WATERS FROM CASCADE HEAD OR TO
FLORENCE OR OUT 60 NM.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS PORTLAND OR
246 AM PDT TUE MAY 8 2012
.SYNOPSIS...AN UPPER LEVEL RIDGE THAT HAS BEEN OVER THE PACIFIC
NORTHWEST THE LAST COUPLE OF DAYS WILL CONTINUE TO MOVE EAST TODAY AS
AN UPPER LEVEL LOW NEAR THE GULF OF ALASKA APPROACHES WESTERN BRITISH
COLUMBIA. ONSHORE FLOW WILL INCREASE TODAY...WITH A WEAKENING COLD
FRONT MOVING ONSHORE THIS AFTERNOON AND THROUGH THE FORECAST AREA
THIS EVENING. A TRAILING UPPER TROUGH WILL MOVE THROUGH THE PACIFIC
NORTHWEST WEDNESDAY AND EARLY WEDNESDAY NIGHT FOR CONTINUED STRONG
ONSHORE FLOW...CLOUDS...AND MUCH COOLER TEMPERATURES...AND A CHANCE
OF SOME SPOTTY LIGHT PRECIPITATION. AN UPPER RIDGE WILL BEGIN
BUILDING AND MOVING INTO THE PACIFIC NORTHWEST THURSDAY AND CONTINUE
TO STRENGTHEN THROUGH THE WEEKEND. THIS WILL BRING DRY WEATHER AND
ABOVE NORMAL TEMPERATURES THAT MAY LAST WELL INTO NEXT WEEK.
&&
.SHORT TERM...AS THE UPPER RIDGE OF THE PAST COUPLE OF DAYS WAS
MOVING EAST EARLY TODAY...THIS HAS ALLOWED SOUTHWEST FLOW ALOFT TO
DEVELOP THAT IS HELPING TO DEVELOP MARINE CLOUDS ALONG THE COAST
EARLY THIS MORNING. THESE CLOUDS ARE PUSHING INTO THE COASTAL GAPS IN
OREGON...A FEW BRIEF LOW CLOUDS MAY REACH INTO THE WILLAMETTE VALLEY
THIS MORNING.
THE ONSHORE FLOW WILL CONTINUE TO INCREASE TODAY AS THE WEAKENING
COLD FRONT THAT HAS MOVED INSIDE 130W EARLY THIS MORNING APPROACHES
THE NORTH COAST LATE THIS MORNING...THEN PUSHES ONSHORE THIS
AFTERNOON. PRECIPITATION LOOKS TO BE SPOTTY AND LIGHT WITH THIS
FRONT...ESPECIALLY NEAR THE COAST AND OVER THE HIGHER TERRAIN IN THE
NORTHERN ZONES. THE BAND WILL MOVE THROUGH THE NORTHERN WILLAMETTE
VALLEY AND CLARK COUNTY DURING THE EVENING COMMUTE WITH MAINLY
CLOUDS...THOUGH A FEW SPRINKLES OR A LITTLE DRIZZLE IS NOT OUT OF
THE QUESTION. EXPECT CLOUDS BUT LITTLE OR NO PRECIPITATION FARTHER
SOUTH IN THE WILLAMETTE VALLEY THIS EVENING. THE BAND WILL PUSH EAST
OF THE CASCADES BY MIDNIGHT.
THE ONSHORE FLOW ASSOCIATED WITH THE FRONT WILL LIKELY GIVE SOME
BREEZY WEST WINDS MUCH OF OUR FORECAST AREA LATER TODAY AND THIS
EVENING...ESPECIALLY THROUGH THE COAST RANGE AND THE GORGE AND OVER
THE CASCADES...BUT SOME IN THE INTERIOR VALLEYS AS WELL.
DESPITE THE RATHER STRONG ONSHORE FLOW CONTINUING OVERNIGHT TONIGHT
AND ON WEDNESDAY...THE LOW LEVEL CLOUDS MAY BREAK UP SOME AT TIMES
ESPECIALLY AFTER THE FRONTAL BAND THIS EVENING AND ON WEDNESDAY. A
TRAILING UPPER TROUGH WILL PUSH THROUGH WEDNESDAY AFTERNOON AND
EVENING AND COULD PRODUCE A FEW SHOWERS ACROSS OUR NORTHERN ZONES AS
IT MOVES THROUGH...ESPECIALLY NEAR THE COAST AND OVER THE HIGHER
TERRAIN. EXPECTED BREEZY WEST WINDS TO CONTINUE. LOOK FOR TEMPS
WEDNESDAY TO FALL BELOW NORMAL...CLOSE TO 60 DEGREES INLAND.
THE UPPER TROUGH WILL MOVE EAST OF THE AREA BY THURSDAY MORNING WITH
PRECIPITATION GENERALLY ENDING. THERE WILL LIKELY BE AREAS OF LOW
CLOUDS AND PATCHY FOG THURSDAY MORNING...THEN CLEARING IN THE
AFTERNOON AS AN UPPER RIDGE BEGINS TO SPREAD ONSHORE. TEMPS WILL
BEGIN TO RECOVER BUT STILL BE A BIT BELOW NORMAL...IN THE LOWER TO
MID 60S. TOLLESON
.LONG TERM...THE UPPER RIDGE FROM THURSDAY IS FORECAST TO AMPLIFY
OVER THE PACIFIC NORTHWEST THROUGH THIS WEEKEND INTO EARLY NEXT
WEEK...GIVING SOUTHWEST WASHINGTON AND NORTHWEST OREGON ITS MOST
PROLONGED WARM AND DRY WEATHER OF THE SPRING SO FAR. WE COULD SEE
SOME 80S THIS WEEKEND INTO NEXT WEEK IN THE INLAND AREAS. THE NEXT
CHANCE OF ANY PRECIPITATION IS LOOKING TO BE THE MIDDLE OR LATTER
PART OF NEXT WEEK. TOLLESON
&&
.AVIATION...IFR/LOW MVFR CEILINGS ARE EXPANDING ALONG THE COAST AS A
WEAKENING COLD FRONT APPROACHES THE REGION. ONCE MORE EXPANSIVE
IFR/MVFR CIGS DO DEVELOP ALONG THE COAST TONIGHT...EXPECT THEM TO
LAST INTO TUESDAY MORNING BEFORE LIFTING AND DISSIPATING TUESDAY
EARLY TO MID AFTERNOON ALONG THE NORTH COAST...AND LATE AFTERNOON TO
EARLY EVENING ALONG THE CENTRAL COAST AS THE FRONT WILL TAKE LONGER
TO MOVE INLAND FARTHER SOUTH.
THE LOW STRATUS IS HAVING A HARD TIME GETTING THROUGH THE COASTAL
GAPS THIS MORNING. LATEST NAM IS STILL TRYING TO BRING LOW CLOUDS
INTO THE SOUTH AND CENTRAL VALLEY AND ALONG THE COLUMBIA RIVER TO
KELSO...WHEREAS THE LATEST HI RESOLUTION MODELS...NAMELY THE WRF/ARW
AND HRRR ARE KEEPING THINGS OUT...AS ARE ALL MOS GUIDANCE BULLETINS.
WE WILL MONITOR SATELLITE TRENDS DURING THE EARLY MORNING TO SEE IF
ANY LOW CLOUDS CAN MAKE IT THROUGH...THOUGH AT THIS TIME WE STILL
EXPECT INLAND TERMINALS SHOULD REMAIN VFR THROUGH THE PERIOD...
THOUGH THERE COULD BE A BRIEF PERIOD OF VERY LIGHT RAIN/DRIZZLE
DURING THE 00Z TO 06Z TIME FRAME WITH A WEAK FRONT MOVING THROUGH.
KMD
KPDX AND APPROACHES...VFR CONDITIONS GENERALLY EXPECTED. EXPECT
BREEZY NW WINDS IN THE 10-15 KT RANGE DURING THE AFTERNOON AND EARLY
EVENING. WE STILL EXPECT THAT BROKEN LOW CLOUDS WILL REMAIN AWAY FROM
THE TERMINAL THIS MORNING...THOUGH THERE IS A CHANCE THAT THEY MAY
MAKE TO KELSO AND A SMALL CHANCE OF GETTING FARTHER DOWN THE
COLUMBIA. KMD
&&
.MARINE...A WEAKENING COLD FRONT WILL BRUSH THE COASTAL WATERS LATE
TONIGHT INTO TUESDAY MORNING...FOLLOWED BY ENHANCED NORTHWEST
FLOW...AS HIGH PRESSURE BUILDS IN BEHIND THE FRONT TUESDAY. SMALL
CRAFT ADVISORY WINDS IN EXCESS OF 21 KT APPEAR LIKELY BY TUE
AFTERNOON. AFTER A BREAK TONIGHT...EXPECT SEVERAL PERIODS OF WIND
GUSTS GREATER IN THE 20 TO 25 KT RANGE IN THE AFTERNOON AND EVENING
PERIODS...ESPECIALLY FOR THE CENTRAL OREGON WATERS...BUT THE NORTH
OREGON WATERS MAY GET IN ON THE ACTION AS WELL. WEST SWELL ASSOCIATED
WITH THE PARENT LOW SHOULD ARRIVE EARLY WED...WILL SNEAK INTO THE LOW
TEENS...THEN QUICKLY DROP BACK BELOW 10 FT THU AFTERNOON.
DESPITE MINIMAL SWELL TODAY AND TUESDAY...THE STRONGEST EBBS OF THE
YEAR ARE STILL CAUSING ROUGH CONDITIONS FOR THE COLUMBIA RIVER
BAR...THUS A SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR
REMAINS FOR THE VERY STRONG EBB EXPECTED THIS MORNING. KMD
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS FROM NOON TODAY TO MIDNIGHT PDT
TONIGHT FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
CASCADE HEAD OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR WINDS FROM NOON TODAY THOUGH EARLY
WED MORNING FOR COASTAL WATERS FROM CASCADE HEAD TO FLORENCE
OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 5 AM TO
9 AM PDT THIS MORNING.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
318 PM CDT TUE MAY 8 2012
.TONIGHT AND WEDNESDAY...FORECAST CONFIDENCE...MEDIUM TO HIGH
500MB SHORTWAVE TROUGH CONTINUES TO SLIDE SOUTHEAST ACROSS MINNESOTA
AND NORTHWEST WISCONSIN. THIS FEATURE HAS 500MB TEMPERATURES OF 24
TO 27 BELOW ZERO CELSIUS PER RUC ANALYSIS IN ITS CORE FROM SOUTHWEST
MINNESOTA TO NORTHERN WISCONSIN. IN ADDITION...STEEP LOW TO MID
LEVEL LAPSE RATES WITH LOW LEVEL MLCAPES OF A HUNDRED OR SO J/KG
SEEN ACROSS THIS AREA. THESE FEATURES HELPING GENERATE SCATTERED TO
NUMEROUS SHOWERS...WHICH ARE ENTERING THE WESTERN AND NORTHWESTERN
COUNTIES.
THESE SHOULD CONTINUE TO SPREAD EAST SOUTHEAST ACROSS THE FORECAST
AREA LATE THIS AFTERNOON AND EARLY THIS EVENING...WITH PASSAGE OF
SHORTWAVE TROUGH. ISOLATED THUNDER POSSIBLE AS WELL...WITH A FEW
LIGHTNING STRIKES SEEN TO THE NORTHWEST OF THE AREA EARLIER TODAY.
LOW FREEZING LEVELS MAY ALLOW FOR SOME GRAUPEL OR SMALL HAIL TO FALL
WITH A STORM. MAIN SURFACE TROUGH DOES NOT SHIFT SOUTH THROUGH THE
AREA UNTIL LATER TONIGHT...SO NOT CONCERNED ABOUT COLD AIR FUNNELS.
AFTER SHORTWAVE TROUGH SWINGS THROUGH BY 06Z WEDNESDAY...ANOTHER
VORTICITY MAXIMUM SLIDES SOUTH THROUGH THE AREA LATE TONIGHT AND
EARLY WEDNESDAY MORNING. ALTHOUGH LOW CLOUDS ARE EXPECTED TO MOVE
INTO THE AREA LATER TONIGHT AND INTO WEDNESDAY MORNING IN THE
EAST...NOT SEEING MUCH MOISTURE ABOVE THIS LAYER TO WARRANT ANYTHING
MORE THAN ISOLATED SHOWERS AFTER MIDNIGHT...WITH WEDNESDAY MORNING
DRY.
CLOUDS GRADUALLY LIFT AND SCATTER OUT BY THE AFTERNOON FROM WEST TO
EAST ACROSS THE AREA...WITH HIGH PRESSURE BRINGING QUIET WEATHER.
PRESSURE GRADIENT WEAKENS ENOUGH FOR WINDS TO VEER NORTHEAST NEAR
THE LAKE IN THE AFTERNOON. HIGHS SHOULD RISE INTO THE UPPER 50S
LAKESIDE...TO THE LOWER TO MID 60S INLAND PER 925MB TEMPERATURES.
.WEDNESDAY NIGHT THROUGH FRIDAY...FORECAST CONFIDENCE...MEDIUM TO HIGH
HIGH PRESSURE CENTERED OVER ILLINOIS WEDNESDAY NIGHT WILL SLOWLY
DRIFT EASTWARD TO THE OHIO RIVER VALLEY BY FRIDAY EVENING. THIS WILL
BRING FAIR WEATHER TO SOUTHERN WISCONSIN THROUGH THIS PERIOD...WITH
ONLY A FEW MID AND HIGH LEVEL CLOUDS PASSING THROUGH AT TIMES.
925 MB TEMPS ANTICIPATED TO INCREASE TO AROUND 14-15C BY THU
AFTERNOON...THEN TO UP TO 18C BY FRI AFTERNOON. WITH A GOOD AMOUNT
OF SUNSHINE EXPECTED...SHOULD BE A NICE COUPLE OF DAYS WITH HIGH
TEMPS RISING TO A FEW DEGREES ABOVE NORMAL BY FRIDAY. LIGHT WINDS
THURSDAY SHOULD ALLOW A LAKE BREEZE TO PUSH INLAND...KEEPING THINGS
COOLER NEAR THE LAKE. AN APPROACHING TROUGH OF LOW PRESSURE FRIDAY
MAY INCREASE SOUTHWEST WINDS ENOUGH TO KEEP THE LAKE BREEZE OFF
SHORE. TEMPS WERE THUS BUMPED UP A BIT NEAR THE LAKE.
.FRIDAY NIGHT AND SATURDAY...FORECAST CONFIDENCE...MEDIUM
WEAK SFC TROUGH AND COLD FRONT TO SLIDE THOUGH FRIDAY NIGHT AND INTO
SATURDAY. LIFT NOT THAT GREAT OVERALL...BUT GFS PRECIPITABLE WATER
VALUES DO GET UP OVER AN INCH...SO KEPT SOME LOW POPS GOING. A
LITTLE BIT OF ELEVATED CAPE IN THE GFS SOUNDINGS...SO LEFT A SLIGHT
CHANCE OF THUNDER IN THE FORECAST AS WELL. TEMPS SHOULD BE COOLER ON
SATURDAY BEHIND THE FRONT...ESPECIALLY IF CLOUDS AND SHOWERS LINGER
THROUGH THE MORNING HOURS.
.SUNDAY THROUGH TUESDAY...FORECAST CONFIDENCE...MEDIUM TO HIGH
HIGH PRESSURE GENERALLY EXPECTED FOR SUNDAY THROUGH TUESDAY...WITH
MOSTLY SUNNY TO PARTLY CLOUDY SKIES AND NEAR NORMAL TEMPERATURES.
LOOKS LIKE A PRETTY NICE START TO NEXT WEEK.
&&
.AVIATION/00Z TAFS/...
SCATTERED TO NUMEROUS RAIN SHOWERS WILL DEVELOP BY 00Z WEDNESDAY
ACROSS TAF SITES...AND LINGER TO AROUND 03Z TO 04Z WEDNESDAY...AS
UPPER LEVEL DISTURBANCE PASSES THROUGH AREA. BROKEN TO NEARLY
OVERCAST VFR CEILINGS ARE EXPECTED LATE THIS AFTERNOON AND EVENING
AS WELL. GUSTY WEST WINDS LATE THIS AFTERNOON WILL WEAKEN BY EARLY
THIS EVENING...AND VEER NORTHWEST TO NORTH LATER TONIGHT WITH
PASSAGE OF SURFACE WIND SHIFT.
CEILINGS WILL LOWER TO MVFR BY 08Z TO 09Z WEDNESDAY ACROSS TAF
SITES...AND SHOULD LINGER UNTIL AROUND 15Z WEDNESDAY BEFORE MIXING
UP TO VFR LEVELS. BROKEN VFR DIURNAL CUMULUS SHOULD THEN LINGER
THROUGH THE REST OF THE DAY. NORTH WINDS AROUND 10 KNOTS ARE
EXPECTED THROUGH THE REST OF WEDNESDAY...VEERING NORTHEAST TO EAST
IN THE AFTERNOON AT MILWAUKEE AND KENOSHA.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TONIGHT/WEDNESDAY AND AVIATION...WOOD
WEDNESDAY NIGHT THROUGH TUESDAY...DDV
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
101 AM EDT THU MAY 10 2012
.Forecast Update...
Issued at 1041 PM EDT Wed May 9 2012
One more quick update now that the showers have ended. The gusty
north winds should settle down over the next 1-2 hours.
Issued at 911 PM EDT Wed May 9 2012
Another update to follow radar trends, with big PoPs over small
areas where rain is currently falling. Also spread the PoPs farther
to the west since the western end of the area of scattered showers
has been holding together fairly well. This resulted in introducing
ISO/SCT showers to the Louisville metro roughly northeast of a line
from Palmyra to Shively to Mount Washington.
Issued at 827 PM EDT Wed May 9 2012
Have upped PoPs to 100% where it is currently raining from northern
Washington County through all of Jefferson County Indiana, with a
buffer zone around that of likelies. Still expecting the showers to
fade away as the sun sets.
Issued at 650 PM EDT Wed May 9 2012
Scattered showers in central Indiana have been holding their own as
they push quickly to the southeast, and there has even been some new
development between Indy and Bloomington along with an increase in
lightning production. The showers are only a couple counties away
from the LMK CWFA at this point, so a decision needed to be made
regarding PoPs this evening (which were dry). After looking at KIND
radar and HRRR progs, have decided to go ahead and insert SCT/ISO
PoPs into the north, basically north of a line from Paoli to
Louisville to Lexington. The showers should fizzle as they reach
the Blue Grass around mid-evening, and we have the PoPs stopping at
02Z.
.Short Term (Tonight through Thursday night)...
Issued at 245 PM EDT May 9 2012
A weak upper disturbance is rotating southeast across the lower
Great Lakes region, sparking off not only widespread, high-based
strato-cu, but also showers and even a few storms across IL/IN/OH.
Most of this activity will stay to our north, however our
northeastern CWA could see some sprinkles perhaps by early evening.
By that time, clouds/precip will start to dissipate with the loss of
afternoon heating, so will keep just the sprinkle wording in the
grids. Best time frame/location will be between 5-10pm northeast of
a line from Louisville to Lexington. Until that timeframe, expect
gusty northwest winds and partly cloudy skies.
Once that trough swings through by roughly midnight, we`ll have
clearing skies thereafter as surface high pressure starts to slide
in from the west. Winds will become light and will help overnight
lows drop into the low-mid 40s north to around 50 south.
The center of the surface high will still be to our west Thursday,
so a steady northerly wind will be in place. Even a few gusts to
about 15 knots or so will be possible especially east of I-65
tomorrow with good mixing. Although skies will be sunny, a steady
northerly wind will keep temps around the same highs as today, maybe
even a tad cooler. Look for highs in the mid-upper 60s north and
east, to the low 70s over the southwest.
Thursday night should be the coolest night with the surface high
directly overhead. Winds will be calm, and with excellent
radiational cooling, lows will plummet into the low 40s most places.
Wouldn`t be surprised to see a few sheltered, Bluegrass locations
drop into the upper 30s.
.Long Term (Friday through Wednesday)...
Issued at 318 PM EDT May 9 2012
Friday Through Sunday Night...
The Ohio Valley will start off in northwesterly flow on Friday as a
large trough exits in the northeast US and weak mid-level low moves
into the southern Plains. High pressure will remain in control of
the weather with dry conditions Friday/Friday night. Short term
shot of upper ridging ahead of the approaching southern Plains wave
will keep the region dry on Saturday, but we`ll likely see a quick
increase in cloud cover throughout the day. Combination of
southerly return flow and isentropic ascent will likely lead to some
isolated showers/storms develop Saturday night especially across
southern KY. Better moisture and synoptic scale lift look much
better on Sunday which looks to be rather dreary with extensive
cloud cover and scattered to numerous showers/storms dotting the
region as the upper wave moves across the region. Clouds and
convection are likely to continue Sunday night as the upper wave
slowly moves east and a surface low and cold front push through the
region. Basically have done an incremental update here as the
previous forecast has this well handled. Given the increasing
forecast convergence here, have raised PoPs a little during the
Sun/Sun night period.
Highs Friday and Saturday will generally be in the mid-upper 70s but
cool into the lower 70s for Sunday. Overnight temps look to remain
rather mild with readings in the upper 40s to the lower 50s.
Monday through Wednesday...
This afternoons long term deterministic and ensemble guidance is in
general agreement with the upper level flow across the CONUS in this
time frame. By and large, the models suggest that a large ridge
will build across the western US early in the period which will
force a downstream trough to develop across the eastern US. A
decent mid-level wave looks to crash into the western US coast by
late in the period which will likely knock down that western ridge.
Considerable spread exists in the height fields across the east
during the period with regards to whether we`ll see a closed low
develop. The 09/00Z and 09/12Z GFS offer the one extreme with a
very pronounced cut off low developing over the east and then
meandering slowly to the east as the flow becomes a bit more zonal.
The 09/00Z and 09/12Z GFS ensembles are not as robust with the upper
low development and actually have a little less spread when compared
with the 09/00Z and 09/12Z OP Euro and its ensembles. Suffice to
say, forecast confidence is average at the beginning of the period
with confidence dropping in the day 6/7 (Tue/Wed) timeframe as the
uncertainty with possible closed low develop complicate the
forecast. With this issuance, have leaned closer the 12Z GFS
Ensemble and Euro solutions which gives decent continuity to the
previous forecast.
This period of the forecast will likely be a rather unsettled one
with the upper trough being situated over the eastern US. Variable
cloudiness is likely with chances of rain throughout the period. It
does seem likely that the best chances of precipitation would be in
the Monday/Tuesday time frame as the trough moves over us with
lesser chances on Wednesday as the GEFS/Euro solutions are slightly
more progressive. For now, will keep slight to low chance PoPs
going with a drier trend for Wednesday. Depending on how the upper
level pattern evolves, future forecasts will likely need some
adjustments over the next few days. As for temperatures, readings
should generally be a little below average with daytime highs in the
upper 60s to lower 70s and overnight lows in the lower-middle 50s.
&&
.Aviation (00Z TAF Issuance)...
Updated at 101 AM EDT May 10 2012
Light rain showers and gusty winds from an outflow boundary have
ended across the TAF sites. High pressure will build into the area
through the forecast period, keeping things dry and VFR throughout.
Expect light winds out of the north-northeast overnight, and
generally out of the north between 7-12 mph later this afternoon. A
few gusts around 13-17 mph cannot be ruled out. Otherwise, expect a
few cu around 6 k feet this afternoon, with winds going calm late
this evening.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........13
Short Term.......AL
Long Term........MJ
Aviation.........BJS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
448 AM EDT THU MAY 10 2012
.SHORT TERM...(TODAY THROUGH FRIDAY NIGHT)
ISSUED AT 447 AM EDT THU MAY 10 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF MOVING ONSHORE
OVER THE PACIFIC NW/SW CANADA. DOWNSTREAM...A RIDGE EXTENDS FROM THE
ROCKIES TO HUDSON BAY. THE ASSOCIATED SFC HIGH PRES RIDGE AND DRY
AIR MASS WILL DOMINATE THE AREA TODAY. NARROW STREAK OF MID CLOUDS
CURRENTLY EXTENDING FROM FAR NE MANITOBA SSE TO NRN LAKE SUPERIOR IN
A RIBBON OF WEAK WAA/ISENTROPIC ASCENT WILL LIKELY AFFECT PORTIONS
OF THE ERN FCST AREA THIS MORNING. NAM/GFS SHOW CONDENSATION PRES
DEFICITS RISING A BIT THRU THE MORNING...SO THERE MAY BE TREND FOR
MID CLOUDS TO DIMINISH AS THEY STREAK SSE. OTHERWISE...ABUNDANT
SUNSHINE AND DRY AIR MASS TODAY WILL ALLOW FOR VERY DEEP MIXING
UPWARDS OF 750-700MB PER 00Z KINL/CWPL SOUNDINGS AND NAM/GFS FCST
SOUNDINGS. THIS YIELDS MAX TEMPS WELL INTO THE 60S/AROUND 70 W AND
LOW/MID 60S E. LAKE BREEZES WILL BE THE RULE IN THE AFTN TO PROVIDE
COOLING NEAR THE GREAT LAKES. UNDER DRY AIR MASS...AFTN RH WILL BE
LOW...FALLING INTO THE 20-30PCT RANGE. FORTUNATELY...WINDS WILL BE
ON THE LIGHT SIDE.
AS SFC HIGH PRES RIDGE DRIFTS E TONIGHT...S TO SW GRADIENT FLOW WILL
DEVELOP. BEFORE GRADIENT TIGHTENS UP A BIT...TEMPS WILL HAVE A
CHANCE TO FALL QUICKLY THIS EVENING. HOWEVER...WITH PRECIPITABLE
WATER RISING TO NEAR OR ABOVE NORMAL...TEMP FALL THIS EVENING
SHOULDN`T BE ANY MORE THAN TYPICAL. AIR MASS IS DRIER OVER THE
E...SO MIN TEMPS THERE WILL BE LOWEST...PROBABLY IN THE UPPER 30S IN
THE TRADITIONAL COLD SPOTS. OTHERWISE...40S SHOULD BE THE RULE
TONIGHT WITH THE WARMER TEMPS IN THE DOWNSLOPE AREAS OUT W.
MIDLEVEL TROF CURRENTLY MOVING ONSHORE OVER THE PACIFIC NW/SW CANADA
WILL SHIFT ACROSS THE NRN PLAINS FRI WITH ASSOCIATED COLD FRONT
MOVING INTO UPPER MI. TIMING OF FRONT IS OVERALL WELL AGREED UPON BY
THE MODELS WITH MOST SHOWING FRONT REACHING WRN UPPER MI 18-21Z AND
THEN EXTENDING FROM NE LAKE SUPERIOR TO ROUGHLY KMQT/KIMT BY 00Z.
WITH ONLY SOME HIGH CLOUDS AHEAD OF FRONT...IT WILL BE A WARM DAY AS
850MB THERMAL RIDGE OF 10-12C SHIFTS ACROSS THE AREA. MAX TEMPS
SHOULD BE WELL INTO THE 70S ACROSS THE W AND CNTRL AS STRONGER S/SW
WINDS WILL PREVENT LAKE SUPERIOR LAKE BREEZE. WARMEST TEMPS WILL BE
IN THE DOWNSLOPE AREAS...POSSIBLY REACHING 80F IF THICKER CLOUDS
HOLD OFF LONG ENOUGH. TO THE E...SRLY FLOW UP LAKE MICHIGAN WILL
KEEP THE E COOLER. TEMPS SHOULD RANGE FROM THE 50S LAKESIDE E OF
KESC TO AROUND 70 TOWARD LAKE SUPERIOR. WITH HIGHER TEMPS...AN
INCREASE IN WINDS AND RH FALLING INTO THE 30-40PCT RANGE...FIRE
CONCERNS WILL INCREASE FRI IN THOSE AREAS THAT FAILED TO RECEIVE
MUCH RAINFALL DURING THE LAST WEEK. AS FOR PCPN...NARROW RIBBON OF
MOISTURE/INSTABILITY WILL KEEP SHRA CONFINED TO A NARROW CORRIDOR
VCNTY OF FRONT. INCLUDED CHC POPS JUST AFTER 18Z W...SPREADING TO
THE ERN FCST AREA AT 00Z. WHILE THUNDER POTENTIAL IS MINIMAL WITH
GFS MLCAPES 100-200J/KG...THE NAM SHOWS MLCAPE BRIEFLY RISING TO
SEVERAL HUNDRED J/KG TOWARD THE WI BORDER...SUGGESTING THUNDER CAN`T
BE RULED OUT. THUS...OPTED TO MAINTAIN A SLIGHT CHC THUNDER MENTION.
SHRA WILL END W TO E FRI NIGHT AS SHORTWAVE/COLD FRONT MAKE STEADY
EASTWARD PROGRESS.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 447 AM EDT THU MAY 10 2012
COLD FRONT WILL BE QUICKLY EXITING THE AREA SAT MORNING...WITH
MUCH IF NOT ALL OF THE PCPN OUT OF UPPER MICHIGAN BY 12Z. DRY NW
FLOW WILL THEN BUILD OVER THE AREA ON SAT AND CONTINUE INTO SUN.
THIS DRY AIR WILL LEAD TO A MOSTLY SUNNY SKY AND PROVIDE DECENT
MIXING. THUS...EXPECT DEWPOINT VALUES TO FALL THROUGH THE
AFTN...ESPECIALLY OVER THE WRN HALF OF THE CWA. MODEL ML DEWPOINTS
ARE IN THE UPPER TEENS TO MID 20S OVER THE WEST...SO HAVE TRENDED
THAT DIRECTION AND DROPPED VALUES 3-5 DEGREES. MIXING TO H800-775
WOULD YIELD HIGHS IN THE LOW/MID 60S AWAY FROM LK SUPERIOR
INFLUENCES UNDER WNW WINDS. THE COMBINATION OF THESE TWO FACTORS
WILL PRODUCE RH VALUES AROUND 20-25 PERCENT...BUT IF BETTER MIXING
OCCURS...COULD SEE VALUES INTO THE UPPER TEENS. WITH WINDS OF
10-15 MPH THERE COULD BE SOME FIRE WX CONCERNS...BUT HOPEFULLY THE
0.1-0.15IN OF RAIN ON FRI NIGHT WILL LIMIT THEM.
SAT NIGHT...HIGH WILL STILL BE CENTERED OVER CNTRL PLAINS/ROCKIES
AND SFC RIDGE SLIDES SE INTO LOWER MI. THIS WILL KEEP A SLIGHTLY
STRONGER PRESSURE GRADIENT ACROSS THE AREA AND SHOULD KEEP LOWS
AT OR SLIGHTLY ABOVE NORMAL EVEN WITH THE CLEAR SKIES.
SUN LOOKS TO BE SIMILAR TO SAT...WITH DRY AIR STILL IN PLACE AND
PRODUCING A MOSTLY SUNNY SKY. ONCE AGAIN...DEWPOINTS ARE THE MAIN
CONCERN AND HAVE DROPPED VALUES INTO THE LOWER 30S. ML DEWPOINTS
ARE SHOWING VALUES IN THE UPPER 20S...SO THEY MAY NEED TO BE
REDUCED IF TREND CONTINUES. WITH HIGHS IN THE 60S...WILL SEE RH
VALUES DROPPING TOWARDS 25 PERCENT AGAIN.
SUN NIGHT THROUGH WED...
MODELS DIFFER IN THE HANDLING OF A SHORTWAVE ROTATING AROUND THE
UPPER LOW STATIONED OVER HUDSON BAY. 12Z ECMWF THE MOST PRONOUNCED
AND S WITH THIS WAVE MOVING THROUGH SRN CANADA AND UPPER GREAT LKS
ON SUN NIGHT...BUT THE LATE ARRIVING 00Z RUN HAS WEAKENED THIS
CONSIDERABLY. 00Z GFS/GEM SHOW WEAKER VARIATIONS OF THIS WAVE MOVING
THROUGH THE NW FLOW AND STAYING MAINLY IN SRN CANADA. PREVIOUS FCST
HAD SLIGHT CHANCES OVER NRN LK SUPERIOR AND FEEL THAT IS THE WAY TO
GO AT THIS POINT. OTHERWISE...THE REST OF THE EXTENDED FORECAST
LOOKS TO BE DOMINATED BY NW FLOW ALOFT. SFC RIDGE FROM THE CNTRL
PLAINS/ROCKIES WILL TRY TO BUILD BACK OVER THE AREA FOR MON/TUES.
THIS LEAVES THE AREA UNDER DRY AIR ALOFT AND FAIRLY LIGHT WINDS.
MODELS HINTING AT ANOTHER WEAK COLD FRONT MOVING THROUGH THE UPPER
GREAT LKS TUES NIGHT INTO WED...BUT CONFIDENCE FOR MEASURABLE
PCPN IS LOW AT THIS POINT. TEMPS SHOULD BE AT OR ABOVE NORMAL
THROUGH THE FIRST PART OF NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 130 AM EDT THU MAY 10 2012
EXPECT VFR CONDITIONS/LIGHT WINDS WITH DRY HI PRES DOMINATING THIS
FCST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 447 AM EDT THU MAY 10 2012
HIGH PRESSURE WILL COVER LAKE SUPERIOR TODAY AND LEAD TO LIGHT
WINDS. A COLD FRONT APPROACHING FROM THE NORTHERN PLAINS WILL CAUSE
WINDS TO BECOME SOUTHERLY TONIGHT AND FRIDAY...BUT THE MARINE
LAYER SHOULD KEEP WINDS BELOW 15KTS. WINDS WILL SHIFT TO THE NW
BEHIND THE FRONT ON FRIDAY NIGHT AND THEN REMAIN OUT OF THE WEST
THROUGH THE WEEKEND. MOSTLY AREAS SHOULD SEE WINDS STAY BELOW 20KTS
DURING THE WEEKEND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...KC
MARINE...SRF
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
1045 PM MDT WED MAY 9 2012
AVIATION SECTION UPDATED
.DISCUSSION...
UPDATE FORTHCOMING. HAVE LOWERED POPS ACROSS THE NORTHERN PORTION OF
THE COUNTY WARNING AREA UNTIL MIDNIGHT. APPROACHING COLD FRONT HAS
SLOWED A LITTLE AND THE AIRMASS OVER THE COUNTY WARNING AREA IS VERY
DRY. EXPECT LITTLE DEVELOPMENT THE REMAINDER OF THE EVENING. THE
COLD FRONT SHOULD PUSH THROUGH THE GREAT FALLS AREA AFTER MIDNIGHT.
SHOWERS LIKELY TO DEVELOP WITH FRONTAL PASSAGE BUT MODELS ARE
BEGINNING TO SCALE BACK QPF NUMBERS. HRRR RADAR PROJECTIONS HAVE A
NARROW BAND OF PRECIPITATION ASSOCIATED WITH THE COLD FRONT AND
LATEST NAM QPF VALUES HAVE NO PRECIPITATION FOR GREAT FALLS AND
POINTS FURTHER NORTH. MIDNIGHT SHIFT WILL HAVE THE COMPLETE 00Z RUNS
TO DETERMINE IF POPS NEED TO BE SCALED BACK THURSDAY MORNING.
EMANUEL
&&
.AVIATION...
UPDATED 0500Z.
PACIFIC COOL FRONT IS SLOWLY MOVING THROUGH THE REGION THIS EVENING.
THE FRONTAL PASSAGE IS NOT A SHARP BOUNDARY...BUT RATHER A GRADUAL
FRONTAL PASSAGE. EXPECT A NARROW BAND OF PRECIPITATION TO
DEVELOP...GENERALLY SOUTH OF A LINE FROM HAVRE TO GREAT FALLS TO
HELENA BY 12Z...AND THEN GRADUALLY MOVE EASTWARD DURING THE MORNING
HOURS. ANOTHER SMALL AREA OF SHOWERS WILL DEVELOP BY LATE MORNING IN
THE CUT BANK AREA. SOME IFR CONDITIONS ARE POSSIBLE IN THE MOUNTAINS
AND THROUGH THE PASSES...ALONG WITH THE CUT BANK UNTIL MID AFTERNOON
THURSDAY. DRY WEATHER WITH VFR CONDITIONS ARE EXPECTED ACROSS THE
REGION AFTER 01Z ON FRIDAY. BRUSDA
&&
.PREV DISCUSSION...ISSUED 241 PM MDT WED MAY 9 2012
TONIGHT THROUGH FRIDAY EVENING...CONTINUED GOOD AGREEMENT AMONG
MODELS WITH A PACIFIC TROF BRINGING A SURFACE COLD FRONT EAST OF
THE CONTINENTAL DIVIDE THIS EVENING. THE FRONT SHOULD PUSH
THROUGH CENTRAL AND SOUTHWEST MT TONIGHT AND DURING THE OVERNIGHT
HOURS. AN ISOLATED SHOWER OR TWO MAY POP UP AHEAD OF THE FRONT BUT
NOTHING MAJOR IS EXPECTED. PROBABILITY FOR PRECIP WILL INCREASE
BEHIND THE FRONT AS ADDITIONAL MOISTURE ARRIVES ALONG WITH COOLER
TEMPERATURES. FREEZING LEVELS WILL FALL THROUGH THE DAY THURSDAY
CREATING FAVORABLE CONDITIONS FOR LIGHT SNOW IN THE MTNS AND FOR
SOME LOCATIONS TO SEE GRAUPEL/SMALL HAIL WITH RAIN SHOWERS THURS
AFTERNOON. PRECIP SHOULD TAPER OFF THURS NIGHT AS THE TROF
CONTINUES EAST ACROSS MONTANA. AN UPPER LEVEL RIDGE BEGINS TO
BUILD BACK IN OVER THE REGION FRI BRINGING A RETURN OF WARM AND
DRY CONDITIONS. AS FOR TEMPERATURES...THE COLDER AIRMASS
ASSOCIATED WITH THE INCOMING FRONT WILL DROP OVERNIGHT LOW TEMPS
TONIGHT INTO THE 20S IN THE MOUNTAINS AND 30S TO LOW 40S ACROSS
THE PLAINS AND VALLEYS. HIGHS IN THE MID 40S TO LOW 50S ON
THURSDAY SHOULD RETURN TO THE UPPER 50S TO LOW 60S ON FRIDAY.
FRIDAY NIGHT THROUGH WEDNESDAY...AN UPPER LEVEL RIDGE OF HIGH
PRESSURE BECOMES ESTABLISHED OVER THE NORTHERN ROCKIES FRIDAY NIGHT
AND STRENGTHENS OVER MUCH OF THE WESTERN U.S. THIS WEEKEND THROUGH
AT LEAST THE FIRST HALF OF NEXT WEEK. THIS WILL BRING AN EXTENDED
PERIOD OF MAINLY DRY WEATHER TO THE FORECAST AREA WITH AFTERNOON
TEMPERATURES INITIALLY NEAR SEASONAL AVERAGES ON SATURDAY...RISING
TO 10-15 DEGREES ABOVE AVERAGE FROM SUNDAY THROUGH THE FIRST HALF OF
NEXT WEEK. OVERNIGHT LOW TEMPERATURES FRIDAY NIGHT/SATURDAY MORNING
WILL LIKELY FALL TO NEAR FREEZING IN MANY AREAS AGAIN WITH WARMING
MINIMUM TEMPS THEREAFTER. SURFACE PRESSURE GRADIENTS AND WINDS ALOFT
ARE RELATIVELY WEAK THROUGH THE PERIOD...WITH SURFACE WINDS EXPECTED
TO BE RELATIVELY LIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 41 52 31 59 / 30 60 20 0
CTB 34 47 27 60 / 10 50 20 0
HLN 41 55 31 63 / 40 60 20 0
BZN 37 54 26 61 / 20 60 10 0
WEY 31 53 24 57 / 10 30 20 0
DLN 39 54 25 61 / 30 40 10 0
HVR 40 50 30 60 / 20 70 30 0
LWT 37 48 29 56 / 30 70 30 0
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
WEATHER.GOV/GREATFALLS
AREA FORECAST DISCUSSION
NWS BUFFALO NY
126 AM EDT THU MAY 10 2012
.SYNOPSIS...
AN UPPER LEVEL TROUGH WILL DIG ACROSS THE AREA TODAY GENERATING A
FEW SHOWERS AND THUNDERSTORMS THIS AFTERNOON. HIGH PRESSURE WILL
THEN GRADUALLY BUILD ACROSS THE REGION DURING THE REMAINDER OF THE
WEEK BRINGING IMPROVING CONDITIONS ON THURSDAY AND DRY WEATHER FOR
FRIDAY AND SATURDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1245 AM...HAVE UPDATED THE FORECAST MERELY TO KEEP IT IN
LINE WITH CURRENT OBS AND RECENT RADAR/SATELLITE
TRENDS...OTHERWISE THERE HAVE BEEN NO CHANGES TO THE PREVIOUS
FORECAST THINKING...WHICH FOLLOWS BELOW.
AN UPPER LEVEL TROF WILL VERY SLOWLY APPROACH FROM THE WEST
OVERNIGHT...EVENTUALLY SETTLING ACROSS WESTERN NEW YORK BY DAYBREAK.
DESPITE THE APPROACH OF THIS FEATURE...THE LOSS OF DAYTIME HEATING
HAS KEYED THE DEMISE OF SHOWERS ACROSS WESTERN NEW YORK.
CONSENSUS QPF OF THE NAM12/RGEM BOTH SHOW LIGHT QPF IN UPSLOPE
REGIONS...BUT LOOKING AT THE OMEGA FIELD...NEARLY ALL THE LIFT IS
GENERATED IN THE LOWEST 3000 FT. THIS WILL PROBABLY NOT BE DEEP
ENOUGH TO PRODUCE SHOWERS. THE HRRR TENDS TO SUPPORT THIS
CONCLUSION...FORECASTING MINIMAL QPF OVERNIGHT. WITH THE UPPER
TROF...AND A LIMITED CHANCE FOR DRIZZLE...WILL HANG ONTO 20 SLIGHT
CHANCE POPS...BUT OUTSIDE OF SOME LINGERING SHOWERS...EXPECT A
MAINLY DRY NIGHT. THERE IS QUITE A BIT OF CLOUD COVER ASSOCIATED
WITH THE UPPER LOW...SO THIS WILL LIMIT RADIATIONAL
COOLING...THOUGH THE NORTHERLY FLOW WILL ADVECT SLIGHTLY COLDER
TEMPERATURES IN. LOWS SHOULD MAINLY BE IN THE 40S ACROSS THE
REGION.
THURSDAY...UPPER TROUGH AXIS WILL BE LOCATED OVER WESTERN NEW YORK
SHIFTING EASTWARD AND CUTTING OFF THROUGH THE DAY. 543 DM LOW
CENTERED OVER SOUTHERN QUEBEC WILL PROVIDE COLD AIR ALOFT YIELDING
INSTABILITY CLOUDS ACROSS THE FORECAST AREA WITH A CHANCE FOR
INSTABILITY SHOWERS FOCUSED MAINLY ACROSS THE COUNTIES EAST OF LAKE
ONTARIO CLOSER TO THE UPPER LOW. MANY LOCATIONS WILL ONLY TOP OUT IN
THE MID TO UPPER 50S WITH THE CLOUD COVER AND COLD AIR ALOFT...850MB
TEMPS NEAR 0C. A FEW AREAS COULD SEE 60. BREEZY WEST TO NORTHWEST
WINDS WILL ALSO DEVELOP IN THE AFTERNOON AS THE SURFACE LOW NEAR
OTTAWA CANADA SHIFTS EAST OVER MAINE AND DEEPENS. A COOL...CLOUDY
AND BREEZY DAY TO SUM IT UP.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
A HIGH AMPLITUDE RIDGE WILL FORCE A BROAD SURFACE RIDGE INTO THE
EASTERN GREAT LAKES REGION THURSDAY NIGHT. THIS WILL BRING A
CLEARING TREND AND THE RISK FOR FROST...ESPECIALLY TO INTERIOR
SECTIONS OF THE SOUTHERN TIER WHERE TEMPERATURES WILL FALL TO THE
MID 30S IN SPOTS...POSSIBLY TO NEAR FREEZING IN THE GENESEE VALLEY.
FRIDAY SHOULD SEE PLENTY OF SUNSHINE...ALTHOUGH THERE MAY BE SOME
DIURNALLY DRIVEN CUMULUS WITH DEPARTING COLD POOL. WITH THE
ADDITIONAL SUNSHINE HIGHS WILL BE A SOLID 5 TO 10 DEGREES WARMER
THAN THURSDAY...MAINLY IN THE MID TO UPPER 60S.
SKIES WILL REMAIN CLEAR DURING FRIDAY NIGHT AND THE APPROACH OF A
WEAK COLD FRONT WILL INCREASE THE SOUTHWESTERLY BREEZE OVERNIGHT...
MIXING THE BOUNDARY LAYER AND HOLDING TEMPS LOWER TO MID 40S...
ALLEVIATING THE RISK OF FROST.
SATURDAY WILL ALSO BE A SUNNY DAY FOR THE MOST PART...SOME HIGH
CLOUDS STREAMING IN AND THICKENING THROUGH THE AFTERNOON. WILL SEE
HIGH TEMPS IN THE MID/UPR 60S EAST OF LAKE ONTARIO WITH LOWER 70S
ELSEWHERE AS 850MB TEMPS RISE TO THE +6C TO +8C RANGE PRECEDING A
WEAKENING TROUGH TO THE WEST. SAID TROUGH WILL CROSS THE REGION
SATURDAY NIGHT WITH LITTLE FANFARE...EXPECT THE COOL FRONT
ASSOCIATED WITH THE TROUGH TO WASH OUT ALMOST COMPLETELY. MID AND
HIGH CLOUDS ACCOMPANYING THE TROUGH/FRONT WILL KEEP OVERNIGHT TEMPS
UP INTO THE MID TO UPPER 40S ACROSS THE FORECAST AREA. GFS HAS COME
IN LINE WITH THE LONG STANDING ECMWF CONCEPT OF HAVING VERY LOW POPS
AND QPF ASSOCIATED WITH THE FRONT...SLIGHT CHANCE ACROSS MOST OF THE
FORECAST AREA WITH LOW CHANCE POPS FOR THE SAINT LAWRENCE VALLEY AND
TUG HILL/ WESTERN ADIRONDACKS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
ON SUNDAY...HIGH PRESSURE CENTERED OVER THE CENTRAL PLAINS WILL
RIDGE EASTWARD FOLLOWING THE PASSAGE OF THE DYING SURFACE TROUGH.
THE THERMAL BOUNDARY WILL REMAIN JUST SOUTH OF THE FORECAST AREA
WITH LOW CHANCE POPS ACROSS THE SOUTHERN TIER AND NIL POPS
ELSEWHERE. CLOUDS WILL LINGER ALONG THE NORTH OF THIS THERMAL
BOUNDARY WITH AFTERNOON TEMPS REACHING THE MID TO UPPER 60S.
HIGH PRESSURE FROM THE PLAINS TO THE MID GREAT LAKES AND ONWARD TO
WESTERN QUEBEC WILL HOLD A BROAD REGION OF LOW PRESSURE TO THE SOUTH
OF THE FORECAST AREA... ACROSS THE SOUTHEASTERN STATES. THE HIGH
PRESSURE SHOULD SUPPRESS ANY CHANCE OF PRECIP MONDAY THROUGH
WEDNESDAY WITH HIGH TEMPS GENERALLY IN THE MID 60S TO THE LOWER 70S.
LOWS WILL BE IN THE MID 40S TO LOW 50S.
&&
.AVIATION /05Z THURSDAY THROUGH MONDAY/...
FOR THE REMAINDER OF THE NIGHT...MOSTLY CLOUDY AND DRY CONDITIONS
WILL CONTINUE TO BE THE GENERAL RULE. CIGS WILL GENERALLY RANGE
FROM MVFR TO LOW-END VFR...WITH MVFR CIGS TENDING TO BE MORE
COMMONPLACE ACROSS THE WESTERN SOUTHERN TIER...FINGER LAKES
REGION...AND NORTH COUNTRY.
ONCE WE GET INTO THE DAYLIGHT HOURS...CIGS WILL TEND TO LIFT BACK
TO VFR FROM WEST TO EAST WITH DIURNAL HEATING/MIXING AND THE SLOW
ENCROACHMENT OF DRIER AIR FROM THE WEST. GENERALLY DRY WEATHER
WILL ALSO CONTINUE...EXCEPT ACROSS THE NORTH COUNTRY WHERE
SCATTERED TO NUMEROUS LIGHT SHOWERS WILL LINGER CLOSER TO THE CORE
OF THE SLOWLY DEPARTING UPPER LEVEL LOW. SURFACE WINDS WILL ALSO
PICK UP WITH INCREASING HEATING OF THE FAIRLY COOL AIRMASS THAT
WILL STILL BE IN PLACE...WITH WEST-NORTHWESTERLY WINDS FREQUENTLY
GUSTING TO AROUND 25 KTS SOUTH OF LAKE ONTARIO AFTER ABOUT 14Z-
15Z.
TONIGHT...EXPECT ANY LINGERING SHOWERS ACROSS THE NORTH COUNTRY TO
WIND DOWN...WHILE CIGS CONTINUE TO IMPROVE FROM WEST TO EAST AS
HIGH PRESSURE AND DRIER AIR BUILD EAST ACROSS NEW YORK STATE.
OUTLOOK...
FRIDAY AND SATURDAY...VFR.
SUNDAY...VFR WITH A CHANCE OF SHOWERS.
MONDAY...VFR.
&&
.MARINE...
A MODEST WEST TO OCCASIONALLY NORTHWESTERLY FLOW WILL PREVAIL ACROSS
THE LOWER GREAT LAKES THROUGH FRIDAY...WITH WINDS AND WAVES EXPECTED
TO REMAIN BELOW ADVISORY CRITERIA. MINIMAL SMALL CRAFT ADVISORY
CONDITIONS NEED TO BE WATCHED ALONG THE SOUTH SHORE OF LK ONTARIO
FOR THURSDAY AFTERNOON THROUGH THURSDAY NIGHT WITH ONSHORE NW
WINDS NEAR 20 KTS.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SMITH
NEAR TERM...APFFEL/JJR/SMITH
SHORT TERM...WCH
LONG TERM...WCH
AVIATION...JJR
MARINE...APFFEL/SMITH
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1249 AM EDT THU MAY 10 2012
.SYNOPSIS...
AN UPPER LEVEL TROUGH WILL DIG ACROSS THE AREA TODAY GENERATING A
FEW SHOWERS AND THUNDERSTORMS THIS AFTERNOON. HIGH PRESSURE WILL
THEN GRADUALLY BUILD ACROSS THE REGION DURING THE REMAINDER OF THE
WEEK BRINGING IMPROVING CONDITIONS ON THURSDAY AND DRY WEATHER FOR
FRIDAY AND SATURDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1245 AM...HAVE UPDATED THE FORECAST MERELY TO KEEP IT IN
LINE WITH CURRENT OBS AND RECENT RADAR/SATELLITE
TRENDS...OTHERWISE THERE HAVE BEEN NO CHANGES TO THE PREVIOUS
FORECAST THINKING...WHICH FOLLOWS BELOW.
AN UPPER LEVEL TROF WILL VERY SLOWLY APPROACH FROM THE WEST
OVERNIGHT...EVENTUALLY SETTLING ACROSS WESTERN NEW YORK BY DAYBREAK.
DESPITE THE APPROACH OF THIS FEATURE...THE LOSS OF DAYTIME HEATING
HAS KEYED THE DEMISE OF SHOWERS ACROSS WESTERN NEW YORK.
CONSENSUS QPF OF THE NAM12/RGEM BOTH SHOW LIGHT QPF IN UPSLOPE
REGIONS...BUT LOOKING AT THE OMEGA FIELD...NEARLY ALL THE LIFT IS
GENERATED IN THE LOWEST 3000 FT. THIS WILL PROBABLY NOT BE DEEP
ENOUGH TO PRODUCE SHOWERS. THE HRRR TENDS TO SUPPORT THIS
CONCLUSION...FORECASTING MINIMAL QPF OVERNIGHT. WITH THE UPPER
TROF...AND A LIMITED CHANCE FOR DRIZZLE...WILL HANG ONTO 20 SLIGHT
CHANCE POPS...BUT OUTSIDE OF SOME LINGERING SHOWERS...EXPECT A
MAINLY DRY NIGHT. THERE IS QUITE A BIT OF CLOUD COVER ASSOCIATED
WITH THE UPPER LOW...SO THIS WILL LIMIT RADIATIONAL
COOLING...THOUGH THE NORTHERLY FLOW WILL ADVECT SLIGHTLY COLDER
TEMPERATURES IN. LOWS SHOULD MAINLY BE IN THE 40S ACROSS THE
REGION.
THURSDAY...UPPER TROUGH AXIS WILL BE LOCATED OVER WESTERN NEW YORK
SHIFTING EASTWARD AND CUTTING OFF THROUGH THE DAY. 543 DM LOW
CENTERED OVER SOUTHERN QUEBEC WILL PROVIDE COLD AIR ALOFT YIELDING
INSTABILITY CLOUDS ACROSS THE FORECAST AREA WITH A CHANCE FOR
INSTABILITY SHOWERS FOCUSED MAINLY ACROSS THE COUNTIES EAST OF LAKE
ONTARIO CLOSER TO THE UPPER LOW. MANY LOCATIONS WILL ONLY TOP OUT IN
THE MID TO UPPER 50S WITH THE CLOUD COVER AND COLD AIR ALOFT...850MB
TEMPS NEAR 0C. A FEW AREAS COULD SEE 60. BREEZY WEST TO NORTHWEST
WINDS WILL ALSO DEVELOP IN THE AFTERNOON AS THE SURFACE LOW NEAR
OTTAWA CANADA SHIFTS EAST OVER MAINE AND DEEPENS. A COOL...CLOUDY
AND BREEZY DAY TO SUM IT UP.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
A HIGH AMPLITUDE RIDGE WILL FORCE A BROAD SURFACE RIDGE INTO THE
EASTERN GREAT LAKES REGION THURSDAY NIGHT. THIS WILL BRING A
CLEARING TREND AND THE RISK FOR FROST...ESPECIALLY TO INTERIOR
SECTIONS OF THE SOUTHERN TIER WHERE TEMPERATURES WILL FALL TO THE
MID 30S IN SPOTS...POSSIBLY TO NEAR FREEZING IN THE GENESEE VALLEY.
FRIDAY SHOULD SEE PLENTY OF SUNSHINE...ALTHOUGH THERE MAY BE SOME
DIURNALLY DRIVEN CUMULUS WITH DEPARTING COLD POOL. WITH THE
ADDITIONAL SUNSHINE HIGHS WILL BE A SOLID 5 TO 10 DEGREES WARMER
THAN THURSDAY...MAINLY IN THE MID TO UPPER 60S.
SKIES WILL REMAIN CLEAR DURING FRIDAY NIGHT AND THE APPROACH OF A
WEAK COLD FRONT WILL INCREASE THE SOUTHWESTERLY BREEZE OVERNIGHT...
MIXING THE BOUNDARY LAYER AND HOLDING TEMPS LOWER TO MID 40S...
ALLEVIATING THE RISK OF FROST.
SATURDAY WILL ALSO BE A SUNNY DAY FOR THE MOST PART...SOME HIGH
CLOUDS STREAMING IN AND THICKENING THROUGH THE AFTERNOON. WILL SEE
HIGH TEMPS IN THE MID/UPR 60S EAST OF LAKE ONTARIO WITH LOWER 70S
ELSEWHERE AS 850MB TEMPS RISE TO THE +6C TO +8C RANGE PRECEDING A
WEAKENING TROUGH TO THE WEST. SAID TROUGH WILL CROSS THE REGION
SATURDAY NIGHT WITH LITTLE FANFARE...EXPECT THE COOL FRONT
ASSOCIATED WITH THE TROUGH TO WASH OUT ALMOST COMPLETELY. MID AND
HIGH CLOUDS ACCOMPANYING THE TROUGH/FRONT WILL KEEP OVERNIGHT TEMPS
UP INTO THE MID TO UPPER 40S ACROSS THE FORECAST AREA. GFS HAS COME
IN LINE WITH THE LONG STANDING ECMWF CONCEPT OF HAVING VERY LOW POPS
AND QPF ASSOCIATED WITH THE FRONT...SLIGHT CHANCE ACROSS MOST OF THE
FORECAST AREA WITH LOW CHANCE POPS FOR THE SAINT LAWRENCE VALLEY AND
TUG HILL/ WESTERN ADIRONDACKS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
ON SUNDAY...HIGH PRESSURE CENTERED OVER THE CENTRAL PLAINS WILL
RIDGE EASTWARD FOLLOWING THE PASSAGE OF THE DYING SURFACE TROUGH.
THE THERMAL BOUNDARY WILL REMAIN JUST SOUTH OF THE FORECAST AREA
WITH LOW CHANCE POPS ACROSS THE SOUTHERN TIER AND NIL POPS
ELSEWHERE. CLOUDS WILL LINGER ALONG THE NORTH OF THIS THERMAL
BOUNDARY WITH AFTERNOON TEMPS REACHING THE MID TO UPPER 60S.
HIGH PRESSURE FROM THE PLAINS TO THE MID GREAT LAKES AND ONWARD TO
WESTERN QUEBEC WILL HOLD A BROAD REGION OF LOW PRESSURE TO THE SOUTH
OF THE FORECAST AREA... ACROSS THE SOUTHEASTERN STATES. THE HIGH
PRESSURE SHOULD SUPPRESS ANY CHANCE OF PRECIP MONDAY THROUGH
WEDNESDAY WITH HIGH TEMPS GENERALLY IN THE MID 60S TO THE LOWER 70S.
LOWS WILL BE IN THE MID 40S TO LOW 50S.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
EXPECT THE REMAINDER OF THE OVERNIGHT PERIOD TO REMAIN DRY...WITH
LOWERING CIGS THE MAIN CONCERN. EXPECT BKN-OVC LOW CLOUDS TO
DEVELOP ACROSS THE REGION...GENERALLY HOVERING AROUND 3000 FT AT
BUF/IAG/ROC/ART...A BIT LOWER AT JHW. THE TREND SHOULD GENERALLY
BE DOWNWARD OVERNIGHT AS THE UPPER TROF APPROACHES...AND THE
INVERSION LOWERS.
THURSDAY...CIGS IMPROVE AFTER 14Z/15Z AND WIND GUSTS DEVELOP WITH
DAYTIME MIXING. BKN VFR SKIES WILL PREVAIL WITH COOL AIR ALOFT
PROVIDED BY UPPER LEVEL TROUGH OVER NY. SCATTERED SHOWERS HAVE
HIGHEST CHANCES EAST OF LAKE ONTARIO WHERE BEST INSTABILITY AND
HIGHER MOISTURE RESIDE.
OUTLOOK...
FRIDAY AND SATURDAY...VFR.
SUNDAY...VFR WITH A CHANCE OF SHOWERS.
&&
.MARINE...
A MODEST WEST TO OCCASIONALLY NORTHWESTERLY FLOW WILL PREVAIL ACROSS
THE LOWER GREAT LAKES THROUGH FRIDAY...WITH WINDS AND WAVES EXPECTED
TO REMAIN BELOW ADVISORY CRITERIA. MINIMAL SMALL CRAFT ADVISORY
CONDITIONS NEED TO BE WATCHED ALONG THE SOUTH SHORE OF LK ONTARIO
FOR THURSDAY AFTERNOON THROUGH THURSDAY NIGHT WITH ONSHORE NW
WINDS NEAR 20 KTS.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SMITH
NEAR TERM...APFFEL/JJR/SMITH
SHORT TERM...WCH
LONG TERM...WCH
AVIATION...APFFEL
MARINE...APFFEL/SMITH
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
105 AM EDT THU MAY 10 2012
.SYNOPSIS...
A COLD FRONT MUCH DRIER AIR WILL OVERSPREAD THE AREA TODAY AS HIGH
PRESSURE RIDGES IN THROUGH THE UPCOMING WEEKEND. THE HIGH WILL SLIP
OFFSHORE FROM THE COAST LATE SUNDAY. A COLD FRONT WILL APPROACH THE
REGION FROM THE NORTH MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 100 AM THURSDAY...UPDATED FORECAST TO END PRECIP AND BEGIN THE
WEST-TO-EAST CLEARING SEVERAL HOURS QUICKER THAN EARLIER FORECAST.
SKIES SHOULD BECOME CLEAR IN THE DARLINGTON AND BENNETTSVILLE
VICINITY WITHIN AN HOUR. THIS ALSO NECESSITATES A MODEST LOWERING OF
LOW TEMPERATURE FORECASTS GIVEN THE LONG PERIOD TO GO OF CLEAR SKIES
AND LIGHT WINDS INLAND. PREVIOUS DISCUSSION FOLLOWS...
LARGE AMPLIFIED UPPER TROF IN CONTROL OF THE EAST COAST THIS NEAR
TERM. AT THE SFC...A COLD FRONT ORIENTED NE-SW ACROSS THE EASTERN
CAROLINAS AT THE MOMENT...WILL TRACK EASTWARD OVERNIGHT...MOVING OFF
THE ILM CWA MAINLAND BETWEEN MIDNIGHT AND 2 AM THURSDAY. LATEST HRRR
MODEL RUNS ALSO INDICATE THE WELL DEFINED COLD FRONT TO MOVE OFF THE
CAROLINA COASTS BY EARLY THU MORNING. PROGGED SFC WIND FIELDS VIA
HRRR LOOKS LIKE THE BEST WAY TO GO. EXPECT EXCELLENT POST FRONTAL
CAA AFTER FROPA...WITH 850 TEMPS DROPPING FROM ROUGHLY 14C TO 7C AND
ALSO 1K-8H THICKNESS DROPPING FROM ROUGHLY 1396M TO 1366M BY
DAYBREAK THURSDAY. MAIN AREA OF CONVECTION VIA KLTX AND SURROUNDING
88DOS...INDICATE THE MAIN AND STRONGER AREAS OF CONVECTION LIE
ACROSS THE ADJACENT ATLANTIC WATERS. COULD OBSERVE SCATTERED -SHRA
PRIOR TO THE CFP. WILL NEED TO FURTHER ADJUST POPS ESPECIALLY WITH
THE MAIN AREA NOW OFF THE COAST. MIN TEMP GUIDANCE TRICKY DUE TO
POST FRONTAL POSSIBLE LOW STRATUS AND FOG. THE LATTER LIKELY NOT TO
OCCUR DUE TO LOW LEVEL WINDS TO INCREASE ENOUGH TO PREVENT FOG.
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...BY THURSDAY DAYBREAK THE BULK OF COLUMN
MOISTURE ASSOCIATED WITH A DEPARTING FRONTAL SYSTEM WILL RESIDE
OFFSHORE. STRONG MID AND UPPER LEVEL DRYING COUPLED WITH MODERATE
NORTH WINDS WILL ALREADY BE OVERSPREADING THE AREA. MAXIMUM TEMPS
THU MAINLY MID/UPPER 70S WITH A FEW LOCATIONS OVER THE SC INTERIOR
APT TO REACH 80. MAINLY CLEAR UNDER LOW-LEVEL NORTH WIND FLOW THU
NIGHT SHOULD YIELD LOW/MID 50S INTO EARLY FRIDAY. NORTH FLOW WILL
ENDURE MUCH OF FRIDAY DELAYING A SIGNIFICANT DAYTIME WARMING TREND
WITH MAXIMUMS VERY SIMILAR TO THURSDAY. UNDER IDEAL RADIATIONAL
COOLING...UPPER 40S INLAND LOOKS PROBABLE WITH LOWER 50S ALONG THE
COASTAL ZONES...AND SURFACE HIGH PRESSURE NEARLY OVERHEAD.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 3 PM WEDNESDAY...SURFACE AND UPPER RIDGE AXIS OVERHEAD SAT
WILL SHIFT OFFSHORE SUN AS BROAD 5H TROUGH STARTS TO DEVELOP OVER
THE EASTERN HALF OF THE COUNTRY. SAT INTO SUN LOOKS DRY BUT
WEAKENING INFLUENCE OF THE UPPER RIDGE AND MOISTURE RETURN IN DEEP
SOUTHWEST FLOW COULD PRODUCE SOME ISOLATED CONVECTION SUN AFTERNOON.
INHERITED SLIGHT CHANCE POP LOOKS GOOD AT THIS POINT. FOR THE
REMAINDER OF THE PERIOD WEATHER WILL REMAIN UNSETTLED WITH 5H TROUGH
AXIS TO THE WEST AND DEEP SOUTHWEST FLOW ADVECTING PLENTY OF
MOISTURE INTO THE REGION. ANY PASSING SHORTWAVE WILL ENHANCE DIURNAL
CONVECTION MON AFTERNOON WHICH WARRANTS A SMALL POP INCREASE...NOW
LOW CHANCE. TUE/WED REMAINS UNCERTAIN WITH THE 12Z GFS MUCH MORE
PROGRESSIVE THAN ITS PREVIOUS RUNS. MEDIUM RANGE GUIDANCE AGREES ON
WEAK LOW PRESSURE DEVELOPING ALONG THE GULF COAST WHICH THEN MOVES
ACROSS NORTHERN FL AND UP THE SE COAST. SIGNIFICANT TIMING
DIFFERENCES BETWEEN THE 12Z GFS...12Z CANADIAN...00Z ECMWF AND LACK
OF CONTINUITY BETWEEN THEIR RESPECTIVE RUNS IS KEEPING CONFIDENCE
LOW LATE IN THE PERIOD. THE MAIN ISSUE IS HOW THE GUIDANCE IS
HANDLING THE COLLAPSE OF THE UPPER RIDGE OUT WEST AND THE IMPACT
THIS HAS ON THE TROUGHING OVER THE EAST. WILL CONTINUE TO CARRY A
CHANCE POP TUE/TUE NIGHT WHICH WILL EXTEND INTO WED AD MUCH OF THE
GUIDANCE...SAVE THE GFS...IS SUGGESTING A SLOWER/WETTER SOLUTION.
HIGHS WILL REMAIN SLIGHTLY BELOW CLIMO THROUGH THE PERIOD WITH LOWS
STARTING OUT SLIGHTLY BELOW CLIMO BUT ENDING UP NEAR TO SLIGHTLY
ABOVE CLIMO.
&&
.AVIATION /06Z THURSDAY THROUGH TUESDAY/...
AS OF 06Z...SFC COLD FRONT IS NOW OFFSHORE AND DRIER AIR IS PUNCHING
IN FROM THE WEST AT THE SURFACE AND ALOFT...EXPECTED TO REACH THE
COAST WITHIN THE NEXT FEW HOURS. NW SFC WINDS 5-10 KT WILL INCR TO
10-15 KT AFTER DAYBREAK AS A LITTLE STRONGER FLOW MIXES DOWN FROM
ALOFT. ONCE THE CURRENT MID-LEVEL CLOUDINESS CLEARS OFFSHORE WE ARE
ONLY EXPECTING A FEW HIGH-BASED CU AT THE TOP OF THE DEEP DAYTIME
MIXED LATER TODAY. SKC EXPECTED TONIGHT.
EXTENDED OUTLOOK...ISOLATED CONVECTION LATE FRIDAY EVENING...
BECOMING SCATTERED TO NUMEROUS SATURDAY. ISOLATED CONVECTION
POSSIBLE SUNDAY. VFR MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 100 AM THURSDAY...TEMPERED WIND SPEED FORECASTS JUST A HAIR
BUT WITH LITTLE REAL CHANGE FROM THE PREVIOUS FORECASTS. BIGGEST
CHANGE WAS TO BRING SEAS AT THE BEACHES UP TO 1-2 FT DESPITE THE
OFFSHORE WIND. PREVIOUS DISCUSSION FOLLOWS.
FOLLOWING THE HRRR MODEL SFC WIND FIELDS. A PRONOUNCED WIND SHIFT
WILL OCCUR...WITH SW 10 TO OCCASIONALLY 15 KT...VEERING TO THE NW 15
TO 20 KT OVERNIGHT. THE LATTER MAY BE A BIT UNDERDONE GIVEN THE
TIGHTENED POST FRONTAL SFC PRESSURE GRADIENT AND COOL/COLD SURGE
RESULTING WITH HIGH. SIG SEAS WILL RUN BASICALLY 2 TO 4 FT.
INITIALLY THE EASTERLY 2 TO 3 FT GROUND SWELL WILL DOMINATE SIG
SEAS. IT WILL GIVE WAY TO AN INCREASING SHORT PERIOD LOCALLY
PRODUCED WIND WAVES EXHIBITING 3 TO 5 SECOND PERIODS. THIS WIND
DRIVEN VARIETY WILL BECOME THE DOMINATE PLAYER WITH REGARD TO SIG.
SEAS LATE TONIGHT.
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
AS OF 3 PM WEDNESDAY...A COLD FRONT MAY BRING LIMITED VISIBILITIES
IN RAIN AND ISOLATED TSTMS...ALONG WITH LOCALLY GUSTY WINDS AND
LOCALLY HIGHER WIND-WAVES TONIGHT. MARINERS SHOULD CONSULT RADAR
BEFORE HEADING OUT LATE THIS AFTERNOON OR EVENING. THE FRONT WILL
BRING A WIND-SHIFT IN THE VERY LATE EVENING AROUND MIDNIGHT. THIS
COULD BRING N WIND GUSTS TO 20 KT THROUGH THURSDAY MORNING...BEFORE
EASING IN THE AFTERNOON. REINFORCING HIGH PRESSURE WILL SUSTAIN N
WINDS THROUGH MOST OF FRIDAY...WITH THE HIGH MOVING OVERHEAD FRIDAY
NIGHT. SEAS MAY APPROACH 5 FEET ACROSS THE OUTER PORTION AND THE
NORTH END OF FRYING PAN SHOALS THURSDAY MORNING.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 PM WEDNESDAY...WEAK GRADIENT SAT INTO SUN WILL KEEP WINDS
LIGHT AND HIGHLY VARIABLE. THERE WILL BE A GENERAL NORTHEAST TO
EAST FLOW WITH SPEEDS 10 KT OR LESS. GRADIENT BECOMES A LITTLE
MORE DEFINED SUN AS HIGH MOVES FARTHER OF THE COAST AND SOUTHEAST
FLOW DEVELOPS. SOME GUIDANCE HINTING AT WEAK COASTAL TROUGH ALONG
THE GA/SOUTHERN SC COAST WHICH MAY ENHANCE FLOW ACROSS SC ZONES.
HOWEVER SPEEDS SHOULD REMAIN UNDER 15 KT INTO MON. SURFACE HIGH
EAST OF THE WATERS AND LACK OF ANY SIGNIFICANT SURFACE FEATURES TO
THE WEST MEANS SOUTHEAST FLOW WILL CONTINUE ON MON. OVERALL LITTLE
CHANGE TO THE SURFACE GRADIENT BETWEEN SUN AND MON SO SPEEDS
SHOULD BE SIMILAR...10 TO 15 KT. SEAS WILL RUN 2 TO 4 FT THROUGH
THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...MJC
LONG TERM...III
AVIATION...TRA
AREA FORECAST DISCUSSION
NWS CARIBOU ME
703 AM EDT THU MAY 10 2012
.SYNOPSIS...
LOW PRESSURE WILL TRACK ACROSS DOWNEAST MAINE TODAY THEN CONTINUE
INTO NEW BRUNSWICK CANADA TONIGHT. AN UPPER LEVEL TROUGH OF LOW
PRESSURE WILL CROSS THE STATE ON FRIDAY. THE TROUGH WILL MOVE EAST
ON SATURDAY AS DRIER AIR MOVES IN.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE 0700L: BASED ON HRRR MODEL, WILL END RAIN ACROSS DOWNEAST
THIS AFTERNOON AS LOW PRESSURE QUICKLY MOVES NORTHEAST OF THE
AREA...OTHERWISE FORECAST ON TRACK.
PREVIOUS DISCUSSION:
LOW PRESSURE DEVELOPING SOUTH OF LONG ISLAND EARLY THIS MORNING
WILL QUICKLY TRACK NORTHEAST TODAY. MODELS NOW FARTHER WEST WITH
THE TRACK WITH LANDFALL AROUND BAR HARBOR AROUND NOONTIME. THE LOW
WILL THEN QUICKLY EXIT INTO NEW BRUNSWICK LATER THIS AFTERNOON.
RAIN WILL INTENSIFY THIS MORNING ESPECIALLY OVER HANCOCK AND
WASHINGTON COUNTIES AS DEEP MOISTURE, LONG MOISTURE FETCH OVER THE
ATLANTIC, AND STRONG UPPER JET CORE OF 120 KTS MOVES ACROSS THE
STATE. A BLEND OF THE MODEL QPF STILL INDICATING OVER 2 INCHES OF
RAIN POSSIBLE OVER HANCOCK AND WASHINGTON COUNTIES TAPERING TO
AROUND AN INCH ACROSS NORTHERN SECTIONS. WITH STRONG UPPER
DYNAMICS WILL INCLUDE ISOLATED THUNDER ACROSS MAINLY HANCOCK AND
WASHINGTON COUNTIES THIS MORNING. RAIN WILL END FROM WEST TO EAST
ACROSS THE REGION THIS AFTERNOON AS UPPER LEVEL DRY SLOT MOVES
ACROSS THE STATE. SCATTERED SHOWERS MAINLY ACROSS NORTHERN
SECTIONS TONIGHT AS UPPER TROUGH SLOWLY MOVES FROM QUEBEC
EASTWARD.
STRONG SOUTHERLY LOW LEVEL JET OF 60 KTS IN ADVANCE OF THE LOW
PRESSURE WILL NOSE INTO WASHINGTON COUNTY CREATING GUSTS UP TO
35 MPH THIS MORNING. AS LOW PRESSURE MOVES INLAND THIS AFTERNOON,
LOW LEVEL JET WILL MOVE EAST OF THE REGION ALLOWING WINDS TO
DIMINISH THIS AFTERNOON. FOR NOW EXPECT WINDS TO REMAIN BELOW
ADVISORY LEVEL BUT SITUATION WILL NEED TO BE CLOSELY MONITORED
TODAY.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
THE UPPER LEVEL TROUGH WHICH IS SUPPORTING OUR STORM TODAY WILL
MOVE ACROSS THE STATE ON FRIDAY. THIS WILL BRING A MOSTLY CLOUDY
DAY WITH SHOWERS SCATTERED THROUGHOUT THE REGION. THE TROUGH WILL
WEAKEN AS IT SLOWLY MOVES TO THE EAST FRIDAY AFTERNOON. THIS MAY
ALLOW SOME BREAKS OF SUNSHINE...ESPECIALLY IN WESTERN AREAS...LATE
IN THE DAY. COOLER AIR FOLLOWING THE TROUGH WILL BRING A CLEAR TO
PARTLY CLOUDY AND COOL NIGHT FRIDAY NIGHT WITH LOWS IN THE MID 30S
IN MOST LOCATIONS. DRIER AIR FOLLOWING THE TROUGH SHOULD THEN
BRING A MOSTLY SUNNY DAY ON SATURDAY IN MOST LOCATIONS. A BIT OF
COOLER AIR POOLED ALOFT AT 850 ACROSS THE NORTH WILL LIKELY RESULT
IN SOME CUMULUS CLOUDS OVER THE NORTH. CLOUDS ARE THEN EXPECTED TO
INCREASE FROM THE WEST LATE IN THE DAY AS A SMALL DISTURBANCE
APPROACHES FROM THE GREAT LAKES REGION. SOME SHOWERS MAY AFFECT
FAR WESTERN AREAS AROUND THE END OF THE DAY WITH THE APPROACH OF
THIS DISTURBANCE.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
A FEW SHOWERS MAY BE AROUND SATURDAY NIGHT AS A WEAK DISTURBANCE
CROSSES THE AREA. WEAK HIGH PRESSURE SHOULD THEN RETURN BRINGING
DRY CONDITIONS SUNDAY INTO MONDAY. A SOUTHWESTERLY FLOW BETWEEN
HIGH PRESSURE OFF TO THE SOUTHEAST AND A LOW IN CENTRAL CANADA
SHOULD DRAW IN INCREASINGLY WARM AIR LATE THIS WEEKEND INTO EARLY
NEXT WEEK. TEMPS MONDAY AND TUESDAY MAY REACH THE 70S OVER THE
AREA. WEDNESDAY MAY BE ANOTHER VERY WARM DAY BEFORE A COLD FRONT
APPROACHES NORTHERN AREAS LATE IN THE DAY.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
NEAR TERM: IFR CONDITIONS TODAY AND TONIGHT ACROSS NORTHERN
TERMINALS. IFR CONDITIONS AT KBGR AND KBHB WILL LIFT TO MVFR
AROUND 21Z TODAY AND THEN TO VFR BETWEEN 00Z AND 03Z TONIGHT.
SHORT TERM: MVFR CONDITIONS ON FRIDAY SHOULD IMPROVE TO VFR FRIDAY
NIGHT AND REMAIN VFR ON SATURDAY. CONDITIONS MAY BRIEFLY LOWER TO
MVFR SATURDAY NIGHT THEN RETURN TO VFR SUNDAY INTO MONDAY WITH THE
POSSIBLE EXCEPTION OF SOME PATCHY FOG LATE SUNDAY NIGHT OR EARLY
MONDAY MORNING.
&&
.MARINE...
NEAR TERM: STRONG SOUTHERLY LOW LEVEL JET OF 60 KTS WILL MOVE
ACROSS EASTERN SECTIONS OF OUR WATERS THIS MORNING WITH STRONG SCA
OVER ANZ050. WINDS WILL DIMINISH THIS AFTERNOON AS JET MOVES EAST OF
OUR WATERS. SOUTHERLY SWELL WILL PERSIST TONIGHT INTO FRIDAY.
SHORT TERM: WINDS AND SEAS ARE EXPECTED TO BE BELOW SCA THROUGH
THIS WEEKEND INTO EARLY NEXT WEEK.
&&
.HYDROLOGY...
TWO TO THREE INCHES OF RAIN WILL FALL ACROSS HANCOCK AND
WASHINGTON COUNTIES THROUGH THIS AFTERNOON WITH RAIN HEAVY AT
TIMES THIS MORNING. EXCESSIVE RUNOFF FROM HEAVY RAINFALL MAY CAUSE
ELEVATED LEVELS ON SMALL BROOKS AND STREAMS AND POSSIBLE MINOR
FLOODING IN POOR DRAINAGE AREAS AND LOW LYING SPOTS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM EDT FRIDAY
FOR ANZ052.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT FRIDAY FOR ANZ050-051.
&&
$$
NEAR TERM...FOSTER
SHORT TERM...BLOOMER
LONG TERM...BLOOMER
AVIATION...FOSTER
MARINE...FOSTER/BLOOMER
HYDROLOGY...FOSTER
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
730 AM EDT THU MAY 10 2012
.SHORT TERM...(TODAY THROUGH FRIDAY NIGHT)
ISSUED AT 447 AM EDT THU MAY 10 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF MOVING ONSHORE
OVER THE PACIFIC NW/SW CANADA. DOWNSTREAM...A RIDGE EXTENDS FROM THE
ROCKIES TO HUDSON BAY. THE ASSOCIATED SFC HIGH PRES RIDGE AND DRY
AIR MASS WILL DOMINATE THE AREA TODAY. NARROW STREAK OF MID CLOUDS
CURRENTLY EXTENDING FROM FAR NE MANITOBA SSE TO NRN LAKE SUPERIOR IN
A RIBBON OF WEAK WAA/ISENTROPIC ASCENT WILL LIKELY AFFECT PORTIONS
OF THE ERN FCST AREA THIS MORNING. NAM/GFS SHOW CONDENSATION PRES
DEFICITS RISING A BIT THRU THE MORNING...SO THERE MAY BE TREND FOR
MID CLOUDS TO DIMINISH AS THEY STREAK SSE. OTHERWISE...ABUNDANT
SUNSHINE AND DRY AIR MASS TODAY WILL ALLOW FOR VERY DEEP MIXING
UPWARDS OF 750-700MB PER 00Z KINL/CWPL SOUNDINGS AND NAM/GFS FCST
SOUNDINGS. THIS YIELDS MAX TEMPS WELL INTO THE 60S/AROUND 70 W AND
LOW/MID 60S E. LAKE BREEZES WILL BE THE RULE IN THE AFTN TO PROVIDE
COOLING NEAR THE GREAT LAKES. UNDER DRY AIR MASS...AFTN RH WILL BE
LOW...FALLING INTO THE 20-30PCT RANGE. FORTUNATELY...WINDS WILL BE
ON THE LIGHT SIDE.
AS SFC HIGH PRES RIDGE DRIFTS E TONIGHT...S TO SW GRADIENT FLOW WILL
DEVELOP. BEFORE GRADIENT TIGHTENS UP A BIT...TEMPS WILL HAVE A
CHANCE TO FALL QUICKLY THIS EVENING. HOWEVER...WITH PRECIPITABLE
WATER RISING TO NEAR OR ABOVE NORMAL...TEMP FALL THIS EVENING
SHOULDN`T BE ANY MORE THAN TYPICAL. AIR MASS IS DRIER OVER THE
E...SO MIN TEMPS THERE WILL BE LOWEST...PROBABLY IN THE UPPER 30S IN
THE TRADITIONAL COLD SPOTS. OTHERWISE...40S SHOULD BE THE RULE
TONIGHT WITH THE WARMER TEMPS IN THE DOWNSLOPE AREAS OUT W.
MIDLEVEL TROF CURRENTLY MOVING ONSHORE OVER THE PACIFIC NW/SW CANADA
WILL SHIFT ACROSS THE NRN PLAINS FRI WITH ASSOCIATED COLD FRONT
MOVING INTO UPPER MI. TIMING OF FRONT IS OVERALL WELL AGREED UPON BY
THE MODELS WITH MOST SHOWING FRONT REACHING WRN UPPER MI 18-21Z AND
THEN EXTENDING FROM NE LAKE SUPERIOR TO ROUGHLY KMQT/KIMT BY 00Z.
WITH ONLY SOME HIGH CLOUDS AHEAD OF FRONT...IT WILL BE A WARM DAY AS
850MB THERMAL RIDGE OF 10-12C SHIFTS ACROSS THE AREA. MAX TEMPS
SHOULD BE WELL INTO THE 70S ACROSS THE W AND CNTRL AS STRONGER S/SW
WINDS WILL PREVENT LAKE SUPERIOR LAKE BREEZE. WARMEST TEMPS WILL BE
IN THE DOWNSLOPE AREAS...POSSIBLY REACHING 80F IF THICKER CLOUDS
HOLD OFF LONG ENOUGH. TO THE E...SRLY FLOW UP LAKE MICHIGAN WILL
KEEP THE E COOLER. TEMPS SHOULD RANGE FROM THE 50S LAKESIDE E OF
KESC TO AROUND 70 TOWARD LAKE SUPERIOR. WITH HIGHER TEMPS...AN
INCREASE IN WINDS AND RH FALLING INTO THE 30-40PCT RANGE...FIRE
CONCERNS WILL INCREASE FRI IN THOSE AREAS THAT FAILED TO RECEIVE
MUCH RAINFALL DURING THE LAST WEEK. AS FOR PCPN...NARROW RIBBON OF
MOISTURE/INSTABILITY WILL KEEP SHRA CONFINED TO A NARROW CORRIDOR
VCNTY OF FRONT. INCLUDED CHC POPS JUST AFTER 18Z W...SPREADING TO
THE ERN FCST AREA AT 00Z. WHILE THUNDER POTENTIAL IS MINIMAL WITH
GFS MLCAPES 100-200J/KG...THE NAM SHOWS MLCAPE BRIEFLY RISING TO
SEVERAL HUNDRED J/KG TOWARD THE WI BORDER...SUGGESTING THUNDER CAN`T
BE RULED OUT. THUS...OPTED TO MAINTAIN A SLIGHT CHC THUNDER MENTION.
SHRA WILL END W TO E FRI NIGHT AS SHORTWAVE/COLD FRONT MAKE STEADY
EASTWARD PROGRESS.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 447 AM EDT THU MAY 10 2012
COLD FRONT WILL BE QUICKLY EXITING THE AREA SAT MORNING...WITH
MUCH IF NOT ALL OF THE PCPN OUT OF UPPER MICHIGAN BY 12Z. DRY NW
FLOW WILL THEN BUILD OVER THE AREA ON SAT AND CONTINUE INTO SUN.
THIS DRY AIR WILL LEAD TO A MOSTLY SUNNY SKY AND PROVIDE DECENT
MIXING. THUS...EXPECT DEWPOINT VALUES TO FALL THROUGH THE
AFTN...ESPECIALLY OVER THE WRN HALF OF THE CWA. MODEL ML DEWPOINTS
ARE IN THE UPPER TEENS TO MID 20S OVER THE WEST...SO HAVE TRENDED
THAT DIRECTION AND DROPPED VALUES 3-5 DEGREES. MIXING TO H800-775
WOULD YIELD HIGHS IN THE LOW/MID 60S AWAY FROM LK SUPERIOR
INFLUENCES UNDER WNW WINDS. THE COMBINATION OF THESE TWO FACTORS
WILL PRODUCE RH VALUES AROUND 20-25 PERCENT...BUT IF BETTER MIXING
OCCURS...COULD SEE VALUES INTO THE UPPER TEENS. WITH WINDS OF
10-15 MPH THERE COULD BE SOME FIRE WX CONCERNS...BUT HOPEFULLY THE
0.1-0.15IN OF RAIN ON FRI NIGHT WILL LIMIT THEM.
SAT NIGHT...HIGH WILL STILL BE CENTERED OVER CNTRL PLAINS/ROCKIES
AND SFC RIDGE SLIDES SE INTO LOWER MI. THIS WILL KEEP A SLIGHTLY
STRONGER PRESSURE GRADIENT ACROSS THE AREA AND SHOULD KEEP LOWS
AT OR SLIGHTLY ABOVE NORMAL EVEN WITH THE CLEAR SKIES.
SUN LOOKS TO BE SIMILAR TO SAT...WITH DRY AIR STILL IN PLACE AND
PRODUCING A MOSTLY SUNNY SKY. ONCE AGAIN...DEWPOINTS ARE THE MAIN
CONCERN AND HAVE DROPPED VALUES INTO THE LOWER 30S. ML DEWPOINTS
ARE SHOWING VALUES IN THE UPPER 20S...SO THEY MAY NEED TO BE
REDUCED IF TREND CONTINUES. WITH HIGHS IN THE 60S...WILL SEE RH
VALUES DROPPING TOWARDS 25 PERCENT AGAIN.
SUN NIGHT THROUGH WED...
MODELS DIFFER IN THE HANDLING OF A SHORTWAVE ROTATING AROUND THE
UPPER LOW STATIONED OVER HUDSON BAY. 12Z ECMWF THE MOST PRONOUNCED
AND S WITH THIS WAVE MOVING THROUGH SRN CANADA AND UPPER GREAT LKS
ON SUN NIGHT...BUT THE LATE ARRIVING 00Z RUN HAS WEAKENED THIS
CONSIDERABLY. 00Z GFS/GEM SHOW WEAKER VARIATIONS OF THIS WAVE MOVING
THROUGH THE NW FLOW AND STAYING MAINLY IN SRN CANADA. PREVIOUS FCST
HAD SLIGHT CHANCES OVER NRN LK SUPERIOR AND FEEL THAT IS THE WAY TO
GO AT THIS POINT. OTHERWISE...THE REST OF THE EXTENDED FORECAST
LOOKS TO BE DOMINATED BY NW FLOW ALOFT. SFC RIDGE FROM THE CNTRL
PLAINS/ROCKIES WILL TRY TO BUILD BACK OVER THE AREA FOR MON/TUES.
THIS LEAVES THE AREA UNDER DRY AIR ALOFT AND FAIRLY LIGHT WINDS.
MODELS HINTING AT ANOTHER WEAK COLD FRONT MOVING THROUGH THE UPPER
GREAT LKS TUES NIGHT INTO WED...BUT CONFIDENCE FOR MEASURABLE
PCPN IS LOW AT THIS POINT. TEMPS SHOULD BE AT OR ABOVE NORMAL
THROUGH THE FIRST PART OF NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 728 AM EDT THU MAY 10 2012
EXPECT VFR CONDITIONS/LIGHT WINDS WITH DRY HI PRES DOMINATING THIS
FCST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 447 AM EDT THU MAY 10 2012
HIGH PRESSURE WILL COVER LAKE SUPERIOR TODAY AND LEAD TO LIGHT
WINDS. A COLD FRONT APPROACHING FROM THE NORTHERN PLAINS WILL CAUSE
WINDS TO BECOME SOUTHERLY TONIGHT AND FRIDAY...BUT THE MARINE
LAYER SHOULD KEEP WINDS BELOW 15KTS. WINDS WILL SHIFT TO THE NW
BEHIND THE FRONT ON FRIDAY NIGHT AND THEN REMAIN OUT OF THE WEST
THROUGH THE WEEKEND. MOSTLY AREAS SHOULD SEE WINDS STAY BELOW 20KTS
DURING THE WEEKEND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...SRF
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1043 AM CDT THU MAY 10 2012
.UPDATE...
MORNING FORECAST UPDATE.
&&
.DISCUSSION...
UPPER LOW CONTINUES TO CHURN AWAY IN THE S ROCKIES NEAR EL PASO
THIS MORNING AND GETTING DEEP CONVECTION ALL THROUGH THE NORTHERN
PORTIONS OF THE RIO GRANDE VALLEY INTO W TX. WEAK SFC LOW WAS
LOCATED OVER THE EDWARDS PLATEAU WITH A WARM FRONT STRETCHING FROM
NEAR JUNCTION TO GALVESTON THIS MORNING. WARM FRONT SHOULD SLOWLY
MOVE NORTHWARD THIS AFTERNOON SO INCREASED POPS A TOUCH FOR ISO
ACTIVITY ALONG THE WARM FRONT. THINK INITIAL CONVECTIVE ACTIVITY
WILL APPROACH WESTERN PORTIONS OF SE TX INTO THE BRAZOS VALLEY
LATE THIS AFTERNOON AND EVENING. THE MAIN SHOW LOOKS TO BE ON
TRACK FOR LATE TONIGHT FRI MORNING AS EXPECTING ORGANIZED
CONVECTION TO MOVE INTO THE AREA BY 12Z FRI. FLASH FLOOD THREAT
WILL BE MARGINAL FOR MUCH OF THE AREA BUT STILL CONCERNED FOR
AREAS MAINLY SOUTH OF A BRENHAM...THE WOODLANDS...BEAUMONT LINE.
THINK THIS WILL BE THE AREA FOR HIGHEST QPF ALTHOUGH AREAS NORTH
OF THAT LINE MAY STILL HAVE SIGNIFICANT RAINFALL BUT HAVE NOT HAD
MUCH IN THE WAY OF RECENT RAINFALL. WILL CONTINUE TO EVALUATE 12Z
MODEL GUIDANCE AND LOOK FOR POSSIBILITY OF FLASH FLOOD WATCH
LATER THIS AFTERNOON.
39
&&
.PREV DISCUSSION... /ISSUED 712 AM CDT THU MAY 10 2012/
DISCUSSION...
SEE AVIATION SECTION BELOW. CORRECTION FOR SOME SPELLING.
AVIATION...
MESSY GUIDANCE FOR TSRA CHANCES ACROSS AREA TAF SITES TODAY. LOTS
OF CLR TO SCT SKIES. OCNL VFR BKN DECKS AT KCLL THIS MORNING BUT
MVFR NOT EXPECTED TIL EVENING. HRRR FCST PCPN FIELDS HAD BEEN
BRING PCPN INTO METRO TAFS BY MID MORNING BUT NEWER RUNS SEEM TO
BE SLOWING DOWN WHICH IS MORE IN AGREEMENT WITH LARGER SCALE GFS
GUIDANCE AND MOS OUTPUT. THERE IS AN ADDITIONAL BOUNDARY VISIBLE
IN 3.9UM IMAGERY MOVING SOUTHWESTWARD FROM NEAR KLBX TO OFFSHORE
PLATFORM KHQI THIS MORNING. WRF AND HRRR RUNS SEEM TO DEVELOP
ADDITIONAL CONVECTION ALONG THIS BOUNDARY THIS MORNING AS WELL.
PROBLEM IS THAT 00Z NAM/GFS SOUNDINGS AGAIN HAD SKINNY CAPE. SORT OF
COMPROMISED ON TAFS WITH VCSH BEGINNING 15Z AT METRO SITES AND VCTS
MOST SITES THIS AFTERNOON. CONFIDENCE IN THIS SET OF TAFS IS LOWER
THAN AVERAGE DUE TO TIMING/OCCURRENCE OF CONVECTION ANDGUIDANCE
DISAGREEMENTS. MAY BE OVERUSING VCTS TODAY AND THIS EVENING BUT
LATER UPDATES CAN FINE TUNE THIS. ANOTHER ROUND OF TSRA EXPECTED
OVERNIGHT AND TRIED TO TIME THIS WITH 5KM WRF ANDARW OUTPUT THAT WE
LIKED...MORE CONFIDENT ON TSRAOCCURRENCE/TIMING OVERNIGHT. 04
PREV DISCUSSION... /ISSUED 541 AM CDT THU MAY 10 2012/
.LOCALLY HEAVY RAINFALL POSSIBLE TONIGHT AND FRIDAY...
DISCUSSION...
THE UPPER LOW CURRENTLY APPROACHING THE EL PASO AREA WILL MOVE
ACROSS THE STATE LATER TODAY AND FRIDAY. SE TX WILL BE UNDER A
FAVORABLE AREA FOR WIDESPREAD SHOWERS AND THUNDERSTORMS BY LATE
TONIGHT THROUGH FRIDAY. FOR THE RAINFALL POTENTIAL...LIKED THE
HIGH RESOLUTION ARW FOR TODAY AND THIS EVENING AND THE GFS
ENSEMBLE QPF OVERNIGHT TONIGHT THROUGH FRIDAY EVENING. THE GFS
THEN LOOKED REASONABLE FOR THE REMAINDER OF THE FORECAST.
FOR TODAY THE MAIN ITEM OF CONCERN WILL BE A POSSIBLE SQUALL LINE
THIS AFTERNOON. EARLY THIS MORNING...FAIRLY DRY AIR WAS IN PLACE
OVER THE NORTHERN HALF OF SE TX WHERE DEWPOINTS WERE IN THE 50S.
THIS FACT INDICATES THAT RAINFALL WILL LIKELY HOLD OFF UNTIL THIS
AFTERNOON OVER THE SOUTHERN-MOST AREAS. THE MODEL FORECAST
SOUNDINGS HAVE A SKINNY TYPE CAPE PROFILE. THE ARW MODEL SHOWS
SQUALL LINE MOVING INTO THE SOUTHWESTERN COUNTIES EARLY THIS
AFTERNOON. THESE SHOULD REACH THE CENTRAL COUNTIES AND
NORTHEASTERN COUNTIES DURING THE LATE AFTERNOON. WITH THE DRY AIR
IN THE MID LEVELS ON THE FORECAST SOUNDINGS...THE POTENTIAL FOR
STRONG OR SEVERE WILL BE MAINLY STRONG WINDS.
THE MAIN CONCERN THEN WILL BE THE POTENTIAL FOR LOCALLY HEAVY
RAINFALL TONIGHT AND FRIDAY. THE ECMWF DOES DIFFER FROM THE GFS...
HOWEVER THE GFS DOES LOOK MORE REASONABLE GIVEN THE MOVEMENT OF
THE UPPER LOW AND ITS DEVELOPMENT OF A COASTAL SURFACE TROUGH. AS
THE UPPER LOW MOVES INTO THE NORTH CENTRAL PORTION OF THE STATE
OVERNIGHT TONIGHT...MORE WIDESPREAD STORMS ARE LIKELY TO
OVERSPREAD THE WESTERN COUNTIES OF THE FORECAST AREA. RAINFALL
AND THUNDERSTORMS WILL BE WIDESPREAD ON FRIDAY AND END FRIDAY
NIGHT AND EARLY SATURDAY. THE LATEST HPC QPF LOOKS REASONABLE IN
PLACING TOTAL RAINFALL AMOUNTS FOR TONIGHT THROUGH EARLY SATURDAY
IN THE 1 TO 3 INCH RANGE. ISOLATED TOTALS OF 3 TO 5 INCHES IS
POSSIBLE.
THE FLASH FLOOD GUIDANCE IS SHOWING 6-HOUR FLASH FLOOD AMOUNTS OF
4 TO 6 INCHES. THERE WERE POCKETS OF 3 TO 5 INCHES OVER THE
COASTAL AREAS WEST OF GALVESTON BAY AND ACROSS GRIMES COUNTY.
HOWEVER...BECAUSE THE POTENTIAL FOR THE HEAVIEST RAINFALL IS ON
FRIDAY AND GIVEN THE HIGH FLASH FLOOD GUIDANCE...DECIDED TO HOLD
OFF ON A FLOOD WATCH FOR NOW. HOWEVER...ANY LOCATION WITH POOR
DRAINAGE THAT DOES RECEIVE RAINFALL APPROACHING 2 TO 3 INCHES IN
A 1 TO 2 HOUR PERIOD MAY EXPERIENCE MINOR FLOODING...ESPECIALLY
AREAS IN URBAN LOCATIONS. WILL RECONSIDER THE POTENTIAL FOR
FLOODING LATER TODAY.
40
MARINE...
EASTERLY WINDS HAVE BEGUN ONSHORE FLOW AND WILL SLOWLY VEER TODAY
AND TONIGHT. AS UPPER LOW APPROACHES FROM THE WEST PRESSURE
GRADIENT BEGINS TO TIGHT AND WINDS FRESHEN UP...RESULTS IN A SCEC
BEGINNING 18Z THIS AFTERNOON THROUGH 18Z FRIDAY FOR 15-20KT WINDS
AND GRADUALLY RISING SIG WAVE HGTS. GFS NO LONGER GENERATES NEAR
GALE FORCE WINDS AS IT DID ON PREVIOUS 00Z RUN AND IS MORE IN LINE
WITH THE REST OF THE GUIDANCE. GENERALLY WENT WITH GFS/ECMWF BLEND
THROUGH 18Z FRIDAY THEN MOSTLY GFS AFTER THAT. DROPPED SIG WAVE
HEIGHTS DOWN TO MAX 6 FEET FRIDAY MORNING PER WW3 AND SWAN
OUTPUT...NOT SURPRISING GIVEN REDUCTION IN GFS WINDS IN RECENT
MODEL RUNS. AFTER THIS MESS OF SHRA/TSRA PASSES THROUGH FRI-SAT
LIGHT TO MODERATE OFFSHORE FLOW RETURNS AND LASTS FOR A FEW DAYS.
04
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 83 64 78 62 78 / 30 80 80 50 40
HOUSTON (IAH) 85 65 78 64 81 / 20 70 80 60 40
GALVESTON (GLS) 83 70 78 70 80 / 20 60 80 60 40
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION THROUGH FRIDAY AFTERNOON FOR
THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS
FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60
NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT
20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...
WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...39
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
712 AM CDT THU MAY 10 2012
.DISCUSSION...
SEE AVIATION SECTION BELOW. CORRECTION FOR SOME SPELLING.
&&
.AVIATION...
MESSY GUIDANCE FOR TSRA CHANCES ACROSS AREA TAF SITES TODAY. LOTS
OF CLR TO SCT SKIES. OCNL VFR BKN DECKS AT KCLL THIS MORNING BUT
MVFR NOT EXPECTED TIL EVENING. HRRR FCST PCPN FIELDS HAD BEEN
BRING PCPN INTO METRO TAFS BY MID MORNING BUT NEWER RUNS SEEM TO
BE SLOWING DOWN WHICH IS MORE IN AGREEMENT WITH LARGER SCALE GFS
GUIDANCE AND MOS OUTPUT. THERE IS AN ADDITIONAL BOUNDARY VISIBLE
IN 3.9UM IMAGERY MOVING SOUTHWESTWARD FROM NEAR KLBX TO OFFSHORE
PLATFORM KHQI THIS MORNING. WRF AND HRRR RUNS SEEM TO DEVELOP
ADDITIONAL CONVECTION ALONG THIS BOUNDARY THIS MORNING AS WELL.
PROBLEM IS THAT 00Z NAM/GFS SOUNDINGS AGAIN HAD SKINNY CAPE. SORT OF
COMPROMISED ON TAFS WITH VCSH BEGINNING 15Z AT METRO SITES AND VCTS
MOST SITES THIS AFTERNOON. CONFIDENCE IN THIS SET OF TAFS IS LOWER
THAN AVERAGE DUE TO TIMING/OCCURRENCE OF CONVECTION ANDGUIDANCE
DISAGREEMENTS. MAY BE OVERUSING VCTS TODAY AND THIS EVENING BUT
LATER UPDATES CAN FINE TUNE THIS. ANOTHER ROUND OF TSRA EXPECTED
OVERNIGHT AND TRIED TO TIME THIS WITH 5KM WRF ANDARW OUTPUT THAT WE
LIKED...MORE CONFIDENT ON TSRAOCCURRENCE/TIMING OVERNIGHT. 04
&&
.PREV DISCUSSION... /ISSUED 541 AM CDT THU MAY 10 2012/
..LOCALLY HEAVY RAINFALL POSSIBLE TONIGHT AND FRIDAY...
DISCUSSION...
THE UPPER LOW CURRENTLY APPROACHING THE EL PASO AREA WILL MOVE
ACROSS THE STATE LATER TODAY AND FRIDAY. SE TX WILL BE UNDER A
FAVORABLE AREA FOR WIDESPREAD SHOWERS AND THUNDERSTORMS BY LATE
TONIGHT THROUGH FRIDAY. FOR THE RAINFALL POTENTIAL...LIKED THE
HIGH RESOLUTION ARW FOR TODAY AND THIS EVENING AND THE GFS
ENSEMBLE QPF OVERNIGHT TONIGHT THROUGH FRIDAY EVENING. THE GFS
THEN LOOKED REASONABLE FOR THE REMAINDER OF THE FORECAST.
FOR TODAY THE MAIN ITEM OF CONCERN WILL BE A POSSIBLE SQUALL LINE
THIS AFTERNOON. EARLY THIS MORNING...FAIRLY DRY AIR WAS IN PLACE
OVER THE NORTHERN HALF OF SE TX WHERE DEWPOINTS WERE IN THE 50S.
THIS FACT INDICATES THAT RAINFALL WILL LIKELY HOLD OFF UNTIL THIS
AFTERNOON OVER THE SOUTHERN-MOST AREAS. THE MODEL FORECAST
SOUNDINGS HAVE A SKINNY TYPE CAPE PROFILE. THE ARW MODEL SHOWS
SQUALL LINE MOVING INTO THE SOUTHWESTERN COUNTIES EARLY THIS
AFTERNOON. THESE SHOULD REACH THE CENTRAL COUNTIES AND
NORTHEASTERN COUNTIES DURING THE LATE AFTERNOON. WITH THE DRY AIR
IN THE MID LEVELS ON THE FORECAST SOUNDINGS...THE POTENTIAL FOR
STRONG OR SEVERE WILL BE MAINLY STRONG WINDS.
THE MAIN CONCERN THEN WILL BE THE POTENTIAL FOR LOCALLY HEAVY
RAINFALL TONIGHT AND FRIDAY. THE ECMWF DOES DIFFER FROM THE GFS...
HOWEVER THE GFS DOES LOOK MORE REASONABLE GIVEN THE MOVEMENT OF
THE UPPER LOW AND ITS DEVELOPMENT OF A COASTAL SURFACE TROUGH. AS
THE UPPER LOW MOVES INTO THE NORTH CENTRAL PORTION OF THE STATE
OVERNIGHT TONIGHT...MORE WIDESPREAD STORMS ARE LIKELY TO
OVERSPREAD THE WESTERN COUNTIES OF THE FORECAST AREA. RAINFALL
AND THUNDERSTORMS WILL BE WIDESPREAD ON FRIDAY AND END FRIDAY
NIGHT AND EARLY SATURDAY. THE LATEST HPC QPF LOOKS REASONABLE IN
PLACING TOTAL RAINFALL AMOUNTS FOR TONIGHT THROUGH EARLY SATURDAY
IN THE 1 TO 3 INCH RANGE. ISOLATED TOTALS OF 3 TO 5 INCHES IS
POSSIBLE.
THE FLASH FLOOD GUIDANCE IS SHOWING 6-HOUR FLASH FLOOD AMOUNTS OF
4 TO 6 INCHES. THERE WERE POCKETS OF 3 TO 5 INCHES OVER THE
COASTAL AREAS WEST OF GALVESTON BAY AND ACROSS GRIMES COUNTY.
HOWEVER...BECAUSE THE POTENTIAL FOR THE HEAVIEST RAINFALL IS ON
FRIDAY AND GIVEN THE HIGH FLASH FLOOD GUIDANCE...DECIDED TO HOLD
OFF ON A FLOOD WATCH FOR NOW. HOWEVER...ANY LOCATION WITH POOR
DRAINAGE THAT DOES RECEIVE RAINFALL APPROACHING 2 TO 3 INCHES IN
A 1 TO 2 HOUR PERIOD MAY EXPERIENCE MINOR FLOODING...ESPECIALLY
AREAS IN URBAN LOCATIONS. WILL RECONSIDER THE POTENTIAL FOR
FLOODING LATER TODAY.
40
MARINE...
EASTERLY WINDS HAVE BEGUN ONSHORE FLOW AND WILL SLOWLY VEER TODAY
AND TONIGHT. AS UPPER LOW APPROACHES FROM THE WEST PRESSURE
GRADIENT BEGINS TO TIGHT AND WINDS FRESHEN UP...RESULTS IN A SCEC
BEGINNING 18Z THIS AFTERNOON THROUGH 18Z FRIDAY FOR 15-20KT WINDS
AND GRADUALLY RISING SIG WAVE HGTS. GFS NO LONGER GENERATES NEAR
GALE FORCE WINDS AS IT DID ON PREVIOUS 00Z RUN AND IS MORE IN LINE
WITH THE REST OF THE GUIDANCE. GENERALLY WENT WITH GFS/ECMWF BLEND
THROUGH 18Z FRIDAY THEN MOSTLY GFS AFTER THAT. DROPPED SIG WAVE
HEIGHTS DOWN TO MAX 6 FEET FRIDAY MORNING PER WW3 AND SWAN
OUTPUT...NOT SURPRISING GIVEN REDUCTION IN GFS WINDS IN RECENT
MODEL RUNS. AFTER THIS MESS OF SHRA/TSRA PASSES THROUGH FRI-SAT
LIGHT TO MODERATE OFFSHORE FLOW RETURNS AND LASTS FOR A FEW DAYS.
04
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 83 64 78 62 78 / 30 80 80 50 40
HOUSTON (IAH) 85 65 78 64 81 / 20 70 80 60 40
GALVESTON (GLS) 83 70 78 70 80 / 20 60 80 60 40
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION FROM 1 PM CDT THIS AFTERNOON
THROUGH FRIDAY AFTERNOON FOR THE FOLLOWING ZONES: WATERS
FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60
NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT
20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...
WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...40
AVIATION/MARINE...04
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
704 AM CDT THU MAY 10 2012
.DISCUSSION...
SEE AVIATION SECTION BELOW.
&&
.AVIATION...
MESSY GUIDANCE FOR TSRA CHANCES ACROSS AREA TAF SITES TODAY. LOTS
OF CLR TO SCT SKIES. OCNL VFR BKN DECKS AT KCLL THIS MORNING BUT
MVFR NOT EXPECTED TIL EVENING. HRRR FCST PCPN FIELDS HAD BEEN
BRING PCPN INTO METRO TAFS BY MID MORNING BUT NEWER RUNS SEEM TO
BE SLOWING DOWN WHICH IS MORE IN AGREEMENT WITH LARGER SCALE GFS
GUIDANCE AND MOS OUTPUT. THERE IS AN ADDITIONAL BOUNDARY VISIBLE
IN 3.9UM IMAGERY MOVING SOUTHWESTWARD FROM NEAR KLBX TO OFFSHORE
PLATFORM KHQI THIS MORNING. WRF AND HRRR RUNS SEEM TO DEVELOP
ADDITIONAL CONVECTION ALONG THIS BOUNDARY THIS MORNING AS WELL.
PROBABLY IS THAT 00Z NAM/GFS SOUNDINGS AGAIN HAD SKINNY CAPE. SORT
OF COMPROMISED ON TAFS WITH VCSH BEGINNING 15Z AT METRO SITES AND
VCTS MOST SITES THIS AFTERNOON. CONFIDENCE IN THIS SET OF TAFS IS
LOWER THAN AVERAGE DUE TO TIMING/OCCURRENCE OF CONVECTION AND
GUIDANCE DISAGREEMENTS. MAY BE OVERUSING VCTS TODAY AND THIS
EVENIGN BUT LATER UPDATES CAN FINE TUNE THIS. ANOTHER ROUND OF
TSRA EXPECTED OVERNIGHT AND TRIED TO TIME THIS WITH 5KM WRF AND
ARW OUTPUT THAT WE LIKED...MORE CONFIDENT ON TSRA
OCCURRENCE/TIMING OVERNIGHT. 04
&&
.PREV DISCUSSION... /ISSUED 541 AM CDT THU MAY 10 2012/
..LOCALLY HEAVY RAINFALL POSSIBLE TONIGHT AND FRIDAY...
DISCUSSION...
THE UPPER LOW CURRENTLY APPROACHING THE EL PASO AREA WILL MOVE
ACROSS THE STATE LATER TODAY AND FRIDAY. SE TX WILL BE UNDER A
FAVORABLE AREA FOR WIDESPREAD SHOWERS AND THUNDERSTORMS BY LATE
TONIGHT THROUGH FRIDAY. FOR THE RAINFALL POTENTIAL...LIKED THE
HIGH RESOLUTION ARW FOR TODAY AND THIS EVENING AND THE GFS
ENSEMBLE QPF OVERNIGHT TONIGHT THROUGH FRIDAY EVENING. THE GFS
THEN LOOKED REASONABLE FOR THE REMAINDER OF THE FORECAST.
FOR TODAY THE MAIN ITEM OF CONCERN WILL BE A POSSIBLE SQUALL LINE
THIS AFTERNOON. EARLY THIS MORNING...FAIRLY DRY AIR WAS IN PLACE
OVER THE NORTHERN HALF OF SE TX WHERE DEWPOINTS WERE IN THE 50S.
THIS FACT INDICATES THAT RAINFALL WILL LIKELY HOLD OFF UNTIL THIS
AFTERNOON OVER THE SOUTHERN-MOST AREAS. THE MODEL FORECAST
SOUNDINGS HAVE A SKINNY TYPE CAPE PROFILE. THE ARW MODEL SHOWS
SQUALL LINE MOVING INTO THE SOUTHWESTERN COUNTIES EARLY THIS
AFTERNOON. THESE SHOULD REACH THE CENTRAL COUNTIES AND
NORTHEASTERN COUNTIES DURING THE LATE AFTERNOON. WITH THE DRY AIR
IN THE MID LEVELS ON THE FORECAST SOUNDINGS...THE POTENTIAL FOR
STRONG OR SEVERE WILL BE MAINLY STRONG WINDS.
THE MAIN CONCERN THEN WILL BE THE POTENTIAL FOR LOCALLY HEAVY
RAINFALL TONIGHT AND FRIDAY. THE ECMWF DOES DIFFER FROM THE GFS...
HOWEVER THE GFS DOES LOOK MORE REASONABLE GIVEN THE MOVEMENT OF
THE UPPER LOW AND ITS DEVELOPMENT OF A COASTAL SURFACE TROUGH. AS
THE UPPER LOW MOVES INTO THE NORTH CENTRAL PORTION OF THE STATE
OVERNIGHT TONIGHT...MORE WIDESPREAD STORMS ARE LIKELY TO
OVERSPREAD THE WESTERN COUNTIES OF THE FORECAST AREA. RAINFALL
AND THUNDERSTORMS WILL BE WIDESPREAD ON FRIDAY AND END FRIDAY
NIGHT AND EARLY SATURDAY. THE LATEST HPC QPF LOOKS REASONABLE IN
PLACING TOTAL RAINFALL AMOUNTS FOR TONIGHT THROUGH EARLY SATURDAY
IN THE 1 TO 3 INCH RANGE. ISOLATED TOTALS OF 3 TO 5 INCHES IS
POSSIBLE.
THE FLASH FLOOD GUIDANCE IS SHOWING 6-HOUR FLASH FLOOD AMOUNTS OF
4 TO 6 INCHES. THERE WERE POCKETS OF 3 TO 5 INCHES OVER THE
COASTAL AREAS WEST OF GALVESTON BAY AND ACROSS GRIMES COUNTY.
HOWEVER...BECAUSE THE POTENTIAL FOR THE HEAVIEST RAINFALL IS ON
FRIDAY AND GIVEN THE HIGH FLASH FLOOD GUIDANCE...DECIDED TO HOLD
OFF ON A FLOOD WATCH FOR NOW. HOWEVER...ANY LOCATION WITH POOR
DRAINAGE THAT DOES RECEIVE RAINFALL APPROACHING 2 TO 3 INCHES IN
A 1 TO 2 HOUR PERIOD MAY EXPERIENCE MINOR FLOODING...ESPECIALLY
AREAS IN URBAN LOCATIONS. WILL RECONSIDER THE POTENTIAL FOR
FLOODING LATER TODAY.
40
MARINE...
EASTERLY WINDS HAVE BEGUN ONSHORE FLOW AND WILL SLOWLY VEER TODAY
AND TONIGHT. AS UPPER LOW APPROACHES FROM THE WEST PRESSURE
GRADIENT BEGINS TO TIGHT AND WINDS FRESHEN UP...RESULTS IN A SCEC
BEGINNING 18Z THIS AFTERNOON THROUGH 18Z FRIDAY FOR 15-20KT WINDS
AND GRADUALLY RISING SIG WAVE HGTS. GFS NO LONGER GENERATES NEAR
GALE FORCE WINDS AS IT DID ON PREVIOUS 00Z RUN AND IS MORE IN LINE
WITH THE REST OF THE GUIDANCE. GENERALLY WENT WITH GFS/ECMWF BLEND
THROUGH 18Z FRIDAY THEN MOSTLY GFS AFTER THAT. DROPPED SIG WAVE
HEIGHTS DOWN TO MAX 6 FEET FRIDAY MORNING PER WW3 AND SWAN
OUTPUT...NOT SURPRISING GIVEN REDUCTION IN GFS WINDS IN RECENT
MODEL RUNS. AFTER THIS MESS OF SHRA/TSRA PASSES THROUGH FRI-SAT
LIGHT TO MODERATE OFFSHORE FLOW RETURNS AND LASTS FOR A FEW DAYS.
04
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 83 64 78 62 78 / 30 80 80 50 40
HOUSTON (IAH) 85 65 78 64 81 / 20 70 80 60 40
GALVESTON (GLS) 83 70 78 70 80 / 20 60 80 60 40
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION FROM 1 PM CDT THIS AFTERNOON
THROUGH FRIDAY AFTERNOON FOR THE FOLLOWING ZONES: WATERS
FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60
NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT
20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...
WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...40
AVIATION/MARINE...04
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
638 AM CDT THU MAY 10 2012
.AVIATION...
DIFFICULT TAF FOR KLBB TODAY/TONIGHT AS THE TERMINAL MAY BE IMPACTED BY
ONE OR MORE ROUNDS OF SHRA AND/OR TSRA...BUT CONFIDENCE IN
OCCURANCE AND TIMING IS LOW. WILL INCLUDE A TEMPO FOR -TSRA THIS
MORNING BUT LEAVE THE REMAINDER OF THE PERIOD VFR FOR NOW. MVFR
CEILINGS ARE ALSO POSSIBLE LATE TONIGHT. KCDS SHOULD BE VFR UNTIL
POSSIBLY LATER THIS EVENING WHEN SHRA/TSRA COULD APPROACH THAT
TERMINAL AS WELL.
&&
.PREV DISCUSSION... /ISSUED 529 AM CDT THU MAY 10 2012/
UPDATE...
A BROAD AREA OF SHOWERS AND THUNDERSTORMS...SOME WITH HEAVY
RAINFALL RATES...ARE MOVING NORTH ACROSS THE WRN PERMIAN BASIN.
THE LATEST HRRR SUGGESTS THIS ACTIVITY WILL PINWHEEL NORTHWESTWARD
AROUND THE BROAD CYCLONIC CIRCULATION OF THE UPPER-LOW. THIS
SHOULD BRING THE ACTIVITY SQUARELY ACROSS COCHRAN...YOAKUM AND
TERRY COUNTIES...WITH A MORE GLANCING BLOW TO LUBBOCK...LYNN AND
HOCKLEY...AND POSSIBLY BAILEY COUNTIES. WE HAVE UPPED POPS AND QPF
FOR THESE AREAS. QUICK RAINFALL OF AN INCH OR SO IS POSSIBLE
ACROSS YOAKUM AND SRN TERRY COUNTIES AND COULD CAUSE SOME MINOR
FLOODING ISSUES.
PREV DISCUSSION... /ISSUED 334 AM CDT THU MAY 10 2012/
SHORT TERM...
THE UPPER-LOW AS SEEN IN SAT. IMAGERY IS MOVING SLOWLY EAST ACROSS
NRN MEXICO THIS MORNING. A BROAD AREA OF LIFT ON THE NORTHERN AND
EASTERN FLANKS OF THE LOW IS SUPPORTING SCATTERED TSTM ACTIVITY
WHICH AT 230 AM WAS CONCENTRATED ACROSS THE TRANS-PECOS AND WESTERN
PERMIAN BASIN...WHICH APPEARS TO BE ENHANCED BY MOISTURE
ADVECTION/LIFT ON A 20 KT SRLY LLJ. MOST MODEL OUTPUT DOES NOT HAVE
A GREAT HANDLE ON THE LOCATION AND EXTENT OF THE CURRENT
ACTIVITY...WHICH IS ALREADY MOVING INTO GAINES COUNTY...AND APPEARS
LIKELY TO MOVE INTO YOAKUM AND POSSIBLY TERRY COUNTIES SHORTLY AFTER
3 AM. THE MAIN FORECAST PROBLEM FOR TODAY WILL BE COVERAGE...TIMING
AND INTENSITY OF PRECIP WITH THIS SYSTEM AS IT MOVES OVER SW TX THIS
AFTN...AND THEN SWINGS NEWD INTO CENTRAL TX THIS EVENING.
OVERALL...THE TRACK FAVORS OUR SW ZONES WITH THE HIGHEST POPS THIS
MORNING....SRN AREAS THIS AFTERNOON...AND THEN EASTERN AREAS THIS
EVENING. THERE MAY BE A FAIRLY ABRUPT CUTOFF TO THE PRECIP SOMEWHERE
ACROSS THE CENTRAL OR NORTHERN ZONES...BUT WE HAVE KEPT A SLIGHT
CHANCE GOING ACROSS MOST OF THE FAR SRN PANHANDLE THIS AFTN AND EVE
BECAUSE IT IS DIFFICULT TO DETERMINE JUST WHERE THAT CUTOFF MAY LIE.
PROGS OF CAPE GENERALLY SHOW SOMEWHERE BETWEEN 400-800 J/KG MAY BE
PRESENT ACROSS THE THE AREA TODAY...WHEN COUPLED WITH WEAK
DEEP-LAYER SHEAR THIS SHOULD BE SUFFICIENT FOR EMBEDDED TSTMS IN THE
SHOWER ACTIVITY BUT LIKELY KEEP THE SVR POTENTIAL VERY LOW. RAINFALL
AMOUNTS ARE LIKELY TO BE MAXIMIZED ACROSS THE SRN ZONES. FORECAST
PWATS CLIMB TO ABOUT 1.25 INCHES ACROSS THE ROLLING PLAINS THIS
EVENING AND WITH THE CYCLONIC FLOW FEEDING DEEPER MOISTURE INTO THAT
AREA AN INCH OR SO OF RAINFALL IS POSSIBLE. OVERALL...IT APPEARS
THAT THE THREAT OF EXCESSIVE RAINFALL WILL REMAIN WELL OFF TO OUR
SOUTHEAST HOWEVER SOME LOCALLY HEAVIER AMOUNTS COULD CAUSE SOME
MINOR FLOODING ISSUES...WITH THE AREAS OF CONCERN MAINLY SRN YOAKUM
AND TERRY COUNTIES THIS MORNING /WHERE THEY SAW POCKETS OF HEAVY
RAINFALL MONDAY/ AND THEN THE SRN ROLLING PLAINS THIS EVENING. WITH
MORE EXTENSIVE CLOUD COVER ACROSS THE WEST AND SOUTH...WE EXPECT
TEMPS TODAY TO BE SOMEWHAT COOLER THAN YESTERDAY...RANGING FROM
HIGHS NEAR 70F IN THE SOUTHWEST TO LOWER 80S IN THE NE.
LONG TERM...
ADDITIONAL CHANCES FOR MEASURABLE RAINFALL WILL BE COMING UP IN
THE LONG TERM FORECAST.
PRECIPITATION WILL CONTINUE THROUGH THE DAY ON FRIDAY. AN AREA OF
DEFORMATION WILL MOVE OVER THE AREA ON THE NORTH AND WEST SIDE OF
THE SLOW MOVING UPPER LEVEL LOW. THE LOW WILL TRACK OVER THE
SOUTHERN ROLLING PLAINS DURING THE DAY ON FRIDAY. THE NAM/SREF
SOLUTIONS STILL TAKE THE LOW FARTHER SOUTH ON FRIDAY AND SATURDAY THAN
ALL OTHER MODEL SOLUTIONS. HEAVY RAIN WILL LIKELY BE A RESULT OF
THIS SLOW MOVING UPPER LOW. UNFORTUNATELY...MOST OF THIS HEAVY
RAIN WILL BE SOUTH OF THE AREA. PRECIPITATION PROCESSES ARE
EXPECTED TO BE VERY EFFICIENT WITH NEARLY SATURATED
SOUNDINGS...ESPECIALLY OFF THE CAPROCK. BEST CHANCES FOR THE FA
WILL BE OVER THE SOUTHERN ROLLING PLAINS.
A FRONT WILL THEN BACK DOOR INTO THE AREA SATURDAY SETTING UP
MOIST UPSLOPE FLOW THROUGH AT LEAST EARLY NEXT WEEK. THE AXIS OF A
SHARP UPPER LEVEL WAVE WILL MOVE SOUTH THROUGH THE ROCKIES FROM
SUNDAY THROUGH MONDAY. THIS WILL BE OUR NEXT SHOT AT PRECIPITATION
WITH NORTHWEST FLOW STORMS DEVELOPING EACH EVENING. THE BEST
CHANCES AT THE MOMENT APPEAR TO BE ON SUNDAY AND MONDAY EVENING
WHEN UPPER LEVEL LIFT WILL BE IN THE AREA. SATURDAY WILL SEE LESS
OF A CHANCE OF PRECIPITATION WITH UPPER LEVEL LIFT LACKING. HAVE
SIDED MORE WITH THE ECMWF SOLUTION GIVEN ITS CONSISTENT MODEL RUNS
OPPOSED TO THE GFS. ADDITIONALLY...THE GFS APPEARS TO BE SUFFERING
FROM SEVERE CONVECTIVE FEEDBACK DURING THIS TIME PERIOD.
FURTHERMORE...A QUICK GLANCE AT ANALOG GUIDANCE SHOWS HIGH
PROBABILITIES FOR SEVERE WEATHER WITH THIS NEXT SHOT OF
THUNDERSTORMS. JDV
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 75 49 70 49 70 / 20 20 20 10 10
TULIA 77 52 68 50 72 / 20 20 30 10 10
PLAINVIEW 75 52 67 50 72 / 20 20 30 10 10
LEVELLAND 71 51 72 53 75 / 40 30 30 10 10
LUBBOCK 73 52 70 51 74 / 30 30 40 10 10
DENVER CITY 69 51 75 53 75 / 80 30 30 10 10
BROWNFIELD 70 52 73 54 76 / 70 30 30 10 10
CHILDRESS 81 57 68 56 75 / 10 30 40 10 10
SPUR 75 54 69 53 76 / 30 40 50 10 10
ASPERMONT 76 56 72 57 76 / 30 60 60 10 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
33
AREA FORECAST DISCUSSION...UPDATED
NWS LUBBOCK TX
529 AM CDT THU MAY 10 2012
.UPDATE...
A BROAD AREA OF SHOWERS AND THUNDERSTORMS...SOME WITH HEAVY
RAINFALL RATES...ARE MOVING NORTH ACROSS THE WRN PERMIAN BASIN.
THE LATEST HRRR SUGGESTS THIS ACTIVITY WILL PINWHEEL NORTHWESTWARD
AROUND THE BROAD CYCLONIC CIRCULATION OF THE UPPER-LOW. THIS
SHOULD BRING THE ACTIVITY SQUARELY ACROSS COCHRAN...YOAKUM AND
TERRY COUNTIES...WITH A MORE GLANCING BLOW TO LUBBOCK...LYNN AND
HOCKLEY...AND POSSIBLY BAILEY COUNTIES. WE HAVE UPPED POPS AND QPF
FOR THESE AREAS. QUICK RAINFALL OF AN INCH OR SO IS POSSIBLE
ACROSS YOAKUM AND SRN TERRY COUNTIES AND COULD CAUSE SOME MINOR
FLOODING ISSUES.
&&
.PREV DISCUSSION... /ISSUED 334 AM CDT THU MAY 10 2012/
SHORT TERM...
THE UPPER-LOW AS SEEN IN SAT. IMAGERY IS MOVING SLOWLY EAST ACROSS
NRN MEXICO THIS MORNING. A BROAD AREA OF LIFT ON THE NORTHERN AND
EASTERN FLANKS OF THE LOW IS SUPPORTING SCATTERED TSTM ACTIVITY
WHICH AT 230 AM WAS CONCENTRATED ACROSS THE TRANS-PECOS AND WESTERN
PERMIAN BASIN...WHICH APPEARS TO BE ENHANCED BY MOISTURE
ADVECTION/LIFT ON A 20 KT SRLY LLJ. MOST MODEL OUTPUT DOES NOT HAVE
A GREAT HANDLE ON THE LOCATION AND EXTENT OF THE CURRENT
ACTIVITY...WHICH IS ALREADY MOVING INTO GAINES COUNTY...AND APPEARS
LIKELY TO MOVE INTO YOAKUM AND POSSIBLY TERRY COUNTIES SHORTLY AFTER
3 AM. THE MAIN FORECAST PROBLEM FOR TODAY WILL BE COVERAGE...TIMING
AND INTENSITY OF PRECIP WITH THIS SYSTEM AS IT MOVES OVER SW TX THIS
AFTN...AND THEN SWINGS NEWD INTO CENTRAL TX THIS EVENING.
OVERALL...THE TRACK FAVORS OUR SW ZONES WITH THE HIGHEST POPS THIS
MORNING....SRN AREAS THIS AFTERNOON...AND THEN EASTERN AREAS THIS
EVENING. THERE MAY BE A FAIRLY ABRUPT CUTOFF TO THE PRECIP SOMEWHERE
ACROSS THE CENTRAL OR NORTHERN ZONES...BUT WE HAVE KEPT A SLIGHT
CHANCE GOING ACROSS MOST OF THE FAR SRN PANHANDLE THIS AFTN AND EVE
BECAUSE IT IS DIFFICULT TO DETERMINE JUST WHERE THAT CUTOFF MAY LIE.
PROGS OF CAPE GENERALLY SHOW SOMEWHERE BETWEEN 400-800 J/KG MAY BE
PRESENT ACROSS THE THE AREA TODAY...WHEN COUPLED WITH WEAK
DEEP-LAYER SHEAR THIS SHOULD BE SUFFICIENT FOR EMBEDDED TSTMS IN THE
SHOWER ACTIVITY BUT LIKELY KEEP THE SVR POTENTIAL VERY LOW. RAINFALL
AMOUNTS ARE LIKELY TO BE MAXIMIZED ACROSS THE SRN ZONES. FORECAST
PWATS CLIMB TO ABOUT 1.25 INCHES ACROSS THE ROLLING PLAINS THIS
EVENING AND WITH THE CYCLONIC FLOW FEEDING DEEPER MOISTURE INTO THAT
AREA AN INCH OR SO OF RAINFALL IS POSSIBLE. OVERALL...IT APPEARS
THAT THE THREAT OF EXCESSIVE RAINFALL WILL REMAIN WELL OFF TO OUR
SOUTHEAST HOWEVER SOME LOCALLY HEAVIER AMOUNTS COULD CAUSE SOME
MINOR FLOODING ISSUES...WITH THE AREAS OF CONCERN MAINLY SRN YOAKUM
AND TERRY COUNTIES THIS MORNING /WHERE THEY SAW POCKETS OF HEAVY
RAINFALL MONDAY/ AND THEN THE SRN ROLLING PLAINS THIS EVENING. WITH
MORE EXTENSIVE CLOUD COVER ACROSS THE WEST AND SOUTH...WE EXPECT
TEMPS TODAY TO BE SOMEWHAT COOLER THAN YESTERDAY...RANGING FROM
HIGHS NEAR 70F IN THE SOUTHWEST TO LOWER 80S IN THE NE.
LONG TERM...
ADDITIONAL CHANCES FOR MEASURABLE RAINFALL WILL BE COMING UP IN
THE LONG TERM FORECAST.
PRECIPITATION WILL CONTINUE THROUGH THE DAY ON FRIDAY. AN AREA OF
DEFORMATION WILL MOVE OVER THE AREA ON THE NORTH AND WEST SIDE OF
THE SLOW MOVING UPPER LEVEL LOW. THE LOW WILL TRACK OVER THE
SOUTHERN ROLLING PLAINS DURING THE DAY ON FRIDAY. THE NAM/SREF
SOLUTIONS STILL TAKE THE LOW FARTHER SOUTH ON FRIDAY AND SATURDAY THAN
ALL OTHER MODEL SOLUTIONS. HEAVY RAIN WILL LIKELY BE A RESULT OF
THIS SLOW MOVING UPPER LOW. UNFORTUNATELY...MOST OF THIS HEAVY
RAIN WILL BE SOUTH OF THE AREA. PRECIPITATION PROCESSES ARE
EXPECTED TO BE VERY EFFICIENT WITH NEARLY SATURATED
SOUNDINGS...ESPECIALLY OFF THE CAPROCK. BEST CHANCES FOR THE FA
WILL BE OVER THE SOUTHERN ROLLING PLAINS.
A FRONT WILL THEN BACK DOOR INTO THE AREA SATURDAY SETTING UP
MOIST UPSLOPE FLOW THROUGH AT LEAST EARLY NEXT WEEK. THE AXIS OF A
SHARP UPPER LEVEL WAVE WILL MOVE SOUTH THROUGH THE ROCKIES FROM
SUNDAY THROUGH MONDAY. THIS WILL BE OUR NEXT SHOT AT PRECIPITATION
WITH NORTHWEST FLOW STORMS DEVELOPING EACH EVENING. THE BEST
CHANCES AT THE MOMENT APPEAR TO BE ON SUNDAY AND MONDAY EVENING
WHEN UPPER LEVEL LIFT WILL BE IN THE AREA. SATURDAY WILL SEE LESS
OF A CHANCE OF PRECIPITATION WITH UPPER LEVEL LIFT LACKING. HAVE
SIDED MORE WITH THE ECMWF SOLUTION GIVEN ITS CONSISTENT MODEL RUNS
OPPOSED TO THE GFS. ADDITIONALLY...THE GFS APPEARS TO BE SUFFERING
FROM SEVERE CONVECTIVE FEEDBACK DURING THIS TIME PERIOD.
FURTHERMORE...A QUICK GLANCE AT ANALOG GUIDANCE SHOWS HIGH
PROBABILITIES FOR SEVERE WEATHER WITH THIS NEXT SHOT OF
THUNDERSTORMS. JDV
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 75 49 70 49 70 / 20 20 20 10 10
TULIA 77 52 68 50 72 / 20 20 30 10 10
PLAINVIEW 75 52 67 50 72 / 20 20 30 10 10
LEVELLAND 71 51 72 53 75 / 40 30 30 10 10
LUBBOCK 73 52 70 51 74 / 30 30 40 10 10
DENVER CITY 69 51 75 53 75 / 80 30 30 10 10
BROWNFIELD 70 52 73 54 76 / 70 30 30 10 10
CHILDRESS 81 57 68 56 75 / 10 30 40 10 10
SPUR 75 54 69 53 76 / 30 40 50 10 10
ASPERMONT 76 56 72 57 76 / 30 60 60 10 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
33
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
454 PM EDT THU MAY 10 2012
.SHORT TERM...(TODAY THROUGH FRIDAY NIGHT)
ISSUED AT 447 AM EDT THU MAY 10 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF MOVING ONSHORE
OVER THE PACIFIC NW/SW CANADA. DOWNSTREAM...A RIDGE EXTENDS FROM THE
ROCKIES TO HUDSON BAY. THE ASSOCIATED SFC HIGH PRES RIDGE AND DRY
AIR MASS WILL DOMINATE THE AREA TODAY. NARROW STREAK OF MID CLOUDS
CURRENTLY EXTENDING FROM FAR NE MANITOBA SSE TO NRN LAKE SUPERIOR IN
A RIBBON OF WEAK WAA/ISENTROPIC ASCENT WILL LIKELY AFFECT PORTIONS
OF THE ERN FCST AREA THIS MORNING. NAM/GFS SHOW CONDENSATION PRES
DEFICITS RISING A BIT THRU THE MORNING...SO THERE MAY BE TREND FOR
MID CLOUDS TO DIMINISH AS THEY STREAK SSE. OTHERWISE...ABUNDANT
SUNSHINE AND DRY AIR MASS TODAY WILL ALLOW FOR VERY DEEP MIXING
UPWARDS OF 750-700MB PER 00Z KINL/CWPL SOUNDINGS AND NAM/GFS FCST
SOUNDINGS. THIS YIELDS MAX TEMPS WELL INTO THE 60S/AROUND 70 W AND
LOW/MID 60S E. LAKE BREEZES WILL BE THE RULE IN THE AFTN TO PROVIDE
COOLING NEAR THE GREAT LAKES. UNDER DRY AIR MASS...AFTN RH WILL BE
LOW...FALLING INTO THE 20-30PCT RANGE. FORTUNATELY...WINDS WILL BE
ON THE LIGHT SIDE.
AS SFC HIGH PRES RIDGE DRIFTS E TONIGHT...S TO SW GRADIENT FLOW WILL
DEVELOP. BEFORE GRADIENT TIGHTENS UP A BIT...TEMPS WILL HAVE A
CHANCE TO FALL QUICKLY THIS EVENING. HOWEVER...WITH PRECIPITABLE
WATER RISING TO NEAR OR ABOVE NORMAL...TEMP FALL THIS EVENING
SHOULDN`T BE ANY MORE THAN TYPICAL. AIR MASS IS DRIER OVER THE
E...SO MIN TEMPS THERE WILL BE LOWEST...PROBABLY IN THE UPPER 30S IN
THE TRADITIONAL COLD SPOTS. OTHERWISE...40S SHOULD BE THE RULE
TONIGHT WITH THE WARMER TEMPS IN THE DOWNSLOPE AREAS OUT W.
MIDLEVEL TROF CURRENTLY MOVING ONSHORE OVER THE PACIFIC NW/SW CANADA
WILL SHIFT ACROSS THE NRN PLAINS FRI WITH ASSOCIATED COLD FRONT
MOVING INTO UPPER MI. TIMING OF FRONT IS OVERALL WELL AGREED UPON BY
THE MODELS WITH MOST SHOWING FRONT REACHING WRN UPPER MI 18-21Z AND
THEN EXTENDING FROM NE LAKE SUPERIOR TO ROUGHLY KMQT/KIMT BY 00Z.
WITH ONLY SOME HIGH CLOUDS AHEAD OF FRONT...IT WILL BE A WARM DAY AS
850MB THERMAL RIDGE OF 10-12C SHIFTS ACROSS THE AREA. MAX TEMPS
SHOULD BE WELL INTO THE 70S ACROSS THE W AND CNTRL AS STRONGER S/SW
WINDS WILL PREVENT LAKE SUPERIOR LAKE BREEZE. WARMEST TEMPS WILL BE
IN THE DOWNSLOPE AREAS...POSSIBLY REACHING 80F IF THICKER CLOUDS
HOLD OFF LONG ENOUGH. TO THE E...SRLY FLOW UP LAKE MICHIGAN WILL
KEEP THE E COOLER. TEMPS SHOULD RANGE FROM THE 50S LAKESIDE E OF
KESC TO AROUND 70 TOWARD LAKE SUPERIOR. WITH HIGHER TEMPS...AN
INCREASE IN WINDS AND RH FALLING INTO THE 30-40PCT RANGE...FIRE
CONCERNS WILL INCREASE FRI IN THOSE AREAS THAT FAILED TO RECEIVE
MUCH RAINFALL DURING THE LAST WEEK. AS FOR PCPN...NARROW RIBBON OF
MOISTURE/INSTABILITY WILL KEEP SHRA CONFINED TO A NARROW CORRIDOR
VCNTY OF FRONT. INCLUDED CHC POPS JUST AFTER 18Z W...SPREADING TO
THE ERN FCST AREA AT 00Z. WHILE THUNDER POTENTIAL IS MINIMAL WITH
GFS MLCAPES 100-200J/KG...THE NAM SHOWS MLCAPE BRIEFLY RISING TO
SEVERAL HUNDRED J/KG TOWARD THE WI BORDER...SUGGESTING THUNDER CAN`T
BE RULED OUT. THUS...OPTED TO MAINTAIN A SLIGHT CHC THUNDER MENTION.
SHRA WILL END W TO E FRI NIGHT AS SHORTWAVE/COLD FRONT MAKE STEADY
EASTWARD PROGRESS.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 452 PM EDT THU MAY 10 2012
SHRA WILL END W TO E FRI NIGHT AS SHORTWAVE/COLD FRONT MAKE STEADY
EASTWARD PROGRESS AND RDG BUILDS IN FROM THE WEST.
COLD FRONT WILL BE EAST OF THE CWA BY 12Z SAT SO HAVE REMOVED POPS
AND PCPN FROM SAT FCST. VERY DRY AIRMASS ASSOC WITH SFC RDG WILL
THEN BUILD OVER THE AREA ON SAT AND CONTINUE INTO SUN LEADING TO LOW
MIN RH/S AND ELEVATED FIRE WEATHER CONCERNS OVER THE WEEKEND. THE
DRY AIR WILL RESULT IN MOSTLY SUNNY SKIES OVER THE WEEKEND AND DEEP
DAYTIME MIXING TO H775 AND POSSIBLY H750. EXPECT DEWPOINT VALUES TO
FALL THROUGH THE AFTN ON SAT AND SUN AS DRIER AIR MIXES TO THE
SFC...ESPECIALLY OVER THE WRN HALF OF THE CWA. MODEL ML DEWPOINTS
ARE IN THE MID TEENS TO LOWER 20S OVER THE WEST ON SAT AND IN THE
MID 20S ON SUNDAY WHILE DEWPOINTS DROP INTO LOWER 30S BOTH DAYS
EAST...SO HAVE CONTINUED THE DOWNWARD TREND IN DEW POINTS FOR GRIDS
OVER BOTH DAYS. THE COMBINATION OF LOWERING DEW POINTS AND HIGH
TEMPS REACHING INTO THE MID 60S AWAY FROM LAKE SUPERIOR WILL PRODUCE
RH VALUES ON SAT BTWN 20-25 PERCENT AND PERHAPS EVEN THE UPPER TEENS
WEST. WITH NW WINDS OF 10-15 MPH THERE COULD BE SOME FIRE WX
CONCERNS...BUT HOPEFULLY THE 0.1 INCH OF RAIN ON FRI NIGHT WILL HELP
LIMIT THEM. FIRE WX CONCERNS WILL CONTINUE ON SUNDAY AS THE
COMBINATION OF HIGH TEMPS IN THE UPPER 60S AND LOWER 70S AND DEW
POINTS LOWERING TO MID 20S COULD DRIVE RH/S AGAIN INTO THE 20-25 PCT
RANGE AND MAYBE EVEN UPPER TEENS AT SOME WRN LOCATIONS.
SHORTWAVE ASSOC WITH THE UPPER LOW NEAR HUDSON BAY LOOKS TO STAY
GENERALLY WELL NORTH OF THE FCST AREA ON SUNDAY AND SUNDAY NIGHT PER
MODEL CONSENSUS SO WILL GO WITH DRY FCST FOR THIS TIME FRAME.
MODELS DIFFER ON TIMING OF WEAK SHORTWAVE/S MOVING THROUGH UPPER
GREAT LAKES IN NW FLOW FOR TUE THROUGH THU TIME FRAME. CONFIDENCE
FOR MEASURABLE PCPN IS LOW AT THIS POINT SO HAVE NO MORE THAN SLIGHT
CHC POPS IN FCST FOR TUE NIGHT INTO THU.
TEMPS SHOULD BE AT OR ABOVE NORMAL THROUGH THE EARLY PART OF NEXT
WEEK WITH A TEMPORARY COOL DOWN BY TUE/WED AND THEN WARMING UP ABV
NORMAL FOR THE END OF THE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 152 PM EDT THU MAY 10 2012
SFC HIGH PRESSURE OVER EASTERN UPPER MI WILL CONTINUE TO MOVE EAST
THIS AFTERNOON...ALLOWING FOR LIGHT WINDS AND LAKE BREEZE
DEVELOPMENT AT ALL SITES. HIGH-BASED CUMULUS FIELD SHOULD LINGER AT
IWD AND SAW BEFORE DISSIPATING EARLY THIS EVENING WITH LOSS OF
HEATING. PRESSURE GRADIENT THEN INCREASES OVERNIGHT AHEAD OF AN
APPROACHING COLD FRONT...RESULTING IN INCREASING WINDS FROM WEST TO
EAST. FRIDAY LOOKS TO HAVE FAIRLY DEEP MIXING...SO WINDS MAY GUST
OVER 20 KTS AT TIMES. A SLIGHT MOISTURE SURGE JUST BELOW H8 AROUND
IWD IN THE MORNING...AND SAW IN THE AFTERNOON...WILL BRING IN SOME
LOWER CLOUDS...BUT CONDITIONS SHOULD REMAIN JUST ABOVE VFR. RIGHT AT
THE END OF THE TAF PERIOD...THE COLD FRONT SHOULD REACH IWD WITH
QUICKLY FALLING CIGS. THE TREND WILL BE THE SAME DURING THE
AFTERNOON HOURS AT CMX.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 452 PM EDT THU MAY 10 2012
HIGH PRESSURE WILL REMAIN OVR MOST OF LK SUPERIOR TONIGHT LEADING TO
LIGHT WINDS. A COLD FRONT APPROACHING FROM THE NORTHERN PLAINS WILL
CAUSE WINDS TO BECOME SOUTHERLY LATE TONIGHT AND FRIDAY...BUT THE
MARINE LAYER SHOULD KEEP WINDS MOSTLY BELOW 15KTS. WINDS WILL SHIFT
TO THE NW BEHIND THE FRONT ON FRIDAY NIGHT AND THEN REMAIN OUT OF
THE WEST THROUGH THE WEEKEND. MOST AREAS SHOULD SEE WINDS STAY BELOW
20KTS DURING THE WEEKEND. WINDS SHOULD REMAIN LESS THAN 20 KTS INTO
MIDDLE PART OF NEXT WEEK AS HIGH PRESSURE IS OVER THE LK SUPERIOR
REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...VOSS
AVIATION...TK
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
152 PM EDT THU MAY 10 2012
.SHORT TERM...(TODAY THROUGH FRIDAY NIGHT)
ISSUED AT 447 AM EDT THU MAY 10 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF MOVING ONSHORE
OVER THE PACIFIC NW/SW CANADA. DOWNSTREAM...A RIDGE EXTENDS FROM THE
ROCKIES TO HUDSON BAY. THE ASSOCIATED SFC HIGH PRES RIDGE AND DRY
AIR MASS WILL DOMINATE THE AREA TODAY. NARROW STREAK OF MID CLOUDS
CURRENTLY EXTENDING FROM FAR NE MANITOBA SSE TO NRN LAKE SUPERIOR IN
A RIBBON OF WEAK WAA/ISENTROPIC ASCENT WILL LIKELY AFFECT PORTIONS
OF THE ERN FCST AREA THIS MORNING. NAM/GFS SHOW CONDENSATION PRES
DEFICITS RISING A BIT THRU THE MORNING...SO THERE MAY BE TREND FOR
MID CLOUDS TO DIMINISH AS THEY STREAK SSE. OTHERWISE...ABUNDANT
SUNSHINE AND DRY AIR MASS TODAY WILL ALLOW FOR VERY DEEP MIXING
UPWARDS OF 750-700MB PER 00Z KINL/CWPL SOUNDINGS AND NAM/GFS FCST
SOUNDINGS. THIS YIELDS MAX TEMPS WELL INTO THE 60S/AROUND 70 W AND
LOW/MID 60S E. LAKE BREEZES WILL BE THE RULE IN THE AFTN TO PROVIDE
COOLING NEAR THE GREAT LAKES. UNDER DRY AIR MASS...AFTN RH WILL BE
LOW...FALLING INTO THE 20-30PCT RANGE. FORTUNATELY...WINDS WILL BE
ON THE LIGHT SIDE.
AS SFC HIGH PRES RIDGE DRIFTS E TONIGHT...S TO SW GRADIENT FLOW WILL
DEVELOP. BEFORE GRADIENT TIGHTENS UP A BIT...TEMPS WILL HAVE A
CHANCE TO FALL QUICKLY THIS EVENING. HOWEVER...WITH PRECIPITABLE
WATER RISING TO NEAR OR ABOVE NORMAL...TEMP FALL THIS EVENING
SHOULDN`T BE ANY MORE THAN TYPICAL. AIR MASS IS DRIER OVER THE
E...SO MIN TEMPS THERE WILL BE LOWEST...PROBABLY IN THE UPPER 30S IN
THE TRADITIONAL COLD SPOTS. OTHERWISE...40S SHOULD BE THE RULE
TONIGHT WITH THE WARMER TEMPS IN THE DOWNSLOPE AREAS OUT W.
MIDLEVEL TROF CURRENTLY MOVING ONSHORE OVER THE PACIFIC NW/SW CANADA
WILL SHIFT ACROSS THE NRN PLAINS FRI WITH ASSOCIATED COLD FRONT
MOVING INTO UPPER MI. TIMING OF FRONT IS OVERALL WELL AGREED UPON BY
THE MODELS WITH MOST SHOWING FRONT REACHING WRN UPPER MI 18-21Z AND
THEN EXTENDING FROM NE LAKE SUPERIOR TO ROUGHLY KMQT/KIMT BY 00Z.
WITH ONLY SOME HIGH CLOUDS AHEAD OF FRONT...IT WILL BE A WARM DAY AS
850MB THERMAL RIDGE OF 10-12C SHIFTS ACROSS THE AREA. MAX TEMPS
SHOULD BE WELL INTO THE 70S ACROSS THE W AND CNTRL AS STRONGER S/SW
WINDS WILL PREVENT LAKE SUPERIOR LAKE BREEZE. WARMEST TEMPS WILL BE
IN THE DOWNSLOPE AREAS...POSSIBLY REACHING 80F IF THICKER CLOUDS
HOLD OFF LONG ENOUGH. TO THE E...SRLY FLOW UP LAKE MICHIGAN WILL
KEEP THE E COOLER. TEMPS SHOULD RANGE FROM THE 50S LAKESIDE E OF
KESC TO AROUND 70 TOWARD LAKE SUPERIOR. WITH HIGHER TEMPS...AN
INCREASE IN WINDS AND RH FALLING INTO THE 30-40PCT RANGE...FIRE
CONCERNS WILL INCREASE FRI IN THOSE AREAS THAT FAILED TO RECEIVE
MUCH RAINFALL DURING THE LAST WEEK. AS FOR PCPN...NARROW RIBBON OF
MOISTURE/INSTABILITY WILL KEEP SHRA CONFINED TO A NARROW CORRIDOR
VCNTY OF FRONT. INCLUDED CHC POPS JUST AFTER 18Z W...SPREADING TO
THE ERN FCST AREA AT 00Z. WHILE THUNDER POTENTIAL IS MINIMAL WITH
GFS MLCAPES 100-200J/KG...THE NAM SHOWS MLCAPE BRIEFLY RISING TO
SEVERAL HUNDRED J/KG TOWARD THE WI BORDER...SUGGESTING THUNDER CAN`T
BE RULED OUT. THUS...OPTED TO MAINTAIN A SLIGHT CHC THUNDER MENTION.
SHRA WILL END W TO E FRI NIGHT AS SHORTWAVE/COLD FRONT MAKE STEADY
EASTWARD PROGRESS.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 447 AM EDT THU MAY 10 2012
COLD FRONT WILL BE QUICKLY EXITING THE AREA SAT MORNING...WITH
MUCH IF NOT ALL OF THE PCPN OUT OF UPPER MICHIGAN BY 12Z. DRY NW
FLOW WILL THEN BUILD OVER THE AREA ON SAT AND CONTINUE INTO SUN.
THIS DRY AIR WILL LEAD TO A MOSTLY SUNNY SKY AND PROVIDE DECENT
MIXING. THUS...EXPECT DEWPOINT VALUES TO FALL THROUGH THE
AFTN...ESPECIALLY OVER THE WRN HALF OF THE CWA. MODEL ML DEWPOINTS
ARE IN THE UPPER TEENS TO MID 20S OVER THE WEST...SO HAVE TRENDED
THAT DIRECTION AND DROPPED VALUES 3-5 DEGREES. MIXING TO H800-775
WOULD YIELD HIGHS IN THE LOW/MID 60S AWAY FROM LK SUPERIOR
INFLUENCES UNDER WNW WINDS. THE COMBINATION OF THESE TWO FACTORS
WILL PRODUCE RH VALUES AROUND 20-25 PERCENT...BUT IF BETTER MIXING
OCCURS...COULD SEE VALUES INTO THE UPPER TEENS. WITH WINDS OF
10-15 MPH THERE COULD BE SOME FIRE WX CONCERNS...BUT HOPEFULLY THE
0.1-0.15IN OF RAIN ON FRI NIGHT WILL LIMIT THEM.
SAT NIGHT...HIGH WILL STILL BE CENTERED OVER CNTRL PLAINS/ROCKIES
AND SFC RIDGE SLIDES SE INTO LOWER MI. THIS WILL KEEP A SLIGHTLY
STRONGER PRESSURE GRADIENT ACROSS THE AREA AND SHOULD KEEP LOWS
AT OR SLIGHTLY ABOVE NORMAL EVEN WITH THE CLEAR SKIES.
SUN LOOKS TO BE SIMILAR TO SAT...WITH DRY AIR STILL IN PLACE AND
PRODUCING A MOSTLY SUNNY SKY. ONCE AGAIN...DEWPOINTS ARE THE MAIN
CONCERN AND HAVE DROPPED VALUES INTO THE LOWER 30S. ML DEWPOINTS
ARE SHOWING VALUES IN THE UPPER 20S...SO THEY MAY NEED TO BE
REDUCED IF TREND CONTINUES. WITH HIGHS IN THE 60S...WILL SEE RH
VALUES DROPPING TOWARDS 25 PERCENT AGAIN.
SUN NIGHT THROUGH WED...
MODELS DIFFER IN THE HANDLING OF A SHORTWAVE ROTATING AROUND THE
UPPER LOW STATIONED OVER HUDSON BAY. 12Z ECMWF THE MOST PRONOUNCED
AND S WITH THIS WAVE MOVING THROUGH SRN CANADA AND UPPER GREAT LKS
ON SUN NIGHT...BUT THE LATE ARRIVING 00Z RUN HAS WEAKENED THIS
CONSIDERABLY. 00Z GFS/GEM SHOW WEAKER VARIATIONS OF THIS WAVE MOVING
THROUGH THE NW FLOW AND STAYING MAINLY IN SRN CANADA. PREVIOUS FCST
HAD SLIGHT CHANCES OVER NRN LK SUPERIOR AND FEEL THAT IS THE WAY TO
GO AT THIS POINT. OTHERWISE...THE REST OF THE EXTENDED FORECAST
LOOKS TO BE DOMINATED BY NW FLOW ALOFT. SFC RIDGE FROM THE CNTRL
PLAINS/ROCKIES WILL TRY TO BUILD BACK OVER THE AREA FOR MON/TUES.
THIS LEAVES THE AREA UNDER DRY AIR ALOFT AND FAIRLY LIGHT WINDS.
MODELS HINTING AT ANOTHER WEAK COLD FRONT MOVING THROUGH THE UPPER
GREAT LKS TUES NIGHT INTO WED...BUT CONFIDENCE FOR MEASURABLE
PCPN IS LOW AT THIS POINT. TEMPS SHOULD BE AT OR ABOVE NORMAL
THROUGH THE FIRST PART OF NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 152 PM EDT THU MAY 10 2012
SFC HIGH PRESSURE OVER EASTERN UPPER MI WILL CONTINUE TO MOVE EAST
THIS AFTERNOON...ALLOWING FOR LIGHT WINDS AND LAKE BREEZE
DEVELOPMENT AT ALL SITES. HIGH-BASED CUMULUS FIELD SHOULD LINGER AT
IWD AND SAW BEFORE DISSIPATING EARLY THIS EVENING WITH LOSS OF
HEATING. PRESSURE GRADIENT THEN INCREASES OVERNIGHT AHEAD OF AN
APPROACHING COLD FRONT...RESULTING IN INCREASING WINDS FROM WEST TO
EAST. FRIDAY LOOKS TO HAVE FAIRLY DEEP MIXING...SO WINDS MAY GUST
OVER 20 KTS AT TIMES. A SLIGHT MOISTURE SURGE JUST BELOW H8 AROUND
IWD IN THE MORNING...AND SAW IN THE AFTERNOON...WILL BRING IN SOME
LOWER CLOUDS...BUT CONDITIONS SHOULD REMAIN JUST ABOVE VFR. RIGHT AT
THE END OF THE TAF PERIOD...THE COLD FRONT SHOULD REACH IWD WITH
QUICKLY FALLING CIGS. THE TREND WILL BE THE SAME DURING THE
AFTERNOON HOURS AT CMX.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 447 AM EDT THU MAY 10 2012
HIGH PRESSURE WILL COVER LAKE SUPERIOR TODAY AND LEAD TO LIGHT
WINDS. A COLD FRONT APPROACHING FROM THE NORTHERN PLAINS WILL CAUSE
WINDS TO BECOME SOUTHERLY TONIGHT AND FRIDAY...BUT THE MARINE
LAYER SHOULD KEEP WINDS BELOW 15KTS. WINDS WILL SHIFT TO THE NW
BEHIND THE FRONT ON FRIDAY NIGHT AND THEN REMAIN OUT OF THE WEST
THROUGH THE WEEKEND. MOSTLY AREAS SHOULD SEE WINDS STAY BELOW 20KTS
DURING THE WEEKEND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...TK
MARINE...SRF
AREA FORECAST DISCUSSION...UPDATED
NWS LUBBOCK TX
1227 PM CDT THU MAY 10 2012
.AVIATION...
MVFR TO OCCASIONAL IFR CONDITIONS WILL CONTINUE AT KLBB WITH
PERIODS OF LIGHT TO MODERATE RAINFALL. THERE MAY BE A LIGHTNING
STRIKE OR TWO AS WELL IN THE STRONGER ACTIVITY. CONFIDENCE IS TOO
LOW TO GO PREVAILING AT THIS TIME BECAUSE RAINFALL COVERAGE HAS
STRUGGLED TO MAKE IT TO THE KLBB TERMINAL. ALSO MAY SEE
PRECIPITATION LINGER THROUGH THE OVERNIGHT HOURS AND MVFR TO IFR
CONDITIONS CONTINUE AS WELL. KCDS SHOULD REMAIN FAR ENOUGH NORTH
TO STAY VFR THROUGH THIS TAF CYCLE.
JORDAN
&&
.PREV DISCUSSION... /ISSUED 638 AM CDT THU MAY 10 2012/
AVIATION...
DIFFICULT TAF FOR KLBB TODAY/TONIGHT AS THE TERMINAL MAY BE IMPACTED BY
ONE OR MORE ROUNDS OF SHRA AND/OR TSRA...BUT CONFIDENCE IN
OCCURANCE AND TIMING IS LOW. WILL INCLUDE A TEMPO FOR -TSRA THIS
MORNING BUT LEAVE THE REMAINDER OF THE PERIOD VFR FOR NOW. MVFR
CEILINGS ARE ALSO POSSIBLE LATE TONIGHT. KCDS SHOULD BE VFR UNTIL
POSSIBLY LATER THIS EVENING WHEN SHRA/TSRA COULD APPROACH THAT
TERMINAL AS WELL.
PREV DISCUSSION... /ISSUED 529 AM CDT THU MAY 10 2012/
UPDATE...
A BROAD AREA OF SHOWERS AND THUNDERSTORMS...SOME WITH HEAVY
RAINFALL RATES...ARE MOVING NORTH ACROSS THE WRN PERMIAN BASIN.
THE LATEST HRRR SUGGESTS THIS ACTIVITY WILL PINWHEEL NORTHWESTWARD
AROUND THE BROAD CYCLONIC CIRCULATION OF THE UPPER-LOW. THIS
SHOULD BRING THE ACTIVITY SQUARELY ACROSS COCHRAN...YOAKUM AND
TERRY COUNTIES...WITH A MORE GLANCING BLOW TO LUBBOCK...LYNN AND
HOCKLEY...AND POSSIBLY BAILEY COUNTIES. WE HAVE UPPED POPS AND QPF
FOR THESE AREAS. QUICK RAINFALL OF AN INCH OR SO IS POSSIBLE
ACROSS YOAKUM AND SRN TERRY COUNTIES AND COULD CAUSE SOME MINOR
FLOODING ISSUES.
PREV DISCUSSION... /ISSUED 334 AM CDT THU MAY 10 2012/
SHORT TERM...
THE UPPER-LOW AS SEEN IN SAT. IMAGERY IS MOVING SLOWLY EAST ACROSS
NRN MEXICO THIS MORNING. A BROAD AREA OF LIFT ON THE NORTHERN AND
EASTERN FLANKS OF THE LOW IS SUPPORTING SCATTERED TSTM ACTIVITY
WHICH AT 230 AM WAS CONCENTRATED ACROSS THE TRANS-PECOS AND WESTERN
PERMIAN BASIN...WHICH APPEARS TO BE ENHANCED BY MOISTURE
ADVECTION/LIFT ON A 20 KT SRLY LLJ. MOST MODEL OUTPUT DOES NOT HAVE
A GREAT HANDLE ON THE LOCATION AND EXTENT OF THE CURRENT
ACTIVITY...WHICH IS ALREADY MOVING INTO GAINES COUNTY...AND APPEARS
LIKELY TO MOVE INTO YOAKUM AND POSSIBLY TERRY COUNTIES SHORTLY AFTER
3 AM. THE MAIN FORECAST PROBLEM FOR TODAY WILL BE COVERAGE...TIMING
AND INTENSITY OF PRECIP WITH THIS SYSTEM AS IT MOVES OVER SW TX THIS
AFTN...AND THEN SWINGS NEWD INTO CENTRAL TX THIS EVENING.
OVERALL...THE TRACK FAVORS OUR SW ZONES WITH THE HIGHEST POPS THIS
MORNING....SRN AREAS THIS AFTERNOON...AND THEN EASTERN AREAS THIS
EVENING. THERE MAY BE A FAIRLY ABRUPT CUTOFF TO THE PRECIP SOMEWHERE
ACROSS THE CENTRAL OR NORTHERN ZONES...BUT WE HAVE KEPT A SLIGHT
CHANCE GOING ACROSS MOST OF THE FAR SRN PANHANDLE THIS AFTN AND EVE
BECAUSE IT IS DIFFICULT TO DETERMINE JUST WHERE THAT CUTOFF MAY LIE.
PROGS OF CAPE GENERALLY SHOW SOMEWHERE BETWEEN 400-800 J/KG MAY BE
PRESENT ACROSS THE THE AREA TODAY...WHEN COUPLED WITH WEAK
DEEP-LAYER SHEAR THIS SHOULD BE SUFFICIENT FOR EMBEDDED TSTMS IN THE
SHOWER ACTIVITY BUT LIKELY KEEP THE SVR POTENTIAL VERY LOW. RAINFALL
AMOUNTS ARE LIKELY TO BE MAXIMIZED ACROSS THE SRN ZONES. FORECAST
PWATS CLIMB TO ABOUT 1.25 INCHES ACROSS THE ROLLING PLAINS THIS
EVENING AND WITH THE CYCLONIC FLOW FEEDING DEEPER MOISTURE INTO THAT
AREA AN INCH OR SO OF RAINFALL IS POSSIBLE. OVERALL...IT APPEARS
THAT THE THREAT OF EXCESSIVE RAINFALL WILL REMAIN WELL OFF TO OUR
SOUTHEAST HOWEVER SOME LOCALLY HEAVIER AMOUNTS COULD CAUSE SOME
MINOR FLOODING ISSUES...WITH THE AREAS OF CONCERN MAINLY SRN YOAKUM
AND TERRY COUNTIES THIS MORNING /WHERE THEY SAW POCKETS OF HEAVY
RAINFALL MONDAY/ AND THEN THE SRN ROLLING PLAINS THIS EVENING. WITH
MORE EXTENSIVE CLOUD COVER ACROSS THE WEST AND SOUTH...WE EXPECT
TEMPS TODAY TO BE SOMEWHAT COOLER THAN YESTERDAY...RANGING FROM
HIGHS NEAR 70F IN THE SOUTHWEST TO LOWER 80S IN THE NE.
LONG TERM...
ADDITIONAL CHANCES FOR MEASURABLE RAINFALL WILL BE COMING UP IN
THE LONG TERM FORECAST.
PRECIPITATION WILL CONTINUE THROUGH THE DAY ON FRIDAY. AN AREA OF
DEFORMATION WILL MOVE OVER THE AREA ON THE NORTH AND WEST SIDE OF
THE SLOW MOVING UPPER LEVEL LOW. THE LOW WILL TRACK OVER THE
SOUTHERN ROLLING PLAINS DURING THE DAY ON FRIDAY. THE NAM/SREF
SOLUTIONS STILL TAKE THE LOW FARTHER SOUTH ON FRIDAY AND SATURDAY THAN
ALL OTHER MODEL SOLUTIONS. HEAVY RAIN WILL LIKELY BE A RESULT OF
THIS SLOW MOVING UPPER LOW. UNFORTUNATELY...MOST OF THIS HEAVY
RAIN WILL BE SOUTH OF THE AREA. PRECIPITATION PROCESSES ARE
EXPECTED TO BE VERY EFFICIENT WITH NEARLY SATURATED
SOUNDINGS...ESPECIALLY OFF THE CAPROCK. BEST CHANCES FOR THE FA
WILL BE OVER THE SOUTHERN ROLLING PLAINS.
A FRONT WILL THEN BACK DOOR INTO THE AREA SATURDAY SETTING UP
MOIST UPSLOPE FLOW THROUGH AT LEAST EARLY NEXT WEEK. THE AXIS OF A
SHARP UPPER LEVEL WAVE WILL MOVE SOUTH THROUGH THE ROCKIES FROM
SUNDAY THROUGH MONDAY. THIS WILL BE OUR NEXT SHOT AT PRECIPITATION
WITH NORTHWEST FLOW STORMS DEVELOPING EACH EVENING. THE BEST
CHANCES AT THE MOMENT APPEAR TO BE ON SUNDAY AND MONDAY EVENING
WHEN UPPER LEVEL LIFT WILL BE IN THE AREA. SATURDAY WILL SEE LESS
OF A CHANCE OF PRECIPITATION WITH UPPER LEVEL LIFT LACKING. HAVE
SIDED MORE WITH THE ECMWF SOLUTION GIVEN ITS CONSISTENT MODEL RUNS
OPPOSED TO THE GFS. ADDITIONALLY...THE GFS APPEARS TO BE SUFFERING
FROM SEVERE CONVECTIVE FEEDBACK DURING THIS TIME PERIOD.
FURTHERMORE...A QUICK GLANCE AT ANALOG GUIDANCE SHOWS HIGH
PROBABILITIES FOR SEVERE WEATHER WITH THIS NEXT SHOT OF
THUNDERSTORMS. JDV
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 75 49 70 49 70 / 20 20 20 10 10
TULIA 77 52 68 50 72 / 20 20 30 10 10
PLAINVIEW 75 52 67 50 72 / 20 20 30 10 10
LEVELLAND 71 51 72 53 75 / 50 30 30 10 10
LUBBOCK 73 52 70 51 74 / 40 30 40 10 10
DENVER CITY 69 51 75 53 75 / 90 30 30 10 10
BROWNFIELD 70 52 73 54 76 / 90 30 30 10 10
CHILDRESS 81 57 68 56 75 / 10 30 40 10 10
SPUR 75 54 69 53 76 / 30 40 50 10 10
ASPERMONT 76 56 72 57 76 / 30 60 60 10 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/99/99