Forecast Discussions mentioning any of "HRRR" "RR" "RUC13" "RUC" received at GSD on 05/05/12

AREA FORECAST DISCUSSION

NWS DENVER CO

 334 PM MDT THU MAY 3 2012

.SHORT TERM...CUMULUS CONTINUES TO DEVELOP ACROSS MOUNTAINS AND
FOOTHILLS AS WELL AS PORTIONS OF URBAN CORRIDOR. BATCH OF PASSING
CIRRUS SEEMS TO HAVE HALTED FURTHER DEVELOPMENT. RECENT RADAR
LOOPS FINALLY A CELL OVER WEST CENTRAL BOULDER COUNTY. OTHER CELLS
SHOWING UP OVER BOULDER AND SOUTHWEST LARIMER COUNTIES IN THE 1.5
DEGREE SCAN. CURRENT LAPS SURFACE ANALYSIS SHOWING CAPES FROM
100-300 J/KG OVER THE HIGH COUNTRY AS WELL AS IN AND NEAR
FOOTHILLS...LESS FURTHER EAST. STILL CANNOT RULE OUT ADDITIONAL STORMS
DEVELOPING ACROSS THE AREA BY THIS EVENING. THIS THINKING IN LINE
WITH LATEST HRR AND RUC WHICH SHOW AREA OF CONVECTION MOVING
QUICKLY ACROSS PLAINS DURING THE EVENING...AND LOOKS REASONABLE.
ACARS SOUNDINGS STILL INDICATING AIRMASS A BIT CAPPED...AND FOR
THIS REASON WILL NOT INCREASE POPS. FORECAST SOUNDINGS SHOW
INVERTED-V TYPE SOUNDINGS SO ANY CONVECTION THAT DEVELOPS WILL
PRODUCE MORE WIND THAN RAIN. LATEST NAM STILL MORE UNSTABLE THAT
THE OTHER MODELS DUE TO HIGHER DEWPOINTS AND THUS INDICATING MORE
PRECIP. SEEMS A BIT OVERDONE. DRIER SUBSIDENT AIR TO MOVE ACROSS
AREA FROM WEST TO EAST THIS EVENING... SO ANY LINGERING STORMS
OVER FAR NORTHEAST CORNER SHOULD DONE BY MIDNIGHT...WITH SKIES
CLEARING OVERNIGHT. REMOVED ANY MENTION OF FOG FAR NORTHEAST
CORNER LATE TONIGHT AND EARLY FRIDAY BOUNDARY LAYER WIND AND
HUMIDITY PROGS SHOW ANY LINGERING LOW LEVEL MOISTURE EAST OF AREA.
ON FRIDAY A DRIER SOUTHWEST FLOW ALOFT WILL BE OVER AREA WITH
AFTERNOON HUMIDITY REMAINING LOW. WINDS ALOFT NOT ALL THAT STRONG
SO SURFACE WINDS SHOULD REMAIN FAIRLY LIGHT DESPITE ANY MIXING.
NO FIRE WEATHER CONCERNS EXPECTED. TEMPERATURES TO BE A FEW
DEGREES WARMER DUE TO A SLIGHTLY WARMER AIRMASS.

.LONG TERM...A MAINLY DRY SOUTHWESTERLY FLOW ALOFT WILL BE OVER
THE CWFA FOR FRIDAY NIGHT AND SATURDAY WITH THE NEXT SYSTEM
MOVING INTO THE NORTHERN ROCKIES BY 00Z SUNDAY. IT WILL REMAIN
WARM AND DRY THROUGH THE DAY SO THE FIRE DANGER WILL REMAIN
ELEVATED BUT THE WINDS STILL LOOK FAIRLY WEAK DURING THE DAY. THE
STRONGEST WINDS THAT DEVELOP ARE NOT EXPECTED TO OCCUR UNTIL THE
PASSAGE OF A COLD FRONT SATURDAY EVENING. MID AND UPPER LEVEL
MOISTURE WILL INCREASE FM THE NORTH AND WEST SATURDAY NIGHT WITH A
COLD FRONT PROGGED TO PUSH THROUGH THE CWFA AT THAT TIME. AS A
RESULT...THERE WILL BE A SLIGHT CHANCE OF SHOWERS AND TSTMS
OVERNIGHT. FOR SUNDAY...A MUCH COOLER AMS WILL BE IN PLACE OVER
THE NORTHEAST PLAINS AS SURFACE HIGH PRESSURE WILL BE FIRMLY IN
CONTROL. TEMPERATURES WILL BE 15-20 DEGREES COOLER THAN SATURDAY.
THE NAM12 FORECAST SOUNDINGS INDICATE A MUCH STRONGER INVERSION
PRESENT AT 700 MB SUNDAY AFTN. THE GFS BUFFER SOUNDINGS STILL SHOW
AN INVERSION BUT NOT AS PRONOUNCED. AS A RESULT...THE BEST CHANCE
OF PCPN WILL LIKELY BE IN AND NEAR THE FRONT RANGE FOOTHILLS. BUT
AT THIS POINT IT LOOKS LIKE SHOWERS VS TSTMS WITH LIMITED
INSTABILITY PRESENT. BY 00Z MONDAY...THE NORTHERN BRANCH THE UPPER
TROUGH WILL BE OVER NORTH DAKOTA WITH THE SRN BRANCH CLOSING OFF
OVER THE CENTRAL CA COAST. SUNDAY NIGHT THE MDLS INDICATE SOME
WEAK MID LEVEL QG ASCENT MOVING ACROSS NORTHERN CO OVERNIGHT. AS A
RESULT...WL CONTINUE WITH CHC/SLGT CHC POPS AT THAT TIME. THE AMS
WILL REMAIN COOL AND UNSETTLED OVER NERN CO THROUGH THE DAY
MONDAY/MONDAY NIGHT. THE FLOW ALOFT APPEARS TO BE WEST/SWLY BUT WITH
LIMITED INSTBY PRESENT. FOR NOW WL CONTINUE WITH A CHC/SLGT CHC OF
SHOWERS/TSTMS. BY TUESDAY...A DRIER NORTHWESTERLY FLOW ALOFT WILL BE
OVER NORTHEASTERN CO. THE SECONDARY BRANCH OF THE TROUGH WILL BE
OVER BAJA CA BY 18Z TUESDAY. IF THIS TREND CONTINUES...THEN THE
CHC OF ANY RAINFALL WILL DECREASE SIGNIFICANTLY OR DIMINISH
ALTOGETHER FOR TUESDAY AND WEDNESDAY. THE TROUGH IS PROGGED TO
SHIFT EAST INTO WESTERN TX BY MIDDAY THURSDAY. IF ITS TRACK SHIFTS
FURTHER NORTH...THEN THE CHANCE OF PCPN WILL INCREASE FM SOUTH TO
NORTH ACROSS THE AREA. THE MDLS DO DIFFER IN TERMS OF THE TIMING
OF THE CLOSED LOW BUT UNFORTUNATELY MOST KEEP IT TOO FAR SOUTH TO
BRING ANY BENEFICIAL PCPN TO THE CWFA AT THIS POINT.


&&

.AVIATION...SOUTHEAST WINDS CONTINUE ACROSS AREA AIRPORTS WITH
SOME GUSTS TO 25 KTS...SHOULD CONTINUE THROUGH 02Z. SOME HIGH
BASED SHOWERS AND STORMS BEGINNING TO DEVELOP ACROSS FOOTHILLS.
STILL A SLIGHT CHANCE OF A HIGH BASED THUNDERSTORM THROUGH 02Z
WITH GUSTY OUFLOW WINDS TO 50 MPH POSSIBLE. WINDS TO WEAKEN AND
SHIFT TO THE SOUTHWEST BY 04Z AS DRAINAGE FLOW DEVELOPS...THEN
SHIFT TO THE NORTHWEST BY 18Z. VFR TO CONTINUE.

&&

.HYDROLOGY...SOME SHOWERS AND THUNDERSTORMS POSSIBLE THIS EVENING
WHICH WILL PRODUCE MORE WIND THAN RAIN. ACTIVITY TO MOVE FAIRLY
QUICKLY WHICH WILL LIMIT THE RAINFALL TO AROUND A TENTH OF AN
INCH. DRY CONDITIONS TO PREVAIL FRIDAY.


&&

.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...COOPER
LONG TERM....D-L
AVIATION...COOPER








AREA FORECAST DISCUSSION

NWS DENVER CO

 1020 AM MDT THU MAY 3 2012

.UPDATE...SOUTHEAST WINDS DOMINATING SURFACE PATTERN ACROSS PLAINS
AT PRESENT. ALL MODELS ARE CONSISTENT WITH INITIAL CONVECTIVE
DEVELOPING ALONG HIGHER TERRAIN...MAINLY FOOTHILLS AROUND 18Z.
THERE IS SOME HINT OF AN EAST-WEST ORIENTED  BOUNDARY IN THE TDEN
VELOCITY DATA ACROSS THE DENVER AREA WHICH MAY PROVIDE A FOCUS FOR
ADDITIONAL STORM DEVELOPMENT. BOTH NAM AND HRRR PUSH A BOUNDARY
EAST OFF THE FOOTHILLS BY LATE AFTERNOON...SO NOT SURE IF THE
CURRENT BOUNDARY WILL BE A FACTOR. NAM IS STILL SHOWING MORE
AFTERNOON INSTABILITY THAT THE OTHER MODELS AND THUS GENERATING
MORE PRECIPITATION. STILL NOT A WELL DEFINED DISTURBANCE TO HELP
WITH CONVECTION...SO WILL MAINTAIN THE CURRENT POPS AND WEATHER.
SURFACE DEWPOINTS IN THE 30S MOST AREAS WITH SOME 40S FAR EASTERN
PLAINS. SO LOW LEVELS STILL A BIT DRY AND ANY SHOWERS OR STORMS
THAT DO DEVELOP WILL PRODUCE MORE WIND THAN RAIN.

&&

.AVIATION...CURRENT TAF TRENDS SEEM ON TRACK...THOUGH THE SOUTHEAST
WINDS A BIT GUSTY AT APA AND DEN AND WILL NEED TO INCREASE THE
SPEEDS A BIT. ISOLATED HIGH BASED STORMS STILL A POSSIBILITY OVER
THE DENVER AREA BETWEEN 21Z AND 01Z...WITH WITH BRIEF GUSTY
OUTFLOW WINDS OF 40-50 MPH.

&&

.PREV DISCUSSION... /ISSUED 346 AM MDT THU MAY 3 2012/

SHORT TERM...SW FLOW ALOFT WILL BE OVER THE AREA TODAY AND
TONIGHT. AT THIS TIME CAN NOT SEE ANY WELL DEFINED DISTURBANCE
EMBEDDED IN THIS FLOW TO ENHANCE CONVECTION THIS AFTN AND EVENING.
MEANWHILE AFTN INSTABILITY ACROSS NERN CO VARIES GREATLY BETWEEN
THE MODELS WITH THE NAM HAVE THE BEST INSTABILITY WHILE THE GFS
..ECMWF AND HI RES WRF ARE NOT AS UNSTABLE. AS A RESULT THE NAM
GENERATES FAR MORE CONVECTION THAN THE OTHER MODELS. AT THIS TIME
WILL KEEP TSTM COVERAGE IN THE WDLY SCT CATEGORY OVER NERN CO AND
OVER THE HIGHER TERRAIN. AS FOR HIGHS WILL KEEP READINGS MAINLY IN
THE UPPER 70S TO LOWER 80S ACROSS NERN CO. FOR TONIGHT ANY TSTM
ACTIVITY DURING THE EVENING HOURS SHOULD GRADUALLY END OVER THE
FAR NERN PLAINS BY MIDNIGHT.

LONG TERM...NO REAL CHANGES TO THE FORECAST PACKAGE THIS TIME
AROUND. FRIDAY AND SATURDAY WILL BE WARM AND DRY AS THE UPPER AIR
PATTERN OVER THE U.S. AMPLIFIES AND SOUTHWEST FLOW ALOFT INCREASES
OVER COLORADO. WARM AIR WILL ADVECT OVER THE STATE FROM THE DESERT
SOUTHWEST. CHANGES ARE IN STORE FOR SUNDAY AS A SURFACE COLD FRONT
DROPS INTO THE STATE SATURDAY NIGHT AND AN UPPER TROUGH PASSES
OVERHEAD. COOLER TEMPERATURES WILL RESULT ALONG WITH A MORE
UNSETTLED AIRMASS. THE CHANCE FOR SHOWERS AND THUNDERSTORMS WILL
CONTINUE FROM SUNDAY THROUGH THE EARLY PART OF NEXT WEEK. UPPER
LEVEL TROUGHINESS WILL CONTINUE OVER THE GREAT BASIN AND CENTRAL
ROCKY MOUNTAIN REGIONS...BUT THE ECMWF...CANADIAN AND GFS MODELS
EACH HAVE DIFFERENT SOLUTIONS WHEN TRYING TO NAIL DOWN ANY
DETAILS. THIS WILL LEAVE US WITH NOTHING TO DO BUT HANG ON TO THE
CHANCE OF SHOWERS THROUGH NEXT WEDNESDAY. TEMPERATURES WILL BE
GRADUALLY MODERATING THROUGH THE EXTENDED PORTION OF THE FORECAST
AFTER THE COOLEST DAYS ON SUNDAY...MONDAY AND TUESDAY.

AVIATION...VFR THRU TONIGHT. ISOLATED HIGHER BASED THUNDERSTORMS
WILL BE POSSIBLE FM 21Z-01Z. THE STORMS MAY PRODUCE SOME BRIEF
GUSTY WINDS OF 40-50 MPH. WINDS WILL BE DRAINAGE THIS MORNING AND
THEN BECOME MORE SSE THIS AFTN. AFT 02Z THE WINDS SHOULD GRADUALLY
SHIFT BACK TO DRAINAGE.

HYDROLOGY...ISOLATED HIGHER BASED THUNDERSTORMS WILL BE POSSIBLE
THIS AFTERNOON. HOWEVER THE STORMS WILL MOVE RATHER QUICKLY WHICH
WILL LIMIT RAINFALL TO AROUND A TENTH OF AN INCH.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...D-L
LONG TERM....DANKERS
AVIATION...D-L






AREA FORECAST DISCUSSION

NWS NEW YORK NY

 750 PM EDT FRI MAY 4 2012

.SYNOPSIS...
A COLD FRONT OVER THE EASTERN GREAT LAKES THIS EVENING WILL DROP
SOUTHEAST AND PASS THROUGH THE REGION NEAR DAYBREAK. HIGH
PRESSURE WILL THEN BUILD DOWN FROM EASTERN CANADA FROM SATURDAY
THROUGH SUNDAY NIGHT...THEN SLOWLY SLIDE TO THE EAST ON MONDAY. A
SLOW MOVING LOW PRESSURE SYSTEM WILL THEN IMPACT THE AREA FROM
MONDAY NIGHT THROUGH THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
SCALED BACK POPS BASED ON RADAR TRENDS AND LATEST HRRR RUN.
NEAREST CONVECTION OVER EAST CENTRAL PA AT THIS TIME...AND EXPECT
MAJORITY OF ACTIVITY TO STAY SOUTHWEST OF THE AREA AS IT
PROPAGATES SOUTHEASTWARD. KEPT CHANCE POPS WESTERN ZONES THROUGH
THE CITY THIS EVENING...THOUGH THAT MIGHT WELL BE GENEROUS. SLIGHT
CHANCE POPS ELSEWHERE THROUGH MIDNIGHT.

ANY CONVECTION SHOULD WIND DOWN BEFORE MIDNIGHT WITH ISOLATED
SHOWERS POSSIBLE THROUGH DAYBREAK. A WEAK TROF OVER THE AREA AND
LIGHT WINDS WILL ALSO ALLOW FOR THE FORMATION OF LOW CLOUDS/FOG...
ESPECIALLY ACROSS LI AND COASTAL SE CT. AT THIS TIME...ANY DENSE
FOG IS FORECAST TO BE ISOLATED. THIS WILL HAVE TO BE CLOSELY
MONITORED SHOULD IT BECOME MORE WIDESPREAD.

OVERNIGHT LOWS WILL BE MILD WITH READINGS GENERALLY IN THE
50S...WITH THE LOWER 60S ACROSS NYC METRO.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
COLD FRONT AT THE LEADING EDGE OF STRONG HIGH PRESSURE BUILDING SE
FROM HUDSON BAY LOOKS TO PASS THROUGH THE FORECAST AREA AROUND
DAYBREAK. THERE IS THE POTENTIAL FOR ISOLATED LOW-TOPPED SHOWERS
DURING THE MORNING HOURS. DRIER AIR WILL WORK IN THE AFTERNOON
WITH SKIES PARTIALLY CLEARING. MODEL TIME HEIGHT CROSS SECTIONS
DEPICT 85H MOISTURE LINGERING FOR MUCH OF THE DAY WITH THE 85H
COLD FRONT IN CLOSE PROXIMITY. THIS COULD BE THE ONE FLY IN THE
OINTMENT AS MORE CLOUDS COULD BE AROUND FOR THE AFTERNOON.

HIGHS WILL BE A FEW DEGREES ABOVE NORMAL WITH READINGS 65 TO 70 AT
THE COAST...AND LOWER 70S INLAND. THESE HIGHS WOULD BE LOWER IF
THE CLOUD COVER WERE TO PERSIST LONGER. LOWS SAT NIGHT WILL BE
CLOSE TO NORMAL...AROUND 50 NYC METRO AND THE 40S ELSEWHERE. SKIES
SHOULD BE CLEAR BY THE TIME SAT NIGHT ROLLS AROUND.

A N/NE FLOW AT 10 MPH OR LESS WILL PREVAIL SAT INTO SAT NIGHT.
THERE IS A CHANCE OF SEA BREEZE DEVELOPMENT SHOULD ENOUGH HEATING
OVERCOME THE WEAK SYNOPTIC FLOW SAT AFTERNOON.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
HIGH PRESSURE REMAINS AS THE DOMINANT FEATURE IN OUR WEATHER SUNDAY
AND MONDAY...PROVIDING US WITH DRY WEATHER AND TEMPERATURES A LITTLE
ABOVE NORMAL LEVELS. FOR TUESDAY...ALTHOUGH A RIDGE AXIS ALOFT IS
OVER US...MOISTURE AHEAD OF THE NEXT LOW PRESSURE SYSTEM STREAMS IN
FROM THE WEST WITH A CHANCE OF SHOWERS.

MODELS APPEAR TO BE IN LESS AGREEMENT THAN THEY WERE YESTERDAY
REGARDING THE UPPER PATTERN...AND CONSEQUENTLY...THE SURFACE
FEATURES AFFECTING US FOR THE REST OF THE LONG TERM PERIOD. THERE
ARE HOWEVER SOME SIGNS OF A TREND TOWARDS NO 500 MB LOW
CUTTING OFF. WENT ALONG THE LINES OF HPC GUIDANCE REGARDING THE
SURFACE FEATURES...BUT ITS POSSIBLE THAT LOW PRESSURE WILL BE
COMPLETELY OUT THE PICTURE BY FRIDAY. AS SUCH...WENT WITH CHANCE
POPS TUESDAY NIGHT THROUGH THURSDAY NIGHT AND KEPT IN "HIDDEN"
SLIGHT CHANCE POPS FOR FRIDAY. ABUNDANT CLOUD COVER SHOULD KEEP
DAYTIME HIGHS AT OR BELOW NORMAL LEVELS THROUGH AT LEAST THURSDAY.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
A COLD FRONT APPROACHES SLOWLY FROM THE NORTH OVERNIGHT AND MOVES
THROUGH THE TERMINALS AROUND 12Z SATURDAY. A DEVELOPING EASTERLY
FLOW AFTER 05Z WILL BRING STRATUS INTO THE TERMINALS WITH IFR TO
LIFR CEILINGS. VISIBILITIES WILL ALSO LOWER TO 3 SM TO 5 SM.
CONDITIONS WILL IMPROVE AFTER 12Z WITH CEILINGS LIFTING TO 2K FT
TO 3500 FT THROUGH EARLY AFTERNOON.

LIGHT AND VARIABLE WINDS THIS EVENING BECOME NORTHEAST UNDER 10 KT
THROUGH THE OVERNIGHT AND THEN MORE EASTERLY AROUND 10 KT DURING
THE DAY.

        NY METRO ENHANCED AVIATION WEATHER SUPPORT...

DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT:  HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)

KJFK FCSTER COMMENTS: AMENDMENTS POSSIBLE EARLY SATURDAY MORNING
FOR CEILINGS SLOWLY IMPROVING FROM IFR.

KLGA FCSTER COMMENTS: AMENDMENTS POSSIBLE EARLY SATURDAY MORNING
FOR CEILINGS SLOWLY IMPROVING FROM IFR.

KEWR FCSTER COMMENTS: AMENDMENTS POSSIBLE EARLY SATURDAY MORNING
FOR CEILINGS SLOWLY IMPROVING FROM IFR.

KTEB FCSTER COMMENTS: AMENDMENTS POSSIBLE EARLY SATURDAY MORNING
FOR CEILINGS SLOWLY IMPROVING FROM IFR.

KHPN FCSTER COMMENTS: AMENDMENTS POSSIBLE EARLY SATURDAY MORNING
FOR CEILINGS SLOWLY IMPROVING FROM IFR.

KISP FCSTER COMMENTS: AMENDMENTS POSSIBLE EARLY SATURDAY MORNING
FOR CEILINGS SLOWLY IMPROVING FROM IFR.

OUTLOOK FOR 00Z SUN THROUGH WED...
.SAT NIGHT-MONDAY...VFR.
.TUE-WED...SUB VFR POSSIBLE IN RAIN.

&&

.MARINE...
OUTSIDE OF ISOLATED TSTMS THIS EVENING...A RELATIVELY WEAK PRESSURE
GRADIENT SHOULD YIELD SUB-SMALL CRAFT CONDITIONS OVER THE WATERS
THROUGH SAT. A VARIABLE FLOW WILL BECOME N/NE AT 5 TO 10 KT LATE
TONIGHT INTO SAT.

SUB SCA CONDITIONS ARE EXPECTED TO CONTINUE DURING SUNDAY AND
MONDAY...WITH A HIGH PRESSURE CENTER APPROACHING AND PASSING THROUGH
THE AREA WATERS. AS A STORM BEGINS TO STRENGTHEN TO THE WEST ON
TUESDAY...SOUTHERLY WINDS ARE EXPECTED TO INCREASE...AND RIGHT NOW
ARE FORECAST TO BE STRONG ENOUGH TO BUILD SEAS ON THE OCEAN UP TO 5
FT LATE TUESDAY AFTERNOON AND NIGHT. THERE IS A GOOD DEGREE OF
UNCERTAINTY WITH THE TRACK AND STRENGTH OF THE STORM...SO THERE IS A
CHANCE THAT SCA CONDITIONS OCCUR INTO A GOOD PORTION OF WEDNESDAY AS
WELL.

&&

.HYDROLOGY...
BASIN AVE QPF LESS THAN 1/4 INCH IS FCST THROUGH THIS EVE. LOCALLY
HEAVIER RAIN IS POSSIBLE IN STRONGER CONVECTION. THE POTENTIAL
EXISTS FOR POCKETS OF MINOR URBAN AND POOR DRAINAGE FLOODING IN
THIS ACTIVITY.

RAINFALL AMOUNTS ASSOCIATED WITH THE NEXT POTENTIAL SYSTEM
AFFECTING THE REGION TUESDAY THROUGH THURSDAY NIGHT ARE SOMEWHAT
UNCERTAIN. BEST ESTIMATE AT THIS TIME WOULD BE FOR AROUND AN INCH
TO AN INCH AND A HALF OF RAINFALL DURING THIS PERIOD.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES SAT AND SUN NIGHT WILL BE WITHIN ONE-HALF
FOOT OF MINOR COASTAL FLOOD BENCHMARKS. THIS COMBINED WITH A NE
FLOW AT 5 TO 10 KT COULD PRODUCE WATER LEVELS CLOSE TO THESE
VALUES. THE CURRENT FORECAST IS TO KEEP LEVELS JUST BELOW.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...DW
NEAR TERM...MAS/DW
SHORT TERM...DW
LONG TERM...JC
AVIATION...MET
MARINE...JC/DW
HYDROLOGY...JC/DW
TIDES/COASTAL FLOODING...








AREA FORECAST DISCUSSION

NWS NEW YORK NY

 711 PM EDT FRI MAY 4 2012

.SYNOPSIS...
A COLD FRONT OVER THE EASTERN GREAT LAKES THIS EVENING WILL DROP
SOUTHEAST AND PASS THROUGH THE REGION NEAR DAYBREAK. HIGH
PRESSURE WILL THEN BUILD DOWN FROM EASTERN CANADA FROM SATURDAY
THROUGH SUNDAY NIGHT...THEN SLOWLY SLIDE TO THE EAST ON MONDAY. A
SLOW MOVING LOW PRESSURE SYSTEM WILL THEN IMPACT THE AREA FROM
MONDAY NIGHT THROUGH THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
SCALED BACK POPS BASED ON RADAR TRENDS AND LATEST HRRR RUN.
NEAREST CONVECTION OVER EAST CENTRAL PA AT THIS TIME...AND EXPECT
MAJORITY OF ACTIVITY TO STAY SOUTHWEST OF THE AREA AS IT
PROPAGATES SOUTHEASTWARD. KEPT CHANCE POPS WESTERN ZONES THROUGH
THE CITY THIS EVENING...THOUGH THAT MIGHT WELL BE GENEROUS. SLIGHT
CHANCE POPS ELSEWHERE THROUGH MIDNIGHT.

ANY CONVECTION SHOULD WIND DOWN BEFORE MIDNIGHT WITH ISOLATED
SHOWERS POSSIBLE THROUGH DAYBREAK. A WEAK TROF OVER THE AREA AND
LIGHT WINDS WILL ALSO ALLOW FOR THE FORMATION OF LOW CLOUDS/FOG...
ESPECIALLY ACROSS LI AND COASTAL SE CT. AT THIS TIME...ANY DENSE
FOG IS FORECAST TO BE ISOLATED. THIS WILL HAVE TO BE CLOSELY
MONITORED SHOULD IT BECOME MORE WIDESPREAD.

OVERNIGHT LOWS WILL BE MILD WITH READINGS GENERALLY IN THE
50S...WITH THE LOWER 60S ACROSS NYC METRO.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
COLD FRONT AT THE LEADING EDGE OF STRONG HIGH PRESSURE BUILDING SE
FROM HUDSON BAY LOOKS TO PASS THROUGH THE FORECAST AREA AROUND
DAYBREAK. THERE IS THE POTENTIAL FOR ISOLATED LOW-TOPPED SHOWERS
DURING THE MORNING HOURS. DRIER AIR WILL WORK IN THE AFTERNOON
WITH SKIES PARTIALLY CLEARING. MODEL TIME HEIGHT CROSS SECTIONS
DEPICT 85H MOISTURE LINGERING FOR MUCH OF THE DAY WITH THE 85H
COLD FRONT IN CLOSE PROXIMITY. THIS COULD BE THE ONE FLY IN THE
OINTMENT AS MORE CLOUDS COULD BE AROUND FOR THE AFTERNOON.

HIGHS WILL BE A FEW DEGREES ABOVE NORMAL WITH READINGS 65 TO 70 AT
THE COAST...AND LOWER 70S INLAND. THESE HIGHS WOULD BE LOWER IF
THE CLOUD COVER WERE TO PERSIST LONGER. LOWS SAT NIGHT WILL BE
CLOSE TO NORMAL...AROUND 50 NYC METRO AND THE 40S ELSEWHERE. SKIES
SHOULD BE CLEAR BY THE TIME SAT NIGHT ROLLS AROUND.

A N/NE FLOW AT 10 MPH OR LESS WILL PREVAIL SAT INTO SAT NIGHT.
THERE IS A CHANCE OF SEA BREEZE DEVELOPMENT SHOULD ENOUGH HEATING
OVERCOME THE WEAK SYNOPTIC FLOW SAT AFTERNOON.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
HIGH PRESSURE REMAINS AS THE DOMINANT FEATURE IN OUR WEATHER SUNDAY
AND MONDAY...PROVIDING US WITH DRY WEATHER AND TEMPERATURES A LITTLE
ABOVE NORMAL LEVELS. FOR TUESDAY...ALTHOUGH A RIDGE AXIS ALOFT IS
OVER US...MOISTURE AHEAD OF THE NEXT LOW PRESSURE SYSTEM STREAMS IN
FROM THE WEST WITH A CHANCE OF SHOWERS.

MODELS APPEAR TO BE IN LESS AGREEMENT THAN THEY WERE YESTERDAY
REGARDING THE UPPER PATTERN...AND CONSEQUENTLY...THE SURFACE
FEATURES AFFECTING US FOR THE REST OF THE LONG TERM PERIOD. THERE
ARE HOWEVER SOME SIGNS OF A TREND TOWARDS NO 500 MB LOW
CUTTING OFF. WENT ALONG THE LINES OF HPC GUIDANCE REGARDING THE
SURFACE FEATURES...BUT ITS POSSIBLE THAT LOW PRESSURE WILL BE
COMPLETELY OUT THE PICTURE BY FRIDAY. AS SUCH...WENT WITH CHANCE
POPS TUESDAY NIGHT THROUGH THURSDAY NIGHT AND KEPT IN "HIDDEN"
SLIGHT CHANCE POPS FOR FRIDAY. ABUNDANT CLOUD COVER SHOULD KEEP
DAYTIME HIGHS AT OR BELOW NORMAL LEVELS THROUGH AT LEAST THURSDAY.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AREA TERMINALS IN A WARM AIR MASS AHEAD OF AN APPROACHING COLD
FRONT WHICH MOVES THROUGH SATURDAY MORNING.

TERMINALS CLEARED AND WILL REMAIN VFR AT LEAST THROUGH THE
EVENING. EXCEPTION IS KGON WHERE WARM FRONT IS CURRENTLY MOVING
THROUGH AND REMAINS IFR.

AREA REMAINS RATHER STABLE AND CAPPED...THEREFORE CHANCES FOR
CONVECTION REMAIN VERY MINIMAL.

BY TONIGHT...LOWER CLOUDS MAY REDEVELOP ALONG WITH AREAS OF
FOG...ESPECIALLY AFTER MIDNIGHT. IFR OR EVEN LIFR POSSIBLE LATE
TONIGHT.

CEILINGS SLOWLY LIFT SATURDAY MORNING...AND AN ISOLATED SHOWER IS POSSIBLE.

AS FOR WINDS...SW TO W WINDS EXPECTED THIS AFTERNOON...EXCEPT
SOUTH NEAR THE COAST. WINDS LIGHTEN THIS EVENING AND
OVERNIGHT...FROM THE NORTH. NORTH TO NORTHEAST WINDS INCREASE
SATURDAY MORNING...AROUND 10 KTS. A GUST OR TWO POSSIBLE IN THE
MORNING TO 15 TO 20 KTS.


     NY METRO ENHANCED AVIATION WEATHER SUPPORT...

DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT:  HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)

KJFK FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR WINDS LATE THIS
AFTERNOON. SEA BREEZE POSSIBLE.

KLGA FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR WINDS LATE THIS
AFTERNOON. LATE DAY SEA BREEZE POSSIBLE.

KEWR FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR WINDS LATE THIS
AFTERNOON.

KTEB FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR WINDS LATE THIS
AFTERNOON.

KHPN FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR WINDS LATE THIS
AFTERNOON.

KISP FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR WINDS LATE THIS
AFTERNOON.

OUTLOOK FOR 18Z SAT THROUGH WED...
.SAT AFTERNOON-MONDAY...VFR.
.TUE-WED...SUB VFR POSSIBLE IN RAIN.

&&

.MARINE...
OUTSIDE OF ISOLATED TSTMS THIS EVENING...A RELATIVELY WEAK PRESSURE
GRADIENT SHOULD YIELD SUB-SMALL CRAFT CONDITIONS OVER THE WATERS
THROUGH SAT. A VARIABLE FLOW WILL BECOME N/NE AT 5 TO 10 KT LATE
TONIGHT INTO SAT.

SUB SCA CONDITIONS ARE EXPECTED TO CONTINUE DURING SUNDAY AND
MONDAY...WITH A HIGH PRESSURE CENTER APPROACHING AND PASSING THROUGH
THE AREA WATERS. AS A STORM BEGINS TO STRENGTHEN TO THE WEST ON
TUESDAY...SOUTHERLY WINDS ARE EXPECTED TO INCREASE...AND RIGHT NOW
ARE FORECAST TO BE STRONG ENOUGH TO BUILD SEAS ON THE OCEAN UP TO 5
FT LATE TUESDAY AFTERNOON AND NIGHT. THERE IS A GOOD DEGREE OF
UNCERTAINTY WITH THE TRACK AND STRENGTH OF THE STORM...SO THERE IS A
CHANCE THAT SCA CONDITIONS OCCUR INTO A GOOD PORTION OF WEDNESDAY AS
WELL.

&&

.HYDROLOGY...
BASIN AVE QPF LESS THAN 1/4 INCH IS FCST THROUGH THIS EVE. LOCALLY
HEAVIER RAIN IS POSSIBLE IN STRONGER CONVECTION. THE POTENTIAL
EXISTS FOR POCKETS OF MINOR URBAN AND POOR DRAINAGE FLOODING IN
THIS ACTIVITY.

RAINFALL AMOUNTS ASSOCIATED WITH THE NEXT POTENTIAL SYSTEM
AFFECTING THE REGION TUESDAY THROUGH THURSDAY NIGHT ARE SOMEWHAT
UNCERTAIN. BEST ESTIMATE AT THIS TIME WOULD BE FOR AROUND AN INCH
TO AN INCH AND A HALF OF RAINFALL DURING THIS PERIOD.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES SAT AND SUN NIGHT WILL BE WITHIN ONE-HALF
FOOT OF MINOR COASTAL FLOOD BENCHMARKS. THIS COMBINED WITH A NE
FLOW AT 5 TO 10 KT COULD PRODUCE WATER LEVELS CLOSE TO THESE
VALUES. THE CURRENT FORECAST IS TO KEEP LEVELS JUST BELOW.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...DW
NEAR TERM...MAS/DW
SHORT TERM...DW
LONG TERM...JC
AVIATION...MET
MARINE...JC/DW
HYDROLOGY...JC/DW
TIDES/COASTAL FLOODING...







AREA FORECAST DISCUSSION

NWS NEW YORK NY

 755 AM EDT THU MAY 3 2012

.SYNOPSIS...
A WARM FRONT OVER THE MID-ATLANTIC WILL SLOWLY TRACK TOWARDS THE
REGION TODAY...DRAWING CLOSE TONIGHT...AND PASSING THROUGH
PORTIONS OF THE TRI-STATE REGION ON FRIDAY. LOW ASSOCIATED WITH
WARM FRONT MOVES SOUTH OF LONG ISLAND BY SATURDAY MORNING. THE
LOW SLOWLY MOVES FARTHER OUT TO SEA WITH HIGH PRESSURE STAYING IN
ONTARIO AND QUEBEC ON SATURDAY. BY SUNDAY...THIS HIGH PRESSURE
AREA WILL START TO BUILD INTO THE NORTHEAST AND OVER THE LOCAL
REGION ON MONDAY. HIGH PRESSURE SHIFTS OFFSHORE MONDAY NIGHT WITH
ANOTHER AREA OF LOW PRESSURE SLOWLY MOVING NEAR THROUGH MIDDLE OF
NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE ANCHORED WELL TO THE NORTH AND EAST WITH THE REGION
ON THE SOUTHWEST PERIPHERY OF IT...YIELDING A LIGHT SOUTHEAST FLOW
ACROSS THE REGION. SHOWERS HAVE ENDED ACROSS THE REGION BUT KEPT
A MENTION OF ISOLATED SHOWERS FOR THIS MORNING THAT COULD DEVELOP
ACROSS THE REGION WITH MOST MODEL QPF SHOWING A FEW HUNDREDTHS OF
AN INCH. HRRR MODEL ALSO SHOWS A FEW SHOWERS ACROSS THE AREA EARLY
THIS MORNING ACCORDING TO ITS REFLECTIVITY FIELDS. THERE WILL BE A
LITTLE FORCING MOSTLY AT LOW LEVELS WITH DPVA AND WEAK SFC
CONVERGENCE WITH THIS MOIST SE FLOW. IN ADDITION...PATCHY FOG WAS
ADDED FOR NEXT FEW HOURS MAINLY ACROSS SOME INLAND AREAS WITH THE
PREVIOUS RAIN ADDING TO THE MOISTURE AND SATURATION AT THE SFC.
FOG SHOULD DISSIPATE BY LATE MORNING AND MOST SHOWERS WILL HAVE
BEEN FINISHED AS WELL BY THAT POINT WITH DYNAMICS LESS FAVORABLE
GOING INTO THE AFTERNOON. OTHERWISE CLOUDS...TEMPS...DEWPOINTS...AND
WINDS ON TRACK.

WARM FRONT WILL REMAIN S OF THE CWA TODAY. THIS WILL ALLOW FOR A
GENERAL E TO ESE FLOW. DESPITE ALL THE DRY AIR AT 6K FT AND
ABV...THE MOIST MARITIME FLOW AT THE LLVLS WILL KEEP THE LOW
CLOUDS LOCKED IN THRU THE DAY. TEMPS A BLEND OF GUIDANCE...WARMEST
ACROSS THE W WHERE IT MAY GO PTCLDY FOR A TIME THIS AFTN.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
LIKELY TO BE ANOTHER MCS IN THE NERN CONUS TNGT. THE CWA WILL BE
IN THE PRIME REGION OF THE MID LVL INSTABILITY AXIS AS IT BUILDS
NWD. HIGH CHANCE POPS. CONVECTION ALONG THE RING OF FIRE IS
PROGGED TO LAST INTO FRI ALONG THE NERN 1/3 OF THE CWA. SECOND
AREA OF CONVECTION...THIS TIME SURFACE BASED...SHOULD DEVELOP
ACROSS WRN PORTIONS OF THE CWA DURING THE AFTN. THE 00Z NAM
INDICATES A PRIME BRN IN THE 15-35 RANGE FOR SUPERCELL POTENTIAL.
IF THIS PANS OUT...SOME SVR CELLS ALONG AND MAINLY WEST OF THE
HUDSON AFT 18Z. AS CONVECTION TRACKS SEWD IN THE LATE AFTN AND
EVE...THE TSTMS SHOULD TRANSITION TO ELEVATED WITH SOME SMALL HAIL
AND HVY RAIN ACROSS THE REST OF THE CWA.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
STARTING OUT THE LONG TERM ON FRIDAY NIGHT...WEATHER WILL STILL BE
UNSETTLED. 500MB PATTERN SHOWS A WNW FLOW ALOFT AS THE REGION WILL
BE EASTERN SIDE OF A RATHER FLAT LONGWAVE RIDGE SETTING UP ACROSS
THE NATION. SMALL IMPULSE SHOWN BY PVA WILL BE MOVING THROUGH ON THE
TOP OF THE RIDGE EARLY IN THE NIGHT WITH SOME NVA TOWARDS SAT
MORNING. THE DYNAMIC FORCING FOR LIFTING WILL BE ON A DECLINE
THROUGH THE NIGHT AS SHOWN BY UNFAVORABLE POSITION OF THE REGION
WITH RESPECT TO THE JET AS THE REGION WILL BE IN THE RIGHT FRONT
QUADRANT ALONG WITH Q VECTOR DIVERGENCE FROM 850 TO 500 MB. AT THE
SURFACE...LOW ASSOCIATED WITH WARM FRONT MOVES SOUTH OF LONG ISLAND
BY SATURDAY MORNING. WITH MUCAPE STILL PRESENT WITH VALUES UP TO
ALMOST 200 J/KG FOR SOUTHERN PORTIONS OF THE FORECAST
REGION...THUNDERSTORMS WILL BE POSSIBLE ALONG WITH SHOWERS. THE
THUNDER POTENTIAL DIMINISHES LATE ALONG WITH SHOWER PROBABILITIES
OVERALL WITH LESS DYNAMICAL FORCING. WITH MOISTURE IN THE BOUNDARY
LAYER AND WINDS BECOMING LIGHT...SOME PATCHY FOG WAS INSERTED INTO
THE FORECAST FOR THE OVERNIGHT PERIOD GOING INTO EARLY SATURDAY
MORNING. LOWS A BLEND OF MAV AND MET BUT WEIGHED MORE TO THE WARMER
MAV NUMBERS.

FOR THE WEEKEND...FLOW ALOFT BECOMES MORE NW...WNW SATURDAY AND NW
SUNDAY. ANOTHER IMPULSE OF PVA AT 500MB APPROACHING SATURDAY
AFTERNOON AND IS FORECAST TO MOVE THROUGH SATURDAY NIGHT. THIS IS A
RESPONSE TO AN UPPER LEVEL LOW IN QUEBEC THAT IS SHOWN TO STRETCH
AND MOVE SOUTHEAST OVER THE COURSE OF THE WEEKEND. THE JET SHARPENS
AND INCREASES JUST NORTH OF THE GREAT LAKES AND GOES INTO NORTHERN
NEW ENGLAND. AT THE SURFACE...REGION STAYS IN A NE FLOW WITH THE
WEAK LOW MOVING SLOWLY FURTHER AWAY OFFSHORE AND A STRONG HIGH
PRESSURE AREA STAYING WITHIN SOUTHEAST CANADA. THIS STARTS TO BUILD
A LITTLE FARTHER SOUTHEAST ON SUNDAY. TOOK AN ENSEMBLE APPROACH TO
THE PRECIP FORECAST...AND WITH GFS ENSEMBLE AND SREF HAVING
SIGNIFICANTLY LOWER CHANCES FOR MEASURABLE RAIN. THEREFORE JUST
HAVE A SLIGHT CHANCE FOR SHOWERS TO REFLECT THIS. MAX TEMPS A BLEND
OF MAV AND MET AS WELL AS NAM12 TO CONVEY LOWER TEMPS. TEMPERATURES
ARE STILL MILD OVERALL THOUGH WITH MAX TEMPS IN THE WESTERN AREAS
CLOSE TO 70 AND PROGRESSIVELY COOLER TO THE EAST WITH MORE MARITIME
INFLUENCE WITH HIGHS THERE NOT GETTING MUCH BEYOND UPPER 50S TO
LOWER 60S.

MORE STABILIZING EFFECT FROM RIDGE TOWARDS LATE SUNDAY NIGHT INTO
MONDAY. HIGH PRESSURE BUILDS AT THE SURFACE MORE INTO THE REGION AND
MORE OF SUBSIDENCE EFFECT OVERALL WILL RESULT IN DRIER CONDITIONS
SATURDAY NIGHT AND DECREASING CLOUDS ON SUNDAY. A MORE WIDESPREAD
MILD DAY IS IN STORE WITH MID TO UPPER 60S FOR MAX TEMPS. SOME
COOLER AIR DOES ADVECT IN ON A MORE NORTHERLY FLOW SATURDAY NIGHT
THROUGH EARLY SUNDAY.

ANOTHER IMPULSE APPROACHES MONDAY NIGHT AND MOVES THROUGH ON
TUESDAY. 250MB RIDGE AXIS MOVES ACROSS BEGINNING OF NEXT WEEK...WITH
DECREASING WINDS...SLOWING DOWN THE SYNOPTIC FLOW. FLOW ALOFT
BECOMES FLAT TO PARTIALLY MERIDIONAL. HIGH PRESSURE SFC DOMINANT
FEATURE FOR MONDAY AS IT BUILDS MORE INTO THE REGION BUT QUICKLY
MOVES OFFSHORE MONDAY NIGHT AND INTO TUESDAY. NEXT FRONTAL SYSTEM
SLOWLY APPROACHES FROM THE WEST MONDAY NIGHT AND INTO THE AREA ON
TUESDAY. WEAK LOW CENTER MOVES JUST SOUTH OF THE REGION BY MIDWEEK.
CHANCES FOR SHOWERS WILL INCREASE TOWARDS MIDWEEK. TIMING
DIFFERENCES OF THESE SFC FEATURES DUE TO UPPER LEVEL FLOW
DIFFERENCES PARTICULARLY BETWEEN THE GFS AND ECMWF. TEMPERATURES A
BLEND OF HPC AND MOSGUIDE. OVERALL...FORECAST TEMPS ARE NEAR TO
SLIGHTLY ABOVE NORMAL FOR EARLY TO MID NEXT WEEK.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
IFR CONDITIONS AT MOST TERMINALS SHOULD LAST INTO AT LEAST MID
MORNING. DAYTIME HEATING SHOULD GRADUALLY LIFT CIGS TO MVFR BY
LATE MORNING OR EARLY AFTERNOON...THEN CIGS LOWER AGAIN TO IFR AT
NIGHT. ANOTHER ROUND OF SHOWERS/TSTMS POSSIBLE TOWARD THE END OF
THE 06Z TAF PERIOD.

SE-S FLOW UNDER 10 KT EARLY WILL BECOME MORE S THIS MORNING...
THEN BACK SE AGAIN SE AGAIN BY LATE AFTERNOON AND REMAIN SE TONIGHT.

...NY METRO ENHANCED AVIATION WEATHER SUPPORT...

DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT:  HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)

KJFK FCSTER COMMENTS: TIMING OF IMPROVEMENT TO MVFR UNCERTAIN.

KLGA FCSTER COMMENTS: TIMING OF IMPROVEMENT TO MVFR UNCERTAIN.

KEWR FCSTER COMMENTS: TIMING OF IMPROVEMENT TO MVFR UNCERTAIN.

THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS YELLOW...WHICH
IMPLIES SLANT RANGE VISIBILITY 4-6SM OUTSIDE OF CLOUD.

KTEB FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.

KHPN FCSTER COMMENTS: TIMING OF IMPROVEMENT TO MVFR UNCERTAIN.

KISP FCSTER COMMENTS: TIMING OF IMPROVEMENT TO MVFR UNCERTAIN.

OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY...
.FRI...GENERALLY MVFR OR LOWER. AREAS ALONG/WEST OF THE HUDSON
COULD BREAK OUT TO VFR IN THE AFTN. CHANCE OF SHOWERS IN THE
MORNING...THEN A CHANCE OF TSTMS WITH HEAVY RAIN/GUSTY WINDS IN
THE AFTERNOON.
.SAT-MON...MAINLY VFR. SCT SHOWERS ON SAT.

&&

.MARINE...
A WARM FRONT WILL REMAIN S OF THE WATERS TODAY. LIGHT ESE FLOW CAN
BE EXPECTED. THE FRONT WILL APPROACH THE WATERS TNGT...THE PASS
THE WRN WATERS ON FRI. WINDS AND SEAS WILL BE BLW SCA LVLS THRU
THE PERIOD. THERE WILL BE A CHANCE OF TSTMS TNGT...THEN AGAIN ON
FRI.

SUB SCA CONDITIONS ARE EXPECTED THROUGH THE LONG TERM WITH PRESSURE
GRADIENTS WEAK ENOUGH TO KEEP WIND GUSTS BELOW 25 KT AND SEAS BELOW
5 FT. THE ONLY CHANCE FOR SCA CONDITIONS WOULD BE ON SATURDAY AND SATURDAY
NIGHT ACROSS THE OUTER OCEAN WHERE THE OFFSHORE LOW AND ITS
ASSOCIATED SWELL THAT MAY PUSH SEAS TO 5 FT.

&&

.HYDROLOGY...
LOCALLY HVY RAINFALL WILL BE POSSIBLE IN TSTMS ON FRI. MINOR URBAN
AND POOR DRAINAGE FLOODING WILL BE POSSIBLE WHERE THE MOST INTENSE
ACTIVITY OCCURS. BASIN AVERAGE QPF THRU FRI WILL BE 1/4 TO 3/4 OF
AN INCH ACROSS THE ENTIRE AREA.

UP TO ANOTHER QUARTER INCH OF RAIN FORECAST FOR FRI NIGHT WITH
SHOWERS AND THUNDERSTORMS...MAINLY IN THE EVENING. SOME LOCALLY
HIGHER AMOUNTS POSSIBLE. SOME MEASURABLE RAIN ALSO POSSIBLE
SATURDAY. OTHERWISE...NO SIGNIFICANT RAINFALL EXPECTED THROUGH
MONDAY.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.

&&

$$

SYNOPSIS...JM/12
NEAR TERM...JM/12
SHORT TERM...12
LONG TERM...JM
AVIATION...GOODMAN
MARINE...JM/12
HYDROLOGY...JM/12







AREA FORECAST DISCUSSION

NWS NEW YORK NY

 149 AM EDT THU MAY 3 2012

.SYNOPSIS...
A HIGH PRESSURE SYSTEM OFF THE NEW ENGLAND COAST AND A WARM FRONT
EXTENDING SOUTHEAST ACROSS NEW YORK AND PENNSYLVANIA WILL REMAIN
NEARLY STATIONARY THROUGH THURSDAY THEN MOVE EAST ON FRIDAY. LOW
PRESSURE OVER NORTHERN NEW YORK FRIDAY NIGHT WILL REFORM SOUTH OF
LONG ISLAND SATURDAY. HIGH PRESSURE NORTH OF THE GREAT LAKES WILL
MOVE SLOWLY SOUTHEAST SUNDAY AND MONDAY. A LOW PRESSURE SYSTEM WILL
MOVE NORTHEAST TOWARD THE AREA TUESDAY.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
TSTMS BEARING DOWN ON THE CWA ATTM. FOLLOWED THE HRRR FOR GENERAL
TIMING IN THE GRIDS. MAIN THREAT WILL BE LOC HVY RAIN AND
LIGHTNING IN THE ELEVATED CONVECTION.

TEMPS NEARLY STEADY THRU 6AM.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM FRIDAY/...
SHORTWAVE ENERGY EXITS WITH FURTHER WEAKENING OF CANADIAN
MARITIME HIGH PRESSURE. LOW LEVEL MOISTURE REMAINS HIGH WITH LOW
CLOUDS STICKING AROUND THE FORECAST AREA THROUGH MUCH OF THE DAY.
THERE IS CHANCE THAT SOME AREAS COULD BREAK OUT OF THE CLOUD COVER
DURING THE AFTERNOON...WHICH WOULD WARM TEMPERATURES WARMER THAN
FORECAST. HIGHS ARE EXPECTED TO RANGE FROM THE LOWER 60S TO UPPER
60S...WITH THE COOLER TEMPERATURES TO THE EAST AND THE WARMEST
TEMPERATURES TO THE WEST. WITH MOSTLY CLOUDY/CLOUDY SKIES FORECAST
FOR THE DAY...HAVE FOLLOWED THE SLIGHTLY COOLER NAM GUIDANCE.

A FRONTAL BOUNDARY AND LOW PRESSURE SYSTEM START TO APPROACH
THURSDAY NIGHT...SO POPS GRADUALLY INCREASE THROUGH THE NIGHT.
AGAIN LOOKING AT CLOUDY SKIES WITH TEMPERATURES NOT FALLING VERY
MUCH. ONCE AGAIN STUCK WITH THE NAM GUIDANCE FOR LOWS...AS
TEMPERATURES RANGE FROM THE UPPER 40S TO MIDDLE 50S.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
UNSETTLED WEATHER IS FORECAST FRIDAY THROUGH SATURDAY THEN TUESDAY
AND WEDNESDAY.

BECAUSE ALL WEATHER FEATURES ARE FORECAST TO REMAIN WEAK THROUGHOUT
THIS PERIOD...TIMING THE CHANCES OF RAIN WILL BE DIFFICULT.

FRIDAY...FORECAST MODELS SHOW HEIGHTS GRADUALLY LOWERING AS WEAK LOW
PRES MVS ACROSS NORTHERN NY STATE. INCLUDED A 40 PCT POP FOR SCT
SHOWERS AND TSTMS. BUST POTENTIAL FOR HIGH TEMPS BASED ON FCST CLOUD
COVER AND WIND DIRECTION WITH THE PASSAGE OF A WARM FRONT.

SATURDAY...MODELS SHOW THIS LOW REFORMING S OF LONG ISLAND AS A NE
WIND FLOW DEVELOPS...MAKING FOR A DAMP CHILLY DAY. LIGHT RAIN OR
DRIZZLE CANNOT BE RULED OUT.

SUNDAY INTO MONDAY...POPS WERE REMOVED FROM THE FCST AS A HIGH PRES
RIDGE BUILDS SE ACROSS THE AREA.

TUESDAY INTO WEDNESDAY...AS THIS HIGH MVS OFFSHORE AND AN UPSTREAM
TROUGH AMPLIFIES...ISENTROPIC LIFT WILL INCREASE CAUSING CLOUDS TO
LOWER AND THICKEN WITH OUR NEXT CHC OF RAIN.

KEEP THOSE UMBRELLAS HANDY ALTHOUGH WIDESPREAD SIGNIFICANT RAINFALL
ARE NOT ON THE HORIZON WITH ANY WELL DEFINED STORMS.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
TSTMS BEARING DOWN ON THE TERMINALS ATTM...WITH IFR VSBY. ONE TSTM
HEADED TOWARD KEWR COULD PRODUCE GUSTS UP TO 30 KT THERE...
OTHERWISE NOT EXPECTING SFC WIND IMPACTS AT OTHER TERMINALS.
AFTER THESE STORMS PASS...GENERALLY IFR TO LIFR CONDS ON TAP
THROUGH THU MORNING...THEN CONDS IMPROVE TO MVFR LATE IN THE
MORNING...THEN TO VFR BY AFTERNOON FOR MOST SITES.

GENERALLY SE WINDS AT 4-8 KT TONIGHT...THEN SOUTHERLY WINDS 5-10
KT THU MORNING.

ANOTHER ROUND OF RAIN EXPECTED THU NIGHT WITH MVFR OR LOWER CONDS.

OUTLOOK FOR 06Z FRIDAY THROUGH MONDAY...
.LATE THU NIGHT...MVFR...POSSIBLY IFR. CHANCE OF SHOWERS.
.FRI...GENERALLY MVFR OR LOWER. AREAS WEST OF THE HUDSON COULD
BREAK OUT TO VFR IN THE AFTN. CHANCE OF SHOWERS IN THE
MORNING...THEN A CHANCE OF TSTMS IN THE AFTERNOON.
.SAT-MON...MAINLY VFR. SCT SHOWERS ON SAT.

&&

.MARINE...
PRESSURE GRADIENT CONTINUES TO WEAKEN AS HIGH PRESSURE TO THE
EAST WEAKENS THROUGH THURSDAY. EXPECT SUB-SCA CONDITIONS ON THE
AREA WATERS THROUGH THURSDAY NIGHT.

THE NEXT CHANCE FOR A SMALL CRAFT ADVISORY WILL BE SATURDAY
AFTERNOON THROUGH SUNDAY MORNING AS A LOW PRESSURE SYSTEM DEVELOPS
SOUTH OF LONG ISLAND. WITH HIGH PRESSURE MOVING SOUTHEAST TOWARD THE
AREA...AN INCREASING NORTHEAST PRESSURE GRADIENT WILL CAUSE
INCREASING NE WINDS AND BUILDING SEAS. STAY TUNED.

OTHERWISE...WINDS AND SEAS ARE FORECAST TO REMAIN BELOW SMALL CRAFT
ADVISORY CRITERIA.

&&

.HYDROLOGY...
BETWEEN A QUARTER TO HALF INCH OF QPF IS FORECAST THROUGH THURSDAY
NIGHT AS RAIN AND SHOWERS MOVE ACROSS THE FORECAST AREA.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...BC/GC
NEAR TERM...12
SHORT TERM...BC
LONG TERM...GC
AVIATION...GOODMAN
MARINE...BC/GC
HYDROLOGY...BC/GC







AREA FORECAST DISCUSSION

NWS NEW YORK NY

 103 AM EDT THU MAY 3 2012

.SYNOPSIS...
A HIGH PRESSURE SYSTEM OFF THE NEW ENGLAND COAST AND A WARM FRONT
EXTENDING SOUTHEAST ACROSS NEW YORK AND PENNSYLVANIA WILL REMAIN
NEARLY STATIONARY THROUGH THURSDAY THEN MOVE EAST ON FRIDAY. LOW
PRESSURE OVER NORTHERN NEW YORK FRIDAY NIGHT WILL REFORM SOUTH OF
LONG ISLAND SATURDAY. HIGH PRESSURE NORTH OF THE GREAT LAKES WILL
MOVE SLOWLY SOUTHEAST SUNDAY AND MONDAY. A LOW PRESSURE SYSTEM WILL
MOVE NORTHEAST TOWARD THE AREA TUESDAY.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
TSTMS BEARING DOWN ON THE CWA ATTM. FOLLOWED THE HRRR FOR GENERAL
TIMING IN THE GRIDS. MAIN THREAT WILL BE LOC HVY RAIN AND
LIGHTNING IN THE ELEVATED CONVECTION.

TEMPS NEARLY STEADY THRU 6AM.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM FRIDAY/...
SHORTWAVE ENERGY EXITS WITH FURTHER WEAKENING OF CANADIAN
MARITIME HIGH PRESSURE. LOW LEVEL MOISTURE REMAINS HIGH WITH LOW
CLOUDS STICKING AROUND THE FORECAST AREA THROUGH MUCH OF THE DAY.
THERE IS CHANCE THAT SOME AREAS COULD BREAK OUT OF THE CLOUD COVER
DURING THE AFTERNOON...WHICH WOULD WARM TEMPERATURES WARMER THAN
FORECAST. HIGHS ARE EXPECTED TO RANGE FROM THE LOWER 60S TO UPPER
60S...WITH THE COOLER TEMPERATURES TO THE EAST AND THE WARMEST
TEMPERATURES TO THE WEST. WITH MOSTLY CLOUDY/CLOUDY SKIES FORECAST
FOR THE DAY...HAVE FOLLOWED THE SLIGHTLY COOLER NAM GUIDANCE.

A FRONTAL BOUNDARY AND LOW PRESSURE SYSTEM START TO APPROACH
THURSDAY NIGHT...SO POPS GRADUALLY INCREASE THROUGH THE NIGHT.
AGAIN LOOKING AT CLOUDY SKIES WITH TEMPERATURES NOT FALLING VERY
MUCH. ONCE AGAIN STUCK WITH THE NAM GUIDANCE FOR LOWS...AS
TEMPERATURES RANGE FROM THE UPPER 40S TO MIDDLE 50S.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
UNSETTLED WEATHER IS FORECAST FRIDAY THROUGH SATURDAY THEN TUESDAY
AND WEDNESDAY.

BECAUSE ALL WEATHER FEATURES ARE FORECAST TO REMAIN WEAK THROUGHOUT
THIS PERIOD...TIMING THE CHANCES OF RAIN WILL BE DIFFICULT.

FRIDAY...FORECAST MODELS SHOW HEIGHTS GRADUALLY LOWERING AS WEAK LOW
PRES MVS ACROSS NORTHERN NY STATE. INCLUDED A 40 PCT POP FOR SCT
SHOWERS AND TSTMS. BUST POTENTIAL FOR HIGH TEMPS BASED ON FCST CLOUD
COVER AND WIND DIRECTION WITH THE PASSAGE OF A WARM FRONT.

SATURDAY...MODELS SHOW THIS LOW REFORMING S OF LONG ISLAND AS A NE
WIND FLOW DEVELOPS...MAKING FOR A DAMP CHILLY DAY. LIGHT RAIN OR
DRIZZLE CANNOT BE RULED OUT.

SUNDAY INTO MONDAY...POPS WERE REMOVED FROM THE FCST AS A HIGH PRES
RIDGE BUILDS SE ACROSS THE AREA.

TUESDAY INTO WEDNESDAY...AS THIS HIGH MVS OFFSHORE AND AN UPSTREAM
TROUGH AMPLIFIES...ISENTROPIC LIFT WILL INCREASE CAUSING CLOUDS TO
LOWER AND THICKEN WITH OUR NEXT CHC OF RAIN.

KEEP THOSE UMBRELLAS HANDY ALTHOUGH WIDESPREAD SIGNIFICANT RAINFALL
ARE NOT ON THE HORIZON WITH ANY WELL DEFINED STORMS.

&&

.AVIATION /05Z THURSDAY THROUGH MONDAY/...
UNSETTLED WEATHER THROUGH THE TAF PERIOD...WITH MVFR CIGS
LOWERING TO IFR AFTER MIDNIGHT. THEN RAIN MOVES INTO THE REGION
THEREAFTER. CANNOT RULE OUT A RUMBLE OF THUNDER...BUT CONFIDENCE
TOO LOW TO WARRANT MENTIONING TS/VCTS IN THE TAF...AS THE
THUNDERSTORMS OVER CENTRAL PA LOOK TO PASS WELL SOUTH AND WEST OF
THE TERMINALS. GENERALLY IFR TO LIFR CONDS ON TAP THROUGH
THURSDAY MORNING...THEN CONDS IMPROVE TO MVFR LATE IN THE
MORNING...THEN TO VFR BY AFTERNOON FOR MOST TAF SITES.

GENERALLY E TO SE WINDS AT 4-8 KT TONIGHT...THEN SOUTHERLY WINDS
INCREASE TO 5-10 KT THURSDAY MORNING.

ANOTHER ROUND OF RAIN EXPECTED THURSDAY NIGHT WITH SUB-VFR CONDS.

OUTLOOK FOR 00Z FRIDAY THROUGH MONDAY...
.THU NIGHT...MVFR...POSSIBLY IFR. CHANCE OF SHOWERS LATE.
.FRI...GENERALLY MVFR OR LOWER. AREAS WEST OF THE HUDSON COULD
BREAK OUT TO VFR IN THE AFTN. CHANCE OF SHOWERS MORNING...THEN A
CHANCE OF TSTMS AFT.
.SAT-MON...MAINLY VFR. SCT SHOWERS SAT.

&&

.MARINE...
PRESSURE GRADIENT CONTINUES TO WEAKEN AS HIGH PRESSURE TO THE
EAST WEAKENS THROUGH THURSDAY. EXPECT SUB-SCA CONDITIONS ON THE
AREA WATERS THROUGH THURSDAY NIGHT.

THE NEXT CHANCE FOR A SMALL CRAFT ADVISORY WILL BE SATURDAY
AFTERNOON THROUGH SUNDAY MORNING AS A LOW PRESSURE SYSTEM DEVELOPS
SOUTH OF LONG ISLAND. WITH HIGH PRESSURE MOVING SOUTHEAST TOWARD THE
AREA...AN INCREASING NORTHEAST PRESSURE GRADIENT WILL CAUSE
INCREASING NE WINDS AND BUILDING SEAS. STAY TUNED.

OTHERWISE...WINDS AND SEAS ARE FORECAST TO REMAIN BELOW SMALL CRAFT
ADVISORY CRITERIA.

&&

.HYDROLOGY...
BETWEEN A QUARTER TO HALF INCH OF QPF IS FORECAST THROUGH THURSDAY
NIGHT AS RAIN AND SHOWERS MOVE ACROSS THE FORECAST AREA.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...BC/GC
NEAR TERM...12
SHORT TERM...BC
LONG TERM...GC
AVIATION...MPS
MARINE...BC/GC
HYDROLOGY...BC/GC







AREA FORECAST DISCUSSION

NWS MOUNT HOLLY NJ

 127 AM EDT THU MAY 3 2012

.SYNOPSIS...
A WARM FRONT TO OUR SOUTH AND WEST WILL MOVE VERY SLOWLY EASTWARD
OVERNIGHT AND THURSDAY. LOW PRESSURE WILL CROSS THE LOWER GREAT
LAKES AND SOUTHERN CANADA THROUGH THE EARLY PART OF THE WEEKEND. A
COLD FRONT ATTACHED TO THE LOW WILL CROSS THE AREA SATURDAY. THIS
WILL BE FOLLOWED BY HIGH PRESSURE FOR THE REST OF THE WEEKEND AND
INTO EARLY NEXT WEEK. ANOTHER DISTURBANCE WILL ARRIVE OVER THE
REGION NEXT TUESDAY INTO WEDNESDAY.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE LAST OF THE ORGANIZED CONVECTION IS MOVING THROUGH NORTHERN
NEW JERSEY EARLY THIS MORNING. THE LIGHTNING HAS DECREASED
STEADILY AS THE ACTIVITY HAS MOVED SOUTHEAST. HOWEVER...DUAL POL
PRODUCTS SUGGEST THAT SOME OF THE STRONGER CONVECTIVE CELLS COULD
HAVE SOME SMALL HAIL. THIS COULD PERSIST THROUGH ABOUT 230 AM OR
SO...ESPECIALLY WITH NEW CONVECTIVE CELLS DEVELOPING SOUTHEAST OF
THE MAIN BATCH.

THE MAIN THREAT IS STILL HEAVY RAIN...AND RADAR INDICATES AS MUCH
AS AN INCH OF RAIN HAS FALLEN IN LESS THAN AN HOUR WITH SOME OF
THE ACTIVITY. SINCE THE ACTIVITY IS MOVING...NO MORE THAN NUISANCE
FLOODING IS EXPECTED. DOPPLER RADARS SHOW 35 TO 40 KNOT WINDS AT
ABOUT 6000-7000 FEET WITH SOME OF THE CONVECTIVE LOOKING LINE
ACROSS NORTHERN NEW JERSEY. HOWEVER...DUE TO THE STRONG AND MOIST
MARINE INVERSION IN PLACE...THIS HAS YET TO TRANSLATE INTO STRONG
WIND GUSTS AT THE SURFACE.

THE CHANCE OF SHOWERS WAS EXPANDED TO INCLUDE A BIT MORE OF THE
AREA...AS THE LATEST HRRR IS SHOWING THIS TREND. NO OTHER
SIGNIFICANT CHANGES TO WINDS OR TEMPERATURES FOR THE REST OF THE
EARLY MORNING.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THIS EVENING/...
PATCHY FOG AND SOME SHOWERS WILL BEGIN THE DAY AS A DISTURBANCE
MOVES OVERHEAD EARLY. A WARM FRONT WILL BE APPROACHING THE REGION
FROM THE WEST, AND WE ARE EXPECTING THIS FRONT TO PUSH THROUGH THE
FORECAST AREA BY LATE IN THE DAY. A FEW SHOWERS AND ISOLATED
THUNDERSTORMS HAVE BEEN RETAINED IN THE FORECAST FOR THE AFTERNOON
HOURS. THE ONSHORE FLOW AND LOWER CLOUDS MAY HANG ON LONGER
ESPECIALLY ACROSS THE NORTHEASTERN PORTION OF OUR CWA. AS A
RESULT, THE HIGHS WERE ADJUSTED DOWN SOME. IF THE WARM FRONT ENDS
UP LIFTING THROUGH FASTER WITH ENOUGH SUNSHINE RETURNING, THE
TEMPERATURES COULD BE OFF TO THE RACES GIVEN THE RATHER MILD AIR
NOT TO FAR ABOVE THE SURFACE.

&&

.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
A SFC WARM FRONT WILL FINALLY PUSH NORTHWARD ACROSS THE AREA THU
NIGHT AND IT WILL BE FOLLOWED BY A MORE WARM AND HUMID AIR MASS. A
LOW PRESSURE SYSTEM WILL BE JUST NORTH OF THE AREA THU NIGHT AND
IT WILL MOVE ACROSS NORTHERN NEW ENGLAND FRI AND THEN DOWN THE ST
LAWRENCE VALLEY FRI NIGHT. AN ATTACHED COLD FRONT WILL CROSS THE
AREA EARLY SAT. THESE FEATURES WILL BE CLOSE ENOUGH TO THE AREA TO
KEEP SLGT CHC OR CHC POPS ACROSS THE AREA. TEMPERATURES THU NIGHT
INTO SAT WILL REMAIN ABOVE NORMAL WITH HIGH TEMPERATURES IN THE
LOW TO MID 80S IN MOST AREAS. SAT WILL BE A LITTLE COOLER ONCE THE
COLD FRONT PASSES.

A DRIER PERIOD WILL ARRIVE SAT NIGHT INTO EARLY TUESDAY AS A SLOW
MOVING RIDGE OF HIGH PRESSURE MOVES ACROSS THE AREA. TEMPERATURES
DURING THIS PERIOD WILL BE SEASONABLE WITH HIGHS MOSTLY IN THE LOW
TO MID 70S AND OVERNIGHT LOWS IN THE UPPER 40S TO LOW 50S.

ANOTHER DISTURBANCE WILL MOVE TOWARD THE AREA TUE AND REMAIN INTO
THU AS A SFC LOW AND COLD FRONT STALL ALONG THE COAST. THIS WILL
KEEP THE TEMPERATURES NEAR OR A LITTLE BELOW NORMAL FOR EARLY MAY.
POPS WILL BE HELD A SLGT CHC OR LOW CHC ATTM.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

LIFR CONDITIONS REMAIN IN PLACE EARLY THIS MORNING. AN AREA OF
SHOWERS AND THUNDERSTORMS CONTINUES TO WEAKEN AS IT MOVES SOUTHEAST.
THE MAIN THUNDERSTORM THREAT SHOULD BE LIMITED TO KABE THROUGH ABOUT
0800 UTC. ELSEWHERE...THE AIRMASS LOOKS TOO STABLE FOR THUNDER THIS
MORNING.

CONDITIONS SHOULD SLOWLY RISE FROM LIFR TO IFR THROUGH ABOUT 1500
UTC AT ALL LOCATIONS...AND FINALLY TO VFR AROUND 1700 TO 1800 UTC.
THE EXCEPTION COULD BE KACY...WHERE THE IFR CONDITIONS COULD LINGER
JUST OFFSHORE...AND REMAIN CLOSE BY MOST OF THE DAY. THUNDERSTORM
ACTIVITY SHOULD BE FAIRLY LIMITED THIS AFTERNOON AND EVENING...AND
NOT MENTIONED IN THE 0600 UTC FORECASTS.

THE IFR CONDITIONS COME BACK IN FROM EAST TO WEST BETWEEN 0000 UTC
AND 0400 UTC. THERE IS SOME INDICATION THAT THE FOG COULD BE MORE
WIDESPREAD LATE TONIGHT...AND LIFR CONDITIONS ARE EXPECTED AFTER
0600 UTC FRIDAY AT ALL LOCATIONS.

OUTLOOK...
FRIDAY...IMPROVING CIGS/VSBYS AS FRONT PASSES EAST OF THE AREA.
LOWER CONDITIONS FRI NIGHT WITH AREAS OF FOG POSSIBLE.

SATURDAY INTO MONDAY...MOSTLY VFR.

&&

.MARINE...
SEAS HAVE DROPPED BELOW 5 FEET AT 44009. WHILE SEAS MAY TEND TO
OSCILLATE NEAR 5 FEET FOR THE REST OF THE EARLY MORNING...THE
OVERALL TREND APPEARS TO BE DOWN. THUS...THE SMALL CRAFT ADVISORY
WAS CANCELLED.

WITH THE CONTINUED EAST TO SOUTHEAST FLOW, PATCHY FOG MAY DEVELOP
OVER THE WATERS TONIGHT. IN ADDITION, A FEW SHOWERS CAN ALSO BE
EXPECTED TONIGHT AHEAD OF AN APPROACHING WARM FRONT. FOR THURSDAY,
WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW ADVISORY CRITERIA. WITH
THE WARM FRONT EXPECTED TO MOVE THROUGH THE AREA LATE TOMORROW,
SHOWERS ARE AGAIN POSSIBLE, ESPECIALLY FOR THE AFTERNOON.

OUTLOOK...
MOSTLY SUB-SCA CONDITIONS WILL BE ON THE WATERS THU NIGHT THROUGH
SAT NIGHT. HIGH PRESSURE BUILDING DOWN FROM CANADA SAT WILL
PROMOTE ONSHORE FLOW SUN-SUN NIGHT. THIS MAY PRODUCE A SHORT
PERIOD OF SCA CONDITIONS SUN WITH SEAS NEAR 5 FT. CONDITIONS WILL
SUBSIDE BACK BELOW SCA MON-TUE.

&&

.TIDES/COASTAL FLOODING...
ASTRONOMICAL TIDES ARE INCREASING THROUGH THIS WEEKEND. ANY PUSH
FROM AN ONSHORE FLOW COULD RAISE WATER LEVELS TO NEAR MINOR TIDAL
FLOOD HEIGHTS. WE WILL MONITOR THIS SITUATION AS WE MOVE THROUGH
THE WEEK.

&&

.EQUIPMENT...
THE ACY ASOS REMAINS OFFLINE DUE TO EQUIPMENT PROBLEMS. THE CLIMATE
DATA IS BEING ESTIMATED FROM NEARBY MESONET SITES.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$

SYNOPSIS...O`HARA
NEAR TERM...HAYES
SHORT TERM...GORSE/KLINE
LONG TERM...O`HARA
AVIATION...HAYES/O`HARA
MARINE...HAYES/O`HARA
TIDES/COASTAL FLOODING...RPW
EQUIPMENT...GORSE







AREA FORECAST DISCUSSION

NWS CHARLESTON SC

 442 AM EDT THU MAY 3 2012

.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL GRADUALLY SINK SOUTHWARD LATE IN THE
WEEK...AS A TROUGH OF LOW PRESSURE DEVELOPS INLAND. A COLD FRONT
WILL MOVE INTO THE REGION SATURDAY NIGHT AND SUNDAY...THEN DROP
SOUTH OF THE AREA EARLY NEXT WEEK AS HIGH PRESSURE BUILDS IN FROM
THE NORTH. ANOTHER COLD FRONT COULD MOVE ACROSS THE AREA FROM
THE NORTHWEST DURING THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE SYNOPTIC PATTERN REMAINS AMAZINGLY PERSISTENT FOR THE MIDDLE
OF SPRING WITH A BLOCKING RIDGE STILL SITTING OVER THE EASTERN
CAROLINAS AND WESTERN ATLANTIC. TODAY LOOKS TO BE THE FINAL DAY IN
THIS PATTERN BEFORE A SUBSTANTIAL SHIFT OCCURS. THROUGH DAYBREAK
WE ARE CARRYING WIDESPREAD FOG AWAY FROM THE COAST. THOUGH
VISIBILITIES HAVE THUS FAR ONLY BRIEFLY DROPPED TO 1/4 MILE IN
SPOTS...WE COULD AGAIN SEE A QUICK DENSIFYING TREND AS THE
BOUNDARY LAYER COOLS A BIT FURTHER CLOSER TO DAYBREAK. A LAST
MINUTE DENSE FOG ADVISORY CANNOT BE COMPLETELY RULED OUT.

BY MID TO LATE MORNING ANY LOW CLOUDS AND FOG WILL HAVE BURNED OFF
BUT SOME CUMULUS IS EXPECTED TO DEVELOP SOON THEREAFTER. OTHERWISE
MOSTLY SUNNY SKIES ARE ANTICIPATED. 850 MB TEMPS ARE AROUND 18C
WHICH...USING THE 1000-850 MB THICKNESS CHARTS...GIVES HIGHS
BETWEEN 88 AND 91. THE EXCEPTION AS USUAL WILL BE THE IMMEDIATE
COASTLINE WHERE THE SEABREEZE WILL STOP THE WARMING IN THE LOWER
80S EARLY THIS AFTERNOON.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
A STRENGTHENING SHORTWAVE TROUGH LIFTING INTO THE TENNESSEE VALLEY
TONIGHT WILL ERODE THE UPPER RIDGE OVER THE SOUTHEAST UNITED
STATES. SOME MID AND HIGH CLOUDS WILL OVERSPREAD FAR WESTERN ZONES
LATE TONIGHT BUT WE THINK THE BEST FORCING FOR PRECIPITATION WILL
REMAIN JUST TO OUR WEST.

FRIDAY AND FRIDAY NIGHT...DEEP LAYERED RIDGING WILL ERODE AS A SHORT
WAVE TROUGH SHIFTS ACROSS THE REGION. MEANWHILE...A SURFACE TROUGH
WILL FORM IN THE LEE OF THE APPALACHIANS AND SHIFT TOWARD THE COAST
LATE FRIDAY AND FRIDAY NIGHT. MOISTURE PROFILES DO NOT APPEAR ALL
THAT IMPRESSIVE...BUT GIVEN LESS SUBSIDENCE AND WEAK FORCING FOR
ASCENT WITH THE SHORT WAVE...ISOLATED CONVECTION CERTAINLY SEEMS
POSSIBLE. WILL MAINTAIN A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS
IN THE FORECAST FOR INLAND AREAS DURING THE AFTERNOON...THEN ACROSS
MUCH OF SOUTHEAST SOUTH CAROLINA IN THE EVENING WHERE CONVERGENCE IN
THE VICINITY OF THE SURFACE TROUGH WILL BE GREATEST. HIGHS ON FRIDAY
WILL BE WELL INTO THE UPPER 80S...BUT CONSIDERABLY COOLER NEAR THE
IMMEDIATE COAST. A MILD NIGHT IS ANTICIPATED...WITH LOWS IN THE MID
TO UPPER 60S.

SATURDAY AND SATURDAY NIGHT...UPPER LEVEL RIDGING WILL AMPLIFY OVER
THE WESTERN GULF OF MEXICO AND SOUTHERN PLAINS STATES...RESULTING IN
A NORTHWEST FLOW ALOFT ACROSS THE REGION. AT THE SURFACE...A LEE
SIDE TROUGH WILL FORM INLAND DURING THE AFTERNOON WHILE A BACKDOOR
COLD FRONT APPROACHES FROM THE NORTH. A SERIES OF SHORT WAVE
DISTURBANCES WILL PUSH THE BACKDOOR FRONT SOUTHWARD AND INTO THE
AREA SATURDAY NIGHT. STRONG FORCING FOR ASCENT AND THE PROXIMITY OF
THE LEE SIDE TROUGH WILL RESULT IN THE FORMATION OF SCATTERED
SHOWERS AND THUNDERSTORMS SATURDAY AFTERNOON INTO EARLY SATURDAY
EVENING. WILL CAP RAIN PROBABILITIES AT 30 PERCENT HOWEVER SINCE
DEEP MOISTURE WILL BE LACKING GIVEN A SOLID DOWNSLOPE FLOW. THERE IS
THE POTENTIAL FOR ISOLATED SEVERE THUNDERSTORMS...AS A 30-35 KT MID
LEVEL JET EMBEDDED WITHIN THE NORTHWEST FLOW ADVANCES ACROSS THE
AREA. IN ADDITION...CONSIDERABLE DESTABILIZATION WILL OCCUR AT THE
SURFACE AS THE DOWNSLOPE FLOW AND COMPRESSIONAL HEATING PUSHES
TEMPERATURES TO AROUND 90 DEGREES AWAY FROM THE IMMEDIATE COAST.
WHILE THE COVERAGE OF CONVECTION WILL DIMINISH BY MID-LATE
EVENING...WILL MAINTAIN A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS
FOR THE REMAINDER OF SATURDAY NIGHT WITH THE ADVANCING COLD FRONT.

SUNDAY...THE BACKDOOR COLD FRONT WILL CONTINUE TO DROP ACROSS THE
AREA...REACHING SOUTH OF THE ALTAMAHA RIVER BY THE END OF THE DAY.
THE FRONT...AND THEN CONSIDERABLE MOISTURE IN THE NORTH-NORTHEAST
FLOW BEHIND IT...WILL WARRANT KEEPING A SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS MENTIONED IN THE FORECAST. TEMPERATURES WILL ONLY
MODERATE SOME...GENERALLY RANGING FROM THE MID 80S NORTH TO THE
UPPER 80S SOUTH.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE WILL BUILD FROM THE NORTH IN THE WAKE OF A BACKDOOR
COLD FRONT SUNDAY NIGHT AND MONDAY...THEN AS THE HIGH SHIFTS INTO
THE WESTERN ATLANTIC A RETURN FLOW WILL DEVELOP ON TUESDAY. A COLD
FRONT COULD AFFECT THE AREA DURING THE MID WEEK PERIOD.

THE FORECAST WILL INDICATE A SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS DURING NEARLY THE ENTIRE LONG TERM PERIOD. MONDAY WILL
BE THE COOLEST DAY WITH NEAR NORMAL TEMPERATURES EXPECTED...THEN
GRADUAL WARMING WILL OCCUR THROUGH THE MIDDLE OF NEXT WEEK.

&&

.AVIATION /08Z THURSDAY THROUGH MONDAY/...
FOG DEVELOPMENT IS AGAIN THE PRIMARY CONCERN THIS MORNING. A VERY
SIMILAR PATTERN EXISTS SINCE 24-HOURS PRIOR WITH THE EXCEPTION OF
A BIT OF CIRRUS OVERSPREADING THE AREA FROM UPSTREAM CONVECTION.
HOWEVER THE CIRRUS APPEARS TO BE DISSIPATING...LEAVING MOSTLY
CLEAR SKIES IN MOST AREAS. THE LATEST HRRR VISIBILITY PLOT SHOWS
THE DENSEST FOG REMAINING JUST INLAND FROM THE TERMINALS SIMILAR
TO WEDNESDAY MORNING. WE ARE KEEPING WITH A PERSISTENCE FORECAST
OVERNIGHT WITH VFR CONDITIONS AT BOTH TERMINALS FOR THE NEXT 24
HRS.

EXTENDED AVIATION OUTLOOK...MVFR OR LOWER CONDITIONS WILL BE
POSSIBLE DURING THE LATE NIGHT/EARLY MORNING HOURS INTO THE
WEEKEND DUE TO LOW CLOUDS/FOG.

&&

.MARINE...
ATLANTIC HIGH PRESSURE WILL MAINTAIN ITS CONTROL OVER THE MARINE
AREA THROUGH TONIGHT WITH SOUTH TO SOUTHWEST WINDS LESS THAN 15
KT.

ATLANTIC HIGH PRESSURE WILL MAINTAIN A SOUTH/SOUTHWEST FLOW ACROSS
THE WATERS THROUGH FRIDAY. THE FLOW WILL BECOME MORE OFFSHORE
SATURDAY AHEAD OF A BACKDOOR COLD FRONT LIKELY DROPPING INTO THE
WATERS LATE IN THE WEEKEND. WINDS WILL THEN VEER NORTHEAST BEHIND
THE FRONT SUNDAY AND MONDAY. WINDS AND SEAS ARE EXPECTED TO REMAIN
BELOW SMALL CRAFT ADVISORY THRESHOLDS INTO EARLY NEXT
WEEK...ALTHOUGH WINDS COULD SURGE AND SEAS BUILD IN THE NORTHEAST
FLOW BEHIND THE FRONT LATE IN THE WEEKEND INTO EARLY NEXT WEEK.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

SYNOPSIS...
NEAR TERM...JRL
SHORT TERM...JRL/JAQ
LONG TERM...JAQ
AVIATION...JRL/JAQ
MARINE...JRL/JAQ







AREA FORECAST DISCUSSION

NWS COLUMBIA SC

 421 AM EDT THU MAY 3 2012

.SYNOPSIS...
THE UPPER RIDGE WILL BEGIN TO WEAKEN FRIDAY AND A GRADUAL
INCREASE IN ATMOSPHERIC MOISTURE WILL PROVIDE A SLIGHT CHANCE OF
MAINLY AFTERNOON AND EARLY EVENING SHOWERS AND THUNDERSTORMS
FRIDAY THROUGH SUNDAY. A SERIES OF UPPER IMPULSES AND SURFACE
BOUNDARIES...ALONG WITH A CONTINUED INCREASE IN MOISTURE...WILL
PROVIDE A CHANCE OF SHOWERS AND THUNDERSTORMS EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
DEVELOPING STRATUS DECK ALONG WITH SOME FOG ACROSS THE EASTERN
MIDLANDS THIS MORNING ACROSS EASTERN GA INTO THE CSRA WILL
CONTINUE TO PROGRESS NORTH/NORTHWESTWARD THROUGH THE EARLY MORNING
HOURS. AS PREVIOUS MORNINGS...EXPECT THE DECK TO DISSIPATE WITH
DAYTIME HEATING BY MID/LATE MORNING. MID/UPPER LEVEL RIDGING
ACROSS THE CAROLINAS WILL CONTINUE TO DOMINATE THE WEATHER THROUGH
THE PERIOD. MODEL TIME SECTIONS SHOW LOW PW VALUES...HIGH LFC
VALUES ALONG WITH WEAK CAPPING THROUGH THE AFTERNOON WITH
RELATIVELY DRY ATMOSPHERE. EXPECT MOSTLY SUNNY SKIES AFTER MORNING
STRATUS ALONG WITH TEMPERATURES SIMILAR TO WEDNESDAY. BOUNDARY
LAYER TEMPERATURES NEARLY THE SAME TODAY...WELL ABOVE NORMAL FOR
EARLY MAY. GUIDANCE AND LOCAL NUMBERS HAVE CONTINUED TO BE A
DEGREE OR TWO TOO COOL THROUGH THE PERIOD AND WILL STAY JUST ABOVE
CONSENSUS. BY TONIGHT...RIDGE STILL HOLDS AND MODELS ONCE AGAIN
SHOW 20 TO 25 KT LOW LEVEL JET ALONG WITH SOME MOISTURE NEAR THE
SURFACE. ANOTHER ROUND OF SOME PATCHY FOG/STRATUS LIKELY TOWARD
MORNING. GUIDANCE AND LOCAL TEMPS VERY CLOSE...BUT WILL STAY WITH
THE TREND OF SLIGHTLY ABOVE GUIDANCE FOR OVERNIGHT MINS.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
THE RIDGE WILL BEGIN TO WEAKEN FRIDAY AS UPPER IMPULSES AND AN
AREA OF HIGHER ATMOSPHERIC MOISTURE TO OUR WEST SLOWLY DRIFTS
TOWARDS OUR REGION FROM THE SOUTHWEST/WEST. THE MID/UPPER LEVEL
FLOW ACROSS THE REGION WILL BECOME MORE NORTHWEST THROUGH THE
PERIOD WITH LOWERING HEIGHTS. THIS WILL INCREASE THE CHANCES FOR
AFTERNOON/EVENING CONVECTION ACROSS THE AREA THROUGH THE PERIOD.
WILL FORECAST SLIGHT CHANCE POPS INCREASING TO LOW CHANCE/SLIGHT
CHANCE BY SATURDAY AFTERNOON/SAT NIGHT. AS FOR
TEMPERATURES...GUIDANCE AND LOCAL NUMBERS SHOW A GRADUAL COOL
DOWN FRIDAY INTO SATURDAY FOR AFTERNOON HIGHS. WILL STAY NEAR THE
HIGH SIDE OF GUIDANCE FOR FRIDAY...BUT NEAR GUIDANCE FOR SAT WITH
ADDITIONAL MOISTURE/CLOUDS AND INCREASED CHANCE OF PRECIPITATION.
EXPECT OVERNIGHT LOWS TO REMAIN IN THE MIDDLE 60S. TEMPERATURES
THROUGH THE PERIOD WILL REMAIN MUCH ABOVE NORMAL.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
BOTH ECMWF/GFS FAIRLY SIMILAR IN EVOLUTION OF SYSTEMS THROUGH THE
EXTENDED PERIOD. MODELS GENERALLY INDICATE A SERIES OF UPPER
IMPULSES AND SURFACE BOUNDARIES TO AFFECT OUR REGION...ALONG WITH
A CONTINUED INCREASE IN ATMOSPHERIC MOISTURE THROUGH THE PERIOD.
LATEST GFS ENSEMBLE MOS POPS AND EXPERIMENTAL ECMWF MOS POPS HAVE
TRENDED UP SOMEWHAT FROM PREVIOUS RUNS. THIS IS IN LINE WITH
LATEST HPC GUIDANCE AS WELL...WHICH PROVIDES SLIGHT CHANCE POPS
SUN AND SLIGHT CHANCE/CHANCE MON THRU WED. TEMPERATURES THROUGH
THE PERIOD WILL BE A LITTLE COOLER THAN CURRENT TEMPERATURES.
EXPECT TEMPERATURES IN THE LOWER/MIDDLE 80S FOR HIGHS AND
LOWER/MIDDLE 60S FOR MINS THROUGH THE PERIOD...STILL SLIGHTLY
ABOVE NORMAL.

&&

.AVIATION /08Z THURSDAY THROUGH MONDAY/...
AS WITH THE PREVIOUS FEW NIGHT...DIURNAL COOLING AND LINGERING
LOW-LEVEL MOISTURE MAY SUPPORT STRATUS AFTER MIDNIGHT LASTING
THROUGH SUNRISE. GFS/NAM BUFKIT TIME SECTIONS SUPPORT THIS ALONG
WITH HRRR GUIDANCE.  STRATUS MORE FAVORABLE THAN FOG DUE TO
PERSISTENT LOW-LEVEL JET 20-25 KTS AROUND 1000 FT. FORECASTED A
PERIOD OF IFR STRATUS. THE STRATUS SHOULD MIX OUT LATER IN THE
MORNING BECAUSE OF STRONG HEATING...WITH VFR CONDITIONS THEN LASTING
THROUGH THE DAY.

EXTENDED AVIATION OUTLOOK FRIDAY THROUGH MONDAY...NO SIGNIFICANT
IMPACTS EXPECTED.

&&

.EQUIPMENT...
THE NATIONAL WEATHER SERVICE DOPPLER RADAR IN COLUMBIA SC WILL BE
OUT OF SERVICE THIS WEEK TO UPGRADE TO DUAL POLARIZATION TECHNOLOGY.
PLEASE REFER TO NEIGHBORING RADARS FOR COVERAGE.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$
SYNOPSIS...77
NEAR TERM...77
SHORT TERM...77
LONG TERM...77
AVIATION...99
EQUIPMENT...







AREA FORECAST DISCUSSION

NWS CHARLESTON SC

 207 AM EDT THU MAY 3 2012

.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL GRADUALLY SINK SOUTHWARD LATE IN THE
WEEK...AS A TROUGH OF LOW PRESSURE DEVELOPS INLAND. A COLD FRONT
COULD MOVE INTO THE REGION ON SUNDAY...THEN STALL NEAR THE AREA
INTO EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE FORECAST AREA WILL LIE UNDER AN AMPLIFYING RIDGE ALOFT OVER
THE SE AND WESTERN PORTION OF THE SUB TROPICAL ATLANTIC RIDGE.
LARGE SCALE SUBSIDENCE AND LITTLE TO NO MOISTURE ABOVE THE
BOUNDARY LAYER SUPPORTS YET ANOTHER NIGHT WITH NO PROSPECTS FOR
RAINFALL...AND OUR DEFICITS GROW FURTHER.

THE MAIN PROBLEM FOR TONIGHT WILL BE THE FORMATION OF FOG AND/OR
STRATUS AND WHETHER OR NOT THE FOG WILL BECOME DENSE ENOUGH FOR A
DENSE FOG ADVISORY. THE FSI VALUES ARE DOWN IN THE SINGLE NUMBERS
AND LOWER TEENS...AND TIME CROSS SECTIONS SHOW CLOSE TO 100
PERCENT RH TRAPPED BENEATH THE NOCTURNAL INVERSION. GEOSTROPHIC
WINDS ARE NO MORE THAN 5 OR 10 KT AND CROSS-OVER TEMPS WILL BE
APPROACHED IF NOT MET IN MANY PLACES. THIS SUGGESTS THAT DENSE FOG
WILL AGAIN DEVELOP. HOWEVER...A SERIOUS CONCERN WOULD BE THE
EXPANDING AREA OF CONVECTIVE CIRRIFORM CLOUDS FROM THE WEST THAT
WILL CONTINUE TO IMPACT WEST AND NW ZONES EARLY TONIGHT. IF THAT
CLOUDINESS HANGS ON THROUGH THE NIGHT IT WOULD LIKELY NEGATE THE
FORMATION OF DENSE FOG. FOR THAT REASON WE HAVE STILL OPTED NOT TO
INCLUDE DENSE FOG WORDING IN THE GRIDDED FORECAST...NOR TO INCLUDE
MENTION IN THE HAZARDOUS WEATHER OUTLOOK. WE WILL OBVIOUSLY NEED
TO CLOSELY EVALUATE THE SITUATION WITH SUBSEQUENT UPDATES THROUGH
THE NIGHT.

FOR NOW WE HAVE MAINTAINED AREAS OF FOG MAINLY NEAR AND WEST-NW
OF A LINE FROM JAMESTOWN TO SUMMERVILLE...CONTINUING TO
JACKSONBORO AND SWITZERLAND IN SC....THEN TO RINCON...FORT STEWART
AND LUDOWICI IN GA. DEVELOPMENT WILL NOT BE UNTIL AFTER 3 OR 4
AM...AS IT/LL TAKE THAT LONG FOR US TO START GETTING CLOSER TO OUR
CROSS-OVER TEMPS. IT IS ALSO THESE AREAS THAT HAVE THE BEST CHANCE
FOR DENSE FOG...BUT ONLY IF CLOUD COVER REMAINS THIN ENOUGH.

VERY SLIGHT WARMING IN THE BOUNDARY LAYER WILL PREVENT TEMPS FROM
FALLING ANY LOWER THAN THE LOWER AND MIDDLE 60S INLAND...AND THE
UPPER 60S AND LOWER 70S ALONG THE COAST. AND THERE IS A SHOT AT
TYING THE RECORD HIGH MINIMUM AT KCHL...WITH THAT MAY 3RD RECORD
OF 72 DEGREES LAST SET IN 2010.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY/...
THURSDAY AND THURSDAY NIGHT...DEEP LAYERED RIDGING WILL PREVAIL OVER
THE REGION. STRONG SUBSIDENCE AND A LACK OF MOISTURE WILL KEEP SKIES
MOSTLY CLEAR AND SUPPRESS ANY CONVECTIVE DEVELOPMENT. LOW LEVEL
THICKNESS VALUES CONTINUE TO ADVERTISE UNSEASONABLY WARM
TEMPERATURES...AND WILL INDICATE AFTERNOON HIGHS RANGING FROM THE
UPPER 80S TO LOWER 90S AWAY FROM THE LOCALLY COOLER COAST. NIGHTTIME
LOW TEMPERATURES WILL ALSO BE QUITE MILD...ONLY FALLING INTO THE MID
60S INLAND TO NEAR 70 AT THE COAST.

FRIDAY AND FRIDAY NIGHT...THE DEEP LAYERED RIDGING WILL GRADUALLY
WEAKEN...AS A SHORT WAVE TROUGH SHIFTS ACROSS THE REGION. AT THE
SAME TIME...A SURFACE TROUGH WILL FORM IN THE LEE OF THE
APPALACHIANS AND DESCEND TOWARD THE COAST LATE FRIDAY AND FRIDAY
NIGHT. A TRANSIENT SWATH OF DEEP MOISTURE WILL FOLLOW THE UPPER
LEVEL ENERGY ON FRIDAY...AND CONSIDERING LESS SUBSIDENCE AND A
WEAKER CAPPING INVERSION...THERE WILL BE A SLIGHT CHANCE FOR
SHOWERS AND THUNDERSTORMS ACROSS INLAND AREAS BY FRIDAY AFTERNOON.
WILL CONTINUE SLIGHT CHANCE POPS FOR MAINLY THE NORTHERN PORTIONS
OF THE FORECAST AREA BETWEEN SUNSET AND MIDNIGHT...AS THESE
LOCATIONS WILL BE NEAREST TO THE SHARPENING SURFACE TROUGH AND
SHORTWAVE ENERGY. SOUTHERLY FLOW AND HEIGHTS ALOFT WILL REMAIN
SUFFICIENT TO SUPPORT CONTINUED WARM TEMPERATURES...WITH HIGHS IN
THE UPPER 80S TO AROUND 90 INLAND AND LOWS IN THE MID TO UPPER
60S.

SATURDAY...UPPER LEVEL RIDGING WILL AMPLIFY OVER THE WESTERN GULF
OF MEXICO...RESULTING IN A MORE NORTHWEST COMPONENT TO THE FLOW
ALOFT. A SERIES OF WEAK SHORTWAVES WILL DESCEND INTO THE REGION
ALONG THE PERIPHERY OF THE GULF RIDGE...WHILE A BACKDOOR FRONT
DEVELOPS WITHIN THE APPROACHING INLAND SURFACE TROUGH. THESE
FEATURES WILL SUPPORT A BIT MORE CONVERGENCE AND FORCING FOR
ASCENT...AND WILL INDICATE SLIGHT CHANCE POPS ACROSS MUCH OF THE
FORECAST AREA ACCORDINGLY. DOWNSLOPE FLOW AND PERHAPS SOME PRE
FRONTAL COMPRESSION WILL ALLOW TEMPERATURES TO RISE TO AROUND 90
DEGREES FOR MOST AREAS AWAY FROM THE IMMEDIATE COASTLINE.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
A BUILDING RIDGE TO THE WEST WILL RESULT IN A NORTHWEST FLOW ALOFT
ACROSS THE REGION LATE IN THE WEEKEND...WHICH SHOULD ENABLE A
BACKDOOR COLD FRONT TO DROP INTO THE AREA. THIS FRONT COULD THEN
STALL NEAR OR JUST SOUTH OF THE AREA INTO EARLY NEXT WEEK AS HIGH
PRESSURE BUILDS FROM THE NORTH. THE HIGH WILL EVENTUALLY SHIFT INTO
THE WESTERN ATLANTIC BY THE MIDDLE OF NEXT WEEK.

THIS OVERALL PATTERN WILL FAVOR INCLUDING A SLIGHT CHANCE OF SHOWERS
AND THUNDERSTORMS IN THE FORECAST THROUGH NEARLY THE ENTIRE LONG
TERM PERIOD...ALTHOUGH MOST OF THE CONVECTION SHOULD GENERALLY OCCUR
DURING THE AFTERNOON/EVENING HOURS DUE TO DIURNAL INFLUENCES.
TEMPERATURES WILL REMAIN WELL ABOVE NORMAL THROUGH THE END OF THE
WEEKEND...THEN MODERATE ONLY A BIT EARLY NEXT WEEK BEHIND THE FRONT.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
FOG DEVELOPMENT IS AGAIN THE PRIMARY CONCERN THIS MORNING. A VERY
SIMILAR PATTERN EXISTS SINCE 24-HOURS PRIOR WITH THE EXCEPTION OF
A BIT OF CIRRUS OVERSPREADING THE AREA FROM UPSTREAM CONVECTION.
HOWEVER THE CIRRUS APPEARS TO BE DISSIPATING...LEAVING MOSTLY
CLEAR SKIES IN MOST AREAS. THE LATEST HRRR VISIBILITY PLOT SHOWS
THE DENSEST FOG REMAINING JUST INLAND FROM THE TERMINALS SIMILAR
TO WEDNESDAY MORNING. WE ARE KEEPING WITH A PERSISTENCE FORECAST
OVERNIGHT WITH VFR CONDITIONS AT BOTH TERMINALS FOR THE NEXT 24
HRS.

EXTENDED AVIATION OUTLOOK...MVFR OR LOWER CONDITIONS WILL BE
POSSIBLE DURING THE LATE NIGHT/EARLY MORNING HOURS INTO THE
WEEKEND DUE TO LOW CLOUDS/FOG.

&&

.MARINE...
THE SUB TROPICAL RIDGE AXIS WILL EXTEND ACROSS THE COASTAL WATERS
TONIGHT...WITH SE AND SOUTH WINDS EARLY VEERING TO SOUTH AND SW
OVERNIGHT AS LAND BREEZE CIRCULATIONS ATTEMPT TO FORM. WIND SPEEDS
WILL HOLD AT 12 KT OR LESS...WHILE SEAS WILL BE NO HIGHER THAN 2-4
FT /HIGHEST ACROSS THE AMZ374 WATERS/.

ATLANTIC HIGH PRESSURE WILL MAINTAIN A SOUTH/SOUTHWEST FLOW
ACROSS THE WATERS THROUGH FRIDAY. THE FLOW WILL BECOME MORE
OFFSHORE SATURDAY AHEAD OF A BACKDOOR COLD FRONT LIKELY DROPPING
INTO THE WATERS LATE IN THE WEEKEND. WINDS WILL THEN VEER NORTHEAST
BEHIND THE FRONT LATE SUNDAY AND MONDAY. WINDS AND SEAS ARE
EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS INTO
EARLY NEXT WEEK...ALTHOUGH WINDS COULD SURGE AND SEAS BUILD IN THE
NORTHEAST FLOW BEHIND THE FRONT LATE SUNDAY AND MONDAY.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

SYNOPSIS...
NEAR TERM...JRL
SHORT TERM...79
LONG TERM...JAQ/79
AVIATION...JRL
MARINE...79







AREA FORECAST DISCUSSION

NWS COLUMBIA SC

 128 AM EDT THU MAY 3 2012

.SYNOPSIS...
THE UPPER RIDGE WILL BEGIN TO WEAKEN FRIDAY AND A GRADUAL
INCREASE IN ATMOSPHERIC MOISTURE WILL PROVIDE A SLIGHT CHANCE OF
MAINLY AFTERNOON AND EARLY EVENING SHOWERS AND THUNDERSTORMS
FRIDAY THROUGH SUNDAY. A SERIES OF UPPER IMPULSES AND SURFACE
BOUNDARIES...ALONG WITH A CONTINUED INCREASE IN MOISTURE...WILL
PROVIDE A CHANCE OF SHOWERS AND THUNDERSTORMS EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
WV LOOP SHOWS RIDGING CONTINUING TO DOMINATE THE WEATHER ACROSS
THE AREA OVERNIGHT. MODEL TIME SECTIONS INDICATE ANOTHER LOW LEVEL
JET FROM 20 TO 25 KTS ALONG WITH SOME SHALLOW LOW LEVEL MOISTURE
THROUGH THE EARLY MORNING HOURS. EXPECT...AS PER THE PAST FEW
MORNINGS TO SEE SOME PREDAWN STRATUS DEVELOPMENT ACROSS THE
REGION. ADJUSTED SKY GRIDS A BIT HIGHER TO ACCOUNT FOR STRATUS
AND SOME CONVECTIVE DEBRIS CLOUDS MOVING IN FROM THE WEST.
HAVE ALSO RAISED OVERNIGHT MINS ABOUT A DEGREE BASED ON CURRENT
OBS.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY NIGHT/...
AN UPPER LEVEL RIDGE WILL REMAIN IN PLACE OVER OUR
FORECAST AREA THROUGH THURSDAY...MAINTAINING FAIR AND WARM
CONDITIONS. THE RIDGE WILL BEGIN TO WEAKEN FRIDAY AS UPPER
IMPULSES AND AN AREA OF HIGHER ATMOSPHERIC MOISTURE TO OUR WEST
SLOWLY DRIFTS TOWARDS OUR REGION. WILL MAINTAIN GOING FORECAST OF
SLIGHT CHANCE POPS FRIDAY AFTERNOON/EARLY EVENING.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
MADE NO SIGNIFICANT CHANGES TO THE ONGOING FORECAST FOR THIS TIME
PERIOD AS WELL. MODELS GENERALLY INDICATE A SERIES OF UPPER
IMPULSES AND SURFACE BOUNDARIES TO AFFECT OUR REGION...ALONG WITH
A CONTINUED INCREASE IN ATMOSPHERIC MOISTURE THROUGH THE PERIOD.
LATEST GFS ENSEMBLE MOS POPS AND EXPERIMENTAL ECMWF MOS POPS HAVE
TRENDED UP SOME. THIS IS IN LINE WITH LATEST HPC GUIDANCE AS
WELL...WHICH PROVIDES SLIGHT CHANCE POPS SAT/SUN AND CHANCE MON
THRU WED...AND CONTINUES TO APPEAR REASONABLE.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS WITH THE PREVIOUS FEW NIGHT...DIURNAL COOLING AND LINGERING
LOW-LEVEL MOISTURE MAY SUPPORT STRATUS AFTER MIDNIGHT LASTING
THROUGH SUNRISE. GFS/NAM BUFKIT TIME SECTIONS SUPPORT THIS ALONG
WITH HRRR GUIDANCE.  STRATUS MORE FAVORABLE THAN FOG DUE TO
PERSISTENT LOW-LEVEL JET 20-25 KTS AROUND 1000 FT. FORECASTED A
PERIOD OF IFR STRATUS. THE STRATUS SHOULD MIX OUT LATER IN THE
MORNING BECAUSE OF STRONG HEATING...WITH VFR CONDITIONS THEN LASTING
THROUGH THE DAY.

EXTENDED AVIATION OUTLOOK FRIDAY THROUGH MONDAY...NO SIGNIFICANT
IMPACTS EXPECTED.

&&

.EQUIPMENT...
THE NATIONAL WEATHER SERVICE DOPPLER RADAR IN COLUMBIA SC WILL BE
OUT OF SERVICE THIS WEEK TO UPGRADE TO DUAL POLARIZATION TECHNOLOGY.
PLEASE REFER TO NEIGHBORING RADARS FOR COVERAGE.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$
SYNOPSIS...77
NEAR TERM...77
SHORT TERM...
LONG TERM...
AVIATION...99
EQUIPMENT...







AREA FORECAST DISCUSSION

NWS CHICAGO/ROMEOVILLE IL

 1004 PM CDT FRI MAY 4 2012

.DISCUSSION...
737 PM CDT

CONCERNS FOR TONIGHT INCLUDE CONVECTIVE CHANCES...ESPECIALLY ACROSS
NORTH CENTRAL ILLINOIS AND AREAS OF FOG ACROSS NORTHEASTERN ILLINOIS
AND NORTHWESTERN INDIANA.

A COLD FRONT HAS PUSHED ACROSS PORTIONS OF NORTH CENTRAL AND
NORTHEASTERN ILLINOIS WITH NORTHEASTERLY FLOW BRINGING COLDER
TEMPERATURES...LOW CLOUDS AND AREAS OF MARINE FOG ONSHORE ACROSS
NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA. AREAS OF DENSE FOG
HAVE BEEN IN PLACE ACROSS SOUTHERN LAKE MICHIGAN FOR MUCH OF THE DAY
AND AS THE WINDS CONTINUE TO VEER TO THE EAST TONIGHT...LOW CLOUDS
AND FOG SHOULD CONTINUE TO PROGRESS INLAND ACROSS THE AREA. MODEL
BUFFER SOUNDINGS AND MODEL ENSEMBLES INDICATE THAT THIS MARINE LAYER
WILL CONTINUE TO PROGRESS INLAND ACROSS MOST OF NORTHEASTERN
ILLINOIS AND NORTHWESTERN INDIANA TONIGHT. WITH THIS IN MIND...I
ADDED FOG TO THE GOING FORECAST TONIGHT. AREAS OF DENSE FOG ARE
POSSIBLE...AND WE WILL MONITOR FOR A POSSIBLE DENSE FOG ADVISORY.

THE OTHER CONCERN TONIGHT IS THE MATURE BOWING MCS CURRENTLY MOVING
EASTWARD ACROSS NORTHERN IA AND SOUTHERN MN. THIS AREA OF CONVECTION
IS ASSOCIATED WITH A MID LEVEL DISTURBANCE PROPAGATING ACROSS FAR
SOUTHERN MN. THIS BOWING MCS WILL ENCOUNTER A MUCH MORE STABLE
ATMOSPHERE AS IT CONTINUES TO MOVE EASTWARD TOWARD SOUTHERN WI AND
NORTHWESTERN IL THIS EVENING. THE LATEST MESOANALYSIS INDICATES ML
CAPES QUICKLY DROPPING UNDER 500 J/KG ACROSS NORTHWESTERN ILLINOIS
WITHIN THE POST COLD FRONTAL AIRMASS. WITH THIS IN MIND...THE MCS
IS EXPECTED TO WEAKEN LATER THIS EVENING AS IT APPROACHES NORTH
CENTRAL ILLINOIS. THEREFORE...ONLY A FEW LEFT OVER SHOWERS ARE
POSSIBLE FROM THIS ACTIVITY ACROSS PORTIONS OF NORTHERN ILLINOIS
LATER THIS EVENING TONIGHT. A FEW SHOWERS HAVE ALSO DEVELOPED
ALONG THE FRONTAL BOUNDARY ACROSS NORTHWESTERN ILLINOIS...THESE
SHOWERS SHOULD DISSIPATE SHORTLY AFTER SUNSET.

KJB

//PREV DISCUSSION...
259 PM CDT

THE MAIN CONCERNS OVER THE COMING DAYS WILL BE THE LOW CHANCES
THUNDERSTORMS ACROSS THE SOUTHWESTERN PORTION OF THE CWA
TONIGHT...AND THEN THE CHANCES FOR THUNDERSTORMS SUNDAY AFTERNOON.

FOR TONIGHT...
THE LATEST SURFACE AND OBSERVED TRENDS SHOW THAT A COOL FRONT LAY
DRAPED ACROSS MUCH OF THE CWA. AS OF THE EARLY AFTERNOON HOURS THE
BOUNDARY STRETCHES FROM KVPZ TO JUST NORTH OF KJOT....THROUGH
NORTHERN DEKALB COUNTY AND INTO WESTERN WINNEBAGO COUNTY. BEHIND
THIS FEATURE WINDS BECAME NORTHERLY TO NORTHEASTERLY...PULLING IN
THE COLD MARINE AIRMASS INTO THE LAND. TEMPS ACROSS CHICAGO PEAKED
THIS MORNING AND HAVE SINCE FALLEN THROUGH THE DAY. TO THROW
INSULT TO INJURY FOR COASTAL LOCATIONS THIS MORNING...THE CHILLY
AIRMASS COLLIDED WITH THE WARM AND HUMID AIRMASS THIS
MORNING...ALLOWING FOG...SOMETIMES THICK AT TIMES TO DEVELOP AND
MEANDER INLAND. GENERALLY SKIES HAVE CLEARED AS OF THIS
AFTERNOON...BUT SOME PATCHY AREAS PERSIST THIS AFTERNOON.

THE SURFACE BOUNDARY IS CLEARLY DENOTED ON VISIBLE IMAGERY THIS
AFTERNOON...AS SURFACE CONVERGENCE IS ALLOWING SOME CU TO POP.
DESPITE THE WARM TEMPERATURES AND HIGH DEWPOINTS PERSISTING...THE
OVERALL ATMOSPHERE IS RATHER WORKED OVER FROM LAST NIGHT AND
OBJECTIVE SPC RAP ANALYSIS CONTINUES TO HIGHLIGHT PERSISTENT CIN
IN PLACE. THE HIGHEST AXIS OF INSTABILITY IS WELL TO THE SOUTH AND
WEST THIS AFTERNOON...AND THAT IS WHERE THE HIGHEST LIKELIHOOD OF
THUNDERSTORM ACTIVITY WILL REMAIN. MODIFIED SOUNDINGS FROM
DAVENPORT SHOW THAT THERE IS MODERATE ELEVATED CAPE /ON THE ORDER
OF 1000 TO 1500 J-KG/. COUPLED WITH THE CONTINUED HIGH PWAT
AIRMASS AND SOME WEAK SURFACE CONVERGENCE ALONG THE
BOUNDARY...WOULDNT BE SURPRISED AT SEEING SOME SHOWERS DEVELOP AND
PERHAPS A CLAP OF THUNDER LATER THIS AFTERNOON AND INTO THE
EVENING HOURS. ONE BIG LACKING INGREDIENT THIS AFTERNOON IS SHEAR
ACROSS OUR AREA. THE BETTER OF THE SHEAR IS WELL TO OUR SOUTH AS A
THE REMNANTS OF A SH/WV IS SHOOTING ACROSS SOUTHERN ILLINOIS AND
SHOWERS AND SOME STRONG STORMS ARE SHOOTING EAST OF ST LOUIS TO
EFFINGHAM. THE SECOND WAVE IS LIFTING THROUGH THE DAKOTAS...AND
WILL MOVE INTO MINNESOTA AND EVENTUALLY NORTHERN
WISCONSIN...LEAVING OUR AREA IN THE VOID OF ANY ORGANIZED
CONVECTION SUPPORTING SHEAR. SO...WHATEVER DOES DECIDE TO POP THIS
AFTERNOON SHOULD GO UP AND COME DOWN IN A QUICK FASHION. WITH THE
HIGH PWATS /ON THE ORDER OF 1.3 TO 1.6 INCHES/ THROUGH THE
COLUMN...ANY OF THESE SHOWERS WILL QUICKLY DROP A GOOD AMOUNT OF
RAIN...BUT OVER A CONFINED AREA. HIGH RESOLUTION GUIDANCE IS
PRETTY CONSISTENT WITH KEEPING THE ACTIVITY FOR OUR AREA GENERALLY
FROM A ROCKFORD TO MENDOTA TO KANKAKEE CORRIDOR. THOUGH THE RAP IS
OVERDONE ACROSS THE SOUTHERN COUNTIES AS OF 20Z...AND THE HRRR IS
TRYING TO SHOW SOME ACTIVITY BEGINNING TO BUBBLE AROUND 02Z.
PRESENT CU FIELD LOOKS ANEMIC...AND GENERALLY THE REST OF THE
AFTERNOON SHOULD REMAIN CALM.

HIGH TEMPERATURES WILL RANGE GREATLY FROM NORTHEAST TO SOUTHWEST
THIS WEEKEND. THE FRONTAL BOUNDARY IS NOT EXPECTED TO MOVE MUCH FROM
ITS PRESENT LOCATION...RATHER MEANDER SLIGHTLY AND WASH OUT. AREAS
NORTH OF THIS WILL REMAIN COLDER WITH A COOL NORTHEAST COMPONENT TO
THE WINDS...WHILE AREAS SOUTH WILL GENERALLY STAY WARMER. AN UPPER
LEVEL RIDGE WILL THEN SWING ACROSS THE AREA AND GUIDANCE STILL
INDICATES A NICE LITTLE RIDGE ROLLER MOVING THROUGH AND BRINGING THE
BETTER CHANCES SHOWERS AND THUNDERSTORMS TO THE REGION OVERNIGHT ON
SUNDAY. PWATS WILL STILL BE FLIRTING WITH THE HIGH SIDE THROUGH
THIS TIME...AND THE CHANCES FOR HEAVY RAINFALL WILL PERSIST
THROUGH THAT EVENT. AS THE RIDGE SLIDES EAST AND A TROUGH MOVES
THROUGH...THE AREA WILL GENERALLY FALL BACK INTO A COOLER
NORTHWESTERLY FLOW REGIME KEEPING DAYTIME HIGHS CLOSER TO SEASONAL
WITH OFF AND ON CHANCES FOR SHOWERS THROUGH THE WEEK.

SHEA

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 03Z...

* IFR CIGS REDEVELOPING OVERNIGHT.

* GRADUAL VIS REDUCTION TO 4-6SM OVERNIGHT.

* LOW PROBABILITY POTENTIAL FOR LIGHT RAIN OVERNIGHT.

RATZER

//DISCUSSION...UPDATED 03Z...

IFR/LIFR CONDITIONS WHICH SPREAD INTO THE ORD/MDW/GYY TERMINALS
EARLIER THIS EVENING HAVE JUST AS QUICKLY RETREATED EAST OF THE
AIRFIELDS AS OF 03Z...DUE TO LOW LEVEL WINDS BACKING MORE NORTH IN
ASSOCIATION WITH THERMALLY INDUCED HIGH PRESSURE RIDGE ALONG/WEST
OF LAKE MICHIGAN. THIS REALLY COMPLICATES CIG/VIS FORECAST FOR THE
NEXT FEW HOURS...THOUGH GUIDANCE CONTINUES TO INDICATE WINDS WILL
EVENTUALLY VEER MORE EAST-NORTHEAST OVERNIGHT WHICH WOULD LIKELY
BRING IFR CONDITIONS BACK INTO THE TERMINALS LATER TONIGHT.
CONFIDENCE HAS DECREASED A BIT THOUGH GIVEN CURRENT FLUCTUATIONS
SO HAVE BACKED OFF LOWER END VIS FOR NOW.

ON A MORE POSITIVE NOTE...THUNDERSTORM COMPLEX THAT WAS OVER
NORTHERN IA AT 00Z IS WEAKENING AS EXPECTED AS IT MOVES ACROSS THE
MISSISSIPPI INTO WESTERN WI. STILL SOME POTENTIAL FOR SHOWERS WITH
THIS FEATURE MAINLY ALONG THE IL/WI BORDER AFTER MIDNIGHT AS THE
MID-LEVEL CIRCULATION PASSES NORTH OF THE TERMINALS.

RATZER

PREVIOUS DISCUSSION FROM 00Z...

COLD FRONT CONTINUES TO SAG SOUTH ALONG A ROUGHLY DBQ-BMI-LAF LINE
EARLY THIS EVENING. IFR CIGS/FOG ALONG/OVER LAKE MICHIGAN DURING
THE AFTERNOON HAS SPREAD INLAND TO PWK-ORD-MDW WITH NORTHEAST LOW
LEVEL WINDS OFF THE LAKE...AND WITH COOLING TEMPS SPREADING IN
BEHIND FRONT COMBINED WITH NOCTURNAL TEMP DROP SHOULD MAINTAIN IFR
CIGS OVERNIGHT WITH VIS GRADUALLY DROPPING INTO THE 4-6SM RANGE.
FORECAST SOUNDINGS INDICATE THESE CONDITIONS TO PREVAIL THROUGH
SUNRISE SATURDAY MORNING...BEFORE DIURNAL WARMING ALLOWS LIFTING
AND EVENTUALLY SCATTERING OF LOWER CLOUDS THROUGH MID-DAY.

ANOTHER CONCERN IS THUNDERSTORM COMPLEX CURRENTLY OVER NORTH
CENTRAL IOWA. INSTABILITY DECREASES RAPIDLY FARTHER NORTH/EAST OF
COLD FRONT...THUS EXPECTATION IS THAT STRONG/SEVERE CONVECTION
WILL RAPIDLY DECAY AS THIS COMPLEX MOVES ACROSS THE MISSISSIPPI
RIVER LATE THIS EVENING. HOWEVER...RADAR/SATELLITE DEPICT A RATHER
WELL-DEFINED MID-LEVEL CIRCULATION ASSOCIATED WITH THIS COMPLEX
WHICH WILL LIKELY CONTINUE TO MOVE EAST ACROSS SOUTHERN WI
OVERNIGHT. THIS COULD MAINTAIN SOME RAIN/SHOWERS ACROSS FAR
NORTHERN IL AFTER MIDNIGHT...THOUGH LATEST HIGH-RES MODEL RUNS
INDICATE PRECIPITATION MAINLY NORTH OF THE IL/WI BORDER. HAVE
INCLUDED A TEMPO FOR -SHRA AT RFD FOR A FEW HOURS AFTER
MIDNIGHT...THOUGH WILL NEED TO MONITOR MCS TRENDS THIS EVENING.
FRONT IS FORECAST TO REMAIN ACROSS FAR WEST/SOUTH PARTS OF THE WFO
CHICAGO FORECAST AREA SATURDAY...AND WILL MAINTAIN LOW PROBABILITY
POTENTIAL FOR AFTERNOON THUNDERSTORM DEVELOPMENT MAINLY WELL
WEST/SOUTH OF TERMINALS. RFD WOULD LIKELY HAVE THE GREATEST...
THOUGH STILL LOW...POTENTIAL OF BEING IMPACTED DIRECTLY BY
CONVECTION SATURDAY AFTERNOON.

WIND WISE...NORTHEAST WINDS AROUND 10 KTS SHOULD GRADUALLY BECOME
MORE EASTERLY THROUGH EARLY SATURDAY...AND SOUTHEAST BY SATURDAY
AFTERNOON. CHICAGO AREA TERMINALS WILL LIKELY MAINTAIN A MORE
EASTERLY WIND SATURDAY AFTERNOON HOWEVER WITH SOME HELP FROM LAKE
BREEZE.

RATZER

//ORD AND MDW CONFIDENCE...UPDATED 03Z...

* MEDIUM-HIGH CONFIDENCE IN IFR CONDITIONS REDEVELOPING OVERNIGHT.

* MEDIUM CONFIDENCE IN TIMING IMPROVEMENT THROUGH MVFR/VFR BY MID
  DAY SATURDAY.

* MEDIUM-HIGH CONFIDENCE IN SHRA/TSRA NOT IMPACTING ORD/MDW
  IMMEDIATE TERMINAL AREAS OVERNIGHT.

RATZER

//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...

SUNDAY THROUGH WEDNESDAY...GENERALLY VFR BUT PERIODIC
CHANCES FOR SHRA/TSRA. THE BEST CHANCE APPEARS TO BE SUNDAY NIGHT
AND MONDAY.

THURSDAY...VFR.

RATZER

&&

.MARINE...
229 PM CDT

A COLD FRONT HAS MOVED ACROSS LAKE MICHIGAN TODAY WITH NORTHERLY
WINDS SETTING UP BEHIND THE FRONT. THE FRONTAL BOUNDARY IS FORECAST
TO STALL ACROSS CENTRAL ILLINOIS THIS EVENING WHILE HIGH PRESSURE
BUILDS ACROSS ONTARIO...THEN EVENTUALLY EAST INTO QUEBEC LATE
SATURDAY INTO SUNDAY. NORTHERLY WINDS WILL GRADUALLY VEER TO THE
NORTHEAST AND EAST AS THE HIGH TRANSLATES EAST. ON SUNDAY...THE
FRONTAL BOUNDARY WILL WAVE NORTHWARD WITH WINDS BECOMING
SOUTHEASTERLY...THEN A COLD FRONT SWEEPS ACROSS THE LAKE ON MONDAY
ALLOWING NORTHWEST/NORTH WINDS TO OVERSPREAD THE LAKE. ALL IN
ALL...NOT LOOKING AT ANY HIGH IMPACT WIND SITUATIONS THROUGH THE
FIRST HALF OF NEXT WEEK...WITH THE STRONGEST WINDS EXPECTED OVER THE
NEXT 48 HRS OR SO IN THE 15 TO 25 KT RANGE.

ANOTHER CONCERN FOR TODAY IS THE FOG OVER THE OPEN WATERS. LATEST
VISIBLE SATELLITE IMAGERY STILL PARTLY BLOCKED BY HIGHER
CLOUDS...BUT LOOKING THROUGH THE GAPS IT DOES APPEAR THAT THERE IS
STILL AN EXPANSIVE AREA OF FOG OVER SOUTHERN LAKE MICHIGAN. DRIER
AIR WILL CONTINUE TO ERODE THIS AREA FROM THE NORTH...BUT IN THE
MEANTIME WILL EXTEND THE DENSE FOG ADVISORY THROUGH THIS EVENING.
BMD

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ080-LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
     LMZ745-LMZ777-LMZ779-LMZ878 UNTIL 11 AM SATURDAY.

&&

$$







AREA FORECAST DISCUSSION

NWS CHICAGO/ROMEOVILLE IL

 749 PM CDT FRI MAY 4 2012

.DISCUSSION...
737 PM CDT

CONCERNS FOR TONIGHT INCLUDE CONVECTIVE CHANCES...ESPECIALLY ACROSS
NORTH CENTRAL ILLINOIS AND AREAS OF FOG ACROSS NORTHEASTERN ILLINOIS
AND NORTHWESTERN INDIANA.

A COLD FRONT HAS PUSHED ACROSS PORTIONS OF NORTH CENTRAL AND
NORTHEASTERN ILLINOIS WITH NORTHEASTERLY FLOW BRINGING COLDER
TEMPERATURES...LOW CLOUDS AND AREAS OF MARINE FOG ONSHORE ACROSS
NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA. AREAS OF DENSE FOG
HAVE BEEN IN PLACE ACROSS SOUTHERN LAKE MICHIGAN FOR MUCH OF THE DAY
AND AS THE WINDS CONTINUE TO VEER TO THE EAST TONIGHT...LOW CLOUDS
AND FOG SHOULD CONTINUE TO PROGRESS INLAND ACROSS THE AREA. MODEL
BUFFER SOUNDINGS AND MODEL ENSEMBLES INDICATE THAT THIS MARINE LAYER
WILL CONTINUE TO PROGRESS INLAND ACROSS MOST OF NORTHEASTERN
ILLINOIS AND NORTHWESTERN INDIANA TONIGHT. WITH THIS IN MIND...I
ADDED FOG TO THE GOING FORECAST TONIGHT. AREAS OF DENSE FOG ARE
POSSIBLE...AND WE WILL MONITOR FOR A POSSIBLE DENSE FOG ADVISORY.

THE OTHER CONCERN TONIGHT IS THE MATURE BOWING MCS CURRENTLY MOVING
EASTWARD ACROSS NORTHERN IA AND SOUTHERN MN. THIS AREA OF CONVECTION
IS ASSOCIATED WITH A MID LEVEL DISTURBANCE PROPAGATING ACROSS FAR
SOUTHERN MN. THIS BOWING MCS WILL ENCOUNTER A MUCH MORE STABLE
ATMOSPHERE AS IT CONTINUES TO MOVE EASTWARD TOWARD SOUTHERN WI AND
NORTHWESTERN IL THIS EVENING. THE LATEST MESOANALYSIS INDICATES ML
CAPES QUICKLY DROPPING UNDER 500 J/KG ACROSS NORTHWESTERN ILLINOIS
WITHIN THE POST COLD FRONTAL AIRMASS. WITH THIS IN MIND...THE MCS
IS EXPECTED TO WEAKEN LATER THIS EVENING AS IT APPROACHES NORTH
CENTRAL ILLINOIS. THEREFORE...ONLY A FEW LEFT OVER SHOWERS ARE
POSSIBLE FROM THIS ACTIVITY ACROSS PORTIONS OF NORTHERN ILLINOIS
LATER THIS EVENING TONIGHT. A FEW SHOWERS HAVE ALSO DEVELOPED
ALONG THE FRONTAL BOUNDARY ACROSS NORTHWESTERN ILLINOIS...THESE
SHOWERS SHOULD DISSIPATE SHORTLY AFTER SUNSET.

KJB

&&

.PREV DISCUSSION...
259 PM CDT

THE MAIN CONCERNS OVER THE COMING DAYS WILL BE THE LOW CHANCES
THUNDERSTORMS ACROSS THE SOUTHWESTERN PORTION OF THE CWA
TONIGHT...AND THEN THE CHANCES FOR THUNDERSTORMS SUNDAY AFTERNOON.

FOR TONIGHT...
THE LATEST SURFACE AND OBSERVED TRENDS SHOW THAT A COOL FRONT LAY
DRAPED ACROSS MUCH OF THE CWA. AS OF THE EARLY AFTERNOON HOURS THE
BOUNDARY STRETCHES FROM KVPZ TO JUST NORTH OF KJOT....THROUGH
NORTHERN DEKALB COUNTY AND INTO WESTERN WINNEBAGO COUNTY. BEHIND
THIS FEATURE WINDS BECAME NORTHERLY TO NORTHEASTERLY...PULLING IN
THE COLD MARINE AIRMASS INTO THE LAND. TEMPS ACROSS CHICAGO PEAKED
THIS MORNING AND HAVE SINCE FALLEN THROUGH THE DAY. TO THROW
INSULT TO INJURY FOR COASTAL LOCATIONS THIS MORNING...THE CHILLY
AIRMASS COLLIDED WITH THE WARM AND HUMID AIRMASS THIS
MORNING...ALLOWING FOG...SOMETIMES THICK AT TIMES TO DEVELOP AND
MEANDER INLAND. GENERALLY SKIES HAVE CLEARED AS OF THIS
AFTERNOON...BUT SOME PATCHY AREAS PERSIST THIS AFTERNOON.

THE SURFACE BOUNDARY IS CLEARLY DENOTED ON VISIBLE IMAGERY THIS
AFTERNOON...AS SURFACE CONVERGENCE IS ALLOWING SOME CU TO POP.
DESPITE THE WARM TEMPERATURES AND HIGH DEWPOINTS PERSISTING...THE
OVERALL ATMOSPHERE IS RATHER WORKED OVER FROM LAST NIGHT AND
OBJECTIVE SPC RAP ANALYSIS CONTINUES TO HIGHLIGHT PERSISTENT CIN
IN PLACE. THE HIGHEST AXIS OF INSTABILITY IS WELL TO THE SOUTH AND
WEST THIS AFTERNOON...AND THAT IS WHERE THE HIGHEST LIKELIHOOD OF
THUNDERSTORM ACTIVITY WILL REMAIN. MODIFIED SOUNDINGS FROM
DAVENPORT SHOW THAT THERE IS MODERATE ELEVATED CAPE /ON THE ORDER
OF 1000 TO 1500 J-KG/. COUPLED WITH THE CONTINUED HIGH PWAT
AIRMASS AND SOME WEAK SURFACE CONVERGENCE ALONG THE
BOUNDARY...WOULDNT BE SURPRISED AT SEEING SOME SHOWERS DEVELOP AND
PERHAPS A CLAP OF THUNDER LATER THIS AFTERNOON AND INTO THE
EVENING HOURS. ONE BIG LACKING INGREDIENT THIS AFTERNOON IS SHEAR
ACROSS OUR AREA. THE BETTER OF THE SHEAR IS WELL TO OUR SOUTH AS A
THE REMNANTS OF A SH/WV IS SHOOTING ACROSS SOUTHERN ILLINOIS AND
SHOWERS AND SOME STRONG STORMS ARE SHOOTING EAST OF ST LOUIS TO
EFFINGHAM. THE SECOND WAVE IS LIFTING THROUGH THE DAKOTAS...AND
WILL MOVE INTO MINNESOTA AND EVENTUALLY NORTHERN
WISCONSIN...LEAVING OUR AREA IN THE VOID OF ANY ORGANIZED
CONVECTION SUPPORTING SHEAR. SO...WHATEVER DOES DECIDE TO POP THIS
AFTERNOON SHOULD GO UP AND COME DOWN IN A QUICK FASHION. WITH THE
HIGH PWATS /ON THE ORDER OF 1.3 TO 1.6 INCHES/ THROUGH THE
COLUMN...ANY OF THESE SHOWERS WILL QUICKLY DROP A GOOD AMOUNT OF
RAIN...BUT OVER A CONFINED AREA. HIGH RESOLUTION GUIDANCE IS
PRETTY CONSISTENT WITH KEEPING THE ACTIVITY FOR OUR AREA GENERALLY
FROM A ROCKFORD TO MENDOTA TO KANKAKEE CORRIDOR. THOUGH THE RAP IS
OVERDONE ACROSS THE SOUTHERN COUNTIES AS OF 20Z...AND THE HRRR IS
TRYING TO SHOW SOME ACTIVITY BEGINNING TO BUBBLE AROUND 02Z.
PRESENT CU FIELD LOOKS ANEMIC...AND GENERALLY THE REST OF THE
AFTERNOON SHOULD REMAIN CALM.

HIGH TEMPERATURES WILL RANGE GREATLY FROM NORTHEAST TO SOUTHWEST
THIS WEEKEND. THE FRONTAL BOUNDARY IS NOT EXPECTED TO MOVE MUCH FROM
ITS PRESENT LOCATION...RATHER MEANDER SLIGHTLY AND WASH OUT. AREAS
NORTH OF THIS WILL REMAIN COLDER WITH A COOL NORTHEAST COMPONENT TO
THE WINDS...WHILE AREAS SOUTH WILL GENERALLY STAY WARMER. AN UPPER
LEVEL RIDGE WILL THEN SWING ACROSS THE AREA AND GUIDANCE STILL
INDICATES A NICE LITTLE RIDGE ROLLER MOVING THROUGH AND BRINGING THE
BETTER CHANCES SHOWERS AND THUNDERSTORMS TO THE REGION OVERNIGHT ON
SUNDAY. PWATS WILL STILL BE FLIRTING WITH THE HIGH SIDE THROUGH
THIS TIME...AND THE CHANCES FOR HEAVY RAINFALL WILL PERSIST
THROUGH THAT EVENT. AS THE RIDGE SLIDES EAST AND A TROUGH MOVES
THROUGH...THE AREA WILL GENERALLY FALL BACK INTO A COOLER
NORTHWESTERLY FLOW REGIME KEEPING DAYTIME HIGHS CLOSER TO SEASONAL
WITH OFF AND ON CHANCES FOR SHOWERS THROUGH THE WEEK.

SHEA

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 00Z...

* IFR CIGS THIS EVENING/OVERNIGHT.

* GRADUAL VIS REDUCTION TO 4-6SM THIS EVENING.

* LOW PROBABILITY POTENTIAL FOR LIGHT RAIN OVERNIGHT.

RATZER

//DISCUSSION...UPDATED 00Z...

COLD FRONT CONTINUES TO SAG SOUTH ALONG A ROUGHLY DBQ-BMI-LAF LINE
EARLY THIS EVENING. IFR CIGS/FOG ALONG/OVER LAKE MICHIGAN DURING
THE AFTERNOON HAS SPREAD INLAND TO PWK-ORD-MDW WITH NORTHEAST LOW
LEVEL WINDS OFF THE LAKE...AND WITH COOLING TEMPS SPREADING IN
BEHIND FRONT COMBINED WITH NOCTURNAL TEMP DROP SHOULD MAINTAIN IFR
CIGS OVERNIGHT WITH VIS GRADUALLY DROPPING INTO THE 4-6SM RANGE.
FORECAST SOUNDINGS INDICATE THESE CONDITIONS TO PREVAIL THROUGH
SUNRISE SATURDAY MORNING...BEFORE DIURNAL WARMING ALLOWS LIFTING
AND EVENTUALLY SCATTERING OF LOWER CLOUDS THROUGH MID-DAY.

ANOTHER CONCERN IS THUNDERSTORM COMPLEX CURRENTLY OVER NORTH
CENTRAL IOWA. INSTABILITY DECREASES RAPIDLY FARTHER NORTH/EAST OF
COLD FRONT...THUS EXPECTATION IS THAT STRONG/SEVERE CONVECTION
WILL RAPIDLY DECAY AS THIS COMPLEX MOVES ACROSS THE MISSISSIPPI
RIVER LATE THIS EVENING. HOWEVER...RADAR/SATELLITE DEPICT A RATHER
WELL-DEFINED MID-LEVEL CIRCULATION ASSOCIATED WITH THIS COMPLEX
WHICH WILL LIKELY CONTINUE TO MOVE EAST ACROSS SOUTHERN WI
OVERNIGHT. THIS COULD MAINTAIN SOME RAIN/SHOWERS ACROSS FAR
NORTHERN IL AFTER MIDNIGHT...THOUGH LATEST HIGH-RES MODEL RUNS
INDICATE PRECIPITATION MAINLY NORTH OF THE IL/WI BORDER. HAVE
INCLUDED A TEMPO FOR -SHRA AT RFD FOR A FEW HOURS AFTER
MIDNIGHT...THOUGH WILL NEED TO MONITOR MCS TRENDS THIS EVENING.
FRONT IS FORECAST TO REMAIN ACROSS FAR WEST/SOUTH PARTS OF THE WFO
CHICAGO FORECAST AREA SATURDAY...AND WILL MAINTAIN LOW PROBABILITY
POTENTIAL FOR AFTERNOON THUNDERSTORM DEVELOPMENT MAINLY WELL
WEST/SOUTH OF TERMINALS. RFD WOULD LIKELY HAVE THE GREATEST...
THOUGH STILL LOW...POTENTIAL OF BEING IMPACTED DIRECTLY BY
CONVECTION SATURDAY AFTERNOON.

WIND WISE...NORTHEAST WINDS AROUND 10 KTS SHOULD GRADUALLY BECOME
MORE EASTERLY THROUGH EARLY SATURDAY...AND SOUTHEAST BY SATURDAY
AFTERNOON. CHICAGO AREA TERMINALS WILL LIKELY MAINTAIN A MORE
EASTERLY WIND SATURDAY AFTERNOON HOWEVER WITH SOME HELP FROM LAKE
BREEZE.

RATZER

//ORD AND MDW CONFIDENCE...UPDATED 00Z...

* HIGH CONFIDENCE IN IFR CONDITIONS THROUGH EARLY SATURDAY
  MORNING.

* MEDIUM CONFIDENCE IN TIMING IMPROVEMENT THROUGH MVFR/VFR BY MID
  DAY SATURDAY.

* MEDIUM-HIGH CONFIDENCE IN SHRA/TSRA NOT IMPACTING ORD/MDW
  IMMEDIATE TERMINAL AREAS OVERNIGHT.

RATZER

//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...

SUNDAY THROUGH WEDNESDAY...GENERALLY VFR BUT PERIODIC
CHANCES FOR SHRA/TSRA. THE BEST CHANCE APPEARS TO BE SUNDAY NIGHT
AND MONDAY.

THURSDAY...VFR.

RATZER

&&

.MARINE...
229 PM CDT

A COLD FRONT HAS MOVED ACROSS LAKE MICHIGAN TODAY WITH NORTHERLY
WINDS SETTING UP BEHIND THE FRONT. THE FRONTAL BOUNDARY IS FORECAST
TO STALL ACROSS CENTRAL ILLINOIS THIS EVENING WHILE HIGH PRESSURE
BUILDS ACROSS ONTARIO...THEN EVENTUALLY EAST INTO QUEBEC LATE
SATURDAY INTO SUNDAY. NORTHERLY WINDS WILL GRADUALLY VEER TO THE
NORTHEAST AND EAST AS THE HIGH TRANSLATES EAST. ON SUNDAY...THE
FRONTAL BOUNDARY WILL WAVE NORTHWARD WITH WINDS BECOMING
SOUTHEASTERLY...THEN A COLD FRONT SWEEPS ACROSS THE LAKE ON MONDAY
ALLOWING NORTHWEST/NORTH WINDS TO OVERSPREAD THE LAKE. ALL IN
ALL...NOT LOOKING AT ANY HIGH IMPACT WIND SITUATIONS THROUGH THE
FIRST HALF OF NEXT WEEK...WITH THE STRONGEST WINDS EXPECTED OVER THE
NEXT 48 HRS OR SO IN THE 15 TO 25 KT RANGE.

ANOTHER CONCERN FOR TODAY IS THE FOG OVER THE OPEN WATERS. LATEST
VISIBLE SATELLITE IMAGERY STILL PARTLY BLOCKED BY HIGHER
CLOUDS...BUT LOOKING THROUGH THE GAPS IT DOES APPEAR THAT THERE IS
STILL AN EXPANSIVE AREA OF FOG OVER SOUTHERN LAKE MICHIGAN. DRIER
AIR WILL CONTINUE TO ERODE THIS AREA FROM THE NORTH...BUT IN THE
MEANTIME WILL EXTEND THE DENSE FOG ADVISORY THROUGH THIS EVENING.
BMD

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-
     LMZ779-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 PM FRIDAY.

&&

$$





AREA FORECAST DISCUSSION

NWS CHICAGO/ROMEOVILLE IL

 704 PM CDT FRI MAY 4 2012

.DISCUSSION...
259 PM CDT

THE MAIN CONCERNS OVER THE COMING DAYS WILL BE THE LOW CHANCES
THUNDERSTORMS ACROSS THE SOUTHWESTERN PORTION OF THE CWA
TONIGHT...AND THEN THE CHANCES FOR THUNDERSTORMS SUNDAY AFTERNOON.

FOR TONIGHT...
THE LATEST SURFACE AND OBSERVED TRENDS SHOW THAT A COOL FRONT LAY
DRAPED ACROSS MUCH OF THE CWA. AS OF THE EARLY AFTERNOON HOURS THE
BOUNDARY STRETCHES FROM KVPZ TO JUST NORTH OF KJOT....THROUGH
NORTHERN DEKALB COUNTY AND INTO WESTERN WINNEBAGO COUNTY. BEHIND
THIS FEATURE WINDS BECAME NORTHERLY TO NORTHEASTERLY...PULLING IN
THE COLD MARINE AIRMASS INTO THE LAND. TEMPS ACROSS CHICAGO PEAKED
THIS MORNING AND HAVE SINCE FALLEN THROUGH THE DAY. TO THROW
INSULT TO INJURY FOR COASTAL LOCATIONS THIS MORNING...THE CHILLY
AIRMASS COLLIDED WITH THE WARM AND HUMID AIRMASS THIS
MORNING...ALLOWING FOG...SOMETIMES THICK AT TIMES TO DEVELOP AND
MEANDER INLAND. GENERALLY SKIES HAVE CLEARED AS OF THIS
AFTERNOON...BUT SOME PATCHY AREAS PERSIST THIS AFTERNOON.

THE SURFACE BOUNDARY IS CLEARLY DENOTED ON VISIBLE IMAGERY THIS
AFTERNOON...AS SURFACE CONVERGENCE IS ALLOWING SOME CU TO POP.
DESPITE THE WARM TEMPERATURES AND HIGH DEWPOINTS PERSISTING...THE
OVERALL ATMOSPHERE IS RATHER WORKED OVER FROM LAST NIGHT AND
OBJECTIVE SPC RAP ANALYSIS CONTINUES TO HIGHLIGHT PERSISTENT CIN
IN PLACE. THE HIGHEST AXIS OF INSTABILITY IS WELL TO THE SOUTH AND
WEST THIS AFTERNOON...AND THAT IS WHERE THE HIGHEST LIKELIHOOD OF
THUNDERSTORM ACTIVITY WILL REMAIN. MODIFIED SOUNDINGS FROM
DAVENPORT SHOW THAT THERE IS MODERATE ELEVATED CAPE /ON THE ORDER
OF 1000 TO 1500 J-KG/. COUPLED WITH THE CONTINUED HIGH PWAT
AIRMASS AND SOME WEAK SURFACE CONVERGENCE ALONG THE
BOUNDARY...WOULDNT BE SURPRISED AT SEEING SOME SHOWERS DEVELOP AND
PERHAPS A CLAP OF THUNDER LATER THIS AFTERNOON AND INTO THE
EVENING HOURS. ONE BIG LACKING INGREDIENT THIS AFTERNOON IS SHEAR
ACROSS OUR AREA. THE BETTER OF THE SHEAR IS WELL TO OUR SOUTH AS A
THE REMNANTS OF A SH/WV IS SHOOTING ACROSS SOUTHERN ILLINOIS AND
SHOWERS AND SOME STRONG STORMS ARE SHOOTING EAST OF ST LOUIS TO
EFFINGHAM. THE SECOND WAVE IS LIFTING THROUGH THE DAKOTAS...AND
WILL MOVE INTO MINNESOTA AND EVENTUALLY NORTHERN
WISCONSIN...LEAVING OUR AREA IN THE VOID OF ANY ORGANIZED
CONVECTION SUPPORTING SHEAR. SO...WHATEVER DOES DECIDE TO POP THIS
AFTERNOON SHOULD GO UP AND COME DOWN IN A QUICK FASHION. WITH THE
HIGH PWATS /ON THE ORDER OF 1.3 TO 1.6 INCHES/ THROUGH THE
COLUMN...ANY OF THESE SHOWERS WILL QUICKLY DROP A GOOD AMOUNT OF
RAIN...BUT OVER A CONFINED AREA. HIGH RESOLUTION GUIDANCE IS
PRETTY CONSISTENT WITH KEEPING THE ACTIVITY FOR OUR AREA GENERALLY
FROM A ROCKFORD TO MENDOTA TO KANKAKEE CORRIDOR. THOUGH THE RAP IS
OVERDONE ACROSS THE SOUTHERN COUNTIES AS OF 20Z...AND THE HRRR IS
TRYING TO SHOW SOME ACTIVITY BEGINNING TO BUBBLE AROUND 02Z.
PRESENT CU FIELD LOOKS ANEMIC...AND GENERALLY THE REST OF THE
AFTERNOON SHOULD REMAIN CALM.

HIGH TEMPERATURES WILL RANGE GREATLY FROM NORTHEAST TO SOUTHWEST
THIS WEEKEND. THE FRONTAL BOUNDARY IS NOT EXPECTED TO MOVE MUCH FROM
ITS PRESENT LOCATION...RATHER MEANDER SLIGHTLY AND WASH OUT. AREAS
NORTH OF THIS WILL REMAIN COLDER WITH A COOL NORTHEAST COMPONENT TO
THE WINDS...WHILE AREAS SOUTH WILL GENERALLY STAY WARMER. AN UPPER
LEVEL RIDGE WILL THEN SWING ACROSS THE AREA AND GUIDANCE STILL
INDICATES A NICE LITTLE RIDGE ROLLER MOVING THROUGH AND BRINGING THE
BETTER CHANCES SHOWERS AND THUNDERSTORMS TO THE REGION OVERNIGHT ON
SUNDAY. PWATS WILL STILL BE FLIRTING WITH THE HIGH SIDE THROUGH
THIS TIME...AND THE CHANCES FOR HEAVY RAINFALL WILL PERSIST
THROUGH THAT EVENT. AS THE RIDGE SLIDES EAST AND A TROUGH MOVES
THROUGH...THE AREA WILL GENERALLY FALL BACK INTO A COOLER
NORTHWESTERLY FLOW REGIME KEEPING DAYTIME HIGHS CLOSER TO SEASONAL
WITH OFF AND ON CHANCES FOR SHOWERS THROUGH THE WEEK.

SHEA

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 00Z...

* IFR CIGS THIS EVENING/OVERNIGHT.

* GRADUAL VIS REDUCTION TO 4-6SM THIS EVENING.

* LOW PROBABILITY POTENTIAL FOR LIGHT RAIN OVERNIGHT.

RATZER

//DISCUSSION...UPDATED 00Z...

COLD FRONT CONTINUES TO SAG SOUTH ALONG A ROUGHLY DBQ-BMI-LAF LINE
EARLY THIS EVENING. IFR CIGS/FOG ALONG/OVER LAKE MICHIGAN DURING
THE AFTERNOON HAS SPREAD INLAND TO PWK-ORD-MDW WITH NORTHEAST LOW
LEVEL WINDS OFF THE LAKE...AND WITH COOLING TEMPS SPREADING IN
BEHIND FRONT COMBINED WITH NOCTURNAL TEMP DROP SHOULD MAINTAIN IFR
CIGS OVERNIGHT WITH VIS GRADUALLY DROPPING INTO THE 4-6SM RANGE.
FORECAST SOUNDINGS INDICATE THESE CONDITIONS TO PREVAIL THROUGH
SUNRISE SATURDAY MORNING...BEFORE DIURNAL WARMING ALLOWS LIFTING
AND EVENTUALLY SCATTERING OF LOWER CLOUDS THROUGH MID-DAY.

ANOTHER CONCERN IS THUNDERSTORM COMPLEX CURRENTLY OVER NORTH
CENTRAL IOWA. INSTABILITY DECREASES RAPIDLY FARTHER NORTH/EAST OF
COLD FRONT...THUS EXPECTATION IS THAT STRONG/SEVERE CONVECTION
WILL RAPIDLY DECAY AS THIS COMPLEX MOVES ACROSS THE MISSISSIPPI
RIVER LATE THIS EVENING. HOWEVER...RADAR/SATELLITE DEPICT A RATHER
WELL-DEFINED MID-LEVEL CIRCULATION ASSOCIATED WITH THIS COMPLEX
WHICH WILL LIKELY CONTINUE TO MOVE EAST ACROSS SOUTHERN WI
OVERNIGHT. THIS COULD MAINTAIN SOME RAIN/SHOWERS ACROSS FAR
NORTHERN IL AFTER MIDNIGHT...THOUGH LATEST HIGH-RES MODEL RUNS
INDICATE PRECIPITATION MAINLY NORTH OF THE IL/WI BORDER. HAVE
INCLUDED A TEMPO FOR -SHRA AT RFD FOR A FEW HOURS AFTER
MIDNIGHT...THOUGH WILL NEED TO MONITOR MCS TRENDS THIS EVENING.
FRONT IS FORECAST TO REMAIN ACROSS FAR WEST/SOUTH PARTS OF THE WFO
CHICAGO FORECAST AREA SATURDAY...AND WILL MAINTAIN LOW PROBABILITY
POTENTIAL FOR AFTERNOON THUNDERSTORM DEVELOPMENT MAINLY WELL
WEST/SOUTH OF TERMINALS. RFD WOULD LIKELY HAVE THE GREATEST...
THOUGH STILL LOW...POTENTIAL OF BEING IMPACTED DIRECTLY BY
CONVECTION SATURDAY AFTERNOON.

WIND WISE...NORTHEAST WINDS AROUND 10 KTS SHOULD GRADUALLY BECOME
MORE EASTERLY THROUGH EARLY SATURDAY...AND SOUTHEAST BY SATURDAY
AFTERNOON. CHICAGO AREA TERMINALS WILL LIKELY MAINTAIN A MORE
EASTERLY WIND SATURDAY AFTERNOON HOWEVER WITH SOME HELP FROM LAKE
BREEZE.

RATZER


//ORD AND MDW CONFIDENCE...UPDATED 00Z...

* HIGH CONFIDENCE IN IFR CONDITIONS THROUGH EARLY SATURDAY
  MORNING.

* MEDIUM CONFIDENCE IN TIMING IMPROVEMENT THROUGH MVFR/VFR BY MID
  DAY SATURDAY.

* MEDIUM-HIGH CONFIDENCE IN SHRA/TSRA NOT IMPACTING ORD/MDW
  IMMEDIATE TERMINAL AREAS OVERNIGHT.

RATZER

//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...

SUNDAY THROUGH WEDNESDAY...GENERALLY VFR BUT PERIODIC
CHANCES FOR SHRA/TSRA. THE BEST CHANCE APPEARS TO BE SUNDAY NIGHT
AND MONDAY.

THURSDAY...VFR.

RATZER

&&

.MARINE...
229 PM CDT

A COLD FRONT HAS MOVED ACROSS LAKE MICHIGAN TODAY WITH NORTHERLY
WINDS SETTING UP BEHIND THE FRONT. THE FRONTAL BOUNDARY IS FORECAST
TO STALL ACROSS CENTRAL ILLINOIS THIS EVENING WHILE HIGH PRESSURE
BUILDS ACROSS ONTARIO...THEN EVENTUALLY EAST INTO QUEBEC LATE
SATURDAY INTO SUNDAY. NORTHERLY WINDS WILL GRADUALLY VEER TO THE
NORTHEAST AND EAST AS THE HIGH TRANSLATES EAST. ON SUNDAY...THE
FRONTAL BOUNDARY WILL WAVE NORTHWARD WITH WINDS BECOMING
SOUTHEASTERLY...THEN A COLD FRONT SWEEPS ACROSS THE LAKE ON MONDAY
ALLOWING NORTHWEST/NORTH WINDS TO OVERSPREAD THE LAKE. ALL IN
ALL...NOT LOOKING AT ANY HIGH IMPACT WIND SITUATIONS THROUGH THE
FIRST HALF OF NEXT WEEK...WITH THE STRONGEST WINDS EXPECTED OVER THE
NEXT 48 HRS OR SO IN THE 15 TO 25 KT RANGE.

ANOTHER CONCERN FOR TODAY IS THE FOG OVER THE OPEN WATERS. LATEST
VISIBLE SATELLITE IMAGERY STILL PARTLY BLOCKED BY HIGHER
CLOUDS...BUT LOOKING THROUGH THE GAPS IT DOES APPEAR THAT THERE IS
STILL AN EXPANSIVE AREA OF FOG OVER SOUTHERN LAKE MICHIGAN. DRIER
AIR WILL CONTINUE TO ERODE THIS AREA FROM THE NORTH...BUT IN THE
MEANTIME WILL EXTEND THE DENSE FOG ADVISORY THROUGH THIS EVENING.
BMD

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-
     LMZ779-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 PM FRIDAY.

&&

$$






AREA FORECAST DISCUSSION

NWS CHICAGO/ROMEOVILLE IL

 550 PM CDT THU MAY 3 2012

.MESOSCALE DISCUSSION...
550 PM CDT

ISOLATED CONVECTIVE CELLS HAVE DEVELOPED FROM NEAR PEORIA
NORTHEAST TO LA SALLE COUNTY...ALONG WITH SOME ECHOES OVER
CHICAGO. THIS DEVELOPMENT ALIGNS WELL WITH LOW-LEVEL SPEED AND
MOISTURE CONVERGENCE. ALONG THIS RIBBON...A LOCALIZED POOL OF 67
TO 70 TDS EXIST...AND AN ASSOCIATED UNCAPPED MLCAPE AXIS OF 3000
TO 4000 J/KG PER MODIFIED RUC SOUNDINGS IN THE SOUTHWEST AND
CENTRAL FORECAST AREA. AMDAR SOUNDINGS TOWARD CHICAGO DO STILL
SHOW A MINOR CAP IN PLACE WHEN LIFTING FROM THE SURFACE...ALTHOUGH
PLENTY OF CAPE ABOVE IT. A MAXIMA OF PRESSURE FALLS OF 3 TO 6 MB
PER 3 HOURS WAS ANALYZED ACROSS THE ILLINOIS RIVER VALLEY AREA OF
CENTRAL IL...POSSIBLY ASSOCIATED WITH A WEAK RIPPLE TRACKING
NORTHEAST ALONG THE SURFACE BOUNDARY.

IF THE ANALYSIS OF CAPE/CIN IS CORRECT...THE CONVECTION SHOULD
FURTHER ENHANCE TO THE NORTHEAST WITH THE CONVERGENCE IN SUCH A
RICH POOL OF UNCAPPED INSTABILITY. FURTHER NORTH AND NORTHEAST
TOWARD CHICAGO...CUMULUS CONGESTUS IS TRYING TO DEVELOP AS
WELL...AND COULD SEE THINGS FILL IN BETWEEN THE ONGOING ECHOES.
THE HRRR AND RAP HAVE BEEN FORECASTING THIS ALL AFTERNOON...THOUGH
THEY HAVE ALREADY BEEN TOO ROBUST. DEEP LAYER SHEAR OF 30 TO 40 KT
WILL BE ENOUGH TO SUPPORT ORGANIZED UPDRAFTS AND OVERALL MORE
PERSISTENT STORMS THAN WHAT WE HAVE SEEN LOCALLY SO FAR. IF STORMS
DO GET DEVELOPING...THEY SHOULD BE ABLE TO FESTER AND CONTINUE NEW
GROWTH OFF OF OUTFLOWS DUE TO SUCH HIGH INSTABILITY. GIVEN THE
INSTABILITY WITH THE SHEAR...THERE CERTAINLY WILL BE PLENTY FOR
HAIL AND WIND POTENTIAL IF ANY STORMS PERSIST AWHILE. THE LOW-
LEVEL WIND FIELD HAS VEERED QUITE A BIT FROM AN HOUR OR TWO AGO IN
THE SOUTHWEST FORECAST AREA. LOW LCLS...SUFFICIENT LOW-LEVEL
CAPE...AND THE PRESENCE OF MULTIPLE BOUNDARIES PER SATELLITE
ANALYSIS MAY OFFSET THIS THOUGH AND CONTINUE TO PROVIDE SOME
TORNADO POTENTIAL. THIS IS ESPECIALLY TRUE IN AND AROUND THE
TORNADO WATCH AREA...WHERE 15 TO 20 KT 0-1KM SHEAR IS PRESENT.

MTF

&&

.DISCUSSION...
315 PM CDT

TONIGHT...
SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED TO BE ONGOING
OVERNIGHT AND IT IS DIFFICULT TO ADD ANY SPECIFICS THIS AFTERNOON
AS TO WHEN THE HEAVIEST OF ACTIVITY WILL POP AND MOVE ACROSS...AS
GUIDANCE HAS BEEN STRUGGLING TO LATCH ONTO A SOLID SOLUTION. THE
HRRR AND RAP HAVE BEEN PRETTY CONSISTENT FROM RUN TO RUN IN
DEVELOPING CONVECTION ACROSS THE NORTHERN BORDER THIS AFTERNOON
AND EVENING...BUT AS THE MODELS HAVE BEEN UNDER PERFORMING THE LAST
FEW DAYS...NOT GOING TO COMPLETELY BITE OFF ON ANY ONE SOLUTION
HAPPENING THIS EVENING...LEADING TO A LOW CONFIDENCE OVERNIGHT
FORECAST. DO BELIEVE THAT THE ONGOING ACTIVITY FROM MKE TO ROUGHLY
MSN WILL TRY TO WORK SOUTH WHILE MOVING EAST...BUT WILL DEFER TO
SPECIFICS THAT FALL WITHIN THE MESO AFD ABOVE. FRONT WILL SLOWLY
BE SAGGING SOUTH ACROSS SOUTHERN WISCONSIN AND WORK INTO ILLINOIS
THROUGH THE OVERNIGHT HOURS. ACTIVITY WILL THEN BE ON THE WANE
AS WE GET CLOSER TO THE MORNING.

THE STRONG WARM AIR ADVECTION THAT SHOT TEMPERATURES INTO THE 80S
TODAY WILL SHIFT SOUTH. WITH THE FRONT DROPPING THROUGH AND ACROSS
CHICAGO...WINDS WILL FLIP AROUND TO THE NORTHEAST AND PULL A
COOLER MARINE AIRMASS ACROSS MUCH OF THE COASTLINE. MODELS CONTINUE
TO SLOW THIS TREND SLIGHTLY OVER PREVIOUS RUNS...BUT DOES CONTINUE TO
KEEP IT DRAPED ACROSS THE AREA. FORECAST SOUNDINGS AND RAW
NUMERICAL GUIDANCE HIGHLIGHTS GOOD INSTABILITY TO PERSIST SOUTH AND
WEST OF THIS FEATURE...THOUGH THE BEST INSTABILITY WILL BE WEST
ACROSS IOWA...AND OVERALL EFFECTIVE SHEAR WILL IS SUGGESTED TO BE AT
OR BELOW 30 KT INTO THE PEAK OF THE AFTERNOON. SPC HAS MOST OF THE
CWA IN A SLIGHT RISK FOR SEVERE STORMS TOMORROW...BUT IT DOES FOLLOW
THE OVERALL LOCATION OF THE FRONT...FAVORING AREAS WITH THE BEST
INSTABILITY. WITH NO REAL FORCING WIGGLING THROUGH THE FLOW
TOMORROW...THE OVERALL THREAT DOES NOT APPEAR TO BE HIGH...BUT
CANNOT RULE OUT THE POSSIBILITY OF SOME UNORGANIZED CELLS DEVELOPING
WITH MARGINAL SEVERE HAIL AND WIND GUSTS.

DID MAKE BIGGER CHANGES TO THE DAYTIME HIGHS ACROSS LAKE AND COOK
COUNTIES. WITH THE FRONT SAGGING SOUTH OF MOST THE METRO INTO THE
EARLY AFTERNOON...SHOULD SEE TEMPS HIT THEIR PEAK IN THE EARLY
AFTERNOON AND THEN FALL. STILL SOME CONSIDERABLE DIFFERENCES BETWEEN
THE MAV AND THE MET THIS AFTERNOON...WITH A 10+ DEGREE DIFFERENCE
BETWEEN THE TWO. THE THOUGHT IS THAT WITH THE FRONT TO THE
SOUTH...MOST COASTAL AREAS /INCLUDING THE CHICAGO METRO/ WILL SEE
HIGHS PEAKING IN THE UPPER 60S TO AROUND 70 BEFORE FALLING INTO THE
AFTERNOON...THOUGH IF MORE RAIN FALLS OVERNIGHT AND KEEPS CLOUDS
IN...MID 60S COULD BE PUSHING IT.

BY THE WEEKEND...UPPER LEVEL RIDGING ACROSS THE FOUR CORNERS REGION
WILL BEGIN TO SHIFT EAST AND OVERHEAD...BUT CONTINUED DISPARITY
BETWEEN LONG RANGE GUIDANCE IS LEADING TO FURTHER LOW END CONFIDENCE
ON PRECIP CHANCES INTO THE NEXT WEEK. TRENDS ARE INDICATING A
WEAK SHORTWAVE ROLLING ACROSS THE RIDGE LATE SUNDAY AND INTO
MONDAY WILL BRING THE NEXT BEST CHANCE FOR SHOWERS. AS THE RIDGE
SLIDES EAST AND A TROUGH MOVES THROUGH...WILL GENERALLY FALL BACK
INTO A COOLER NORTHWESTERLY FLOW REGIME KEEPING DAYTIME HIGHS
CLOSE TO SEASONAL WITH OFF AND ON CHANCES THROUGH THE WEEK.

SHEA

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 22Z...

* CONVECTIVE CHANCES THIS AFTERNOON/EVENING/OVERNIGHT.
* GUSTY SOUTHWEST WINDS THIS AFTERNOON AND EVENING...BECOMING
  NORTHEAST FRIDAY.

BMD/KB

//DISCUSSION...UPDATED 20Z...

OVERHAUL TO THE FORECAST THIS AFTERNOON. PREVIOUS CU FIELD THAT
WAS LOOKING SOMEWHAT HEALTHY A COUPLE HOURS AGO HAS DISSIPATED
WITH UPPER LEVEL WAVE OUTRUNNING SURFACE INSTABILITY AND HAVE
DECIDED TO REMOVE MENTION OF THUNDER IN TAFS. WHILE CONFIDENCE IS
NO LONGER HIGH ENOUGH TO CARRY IN TAFS...CHANCES ARE NOT ZERO FOR
THUNDER AND THERE ARE STILL LINGERING CONCERNS. FIRSTLY...AS COLD
POOL CONTINUES TO DEVELOP FROM THUNDERSTORM ACTIVITY OVER SOUTHERN
WISCONSIN...SOME MODEL GUIDANCE SUGGESTS THIS MAY PUSH SOUTH AND
BE FOCUS FOR ADDITIONAL DEVELOPMENT. THUS FAR HOWEVER...THIS HAS
NOT OCCURRED WITH BRISK SOUTHERLY FLOW IMPEDING SOUTHWARD
DEVELOPMENT. SECONDLY...MODEL GUIDANCE SUGGESTS THAT A
THUNDERSTORM COMPLEX MAY DEVELOP TO OUR WEST OVERNIGHT...
HOWEVER...HAVE NO BETTER CONFIDENCE THAN WHAT WE WERE CARRYING IN
THE PROB30 AND HAVE HAD TO REMOVE WITH LATEST AMD. AGAIN...WILL
HAVE TO MONITOR TRENDS CLOSELY...BUT CHANCES SEEM TOO LOW AT THIS
TIME TO CARRY IN FORECAST.

PREVIOUS DISCUSSION...UPDATED 18Z...

MAIN CONCERN WITH THE AFTERNOON  TAFS WILL BE DEALING WITH
CONVECTIVE CHANCES THIS AFTERNOON...AND AGAIN THIS EVENING INTO
THE OVERNIGHT HOURS. THIS AFTERNOON... INSTABILITY CONTINUES TO
GROW ACROSS THE REGION BUT THUS FAR REMAINS WELL CAPPED ACROSS
NORTHERN ILLINOIS. MODEL GUIDANCE CONTINUES TO DEVELOP SPURIOUS
PRECIP ACROSS THE AREA...HOWEVER 16Z AND 17Z AMDAR SOUNDING OUT OF
ORD STILL SHOW A FAIRLY STOUT CAP IN PLACE AND TCU FIELD TO THE
WEST WEAKENED AS IT MOVED ACROSS NORTHERN ILLINOIS. CUMULUS FIELD
CONTINUES TO FLUCTUATE TO THE WEST AND WOULD EXPECT EVENTUALLY TO
BE ABLE TO BREAK THROUGH THE CAP...THOUGH NO DISTINCT MECHANISM IS
EVIDENT TO HONE IN ON SPECIFIC TIMING. SHOULD ANYTHING DEVELOP
EARLIER IN THE AFTERNOON...EXPECT COVERAGE TO BE SOMEWHAT ISOLATED
OR WIDELY SCATTERED. THIS EVENING...A MODEST LOW LEVEL JET ALIGNS
FROM SOUTHWESTERN MISSOURI INTO SOUTHERN IOWA AND IS EXPECTED
ALLOW CONVECTIVE ACTIVITY TO EXPAND IN COVERAGE. THUNDERSTORMS ARE
EXPECTED TO TRAIN TO THE ENE ALONG REMNANT OUTFLOW/BAROCLINIC ZONE
AS IT SINKS SOUTH ACROSS THE REGION. IN THE EARLY MORNING HOURS
FRIDAY...EXPECT WINDS TO DIMINISH IN THE FRONTAL TROUGH AND WITH
HIGH DEWPOINTS IN PLACE...COULD SEE VSBY DROP WITH BR/FOG. LATER
IN THE MORNING...EXPECT NORTHEASTERLY WINDS TO SINK SOUTH ACROSS
THE AREA. BMD

//ORD AND MDW CONFIDENCE...UPDATED 22Z...

* LOW CONFIDENCE ON THUNDERSTORMS THIS AFTERNOON AND EVENING.
* MEDIUM TO HIGH CONFIDENCE ON WIND TRENDS.

BMD/KB

//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...

FRIDAY NIGHT THROUGH TUESDAY...GENERALLY PREVAILING VFR BUT WITH
PERIODIC CHANCES FOR SHRA/TSRA. BEST CHANCES FOR TSRA APPEAR TO BE
FRIDAY INTO THE WEEKEND.

WEDNESDAY...CHANCE SHRA. OTRW...VFR.

KREIN

&&

.MARINE...
223 PM CDT

BROAD LOW PRESSURE WILL EVOLVE EAST ACROSS THE CENTRAL PORTION OF
LAKE MICHIGAN TONIGHT. IN ASSOCIATION WITH THIS FEATURE...CLUSTERS
OF THUNDERSTORMS WILL TRAVERSE ACROSS THE SOUTHERN TWO-THIRDS OF THE
LAKE...SOME OF THESE POTENTIALLY PRODUCING GUSTY WINDS IN EXCESS OF
35 KTS. GUSTY SOUTHWEST WINDS WILL CONTINUE INTO EARLY THIS EVENING
FROM CHICAGO EASTWARD ACROSS NEARSHORE AREAS...POTENTIALLY
CONTINUING INTO SMALL CRAFT ADVISORY CRITERIA THROUGH 8 OR 9 PM.
THE LOW WILL STEER A COLD FRONT SLOWLY SOUTHWARD ACROSS THE LAKE
TONIGHT INTO FRIDAY MORNING. THIS WILL REACH THE SOUTHERN PORTION OF
THE LAKE BY MIDDAY FRIDAY.  NORTHEAST WINDS WILL TURN EAST THIS
WEEKEND AS LOW PRESSURE EVOLVES EASTWARD FROM THE CENTRAL
PLAINS...REACHING THE SOUTHERN GREAT LAKES TO MIDDLE OHIO VALLEY BY
SOMETIME EARLY NEXT WEEK.

MTF

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 10 PM THURSDAY.

     SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 7 PM THURSDAY.

&&

$$






AREA FORECAST DISCUSSION

NWS LINCOLN IL

 1256 PM CDT THU MAY 3 2012

.DISCUSSION...
ISSUED 946 AM CDT THU MAY 3 2012

A BREEZY AND VERY WARM DAY IS UNFOLDING ACROSS CENTRAL ILLINOIS
TODAY. CONVECTIVE COMPLEX OVER NORTHWEST MISSOURI WILL CONTINUE TO
DISSIPATE AS IT TRACKS EASTWARD...WITH LITTLE OR NO PRECIP FROM
THIS SYSTEM EXPECTED TO CROSS THE MISSISSIPPI RIVER. MAIN QUESTION
WILL BE WHETHER OR NOT ANY STORMS CAN FIRE ALONG MESOSCALE BOUNDARIES
ACROSS THE AREA THIS AFTERNOON. FORECAST SOUNDINGS INDICATE A
MODERATELY UNSTABLE ENVIRONMENT WITH LITTLE OR NO CAPPING...SO
ONLY MISSING INGREDIENT WOULD BE A GOOD FOCUSING MECHANISM. IT
APPEARS THE PRIMARY OUTFLOW BOUNDARY FROM THE MISSOURI COMPLEX IS
DROPPING S/SE INTO CENTRAL MISSOURI...HOWEVER OTHER SMALLER SCALE
BOUNDARIES COULD BE PRESENT FURTHER EAST INTO ILLINOIS. AT THIS
TIME...WILL CONFINE AFTERNOON STORM CHANCES TO THE ILLINOIS RIVER
VALLEY WESTWARD. DUE TO MOIST AIRMASS AND STEEP LAPSE RATES...SCT-BKN
CU WILL LIKELY DEVELOP TODAY. CU-RULE SUPPORTS THIS...SO HAVE
UPDATED SKY GRIDS TO GO WITH PARTLY SUNNY WORDING ACROSS MUCH OF
THE AREA. WITH A GOOD DEAL OF SUNSHINE AND STRONG SOUTHERLY WINDS
EXPECTED...AFTERNOON HIGH TEMPS WILL REACH THE MIDDLE TO UPPER 80S
ACROSS THE BOARD.



&&

.AVIATION...
ISSUED 1255 PM CDT THU MAY 3 2012

CU-FIELD WILL CONTINUE TO DEVELOP ACROSS CENTRAL ILLINOIS THIS
AFTERNOON...WITH CU-RULE SUGGESTING SCT-BKN AT AROUND 4000FT. WILL
MONITOR OUTFLOW BOUNDARY ADVANCING EAST OF I-55 FOR POTENTIAL
CONVECTIVE DEVELOPMENT OVER THE NEXT COUPLE OF HOURS...ALTHOUGH
LACK OF CONVERGENCE ALONG SHALLOW BOUNDARY SUPPORTS LITTLE OR NO
DEVELOPMENT. MAIN CONVECTIVE EVENT STILL APPEARS TO BE ON TARGET
FOR LATER THIS EVENING...AS A COLD FRONT SLOWLY SETTLES SOUTHWARD
TOWARD THE REGION. RAP/HRRR MODELS BOTH INDICATE SHOWERS/STORMS
DEVELOPING FROM SOUTHERN WISCONSIN W/SW INTO IOWA LATER THIS
AFTERNOON...THEN SINKING SOUTHWARD INTO NORTH-CENTRAL ILLINOIS
DURING THE EVENING. WITH LOW-LEVEL JET ORIENTED FROM THE SOUTHERN
PLAINS INTO NORTHERN MISSOURI...THINK A MORE ROBUST CLUSTER OF
STORMS WILL DEVELOP AHEAD OF THE APPROACHING FRONT OVER NORTHERN
MISSOURI/SOUTHERN IOWA THIS EVENING...WITH THE COMPLEX TRACKING
EASTWARD ACROSS THE NORTHERN TERMINALS OVERNIGHT. AS SUCH...HAVE
INCLUDED TEMPO GROUPS FOR THUNDER AT BOTH KPIA AND KBMI BETWEEN
03Z AND 08Z. FURTHER SOUTH...HAVE ONLY MENTIONED VCTS AT THE
REMAINING TERMINALS. SOUTHWESTERLY WINDS WILL INITIALLY GUST TO
AROUND 20KT THIS AFTERNOON...THEN WILL BACK TO SOUTHERLY AND
DECREASE TO AROUND 10KT TONIGHT INTO EARLY FRIDAY.

BARNES
&&

.PREV DISCUSSION...
ISSUED 320 AM CDT THU MAY 3 2012
WEAK RIDGING OVER THE EASTERN HALF OF THE CONUS THIS
MORNING...AND SOUTHWESTERLY FLOW OVER MUCH OF THE SOUTHERN PLAINS
AND INTO THE MIDWEST KEEPING A STRING OF CONVECTIVE WAVES MOVING
INTO THE REGION. THIS MORNING...ANOTHER WAVE OVER THE CENTRAL
MISSOURI RIVER VALLEY AND WRN IA EXPECTED TO MOVE INTO THE UPPER
MIDWEST LATER TODAY. FIRST ISSUE FOR THE FORECAST IS THE TIMING OF
THE WAVE...AND THE PRECIP INTO THE CURRENT AIRMASS FOR CENTRAL
ILLINOIS...WHICH BY THE 00Z SOUNDING IS RELATIVELY DRY. MODELS
HAVING A BIT OF AN ISSUE WORKING OUT THE CURRENT CONVECTION...MUCH
LESS ITS PROGRESSION. BOUNDARY SINKING THROUGH TONIGHT AND
INCREASING THE POPS THROUGH TONIGHT AND INTO TOMORROW MORNING.
SHOWERS AND TS CONTINUE THROUGH THE FIRST PORTION OF THE WEEKEND.
CONCERNS STILL FOR WHERE THE BREAKS IN THE PRECIP MAY BE...BEFORE
THE LARGER SCALE TROF OVER THE NWRN CONUS BEGINS TO MOVE OUT...AND
THE SFC LOW DRAGS THROUGH THE MIDWEST MON/MON NIGHT...LEAVING A
BRIEF RESPITE FROM THE RAINFALL IN THE MIDDLE OF THE NEXT WORK
WEEK.

SHORT TERM...TODAY AND TOMORROW...
WARM AND MUGGY CONDITIONS AS SOUTHERLY WINDS USHER WARM AIR INTO
THE MIDWEST. A BIT OF A QUESTION MARK REMAINS THE HIGH TEMPS NW OF
THE ILLINOIS RIVER VALLEY...WHERE CLOUD COVER IS ENHANCED BY DYING
MCS PASSING TO THE NW THIS MORNING. CLOUD COVER/COLD POOL LIKELY TO
INHIBIT THE WARM UP A BIT...THOUGH THE SOUTHERLY WINDS ARE
COUNTERING. MUCH SUNNIER TO THE SOUTH AND EAST OF THE INTERSTATE
55 CORRIDOR...AND TEMPS SOARING INTO THE MID TO UPPER 80S...850MB
TEMPS IN THE 17-18C RANGE...AND MIXING DOWN SOME 20-25MPH GUSTS.
ISSUE FOR THE CURRENT POPS...WHICH THE HRRR IS THE ONLY MODEL TO
REALLY DEPICT WELL...ALBEIT ABOUT 2 HOURS BEHIND AND A LITTLE
UNDERDONE...IS THE ARRIVAL AND POTENTIAL IMPACT TO AREAS IN THE
NRN TIER OF THE STATE AND CWA LATER THIS AFTERNOON. HAVE SLIGHTLY
ADJUSTED SOME HIGHER CHANCE POPS FOR THIS TREND AND MAY NEED TO
KEEP A CLOSE LOOK FOR THIS AFTERNOON IN MORE OF THE HIGH RES
SOLUTIONS. THIS EVENING AND TONIGHT...PRECIP CHANCES INCREASE AS
THE UPPER RIDGE STARTS TO BREAK DOWN AND THE CONVECTION TO THE NW
PUSHES INTO THE FA. MODELS CONTINUE TO PUSH SMALL REINFORCING
SHORTWAVES TO KEEP THE REGION IN PRECIP THROUGH MUCH OF FRIDAY OFF
AND ON.

LONG TERM...SATURDAY THROUGH WEDNESDAY...
POSSIBLE BREAK FOR PART OF SATURDAY IN THE SHOWERY PRECIP...AT
LEAST BEING HINTED IN THE MODELS AS MORE DETAIL WORKS IN...WITH
THE LARGER SCALE SYSTEM PUSHING IN SAT NIGHT WITH THE UPPER LOW ON
THE MOVE ACROSS THE NRN PLAINS. STRONGER SFC LOW ACROSS THE NRN
BOUNDARY OF THE CONUS...DEEP TROF/FRONTAL BOUNDARY TO WEAKER
SOUTHERN SFC LOW PUSHING A BOUNDARY THROUGH THE MIDWEST SUN/MON
AND A RETURN OF THE POPS AGAIN THROUGH THE END OF THE
FORECAST...WITH BEST CHANCES SUN NIGHT THROUGH MON NIGHT FOR MORE
EXTENSIVE RAIN AS THE SFC LOW IS SLIGHTLY SLUGGISH TO MOVE OUT.
ECMWF IS A BIT SLOWER THAN THE GFS...BUT NOT TOO FAR OFF
ALTOGETHER. A SMALL BREAK IN THE HEAT WITH THE SYSTEM AS HIGHS FOR
MON/TUES A BIT LOWER WITH THE MID LEVEL TROF GETTING SOME COOLER
AIR OVHD BEHIND THE RIDGE. COOLER TEMPS CONTINUE THROUGH MIDWEEK
AS THE UPPER TROF SLOWS AS WELL...THOUGH SFC STARTS TO DRY OUT A
BIT WED NIGHT.

HJS


&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$








AREA FORECAST DISCUSSION

NWS LINCOLN IL

 946 AM CDT THU MAY 3 2012

.DISCUSSION...
ISSUED 946 AM CDT THU MAY 3 2012

A BREEZY AND VERY WARM DAY IS UNFOLDING ACROSS CENTRAL ILLINOIS
TODAY. CONVECTIVE COMPLEX OVER NORTHWEST MISSOURI WILL CONTINUE TO
DISSIPATE AS IT TRACKS EASTWARD...WITH LITTLE OR NO PRECIP FROM
THIS SYSTEM EXPECTED TO CROSS THE MISSISSIPPI RIVER. MAIN QUESTION
WILL BE WHETHER OR NOT ANY STORMS CAN FIRE ALONG MESOSCALE BOUNDARIES
ACROSS THE AREA THIS AFTERNOON. FORECAST SOUNDINGS INDICATE A
MODERATELY UNSTABLE ENVIRONMENT WITH LITTLE OR NO CAPPING...SO
ONLY MISSING INGREDIENT WOULD BE A GOOD FOCUSING MECHANISM. IT
APPEARS THE PRIMARY OUTFLOW BOUNDARY FROM THE MISSOURI COMPLEX IS
DROPPING S/SE INTO CENTRAL MISSOURI...HOWEVER OTHER SMALLER SCALE
BOUNDARIES COULD BE PRESENT FURTHER EAST INTO ILLINOIS. AT THIS
TIME...WILL CONFINE AFTERNOON STORM CHANCES TO THE ILLINOIS RIVER
VALLEY WESTWARD. DUE TO MOIST AIRMASS AND STEEP LAPSE RATES...SCT-BKN
CU WILL LIKELY DEVELOP TODAY. CU-RULE SUPPORTS THIS...SO HAVE
UPDATED SKY GRIDS TO GO WITH PARTLY SUNNY WORDING ACROSS MUCH OF
THE AREA. WITH A GOOD DEAL OF SUNSHINE AND STRONG SOUTHERLY WINDS
EXPECTED...AFTERNOON HIGH TEMPS WILL REACH THE MIDDLE TO UPPER 80S
ACROSS THE BOARD.

BARNES
&&

.AVIATION...
ISSUED 631 AM CDT THU MAY 3 2012

VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES NEXT 24RHS. HIGH
CIRRUS WILL OVERSPREAD THE AREA AND ALL SITES THIS MORNING.
HOWEVER...SOME SCATTERED CU SHOULD DEVELOP OVER THE AREA AS WELL
AND AFFECT THE TAFS STARTING AROUND 15Z. THESE CONDITIONS WILL
CONTINUE THROUGH THIS AFTERNOON AND INTO EARLY EVENING. A LARGE
AREA OF THUNDERSTORMS IN NORTHEAST MO WILL MOVE EAST ACROSS
NORTHERN MO AND PUSH INTO WEST CENTRAL IL TONIGHT. ADDITIONAL
THUNDERSTORMS SHOULD DEVELOP ON OUTFLOWS OF THE EXISTING SYSTEM
AND SHOULD AFFECT PIA AROUND 01Z AND 02Z AT BMI. STORMS COULD TAKE
A TURN TO THE SOUTH TONIGHT SO THUNDERSTORMS SHOULD GET INTO
SPI/DEC/CMI AROUND 04Z. SHORT TERM MODELS STILL DO NOT SEEM TO
HAVE GOOD HANDLE ON CURRENT TRENDS. SO WILL JUST HAVE VCTS IN
FORECAST FOR TONIGHT AND LET LATER SHIFTS DECIDE ON TIMING OF
TEMPO GROUPS. WINDS WILL BECOME A LITTLE BIT SOUTHWESTERLY AND
INCREASE IN SPEED TODAY...THEN TAPER OFF AGAIN DURING THE EVENING.

AUTEN
&&

.PREV DISCUSSION...
ISSUED 320 AM CDT THU MAY 3 2012
WEAK RIDGING OVER THE EASTERN HALF OF THE CONUS THIS
MORNING...AND SOUTHWESTERLY FLOW OVER MUCH OF THE SOUTHERN PLAINS
AND INTO THE MIDWEST KEEPING A STRING OF CONVECTIVE WAVES MOVING
INTO THE REGION. THIS MORNING...ANOTHER WAVE OVER THE CENTRAL
MISSOURI RIVER VALLEY AND WRN IA EXPECTED TO MOVE INTO THE UPPER
MIDWEST LATER TODAY. FIRST ISSUE FOR THE FORECAST IS THE TIMING OF
THE WAVE...AND THE PRECIP INTO THE CURRENT AIRMASS FOR CENTRAL
ILLINOIS...WHICH BY THE 00Z SOUNDING IS RELATIVELY DRY. MODELS
HAVING A BIT OF AN ISSUE WORKING OUT THE CURRENT CONVECTION...MUCH
LESS ITS PROGRESSION. BOUNDARY SINKING THROUGH TONIGHT AND
INCREASING THE POPS THROUGH TONIGHT AND INTO TOMORROW MORNING.
SHOWERS AND TS CONTINUE THROUGH THE FIRST PORTION OF THE WEEKEND.
CONCERNS STILL FOR WHERE THE BREAKS IN THE PRECIP MAY BE...BEFORE
THE LARGER SCALE TROF OVER THE NWRN CONUS BEGINS TO MOVE OUT...AND
THE SFC LOW DRAGS THROUGH THE MIDWEST MON/MON NIGHT...LEAVING A
BRIEF RESPITE FROM THE RAINFALL IN THE MIDDLE OF THE NEXT WORK
WEEK.

SHORT TERM...TODAY AND TOMORROW...
WARM AND MUGGY CONDITIONS AS SOUTHERLY WINDS USHER WARM AIR INTO
THE MIDWEST. A BIT OF A QUESTION MARK REMAINS THE HIGH TEMPS NW OF
THE ILLINOIS RIVER VALLEY...WHERE CLOUD COVER IS ENHANCED BY DYING
MCS PASSING TO THE NW THIS MORNING. CLOUD COVER/COLD POOL LIKELY TO
INHIBIT THE WARM UP A BIT...THOUGH THE SOUTHERLY WINDS ARE
COUNTERING. MUCH SUNNIER TO THE SOUTH AND EAST OF THE INTERSTATE
55 CORRIDOR...AND TEMPS SOARING INTO THE MID TO UPPER 80S...850MB
TEMPS IN THE 17-18C RANGE...AND MIXING DOWN SOME 20-25MPH GUSTS.
ISSUE FOR THE CURRENT POPS...WHICH THE HRRR IS THE ONLY MODEL TO
REALLY DEPICT WELL...ALBEIT ABOUT 2 HOURS BEHIND AND A LITTLE
UNDERDONE...IS THE ARRIVAL AND POTENTIAL IMPACT TO AREAS IN THE
NRN TIER OF THE STATE AND CWA LATER THIS AFTERNOON. HAVE SLIGHTLY
ADJUSTED SOME HIGHER CHANCE POPS FOR THIS TREND AND MAY NEED TO
KEEP A CLOSE LOOK FOR THIS AFTERNOON IN MORE OF THE HIGH RES
SOLUTIONS. THIS EVENING AND TONIGHT...PRECIP CHANCES INCREASE AS
THE UPPER RIDGE STARTS TO BREAK DOWN AND THE CONVECTION TO THE NW
PUSHES INTO THE FA. MODELS CONTINUE TO PUSH SMALL REINFORCING
SHORTWAVES TO KEEP THE REGION IN PRECIP THROUGH MUCH OF FRIDAY OFF
AND ON.

LONG TERM...SATURDAY THROUGH WEDNESDAY...
POSSIBLE BREAK FOR PART OF SATURDAY IN THE SHOWERY PRECIP...AT
LEAST BEING HINTED IN THE MODELS AS MORE DETAIL WORKS IN...WITH
THE LARGER SCALE SYSTEM PUSHING IN SAT NIGHT WITH THE UPPER LOW ON
THE MOVE ACROSS THE NRN PLAINS. STRONGER SFC LOW ACROSS THE NRN
BOUNDARY OF THE CONUS...DEEP TROF/FRONTAL BOUNDARY TO WEAKER
SOUTHERN SFC LOW PUSHING A BOUNDARY THROUGH THE MIDWEST SUN/MON
AND A RETURN OF THE POPS AGAIN THROUGH THE END OF THE
FORECAST...WITH BEST CHANCES SUN NIGHT THROUGH MON NIGHT FOR MORE
EXTENSIVE RAIN AS THE SFC LOW IS SLIGHTLY SLUGGISH TO MOVE OUT.
ECMWF IS A BIT SLOWER THAN THE GFS...BUT NOT TOO FAR OFF
ALTOGETHER. A SMALL BREAK IN THE HEAT WITH THE SYSTEM AS HIGHS FOR
MON/TUES A BIT LOWER WITH THE MID LEVEL TROF GETTING SOME COOLER
AIR OVHD BEHIND THE RIDGE. COOLER TEMPS CONTINUE THROUGH MIDWEEK
AS THE UPPER TROF SLOWS AS WELL...THOUGH SFC STARTS TO DRY OUT A
BIT WED NIGHT.

HJS

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$








AREA FORECAST DISCUSSION

NWS LINCOLN IL

 631 AM CDT THU MAY 3 2012

.DISCUSSION...
ISSUED 320 AM CDT THU MAY 3 2012
WEAK RIDGING OVER THE EASTERN HALF OF THE CONUS THIS
MORNING...AND SOUTHWESTERLY FLOW OVER MUCH OF THE SOUTHERN PLAINS
AND INTO THE MIDWEST KEEPING A STRING OF CONVECTIVE WAVES MOVING
INTO THE REGION. THIS MORNING...ANOTHER WAVE OVER THE CENTRAL
MISSOURI RIVER VALLEY AND WRN IA EXPECTED TO MOVE INTO THE UPPER
MIDWEST LATER TODAY. FIRST ISSUE FOR THE FORECAST IS THE TIMING OF
THE WAVE...AND THE PRECIP INTO THE CURRENT AIRMASS FOR CENTRAL
ILLINOIS...WHICH BY THE 00Z SOUNDING IS RELATIVELY DRY. MODELS
HAVING A BIT OF AN ISSUE WORKING OUT THE CURRENT CONVECTION...MUCH
LESS ITS PROGRESSION. BOUNDARY SINKING THROUGH TONIGHT AND
INCREASING THE POPS THROUGH TONIGHT AND INTO TOMORROW MORNING.
SHOWERS AND TS CONTINUE THROUGH THE FIRST PORTION OF THE WEEKEND.
CONCERNS STILL FOR WHERE THE BREAKS IN THE PRECIP MAY BE...BEFORE
THE LARGER SCALE TROF OVER THE NWRN CONUS BEGINS TO MOVE OUT...AND
THE SFC LOW DRAGS THROUGH THE MIDWEST MON/MON NIGHT...LEAVING A
BRIEF RESPITE FROM THE RAINFALL IN THE MIDDLE OF THE NEXT WORK
WEEK.

SHORT TERM...TODAY AND TOMORROW...
WARM AND MUGGY CONDITIONS AS SOUTHERLY WINDS USHER WARM AIR INTO
THE MIDWEST. A BIT OF A QUESTION MARK REMAINS THE HIGH TEMPS NW OF
THE ILLINOIS RIVER VALLEY...WHERE CLOUD COVER IS ENHANCED BY DYING
MCS PASSING TO THE NW THIS MORNING. CLOUD COVER/COLD POOL LIKELY TO
INHIBIT THE WARM UP A BIT...THOUGH THE SOUTHERLY WINDS ARE
COUNTERING. MUCH SUNNIER TO THE SOUTH AND EAST OF THE INTERSTATE
55 CORRIDOR...AND TEMPS SOARING INTO THE MID TO UPPER 80S...850MB
TEMPS IN THE 17-18C RANGE...AND MIXING DOWN SOME 20-25MPH GUSTS.
ISSUE FOR THE CURRENT POPS...WHICH THE HRRR IS THE ONLY MODEL TO
REALLY DEPICT WELL...ALBEIT ABOUT 2 HOURS BEHIND AND A LITTLE
UNDERDONE...IS THE ARRIVAL AND POTENTIAL IMPACT TO AREAS IN THE
NRN TIER OF THE STATE AND CWA LATER THIS AFTERNOON. HAVE SLIGHTLY
ADJUSTED SOME HIGHER CHANCE POPS FOR THIS TREND AND MAY NEED TO
KEEP A CLOSE LOOK FOR THIS AFTERNOON IN MORE OF THE HIGH RES
SOLUTIONS. THIS EVENING AND TONIGHT...PRECIP CHANCES INCREASE AS
THE UPPER RIDGE STARTS TO BREAK DOWN AND THE CONVECTION TO THE NW
PUSHES INTO THE FA. MODELS CONTINUE TO PUSH SMALL REINFORCING
SHORTWAVES TO KEEP THE REGION IN PRECIP THROUGH MUCH OF FRIDAY OFF
AND ON.

LONG TERM...SATURDAY THROUGH WEDNESDAY...
POSSIBLE BREAK FOR PART OF SATURDAY IN THE SHOWERY PRECIP...AT
LEAST BEING HINTED IN THE MODELS AS MORE DETAIL WORKS IN...WITH
THE LARGER SCALE SYSTEM PUSHING IN SAT NIGHT WITH THE UPPER LOW ON
THE MOVE ACROSS THE NRN PLAINS. STRONGER SFC LOW ACROSS THE NRN
BOUNDARY OF THE CONUS...DEEP TROF/FRONTAL BOUNDARY TO WEAKER
SOUTHERN SFC LOW PUSHING A BOUNDARY THROUGH THE MIDWEST SUN/MON
AND A RETURN OF THE POPS AGAIN THROUGH THE END OF THE
FORECAST...WITH BEST CHANCES SUN NIGHT THROUGH MON NIGHT FOR MORE
EXTENSIVE RAIN AS THE SFC LOW IS SLIGHTLY SLUGGISH TO MOVE OUT.
ECMWF IS A BIT SLOWER THAN THE GFS...BUT NOT TOO FAR OFF
ALTOGETHER. A SMALL BREAK IN THE HEAT WITH THE SYSTEM AS HIGHS FOR
MON/TUES A BIT LOWER WITH THE MID LEVEL TROF GETTING SOME COOLER
AIR OVHD BEHIND THE RIDGE. COOLER TEMPS CONTINUE THROUGH MIDWEEK
AS THE UPPER TROF SLOWS AS WELL...THOUGH SFC STARTS TO DRY OUT A
BIT WED NIGHT.

HJS
&&

.AVIATION...
ISSUED 631 AM CDT THU MAY 3 2012

VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES NEXT 24RHS. HIGH
CIRRUS WILL OVERSPREAD THE AREA AND ALL SITES THIS MORNING.
HOWEVER...SOME SCATTERED CU SHOULD DEVELOP OVER THE AREA AS WELL
AND AFFECT THE TAFS STARTING AROUND 15Z. THESE CONDITIONS WILL
CONTINUE THROUGH THIS AFTERNOON AND INTO EARLY EVENING. A LARGE
AREA OF THUNDERSTORMS IN NORTHEAST MO WILL MOVE EAST ACROSS
NORTHERN MO AND PUSH INTO WEST CENTRAL IL TONIGHT. ADDITIONAL
THUNDERSTORMS SHOULD DEVELOP ON OUTFLOWS OF THE EXISTING SYSTEM
AND SHOULD AFFECT PIA AROUND 01Z AND 02Z AT BMI. STORMS COULD TAKE
A TURN TO THE SOUTH TONIGHT SO THUNDERSTORMS SHOULD GET INTO
SPI/DEC/CMI AROUND 04Z. SHORT TERM MODELS STILL DO NOT SEEM TO
HAVE GOOD HANDLE ON CURRENT TRENDS. SO WILL JUST HAVE VCTS IN
FORECAST FOR TONIGHT AND LET LATER SHIFTS DECIDE ON TIMING OF
TEMPO GROUPS. WINDS WILL BECOME A LITTLE BIT SOUTHWESTERLY AND
INCREASE IN SPEED TODAY...THEN TAPER OFF AGAIN DURING THE EVENING.

AUTEN
&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$








AREA FORECAST DISCUSSION

NWS LINCOLN IL

 347 AM CDT THU MAY 3 2012

.DISCUSSION...
ISSUED 320 AM CDT THU MAY 3 2012
WEAK RIDGING OVER THE EASTERN HALF OF THE CONUS THIS
MORNING...AND SOUTHWESTERLY FLOW OVER MUCH OF THE SOUTHERN PLAINS
AND INTO THE MIDWEST KEEPING A STRING OF CONVECTIVE WAVES MOVING
INTO THE REGION. THIS MORNING...ANOTHER WAVE OVER THE CENTRAL
MISSOURI RIVER VALLEY AND WRN IA EXPECTED TO MOVE INTO THE UPPER
MIDWEST LATER TODAY. FIRST ISSUE FOR THE FORECAST IS THE TIMING OF
THE WAVE...AND THE PRECIP INTO THE CURRENT AIRMASS FOR CENTRAL
ILLINOIS...WHICH BY THE 00Z SOUNDING IS RELATIVELY DRY. MODELS
HAVING A BIT OF AN ISSUE WORKING OUT THE CURRENT CONVECTION...MUCH
LESS ITS PROGRESSION. BOUNDARY SINKING THROUGH TONIGHT AND
INCREASING THE POPS THROUGH TONIGHT AND INTO TOMORROW MORNING.
SHOWERS AND TS CONTINUE THROUGH THE FIRST PORTION OF THE WEEKEND.
CONCERNS STILL FOR WHERE THE BREAKS IN THE PRECIP MAY BE...BEFORE
THE LARGER SCALE TROF OVER THE NWRN CONUS BEGINS TO MOVE OUT...AND
THE SFC LOW DRAGS THROUGH THE MIDWEST MON/MON NIGHT...LEAVING A
BRIEF RESPITE FROM THE RAINFALL IN THE MIDDLE OF THE NEXT WORK
WEEK.

SHORT TERM...TODAY AND TOMORROW...
WARM AND MUGGY CONDITIONS AS SOUTHERLY WINDS USHER WARM AIR INTO
THE MIDWEST. A BIT OF A QUESTION MARK REMAINS THE HIGH TEMPS NW OF
THE ILLINOIS RIVER VALLEY...WHERE CLOUD COVER IS ENHANCED BY DYING
MCS PASSING TO THE NW THIS MORNING. CLOUD COVER/COLD POOL LIKELY TO
INHIBIT THE WARM UP A BIT...THOUGH THE SOUTHERLY WINDS ARE
COUNTERING. MUCH SUNNIER TO THE SOUTH AND EAST OF THE INTERSTATE
55 CORRIDOR...AND TEMPS SOARING INTO THE MID TO UPPER 80S...850MB
TEMPS IN THE 17-18C RANGE...AND MIXING DOWN SOME 20-25MPH GUSTS.
ISSUE FOR THE CURRENT POPS...WHICH THE HRRR IS THE ONLY MODEL TO
REALLY DEPICT WELL...ALBEIT ABOUT 2 HOURS BEHIND AND A LITTLE
UNDERDONE...IS THE ARRIVAL AND POTENTIAL IMPACT TO AREAS IN THE
NRN TIER OF THE STATE AND CWA LATER THIS AFTERNOON. HAVE SLIGHTLY
ADJUSTED SOME HIGHER CHANCE POPS FOR THIS TREND AND MAY NEED TO
KEEP A CLOSE LOOK FOR THIS AFTERNOON IN MORE OF THE HIGH RES
SOLUTIONS. THIS EVENING AND TONIGHT...PRECIP CHANCES INCREASE AS
THE UPPER RIDGE STARTS TO BREAK DOWN AND THE CONVECTION TO THE NW
PUSHES INTO THE FA. MODELS CONTINUE TO PUSH SMALL REINFORCING
SHORTWAVES TO KEEP THE REGION IN PRECIP THROUGH MUCH OF FRIDAY OFF
AND ON.

LONG TERM...SATURDAY THROUGH WEDNESDAY...
POSSIBLE BREAK FOR PART OF SATURDAY IN THE SHOWERY PRECIP...AT
LEAST BEING HINTED IN THE MODELS AS MORE DETAIL WORKS IN...WITH
THE LARGER SCALE SYSTEM PUSHING IN SAT NIGHT WITH THE UPPER LOW ON
THE MOVE ACROSS THE NRN PLAINS. STRONGER SFC LOW ACROSS THE NRN
BOUNDARY OF THE CONUS...DEEP TROF/FRONTAL BOUNDARY TO WEAKER
SOUTHERN SFC LOW PUSHING A BOUNDARY THROUGH THE MIDWEST SUN/MON
AND A RETURN OF THE POPS AGAIN THROUGH THE END OF THE
FORECAST...WITH BEST CHANCES SUN NIGHT THROUGH MON NIGHT FOR MORE
EXTENSIVE RAIN AS THE SFC LOW IS SLIGHTLY SLUGGISH TO MOVE OUT.
ECMWF IS A BIT SLOWER THAN THE GFS...BUT NOT TOO FAR OFF
ALTOGETHER. A SMALL BREAK IN THE HEAT WITH THE SYSTEM AS HIGHS FOR
MON/TUES A BIT LOWER WITH THE MID LEVEL TROF GETTING SOME COOLER
AIR OVHD BEHIND THE RIDGE. COOLER TEMPS CONTINUE THROUGH MIDWEEK
AS THE UPPER TROF SLOWS AS WELL...THOUGH SFC STARTS TO DRY OUT A
BIT WED NIGHT.


HJS
&&

.AVIATION...
ISSUED 1125 PM CDT WED MAY 2 2012

FRONTAL BOUNDARY OUT ALONG THE MISSOURI RIVER HAS SPARKED A LARGE
AREA OF CONVECTION THIS EVENING WITH MOST OF THE ACTIVITY TRACKING
MORE TO THE NORTHEAST WHICH WOULD KEEP THE PRECIP AWAY FROM THE
TAF SITES THRU DAWN THURSDAY. A FEW OF THE MODELS CONTINUE TO
SUGGEST SOME LOW VFR/HIGH END MVFR CIGS MAY PUSH INTO WESTERN
IL BY DAWN THURSDAY...HOWEVER...SURFACE OBS AND SATELLITE DATA
WERE NOT INDICATING MUCH IN THE WAY OF LOW CLOUDS TO OUR SW WHERE
IT SHOULD AT THIS TIME ACCORDING TO THE MODEL. WILL CONTINUE FROM
THE PREVIOUS FORECAST IN HOLDING ON TO A SCATTERED DECK AT 2000-2500
FEET AT PIA AND SPI. OTHERWISE...SOME SCATTERED CU DEVELOPING
TOMORROW ALONG WITH A GUSTY SOUTH WIND BY AFTN WITH A FEW GUSTS
AROUND 25 KTS. VAD WIND PROFILES CURRENTLY SHOWING 30-35 KTS AT
1500 FEET WITH MODELS SUGGESTING BORDERLINE LOW LEVEL WIND SHEAR
CRITERIA...ESP ACRS THE WEST IN THE 06Z-11Z TIME FRAME.

SMITH
&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$








AREA FORECAST DISCUSSION

NWS CHICAGO/ROMEOVILLE IL

 325 AM CDT THU MAY 3 2012

.DISCUSSION...
840 PM CDT

FOR EVENING UPDATE....

HAVE MADE SOME SIGNIFICANT ADJUSTMENTS TO POP/WX GRIDS INTO THE
OVERNIGHT HOURS BASED ON ANALYSIS/CONVECTIVE TRENDS UPSTREAM.

WARM FRONT WHICH LIFTED NORTH OF THE FORECAST AREA EARLIER THIS
MORNING HAS BECOME SOMEWHAT ILL-DEFINED ACROSS WISCONSIN AND LOWER
MICHIGAN THIS EVENING...WHILE A SECONDARY TROUGH/WARM FRONT WAS
NOTED FROM NORTHERN MISSOURI INTO CENTRAL IL/IND ENHANCED FROM
COMBINATION OF RETREATING CONVECTIVE OUTFLOW FROM MORNING MCS AND
DIFFERENTIAL HEATING FROM CLOUD COVER EARLIER IN THE DAY. THIS AREA
HAD BECOME RELATIVELY CLOUD-FREE LATE THIS AFTERNOON IN THE WAKE OF
THE SHORT-WAVE TROUGH AXIS WHICH HAS MOVED EAST OF THE AREA PER
WATER VAPOR IMAGERY AND PROFILER WINDS AT WOLCOTT IN. WHILE AIR MASS
IS WARM AND RATHER HUMID...WITH TEMPS STILL IN MID 70S AND DEW
POINTS IN THE MID-UPPER 60S ACROSS SOUTHERN CWA...00Z RAOBS FROM DVN
AND ILX DEPICT STRONG CAPPING INVERSION EXISTS FOR SFC/NEAR SFC
BASED CONVECTION. IN ADDITION...AIR MASS TO THE WEST ACROSS IOWA HAS
REMAINED STABILIZED WITH EXTENSIVE STRATUS DECK THROUGH THE
AFTERNOON AND HAS PREVENTED NEAR SFC BASED CONVECTION FROM
DEVELOPING SAVE FAR SOUTHERN MN/EASTERN NEBRASKA AREAS FARTHER NORTH
AND WEST.

CONVECTION-ALLOWING GUIDANCE INCLUDING WRF-NMM AND HRRR/RAP HAVE
BEEN INDICATING SIGNIFICANT CONVECTIVE DEVELOPMENT ACROSS EASTERN
IOWA INTO SOUTHWEST WISCONSIN DURING THE AFTERNOON AND EVENING
HOURS...BUT BASED ON THERMODYNAMIC PROFILES AND PRE-SUNSET VIS
SATELLITE TRENDS...EARLIER RUNS APPEAR TO HAVE OVER-FORECAST EXTENT
OF DEVELOPMENT. SOME FACTORS DO SUPPORT THE POTENTIAL FOR INCREASING
SHRA/TSRA THREAT THIS EVENING...MAINLY WITH BETTER MOIST ASCENT
DEVELOPING ABOVE STABLE BOUNDARY LAYER AS H9-H8 LOW LEVEL JET
INCREASES TO 35-40 KT AND MID-LEVEL SPEED MAX APPROACHES FROM THE
SOUTHWEST WITHIN AND AREA OF VERY STEEP MID-LEVEL LAPSE RATES WITH
EML NOTED IN OAX/DVN SOUNDINGS. AN ISOLATED AREA OF SHOWERS/WEAK
TSRA HAVE DEVELOPED ALONG A CONVERGENCE ZONE ACROSS FAR EASTERN IA
FROM NEAR MUSCATINE TO JUST WEST OF SAVANNA IL...LIKELY A
REPRESENTATION OF WHAT THE WRF-NMM AND HRRR/RAP WERE TRYING TO
DEPICT BUT ON A MORE LIMITED SCALE. TREND FROM THESE MODELS WOULD
SUGGEST THIS ACTIVITY WILL LIKELY FOCUS MORE ACROSS OUR FAR
NORTHWEST/NORTHERN CWA INTO THE OVERNIGHT HOURS...AND PERHAPS MORE
SO OVER SOUTHERN WI WHERE BETTER DEEP MOIST CONVERGENCE IS NOTED IN
ASSOCIATION WITH SYNOPTIC H9-H8 WARM FRONT. BASED ON ALL OF THIS...
HAVE GENERALLY LOWERED/REMOVED POPS ACROSS THE SOUTHERN CWA
OVERNIGHT. THE RECENT HRRR RUNS WOULD EVEN SUGGEST WE MAY BE DRY
ACROSS THE NORTH EXCEPT FOR RIGHT ALONG THE WI/IL LINE AFTER
MIDNIGHT...THOUGH MY CONFIDENCE IS NOT HIGH ENOUGH TO PULL POPS WITH
UNCERTAIN EVOLUTION OF CONVECTION CURRENTLY FARTHER UPSTREAM. THUS
HAVE GENERALLY LEFT HIGHER POPS GENERALLY NORTH OF I-88 ACROSS
NORTHERN IL...WITH FAR SOUTHERN COUNTIES DRY. HRRR ALSO INDICATES
MCS DEVELOPMENT ACROSS NEBRASKA...WHERE KS/NEBR ACTIVITY IS
CURRENTLY JUST GETTING GOING. LATEST GUIDANCE INDICATES THIS WOULD
NOT ARRIVE UNTIL AFTER 12Z WEDNESDAY IN DECAYING FORM.

RATZER

//PREV DISCUSSION...
329 PM CDT

MAIN FORECAST CHALLENGES REVOLVE AROUND SHOWER/THUNDERSTORM
CHANCES OVER THE NEXT SEVERAL DAYS WITH THE SEVERE POTENTIAL
REMAINING FOR TONIGHT AS WELL AS THURSDAY NIGHT...WITH HIGH
TEMPERATURES BEING DICTATED BY REMNANT PRECIP/CLOUD COVER THROUGH
EACH DAY.

LATEST RADAR IMAGERY DEPICTING AREA OF SHOWERS AND THUNDERSTORMS
WHICH SLOWLY PROGRESSED THROUGH PORTIONS OF THE CWA...CONTINUING
TO DIMINISH THIS AFTERNOON WITH MOST AREAS CURRENTLY DRY. EXPECT
THESE RELATIVELY DRY CONDITIONS TO REMAIN FOR A PORTION OF THIS
AFTERNOON INTO EARLY EVENING...OUTSIDE OF SOME ISOLATED/BRIEF
SHOWERS AND THUNDERSTORMS POSSIBLY DEVELOPING ALONG LINGERING
OUTFLOW BOUNDARIES WHICH SEVERAL ARE CURRENTLY SITUATED OVER THE
CWA. ANY SHOWERS/THUNDERSTORMS WHICH DO DEVELOP THIS AFTERNOON
SHOULD NOT BECOME SEVERE AS INSTABILITY IS STILL LACKING DUE TO A
RECOVERING ENVIRONMENT AND STRONGER WESTERLIES REMAINING TO THE
NORTHWEST.

STRONG SOUTHERLY FLOW OUT AHEAD OF A TROUGH OF LOW PRESSURE WELL
TO THE WEST OVER THE CENTRAL PLAINS WILL HELP FOR THE ENVIRONMENT
OVER THE CWA TO TO SLIGHTLY RECOVER THIS EVENING THROUGH EARLY
THURSDAY MORNING BRINGING LOW TO MID 60S DEWPOINT AIR BACK NORTH
ACROSS NORTHERN ILLINOIS AND NORTHWEST INDIANA. THIS SHOULD HELP
TO INCREASE OVERALL INSTABILITY OVER THE CWA THIS EVENING WHICH
COULD PROVIDE A SETUP FOR ANOTHER ROUND OF THUNDERSTORMS TO RACE
ACROSS THE CWA. MODEL GUIDANCE CONTINUES TO BE ALL OVER THE PLACE
IN REGARDS TO ENVIRONMENTAL DETAILS DUE TO MESOCALE FEATURES WHICH
CONTINUE TO DISRUPT THE LARGE SCALE PATTERN. THIS IS TRANSLATING
TO A LACK OF CONFIDENCE IN MODEL GENERATED PRECIP IN THE NEAR TERM
AS WELL AS FOR THE NEXT SEVERAL DAYS. DESPITE THIS LACK OF
CONFIDENCE IN NUMERICAL GUIDANCE...CAN STILL MAKE OUT SOME OF AREA
FOCUS FOR THUNDERSTORM DEVELOPMENT. ENVIRONMENT SHOULD CONTINUE TO
RECOVER ACROSS THE ENTIRE REGION FROM THE CENTRAL PLAINS BACK EAST
TO THE GREAT LAKES REGION WITH DEEP MOISTURE BACK ON THE RISE.
MAIN INSTABILITY AXIS IS SITUATED FROM WESTERN IOWA EAST INTO
SOUTHERN WISCONSIN...WITH INSTABILITY ANTICIPATED TO CONTINUE TO
INCREASE OVER NORTHEAST ILLINOIS AND NORTHWEST INDIANA. ALTHOUGH
THE EXTENT OF THIS INCREASE OVER THE CWA IS STILL IN
QUESTION...WHICH WILL PLAY A FACTOR IN THUNDERSTORM INTENSITY
TONIGHT. A SUBTLE MID LEVEL IMPULSE CURRENTLY OBSERVED EJECTING
ACROSS THE CENTRAL PLAINS COINCIDING WITH AN INCREASING LLJ SHOULD
INTERACT WITH A FRONTAL BOUNDARY OVER THE CENTRAL PLAINS LATER
THIS EVENING AND HELP FOR THE DEVELOPMENT OF THUNDERSTORMS ACROSS
IOWA. INSTABILITY SHOULD BE MORE THAN ENOUGH TO GET ROBUST
DEVELOPMENT WITH STEERING FLOW/LOW LEVEL SHEAR HELPING TO SHIFT
THIS THUNDERSTORM DEVELOPMENT EAST. A GROWING COMPLEX SHOULD WORK
ITS WAY EAST MAINLY AFFECTING THE NORTHERN HALF OF THE CWA LATER
TONIGHT INTO EARLY THURSDAY MORNING. OVERALL INSTABILITY IS STILL
IN QUESTION ACROSS THE CWA...BUT WITH DEEP MOISTURE NOT. IF
INSTABILITY INCREASES...A HAIL AND WIND THREAT WILL BE POSSIBLE
TONIGHT. IF NOT...AM STILL CONCERNED ABOUT THE POTENTIAL FOR VERY
RAIN EFFICIENT THUNDERSTORMS AS A VERY WARM AND JUICY AIRMASS WILL
BE IN PLACE. WITH ANY MCS PASSAGE TONIGHT...COULD ENVISION FURTHER
UPSCALE DEVELOPMENT AS A STRONG LLJ INTERACTS WITH ANY LINGERING
BOUNDARIES. THIS COULD PROVIDE A SETUP FOR TRAINING OF
THUNDERSTORMS AND HEAVY RAINFALL INTO THURSDAY MORNING.

ADVECTION OF A MUCH WARMER AIRMASS WILL CONTINUE ON THURSDAY WITH
WELL ABOVE NORMAL TEMPERATURES FORECAST. HAVE MAINTAINED MID AND
UPPER 80S FOR THE SOUTHERN HALF OF THE CWA BUT HAVE LOWERED TEMPS
TO AROUND 80 FOR THE NORTHERN HALF DUE TO POSSIBLE LINGERING
CONVECTION AND CLOUD COVER THURSDAY MORNING. ONGOING CONVECTION
DURING THE DAY THURSDAY WILL DEFINITELY BE KEY WITH FURTHER
DEVELOPMENT FOR THE REMAINDER OF THURSDAY INTO FRIDAY
MORNING...WHICH ONCE AGAIN SEEMS PROBABLE. ADVECTION OF A WARM AND
VERY MOIST AIR WILL CONTINUE AIDING IN INSTABILITY WITH THE SETUP
WHICH IS POSSIBLE TONIGHT LIKELY OCCURRING OVER NORTHERN ILLINOIS
ON THURSDAY. THIS WILL BRING ANOTHER ROUND OF THUNDERSTORMS WHICH
WILL BE CAPABLE OF PRODUCING LARGE HAIL/DAMAGING WINDS AND HAIL.

RODRIGUEZ

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 06Z...

* CHANCE FOR MVFR VIS IN BR DURING THE EARLY MORNING HOURS.

* SELY WINDS VEERING SWLY IN THE MORNING THAN THEN BECOMING GUSTY
  IN THE AFTERNOON.

* CHANCE OF SHRA/TSRA TOMORROW EVENING.

KREIN

//DISCUSSION...UPDATED 06Z...

EXPECT THAT THE REMAINDER OF THE NIGHT SHOULD BE RELATIVELY QUIET
AT THE TERMINALS. THE LATEST RADAR IMAGERY INDICATES THAT ALL OF
THE ONGOING PCPN IS WELL TO THE NORTH IN WISCONSIN. WHILE THERE IS
SOME NEW DEVELOPMENT OVER FAR NERN IOWA AND SWRN WI...FEEL THAT
THE LOCAL TERMINALS WILL REMAIN DRY. THE ONLY WX IMPACT AT THE
TERMINALS TONIGHT WILL LIKELY BE REDUCED VISIBILITY DURG THE EARLY
MORNING HOURS. WITH THE ABSENCE OF ANY SGFNT CLOUDCOVER AND WITH
LIGHT WINDS AND A MOIST AIRMASS AT THE SFC...EXPECT THAT VIS WILL
DROP TO 3-4SM.

THE NEXT CHANCE FOR PCPN WILL COME TOMORROW EVENING.
HOWEVER...CONFIDENCE REMAINS LOW IN TIMING AND COVERAGE. THE MAIN
FEATURE OF CONCERN IS A VERY WEAK COLD FRONT DROPPING OUT OF THE
UPPER MISSISSIPPI VALLEY. THIS BOUNDARY WILL BE THE PRIMARY FOCUS
FOR PCPN ACTIVITY. HOWEVER...SINCE IT IS SUCH A DIFFUSE
BOUNDARY...WILL ONLY CARRY MENTION OF POSSIBLE TSRA IN A PROB30 GROUP.

KREIN

//ORD AND MDW CONFIDENCE...UPDATED 06Z...

* MEDIUM CONFIDENCE IN VIS TREND OVERNIGHT AND CHANCES FOR MVFR
  DURG THE EARLY MORNING HOURS.

* MEDIUM TO HIGH CONFIDENCE ON WIND TRENDS.

* LOW CONFIDENCE IN PCPN FORECAST TOMORROW EVENING.

KREIN

//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...

* FRIDAY THROUGH TUESDAY...GENERALLY PREVAILING VFR BUT WITH PERIODIC
  CHANCES FOR SHRA/TSRA. BEST CHANCES FOR TSRA APPEAR TO BE FRIDAY
  INTO THE WEEKEND.

KJB

&&

.MARINE...
325 AM CDT

A COLD FRONT EXTENDING FROM THE UPPER MISSISSIPPI VALLEY
THROUGH THE CENTRAL PLAINS WILL GRADUALLY SAG SOUTHWARD DOWN THE
LENGTH OF LAKE MICHIGAN LATER THIS MORNING. WINDS OVER THE LAKE
WILL GRADUALLY SHIFT FROM GENERALLY SOUTHERLY TO GENERALLY
NORTHERLY FOLLOWING THE FRONTAL PASSAGE. WINDS SHOULD THEN SETTLE
INTO NORTHEASTERLY TO EASTERLY THROUGH THE WEEKEND AND INTO EARLY
NEXT WEEK AS THE FRONT REMAINS STALLED OUT OVER THE OHIO VALLEY AND
HIGH PRESSURE REMAINS SITUATED OVER EASTERN CANADA.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$






AREA FORECAST DISCUSSION

NWS CHICAGO/ROMEOVILLE IL

 119 AM CDT THU MAY 3 2012

.DISCUSSION...
840 PM CDT

FOR EVENING UPDATE....

HAVE MADE SOME SIGNIFICANT ADJUSTMENTS TO POP/WX GRIDS INTO THE
OVERNIGHT HOURS BASED ON ANALYSIS/CONVECTIVE TRENDS UPSTREAM.

WARM FRONT WHICH LIFTED NORTH OF THE FORECAST AREA EARLIER THIS
MORNING HAS BECOME SOMEWHAT ILL-DEFINED ACROSS WISCONSIN AND LOWER
MICHIGAN THIS EVENING...WHILE A SECONDARY TROUGH/WARM FRONT WAS
NOTED FROM NORTHERN MISSOURI INTO CENTRAL IL/IND ENHANCED FROM
COMBINATION OF RETREATING CONVECTIVE OUTFLOW FROM MORNING MCS AND
DIFFERENTIAL HEATING FROM CLOUD COVER EARLIER IN THE DAY. THIS AREA
HAD BECOME RELATIVELY CLOUD-FREE LATE THIS AFTERNOON IN THE WAKE OF
THE SHORT-WAVE TROUGH AXIS WHICH HAS MOVED EAST OF THE AREA PER
WATER VAPOR IMAGERY AND PROFILER WINDS AT WOLCOTT IN. WHILE AIR MASS
IS WARM AND RATHER HUMID...WITH TEMPS STILL IN MID 70S AND DEW
POINTS IN THE MID-UPPER 60S ACROSS SOUTHERN CWA...00Z RAOBS FROM DVN
AND ILX DEPICT STRONG CAPPING INVERSION EXISTS FOR SFC/NEAR SFC
BASED CONVECTION. IN ADDITION...AIR MASS TO THE WEST ACROSS IOWA HAS
REMAINED STABILIZED WITH EXTENSIVE STRATUS DECK THROUGH THE
AFTERNOON AND HAS PREVENTED NEAR SFC BASED CONVECTION FROM
DEVELOPING SAVE FAR SOUTHERN MN/EASTERN NEBRASKA AREAS FARTHER NORTH
AND WEST.

CONVECTION-ALLOWING GUIDANCE INCLUDING WRF-NMM AND HRRR/RAP HAVE
BEEN INDICATING SIGNIFICANT CONVECTIVE DEVELOPMENT ACROSS EASTERN
IOWA INTO SOUTHWEST WISCONSIN DURING THE AFTERNOON AND EVENING
HOURS...BUT BASED ON THERMODYNAMIC PROFILES AND PRE-SUNSET VIS
SATELLITE TRENDS...EARLIER RUNS APPEAR TO HAVE OVER-FORECAST EXTENT
OF DEVELOPMENT. SOME FACTORS DO SUPPORT THE POTENTIAL FOR INCREASING
SHRA/TSRA THREAT THIS EVENING...MAINLY WITH BETTER MOIST ASCENT
DEVELOPING ABOVE STABLE BOUNDARY LAYER AS H9-H8 LOW LEVEL JET
INCREASES TO 35-40 KT AND MID-LEVEL SPEED MAX APPROACHES FROM THE
SOUTHWEST WITHIN AND AREA OF VERY STEEP MID-LEVEL LAPSE RATES WITH
EML NOTED IN OAX/DVN SOUNDINGS. AN ISOLATED AREA OF SHOWERS/WEAK
TSRA HAVE DEVELOPED ALONG A CONVERGENCE ZONE ACROSS FAR EASTERN IA
FROM NEAR MUSCATINE TO JUST WEST OF SAVANNA IL...LIKELY A
REPRESENTATION OF WHAT THE WRF-NMM AND HRRR/RAP WERE TRYING TO
DEPICT BUT ON A MORE LIMITED SCALE. TREND FROM THESE MODELS WOULD
SUGGEST THIS ACTIVITY WILL LIKELY FOCUS MORE ACROSS OUR FAR
NORTHWEST/NORTHERN CWA INTO THE OVERNIGHT HOURS...AND PERHAPS MORE
SO OVER SOUTHERN WI WHERE BETTER DEEP MOIST CONVERGENCE IS NOTED IN
ASSOCIATION WITH SYNOPTIC H9-H8 WARM FRONT. BASED ON ALL OF THIS...
HAVE GENERALLY LOWERED/REMOVED POPS ACROSS THE SOUTHERN CWA
OVERNIGHT. THE RECENT HRRR RUNS WOULD EVEN SUGGEST WE MAY BE DRY
ACROSS THE NORTH EXCEPT FOR RIGHT ALONG THE WI/IL LINE AFTER
MIDNIGHT...THOUGH MY CONFIDENCE IS NOT HIGH ENOUGH TO PULL POPS WITH
UNCERTAIN EVOLUTION OF CONVECTION CURRENTLY FARTHER UPSTREAM. THUS
HAVE GENERALLY LEFT HIGHER POPS GENERALLY NORTH OF I-88 ACROSS
NORTHERN IL...WITH FAR SOUTHERN COUNTIES DRY. HRRR ALSO INDICATES
MCS DEVELOPMENT ACROSS NEBRASKA...WHERE KS/NEBR ACTIVITY IS
CURRENTLY JUST GETTING GOING. LATEST GUIDANCE INDICATES THIS WOULD
NOT ARRIVE UNTIL AFTER 12Z WEDNESDAY IN DECAYING FORM.

RATZER

//PREV DISCUSSION...
329 PM CDT

MAIN FORECAST CHALLENGES REVOLVE AROUND SHOWER/THUNDERSTORM
CHANCES OVER THE NEXT SEVERAL DAYS WITH THE SEVERE POTENTIAL
REMAINING FOR TONIGHT AS WELL AS THURSDAY NIGHT...WITH HIGH
TEMPERATURES BEING DICTATED BY REMNANT PRECIP/CLOUD COVER THROUGH
EACH DAY.

LATEST RADAR IMAGERY DEPICTING AREA OF SHOWERS AND THUNDERSTORMS
WHICH SLOWLY PROGRESSED THROUGH PORTIONS OF THE CWA...CONTINUING
TO DIMINISH THIS AFTERNOON WITH MOST AREAS CURRENTLY DRY. EXPECT
THESE RELATIVELY DRY CONDITIONS TO REMAIN FOR A PORTION OF THIS
AFTERNOON INTO EARLY EVENING...OUTSIDE OF SOME ISOLATED/BRIEF
SHOWERS AND THUNDERSTORMS POSSIBLY DEVELOPING ALONG LINGERING
OUTFLOW BOUNDARIES WHICH SEVERAL ARE CURRENTLY SITUATED OVER THE
CWA. ANY SHOWERS/THUNDERSTORMS WHICH DO DEVELOP THIS AFTERNOON
SHOULD NOT BECOME SEVERE AS INSTABILITY IS STILL LACKING DUE TO A
RECOVERING ENVIRONMENT AND STRONGER WESTERLIES REMAINING TO THE
NORTHWEST.

STRONG SOUTHERLY FLOW OUT AHEAD OF A TROUGH OF LOW PRESSURE WELL
TO THE WEST OVER THE CENTRAL PLAINS WILL HELP FOR THE ENVIRONMENT
OVER THE CWA TO TO SLIGHTLY RECOVER THIS EVENING THROUGH EARLY
THURSDAY MORNING BRINGING LOW TO MID 60S DEWPOINT AIR BACK NORTH
ACROSS NORTHERN ILLINOIS AND NORTHWEST INDIANA. THIS SHOULD HELP
TO INCREASE OVERALL INSTABILITY OVER THE CWA THIS EVENING WHICH
COULD PROVIDE A SETUP FOR ANOTHER ROUND OF THUNDERSTORMS TO RACE
ACROSS THE CWA. MODEL GUIDANCE CONTINUES TO BE ALL OVER THE PLACE
IN REGARDS TO ENVIRONMENTAL DETAILS DUE TO MESOCALE FEATURES WHICH
CONTINUE TO DISRUPT THE LARGE SCALE PATTERN. THIS IS TRANSLATING
TO A LACK OF CONFIDENCE IN MODEL GENERATED PRECIP IN THE NEAR TERM
AS WELL AS FOR THE NEXT SEVERAL DAYS. DESPITE THIS LACK OF
CONFIDENCE IN NUMERICAL GUIDANCE...CAN STILL MAKE OUT SOME OF AREA
FOCUS FOR THUNDERSTORM DEVELOPMENT. ENVIRONMENT SHOULD CONTINUE TO
RECOVER ACROSS THE ENTIRE REGION FROM THE CENTRAL PLAINS BACK EAST
TO THE GREAT LAKES REGION WITH DEEP MOISTURE BACK ON THE RISE.
MAIN INSTABILITY AXIS IS SITUATED FROM WESTERN IOWA EAST INTO
SOUTHERN WISCONSIN...WITH INSTABILITY ANTICIPATED TO CONTINUE TO
INCREASE OVER NORTHEAST ILLINOIS AND NORTHWEST INDIANA. ALTHOUGH
THE EXTENT OF THIS INCREASE OVER THE CWA IS STILL IN
QUESTION...WHICH WILL PLAY A FACTOR IN THUNDERSTORM INTENSITY
TONIGHT. A SUBTLE MID LEVEL IMPULSE CURRENTLY OBSERVED EJECTING
ACROSS THE CENTRAL PLAINS COINCIDING WITH AN INCREASING LLJ SHOULD
INTERACT WITH A FRONTAL BOUNDARY OVER THE CENTRAL PLAINS LATER
THIS EVENING AND HELP FOR THE DEVELOPMENT OF THUNDERSTORMS ACROSS
IOWA. INSTABILITY SHOULD BE MORE THAN ENOUGH TO GET ROBUST
DEVELOPMENT WITH STEERING FLOW/LOW LEVEL SHEAR HELPING TO SHIFT
THIS THUNDERSTORM DEVELOPMENT EAST. A GROWING COMPLEX SHOULD WORK
ITS WAY EAST MAINLY AFFECTING THE NORTHERN HALF OF THE CWA LATER
TONIGHT INTO EARLY THURSDAY MORNING. OVERALL INSTABILITY IS STILL
IN QUESTION ACROSS THE CWA...BUT WITH DEEP MOISTURE NOT. IF
INSTABILITY INCREASES...A HAIL AND WIND THREAT WILL BE POSSIBLE
TONIGHT. IF NOT...AM STILL CONCERNED ABOUT THE POTENTIAL FOR VERY
RAIN EFFICIENT THUNDERSTORMS AS A VERY WARM AND JUICY AIRMASS WILL
BE IN PLACE. WITH ANY MCS PASSAGE TONIGHT...COULD ENVISION FURTHER
UPSCALE DEVELOPMENT AS A STRONG LLJ INTERACTS WITH ANY LINGERING
BOUNDARIES. THIS COULD PROVIDE A SETUP FOR TRAINING OF
THUNDERSTORMS AND HEAVY RAINFALL INTO THURSDAY MORNING.

ADVECTION OF A MUCH WARMER AIRMASS WILL CONTINUE ON THURSDAY WITH
WELL ABOVE NORMAL TEMPERATURES FORECAST. HAVE MAINTAINED MID AND
UPPER 80S FOR THE SOUTHERN HALF OF THE CWA BUT HAVE LOWERED TEMPS
TO AROUND 80 FOR THE NORTHERN HALF DUE TO POSSIBLE LINGERING
CONVECTION AND CLOUD COVER THURSDAY MORNING. ONGOING CONVECTION
DURING THE DAY THURSDAY WILL DEFINITELY BE KEY WITH FURTHER
DEVELOPMENT FOR THE REMAINDER OF THURSDAY INTO FRIDAY
MORNING...WHICH ONCE AGAIN SEEMS PROBABLE. ADVECTION OF A WARM AND
VERY MOIST AIR WILL CONTINUE AIDING IN INSTABILITY WITH THE SETUP
WHICH IS POSSIBLE TONIGHT LIKELY OCCURRING OVER NORTHERN ILLINOIS
ON THURSDAY. THIS WILL BRING ANOTHER ROUND OF THUNDERSTORMS WHICH
WILL BE CAPABLE OF PRODUCING LARGE HAIL/DAMAGING WINDS AND HAIL.

RODRIGUEZ

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 06Z...

* CHANCE FOR MVFR VIS IN BR DURING THE EARLY MORNING HOURS.

* SELY WINDS VEERING SWLY IN THE MORNING THAN THEN BECOMING GUSTY
  IN THE AFTERNOON.

* CHANCE OF SHRA/TSRA TOMORROW EVENING.

KREIN

//DISCUSSION...UPDATED 06Z...

EXPECT THAT THE REMAINDER OF THE NIGHT SHOULD BE RELATIVELY QUIET
AT THE TERMINALS. THE LATEST RADAR IMAGERY INDICATES THAT ALL OF
THE ONGOING PCPN IS WELL TO THE NORTH IN WISCONSIN. WHILE THERE IS
SOME NEW DEVELOPMENT OVER FAR NERN IOWA AND SWRN WI...FEEL THAT
THE LOCAL TERMINALS WILL REMAIN DRY. THE ONLY WX IMPACT AT THE
TERMINALS TONIGHT WILL LIKELY BE REDUCED VISIBILITY DURG THE EARLY
MORNING HOURS. WITH THE ABSENCE OF ANY SGFNT CLOUDCOVER AND WITH
LIGHT WINDS AND A MOIST AIRMASS AT THE SFC...EXPECT THAT VIS WILL
DROP TO 3-4SM.

THE NEXT CHANCE FOR PCPN WILL COME TOMORROW EVENING.
HOWEVER...CONFIDENCE REMAINS LOW IN TIMING AND COVERAGE. THE MAIN
FEATURE OF CONCERN IS A VERY WEAK COLD FRONT DROPPING OUT OF THE
UPPER MISSISSIPPI VALLEY. THIS BOUNDARY WILL BE THE PRIMARY FOCUS
FOR PCPN ACTIVITY. HOWEVER...SINCE IT IS SUCH A DIFFUSE
BOUNDARY...WILL ONLY CARRY MENTION OF POSSIBLE TSRA IN A PROB30 GROUP.

KREIN

//ORD AND MDW CONFIDENCE...UPDATED 06Z...

* MEDIUM CONFIDENCE IN VIS TREND OVERNIGHT AND CHANCES FOR MVFR
  DURG THE EARLY MORNING HOURS.

* MEDIUM TO HIGH CONFIDENCE ON WIND TRENDS.

* LOW CONFIDENCE IN PCPN FORECAST TOMORROW EVENING.

KREIN

//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...

* FRIDAY THROUGH TUESDAY...GENERALLY PREVAILING VFR BUT WITH PERIODIC
  CHANCES FOR SHRA/TSRA. BEST CHANCES FOR TSRA APPEAR TO BE FRIDAY
  INTO THE WEEKEND.

KJB

&&

.MARINE...
240 PM CDT

GENERALLY SOUTHERLY WINDS SHOULD CONTINUE THROUGH THURSDAY
EVENING...THOUGH PERIODIC PASSAGE OF THUNDERSTORM CLUSTERS COULD
RESULT IN VARIABLE AND AT TIMES STRONGER WINDS. FRONT WILL DROP DOWN
THE LAKE THURSDAY NIGHT INTO FRIDAY MORNING RESULTING IN A WIND
SHIFT TO NORTHERLY TO NORTHEASTERLY. WINDS LIKELY TO REMAIN
NORTHEAST TO EAST INTO EARLY NEXT WEEK AS FRONT REMAINS STALLED OUT
TO THE SOUTHWEST OF THE LAKE AND HIGH PRESSURE REMAINS SITUATED OVER
EASTERN CANADA.

IZZI

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$






AREA FORECAST DISCUSSION

NWS NORTHERN INDIANA

 725 PM EDT FRI MAY 4 2012

.AVIATION...

NUMEROUS BOUNDARIES ACROSS THE AREA FROM COMBINATION OF RECENT
CONVECTIVE ACTIVITY...LAKE BREEZE AND SYNOPTIC BOUNDARY. ALL FIRING
CONVECTION BUT SO FAR NOTHING CLOSE TO TAF SITES. ODDS OF TSRA IN
VICINITY OF KSBN OR KFWA QUITE SMALL BUT STILL A VERY SLIGHT CHANCE
AT KFWA WITH A WESTWARD MOVING BOUNDARY SEEN ON KIWX RADAR. NO TSRA
INCLUSION IN TAFS BUT WILL MONITOR BOUNDARIES CLOSELY. LOW LEVEL
EASTERLY FLOW WILL STRENGTHEN THROUGH THE NIGHT WITH WARM MOIST AIR
OVER TOP. PREVIOUS IDEA OF DEVELOPING STRATUS LOOKS GOOD AND LATEST
20Z HRRR MODEL CONCURS WITH IFR AND LIFR DEVELOPING AFTER 06Z. WILL
KEEP PREVIOUS IDEA INTACT WITH SLOW MIXING AND IMPROVEMENT SATURDAY
AFTERNOON.

&&


.SHORT TERM... / THIS AFTERNOON THROUGH SATURDAY NIGHT /

COLD FRONT JUST NORTH OF THE AREA WILL SINK SWD THROUGH THE
FORECAST AREA TONIGHT IN RESPONSE TO HEIGHT FALLS ACROSS THE
NORTHEAST CONUS. ENOUGH DIURNAL HEATING WITH SFC DEWPOINTS IN THE
MID 60S HAS ALLOWED SBCAPE VALUES TO INCREASE TO 1-2K J/KG. THIS
INSTABILITY IN CONJUNCTION WITH A WEAK MID LEVEL IMPULSE NOW ACROSS
SE MI...AND A TRAILING AREA OF LOW LEVEL MOISTURE
CONVERGENCE...WAS JUST ENOUGH TO FORCE CONVECTION MAINLY JUST EAST
OF THE FA THIS AFTERNOON. THIS RATHER WEAK TRIGGER WILL CONTINUE
EAST SO EXPECT ANY ADDITIONAL CONVECTION TO BE MORE ISOLATED IN
NATURE AHEAD OF THE AFOREMENTIONED SWD SINKING FRONTAL BOUNDARY
THROUGH THE EARLY EVENING HOURS...WITH BEST CHANCES FOR MEASURABLE
RAINFALL ACROSS THE SOUTHEAST GIVEN SOME ADDED ASCENT/MOISTURE ON
THE NORTHERN FRINGE OF A REMNANT MCS TRACKING INTO
CENTRAL/SOUTHERN INDIANA. MODERATE INSTABILITY AND LACK OF FLOW
ALOFT WILL SUPPORT PULSE STORMS WITH A SLIGHT RISK FOR ISOLATED
DAMAGING WINDS/LARGE HAIL SOUTH OF HIGHWAY 24 THROUGH EARLY THIS
EVENING.

A LOW LEVEL RIDGE AXIS WILL BUILD INTO THE EASTERN GREAT LAKES
TONIGHT THROUGH SATURDAY NIGHT. THIS WILL ESTABLISH EASTERLY LOW
LEVEL FLOW ACROSS THE SRN GREAT LAKES...ADVECTING A COOLER MORE
STABLE AIRMASS INTO THE REGION. THIS UNDERCUTTING SHALLOW COOL
AIRMASS UNDER THE LINGERING WARMTH ALOFT WILL LIKELY ALLOW A STRATUS
DECK TO DEVELOP ACROSS AT LEAST NORTHERN PORTIONS OF THE FA TONIGHT
INTO SATURDAY MORNING. THIS LOW LEVEL CLOUD DECK COULD HANG ON FOR
MUCH OF THE DAY...ESPECIALLY IF MID/HIGH LEVEL CLOUDS FROM UPSTREAM
CONVECTION ADVECTS OVER IT. TRENDED SLIGHTLY COOLER TOWARDS A MOS
BLEND...ESPECIALLY NORTHERN AREAS. HELD ON TO LOWER CHC POPS FAR
W/SW TOMORROW GIVEN CONCERNS WITH EVOLUTION OF UPSTREAM CONVECTIVE
COMPLEXES THAT WILL RE-FOCUS/ORGANIZE TONIGHT. THIS ACTIVITY
SHOULD MAINLY IMPACT AREAS ALONG A COMPOSITE OUTFLOW/THETA-E RIDGE
ON THE NORTHERN FRINGE OF A PLAINS EML...FROM THE DAKOTAS SEWD
INTO THE MID MS AND WESTERN OH VALLEYS. A WEAKENING AREA OF RAIN
COULD REACH OUR WESTERN ZONES TOMORROW IF A MCV DEVELOPS.

&&

.LONG TERM...SUNDAY THROUGH FRIDAY

FOR SUNDAY...SFC BOUNDARY WILL REMAIN STALLED SOUTH OF THE AREA WITH
MID/UPPER LEVEL RIDGING REMAINING DOMINANT ACROSS THE UPPER MS
VALLEY AND GREAT LAKES REGION. THIS PATTERN WILL EVENTUALLY
BREAKDOWN LATE SUNDAY INTO MONDAY AS NEXT AMPLIFIED PACIFIC SYSTEM
KICKS OUT OF THE NORTHERN ROCKIES. GUIDANCE DEPICTING QUITE A SPREAD
IN THE PROGRESSION OF THIS FEATURE WITH NAM REMAINING A FAST OUTLIER
AND MORE AGGRESSIVE IN BREAKING DOWN THIS RIDGE. MAIN IMPACT ON THE
LOCAL AREA CONCERNING THESE DIFFERENCES IS MAGNITUDE OF LOW LEVEL
MOISTURE RETURN FOR SUNDAY...WITH GFS/ECMWF REMAINING MORE MEAGER
WITH LOW LEVEL MOISTURE UNDER THE INFLUENCE OF SOUTHEAST LOW LEVEL
FLOW ON SOUTHERN PERIPHERY OF SOUTHEAST CANADIAN ANTICYCLONE IN
COMPARISON TO THE NAM. THUS...HAVE REMAINED QUITE CONSERVATIVE ON
POPS DURING THE DAY SUNDAY CONFINING LOW CHANCE/SLIGHT CHANCE POPS
MAINLY ACROSS FAR WEST.

LOW LEVEL FLOW TO VEER SUNDAY NIGHT AS SFC LOW PRESSURE TRACKS INTO
THE MID MS RIVER VALLEY IN ASSOCIATION WITH UPPER TROUGH SKIRTING
ACROSS FAR NORTH CENTRAL US. FAIRLY STRONG LOW LEVEL THETAE
ADVECTION TO ACCOMPANY THIS SOUTHWESTERLY LOW LEVEL JET SUNDAY NIGHT
WITH MODEST INCREASES IN ELEVATED INSTABILITY...ESPECIALLY DURING
THE OVERNIGHT HOURS. NO CHANGE FROM PREVIOUS LIKELY POPS ACROSS THE
WEST TAPERING TO CHANCE EAST WHERE LOW LEVEL MOISTURE RETURN WILL
RAMP UP MORE SIGNIFICANTLY TOWARD MONDAY MORNING.

BY MONDAY...MAIN FORECAST CHALLENGE CENTERS ON THE TRACK AND
AMPLITUDE OF THE NORTH CENTRAL CONUS UPPER TROUGH AND TIMING SFC
COLD FRONT THROUGH THE AREA. 12Z NAM REMAINS MUCH MORE PROGRESSIVE
KICKING FRONT THROUGH THE AREA EARLY MONDAY AS OPPOSED TO MAJORITY
OF OTHER DETERMINISTIC SOLUTIONS THAT TRACK SFC LOW INTO NORTHEAST
INDIANA AND SOUTH CENTRAL LOWER MICHIGAN BY EARLY MONDAY EVENING.
GIVEN CONCERNS OF NAM BEING OVERAGGRESSIVE BREAKING DOWN THE
RIDGE...HAVE CONTINUED WITH CONSENSUS SOLUTION OF A SLOWER
EVOLUTION. THIS SOLUTION ALSO SEEMS TO HAVE SUPPORT FROM RECENT
TREND IN GEFS MEANS TOWARD THIS CLUSTER IDEA. THUS...HAVE MAINTAINED
LIKELY TSRA POPS FOR MOST OF FORECAST AREA MONDAY WITH PRECIP
CHANCES ENDING FROM WEST TO EAST LATE MONDAY AFTERNOON/MONDAY
EVENING. SEVERE POTENTIAL STILL SOMEWHAT UNCLEAR AT THIS POINT WITH
QUESTIONS REGARDING INSTABILITY MAGNITUDE AND NORTHWARD EXTENT OF
WARM FRONT.

TREND TO COOLER TEMPS STILL LOOKS INLINE FOR TUES-THU WITH UPPER LOW
TRACKING INTO ONTARIO/NORTHERN GREAT LAKES MID WEEK. TEMPERATURES
SHOULD MODERATE TOWARD THE END OF THE PERIOD AS THIS TROUGH EXITS.
HAVE ALSO MAINTAINED LOW CHANCE POPS FOR SHRA TUESDAY
NIGHT/WEDNESDAY NIGHT CORRESPONDING TO THE PERIOD OF STRONGEST UPPER
FORCING FROM THE UPPER TROUGH.

&&


.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

SHORT TERM...STEINWEDEL
LONG TERM...MARSILI
AVIATION...LASHLEY







AREA FORECAST DISCUSSION...UPDATED

NWS DES MOINES IA

 1247 PM CDT THU MAY 3 2012

...UPDATED AVIATION DISCUSSION...

.SHORT TERM /TODAY/...
FORECAST CONCERN INVOLVES THE ONGOING CONVECTION ASSOCIATED WITH A
DYING MCS MOVING ACROSS THE SOUTHERN TWO-THIRDS OF THE FORECAST AREA
THIS MORNING. LATEST HRRR (05Z RUN) HAS CONVECTION DISSIPATING AND
MOVING EAST THROUGH 15Z AND THE 00Z 4KM WRF HAS CONVECTION
DISSIPATING BY AROUND 18Z IN EASTERN PORTIONS OF THE FORECAST AREA.
Q2 CURRENTLY DEPICTING RAINFALL RATES AROUND 2 IN/HR OR LESS WITHIN
THE STRONGER CORES...BUT LINE IS MOVING FAIRLY PROGRESSIVE AT
30-35KTS. SO NOT ANTICIPATING MUCH FLOODING ISSUES...ESPECIALLY
FURTHER EAST WITHIN THE FLASH FLOOD WATCH AREA IN NORTHEAST IOWA.
CONVECTION SHOULD BE MUCH WEAKER BY THE TIME IT REACHES IT AND
THUS...WENT AHEAD AND CANCELLED FLASH FLOOD WATCH.

OTHER CONCERN IS WITH POTENTIAL FOR AFTERNOON CONVECTION ALONG AND
SOUTH OF THE BOUNDARY IN NORTHERN IOWA.  RUC/NAM/GFS ALL KEEP THE
SURFACE FRONT LAID UP ALONG THE MN/IA BORDER KEEPING THE FORECAST
AREA WITHIN THE WARM SECTOR.  BEST INSTABILITY WILL BE LOCATED SOUTH
OF HIGHWAY 30 WHERE LOW LEVEL CAPE INCREASES TO AROUND 2000-3000
J/KG BUT LOW LEVEL SHEAR VALUES NOT IMPRESSIVE. CLOUDS LEFTOVER FROM
DYING MCS SHOULD LIMIT SOME OF THE DAYTIME HEATING...BUT THINKING
THE WAA WILL BE STRONG ENOUGH TO BUMPED TEMPS BACK INTO THE LOWER
80S BY THIS AFTERNOON. TIMING OF AFTERNOON CONVECTION LOOKS TO BE
AFTER 21Z WITH MID-LEVEL SHORTWAVE MOVING INTO WESTERN IOWA BY 00Z
FRIDAY. SURFACE DEW POINTS REMAIN WELL INTO THE 60S...SO PLENTY OF
MOISTURE AVAILABLE.

.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
CURRENT LONG WAVE PATTERN...WRN CONUS TROUGH/ERN RIDGE...WILL REMAIN
INTACT THROUGH MUCH OF THE PERIOD BUT WITH SLOW PROGRESS.  THIS
SHOULD HAVE TROUGH ONLY REACH CENTRAL CONUS BY EARLY NEXT WEEK.
EXPECT CONVERGENCE FROM CURRENT NE TO MN FRONTAL BOUNDARY AND/OR
OUTFLOW FROM WEAKENING WRN IA MCS TO EVENTUALLY POSITION ITSELF INTO
CENTRAL/SRN IA BY EARLY THIS EVENING AND TRIGGER ANOTHER ROUND OF
CONVECTION...TIMED MUCH LIKE PAST FEW EVENTS MAINLY AT NIGHT.  MCS
SHOULD THEN PUSH TO THE SOUTH AND EAST DIMINISHING POPS OVERNIGHT.
CONFIDENCE IN THIS SCENARIO IS SOMEWHAT LOW HOWEVER AS CURRENT MCS
CONTINUES TO BACK BUILD ACROSS SRN NE.  FORECASTING EVENTUAL
POSITION OF SYNOPTIC AND/OR MESOSCALE BOUNDARIES WILL BE DIFFICULT.

BY FRI MODEL CONSENSUS SUGGESTS A RELATIVE LULL WITH IA IN FAIRLY
WEAK SELY SURFACE FLOW.  STILL UNSTABLE BUT LITTLE FOCUS.  ATTENTION
TURNS TO THE WEST AGAIN EYING RESPONSE TO GRADUALLY APPROACHING
WRN TROUGH.  THIS WILL LEAD TO INCREASING WARM ADVECTION AND
BAROCLINICITY THROUGH SIOUXLAND MO VALLEY REGION.  305K FLOW IS
FAIRLY WEAK SO DO NOT EXPECT SIGNIFICANT MCS BUT INCREASING POPS.
CONVECTION MAY BE MORE SIGNIFICANT BY SAT NIGHT AND SUNDAY HOWEVER
AS FLOW AND ASSOCIATED THETA-E ADVECTION INCREASE.  KINEMATIC
FORCING WILL INCREASE AS WELL AS LOBE OF UVM PUSHES ACROSS NRN
PLAINS INTO EARLY SUN WHICH IS ALSO FOCUSED BY PASSAGE OF INVERTED
SURFACE TROUGH.  THIS ALL LEADS TO POPS BACK UP INTO LIKELIES DURING
THIS PERIOD.

BY EARLY NEXT WEEK PATTERN WILL SHIFT SUFFICIENTLY TO LOWER OUR
PRECIP CHANCES AND COOL TEMPS SOMEWHAT AS IA ENDS UP IN NWLY SURFACE
FLOW.  THIS RESULTS IN EXTENDED FORECAST EITHER DRY OR WITH ONLY
SLIGHT CHANCES AND MAXES ONLY IN THE 60S OR POSSIBLY LOWER 70S.

&&

.AVIATION...03/18Z
IN WAKE OF MORNING SHRA/TSRA A SMALL AREA OF HIGH PRESSURE HAS
DEVELOPED...CREATING SMALL-SCALE WIND FIELD EFFECTS THAT ARE PROVING
DIFFICULT TO PREDICT WITH WINDS ANYWHERE FROM 170-270 AND FROM
NEARLY CALM TO ABOUT 15G25KT. HAVE TAKEN A BEST GUESS IN THE TAFS
BUT WINDS WILL BE TRICKY UNTIL THE HIGH DISSIPATES. MEANWHILE...MORE
STORMS ANTICIPATED LATE TODAY HAVE A HIGH DEGREE OF UNCERTAINTY.
BEST CHANCES APPEAR TO BE IN OUR FAR NORTH AND FAR SOUTH THIS EVE
WHERE PRONOUNCED BOUNDARIES ARE PRESENT...HOWEVER HAVE SO LITTLE
CONFIDENCE IN TIMING/EXTENT THAT VCTS IS ALL THAT CAN BE JUSTIFIED
IN 18Z TAFS. IN ANY EVENT STORMS SHOULD END BY MIDNIGHT...WITH MVFR
OR LOWER CIGS/VSBYS IN FOG AND STRATUS POSSIBLE DURING THE EARLY
MORNING HOURS FRI WITH LIGHT/VRBL WINDS AND AMPLE LOW-LEVEL MOISTURE.

&&

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

&&

$$

SHORT TERM...KLP
LONG TERM...BSS
AVIATION...LEE







AREA FORECAST DISCUSSION

NWS DES MOINES IA

 656AM CDT THU MAY 3 2012

...UPDATED AVIATION DISCUSSION...

.SHORT TERM /TODAY/...
FORECAST CONCERN INVOLVES THE ONGOING CONVECTION ASSOCIATED WITH A
DYING MCS MOVING ACROSS THE SOUTHERN TWO-THIRDS OF THE FORECAST AREA
THIS MORNING. LATEST HRRR (05Z RUN) HAS CONVECTION DISSIPATING AND
MOVING EAST THROUGH 15Z AND THE 00Z 4KM WRF HAS CONVECTION
DISSIPATING BY AROUND 18Z IN EASTERN PORTIONS OF THE FORECAST AREA.
Q2 CURRENTLY DEPICTING RAINFALL RATES AROUND 2 IN/HR OR LESS WITHIN
THE STRONGER CORES...BUT LINE IS MOVING FAIRLY PROGRESSIVE AT
30-35KTS. SO NOT ANTICIPATING MUCH FLOODING ISSUES...ESPECIALLY
FURTHER EAST WITHIN THE FLASH FLOOD WATCH AREA IN NORTHEAST IOWA.
CONVECTION SHOULD BE MUCH WEAKER BY THE TIME IT REACHES IT AND
THUS...WENT AHEAD AND CANCELLED FLASH FLOOD WATCH.

OTHER CONCERN IS WITH POTENTIAL FOR AFTERNOON CONVECTION ALONG AND
SOUTH OF THE BOUNDARY IN NORTHERN IOWA.  RUC/NAM/GFS ALL KEEP THE
SURFACE FRONT LAID UP ALONG THE MN/IA BORDER KEEPING THE FORECAST
AREA WITHIN THE WARM SECTOR.  BEST INSTABILITY WILL BE LOCATED SOUTH
OF HIGHWAY 30 WHERE LOW LEVEL CAPE INCREASES TO AROUND 2000-3000
J/KG BUT LOW LEVEL SHEAR VALUES NOT IMPRESSIVE. CLOUDS LEFTOVER FROM
DYING MCS SHOULD LIMIT SOME OF THE DAYTIME HEATING...BUT THINKING
THE WAA WILL BE STRONG ENOUGH TO BUMPED TEMPS BACK INTO THE LOWER
80S BY THIS AFTERNOON. TIMING OF AFTERNOON CONVECTION LOOKS TO BE
AFTER 21Z WITH MID-LEVEL SHORTWAVE MOVING INTO WESTERN IOWA BY 00Z
FRIDAY. SURFACE DEW POINTS REMAIN WELL INTO THE 60S...SO PLENTY OF
MOISTURE AVAILABLE.

.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
CURRENT LONG WAVE PATTERN...WRN CONUS TROUGH/ERN RIDGE...WILL REMAIN
INTACT THROUGH MUCH OF THE PERIOD BUT WITH SLOW PROGRESS.  THIS
SHOULD HAVE TROUGH ONLY REACH CENTRAL CONUS BY EARLY NEXT WEEK.
EXPECT CONVERGENCE FROM CURRENT NE TO MN FRONTAL BOUNDARY AND/OR
OUTFLOW FROM WEAKENING WRN IA MCS TO EVENTUALLY POSITION ITSELF INTO
CENTRAL/SRN IA BY EARLY THIS EVENING AND TRIGGER ANOTHER ROUND OF
CONVECTION...TIMED MUCH LIKE PAST FEW EVENTS MAINLY AT NIGHT.  MCS
SHOULD THEN PUSH TO THE SOUTH AND EAST DIMINISHING POPS OVERNIGHT.
CONFIDENCE IN THIS SCENARIO IS SOMEWHAT LOW HOWEVER AS CURRENT MCS
CONTINUES TO BACK BUILD ACROSS SRN NE.  FORECASTING EVENTUAL
POSITION OF SYNOPTIC AND/OR MESOSCALE BOUNDARIES WILL BE DIFFICULT.

BY FRI MODEL CONSENSUS SUGGESTS A RELATIVE LULL WITH IA IN FAIRLY
WEAK SELY SURFACE FLOW.  STILL UNSTABLE BUT LITTLE FOCUS.  ATTENTION
TURNS TO THE WEST AGAIN EYING RESPONSE TO GRADUALLY APPROACHING
WRN TROUGH.  THIS WILL LEAD TO INCREASING WARM ADVECTION AND
BAROCLINICITY THROUGH SIOUXLAND MO VALLEY REGION.  305K FLOW IS
FAIRLY WEAK SO DO NOT EXPECT SIGNIFICANT MCS BUT INCREASING POPS.
CONVECTION MAY BE MORE SIGNIFICANT BY SAT NIGHT AND SUNDAY HOWEVER
AS FLOW AND ASSOCIATED THETA-E ADVECTION INCREASE.  KINEMATIC
FORCING WILL INCREASE AS WELL AS LOBE OF UVM PUSHES ACROSS NRN
PLAINS INTO EARLY SUN WHICH IS ALSO FOCUSED BY PASSAGE OF INVERTED
SURFACE TROUGH.  THIS ALL LEADS TO POPS BACK UP INTO LIKELIES DURING
THIS PERIOD.

BY EARLY NEXT WEEK PATTERN WILL SHIFT SUFFICIENTLY TO LOWER OUR
PRECIP CHANCES AND COOL TEMPS SOMEWHAT AS IA ENDS UP IN NWLY SURFACE
FLOW.  THIS RESULTS IN EXTENDED FORECAST EITHER DRY OR WITH ONLY
SLIGHT CHANCES AND MAXES ONLY IN THE 60S OR POSSIBLY LOWER 70S.

&&

.AVIATION...03/12Z
CONVECTION DIMINISHING ACROSS CENTRAL IOWA THIS MORNING WITH GRAVITY
WAVE CAUSING SOME GUSTY WINDS ACROSS NORTHERN IOWA.  WINDS SHOULD
SHIFT AROUND TO THE SOUTH ONCE RAIN/TSRA DIMINISH AND BUFR SOUNDINGS
HAVE ENOUGH MIXING TO WARRANT GUSTS IN THE UPPER TEENS THROUGH THE
DAY. LOW CONFIDENCE WITH TIMING OF CONVECTION THIS
AFTERNOON/EVENING...AND ONLY HAVE VCTS MENTIONED AT OTM/DSM ATTM
WITH THE BOUNDARY DRIFTING SOUTH. DECENT CHANCE FOR SOME FOG
DEVELOPMENT OVERNIGHT INTO FRIDAY MORNING AND HAVE MVFR VIS MENTION
FOR ALL TAF SITES EXCEPT DSM.

&&

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

&&

$$

SHORT TERM...KLP
LONG TERM...BSS
AVIATION...KLP









AREA FORECAST DISCUSSION

NWS DES MOINES IA

 405 AM CDT THU MAY 3 2012

.SHORT TERM /TODAY/...
FORECAST CONCERN INVOLVES THE ONGOING CONVECTION ASSOCIATED WITH A
DYING MCS MOVING ACROSS THE SOUTHERN TWO-THIRDS OF THE FORECAST AREA
THIS MORNING. LATEST HRRR (05Z RUN) HAS CONVECTION DISSIPATING AND
MOVING EAST THROUGH 15Z AND THE 00Z 4KM WRF HAS CONVECTION
DISSIPATING BY AROUND 18Z IN EASTERN PORTIONS OF THE FORECAST AREA.
Q2 CURRENTLY DEPICTING RAINFALL RATES AROUND 2 IN/HR OR LESS WITHIN
THE STRONGER CORES...BUT LINE IS MOVING FAIRLY PROGRESSIVE AT
30-35KTS. SO NOT ANTICIPATING MUCH FLOODING ISSUES...ESPECIALLY
FURTHER EAST WITHIN THE FLASH FLOOD WATCH AREA IN NORTHEAST IOWA.
CONVECTION SHOULD BE MUCH WEAKER BY THE TIME IT REACHES IT AND
THUS...WENT AHEAD AND CANCELLED FLASH FLOOD WATCH.

OTHER CONCERN IS WITH POTENTIAL FOR AFTERNOON CONVECTION ALONG AND
SOUTH OF THE BOUNDARY IN NORTHERN IOWA.  RUC/NAM/GFS ALL KEEP THE
SURFACE FRONT LAID UP ALONG THE MN/IA BORDER KEEPING THE FORECAST
AREA WITHIN THE WARM SECTOR.  BEST INSTABILITY WILL BE LOCATED SOUTH
OF HIGHWAY 30 WHERE LOW LEVEL CAPE INCREASES TO AROUND 2000-3000
J/KG BUT LOW LEVEL SHEAR VALUES NOT IMPRESSIVE. CLOUDS LEFTOVER FROM
DYING MCS SHOULD LIMIT SOME OF THE DAYTIME HEATING...BUT THINKING
THE WAA WILL BE STRONG ENOUGH TO BUMPED TEMPS BACK INTO THE LOWER
80S BY THIS AFTERNOON. TIMING OF AFTERNOON CONVECTION LOOKS TO BE
AFTER 21Z WITH MID-LEVEL SHORTWAVE MOVING INTO WESTERN IOWA BY 00Z
FRIDAY. SURFACE DEW POINTS REMAIN WELL INTO THE 60S...SO PLENTY OF
MOISTURE AVAILABLE.

.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
CURRENT LONG WAVE PATTERN...WRN CONUS TROUGH/ERN RIDGE...WILL REMAIN
INTACT THROUGH MUCH OF THE PERIOD BUT WITH SLOW PROGRESS.  THIS
SHOULD HAVE TROUGH ONLY REACH CENTRAL CONUS BY EARLY NEXT WEEK.
EXPECT CONVERGENCE FROM CURRENT NE TO MN FRONTAL BOUNDARY AND/OR
OUTFLOW FROM WEAKENING WRN IA MCS TO EVENTUALLY POSITION ITSELF INTO
CENTRAL/SRN IA BY EARLY THIS EVENING AND TRIGGER ANOTHER ROUND OF
CONVECTION...TIMED MUCH LIKE PAST FEW EVENTS MAINLY AT NIGHT.  MCS
SHOULD THEN PUSH TO THE SOUTH AND EAST DIMINISHING POPS OVERNIGHT.
CONFIDENCE IN THIS SCENARIO IS SOMEWHAT LOW HOWEVER AS CURRENT MCS
CONTINUES TO BACK BUILD ACROSS SRN NE.  FORECASTING EVENTUAL
POSITION OF SYNOPTIC AND/OR MESOSCALE BOUNDARIES WILL BE DIFFICULT.

BY FRI MODEL CONSENSUS SUGGESTS A RELATIVE LULL WITH IA IN FAIRLY
WEAK SELY SURFACE FLOW.  STILL UNSTABLE BUT LITTLE FOCUS.  ATTENTION
TURNS TO THE WEST AGAIN EYING RESPONSE TO GRADUALLY APPROACHING
WRN TROUGH.  THIS WILL LEAD TO INCREASING WARM ADVECTION AND
BAROCLINICITY THROUGH SIOUXLAND MO VALLEY REGION.  305K FLOW IS
FAIRLY WEAK SO DO NOT EXPECT SIGNIFICANT MCS BUT INCREASING POPS.
CONVECTION MAY BE MORE SIGNIFICANT BY SAT NIGHT AND SUNDAY HOWEVER
AS FLOW AND ASSOCIATED THETA-E ADVECTION INCREASE.  KINEMATIC
FORCING WILL INCREASE AS WELL AS LOBE OF UVM PUSHES ACROSS NRN
PLAINS INTO EARLY SUN WHICH IS ALSO FOCUSED BY PASSAGE OF INVERTED
SURFACE TROUGH.  THIS ALL LEADS TO POPS BACK UP INTO LIKELIES DURING
THIS PERIOD.

BY EARLY NEXT WEEK PATTERN WILL SHIFT SUFFICIENTLY TO LOWER OUR
PRECIP CHANCES AND COOL TEMPS SOMEWHAT AS IA ENDS UP IN NWLY SURFACE
FLOW.  THIS RESULTS IN EXTENDED FORECAST EITHER DRY OR WITH ONLY
SLIGHT CHANCES AND MAXES ONLY IN THE 60S OR POSSIBLY LOWER 70S.

&&

.AVIATION...03/06Z
THUNDERSTORM ACTIVITY CONTINUES TO BE MOSTLY NON-EXISTENT ACROSS THE
CWA...WITH A FEW CELLS PUSHING THROUGH EXTREME NORTHERN CWA. FORCING
FOR THUNDERSTORMS REMAINS STRONGER TO THE WEST OF THE CWA...AND
STILL MAY GET SOME MOVING THROUGH THE AREA LATE TONIGHT TOWARD
SUNRISE OR A LITTLE BEFORE. THEREFORE HAVE GONE MORE PESSIMISTIC
WITH THE TAFS AND ONLY MENTIONED VCSH FOR KDSM AND KOTM WHERE THE
BETTER CHANCES WILL BE VERSUS THE NORTHERN CWA AT THIS TIME.

&&

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

&&

$$

SHORT TERM...KLP
LONG TERM...BSS
AVIATION...MJB






AREA FORECAST DISCUSSION

NWS DES MOINES IA

 1205 AM CDT THU MAY 3 2012

.UPDATE...
PREVIOUS THOUGHTS OF CONVECTION DEVELOPING ACROSS NORTHERN IOWA IN
THE LATE AFTERNOON/EARLY EVENING HAVE NOT OCCURRED...WITH DECENT CAP
STILL IN PLACE ALOFT VIA DVN 00Z SOUNDING DUE TO STRATUS/LOW CLOUD
COVER LINGERING MUCH OF THE DAY. THEREFORE HAVE TAPERED POPS DOWN
FOR THE EARLY EVENING HOURS AT THIS TIME. A FEW CELLS ARE TRYING TO
GO UP ON SFC BOUNDARY SITUATED ACROSS ERN NE/SE SD INTO SRN MN.
THESE CELLS HAVING TOUGHER TIME SUSTAINING THEMSELVES AS WELL.
THEREFORE FOCUS ON THUNDERSTORM DEVELOPMENT TURNS TO LATER TONIGHT
WITH MID LEVEL WAVE APPROACHES FROM THE WEST AND LLJ INCREASES AND
LOW LEVEL MOISTURE TRANSPORT BECOMES ORIENTED RIGHT INTO CENTRAL
IOWA. HRRR MODEL SUGGESTING STORMS PUSHING INTO CENTRAL IOWA AROUND
MIDNIGHT OR LATER AT THIS TIME...SO HAVE TRENDED GREATEST POPS
ACROSS THE CWA FOR THE LATE NIGHT HOURS.

.SHORT TERM /TONIGHT/...
SEVERAL CONCERNS OVERNIGHT AS ACTIVE WSW FLOW ALOFT CONTINUES.
OUTFLOW FROM THE MORNING CONVECTION HAD CLEARED WELL SOUTH OF THE
BORDER EARLIER TODAY AND THERE HAS BEEN GRADUAL RECOVER THROUGH THE
AFTERNOON AS SOUTHERLY WINDS HAVE INCREASED ALONG WITH MOISTURE.
CAPES HAVE STEADILY INCREASED WITH 100MB MIXED LAYER OF 2000-3000
J/KG ACROSS WESTERN AND NORTHERN IOWA.  HOWEVER...18Z SOUNDING AT
KOAX HAS INDICATED SOME CAPPING ALONG WITH A GENERALLY DIVERGENT
SURFACE FLOW IN NORTHERN IOWA.  THESE PARTICULAR FEATURES ARE LIKELY
INHIBITING CONVECTION AT THIS POINT BUT THIS SHOULD CHANGE BY THIS
EVENING WITH THE APPROACH OF A SHORTWAVE IN THE PLAINS.  MODELS HAVE
BEEN INDICATING CONVECTION IN NORTH CENTRAL AND NORTHEAST IOWA THIS
EVENING WHERE LOW LEVEL JET/FLOW WILL BE DIRECTED.  THIS AREA HAS
VERY HIGH PWATS AND WITH THIS PERSISTENT LOW LEVEL FLOW DIRECTED IN
THAT LOCATION AND FLASH FLOOD GUIDANCE VALUES OF ONE TO ONE AND A
HALF INCHES...HAVE OPTED FOR A FLASH FLOOD WATCH IN FAR NORTHEAST.
ELSEWHERE...CONVECTION EXPECTED IN THE NORTH THIS EVENING WHERE CAP
IS WEAKEST WITH ADDITIONAL CONVECTION IN NEBRASKA HEADING TOWARD
CENTRAL AND SOUTHERN IOWA LATE TONIGHT INTO EARLY THURSDAY MORNING.
THIS CONVECTION WILL HAVE THE THREAT FOR SEVERE STRAIGHT LINE WINDS
ALONG WITH LARGE HAIL AND A ISOLATED TORNADOES AS IT PROGRESSES
RAPIDLY EASTWARD OVERNIGHT.

.LONG TERM /THURSDAY THROUGH WEDNESDAY/...
COMPLICATED LONG TERM FORECAST...WITH LOW CONFIDENCE. ANTICIPATE
OVERNIGHT MCS TO BE LINGERING ACROSS THE NORTH AND EAST FOR
BEGINNING OF TOMORROW BEFORE PUSHING OUT OF CWA. CONDITIONS WILL
IMPROVE THROUGH THE DAY...BUT WITH LINGERING FRONTAL BOUNDARY ACROSS
SOUTHERN IOWA BY THURSDAY AFTERNOON...EXPECT TO SEE AFTERNOON
DEVELOPMENT. BUT AGAIN ANTICIPATE BEST CHANCES FOR PRECIPITATION TO
BE ANOTHER ROUND OF OVERNIGHT MCS CONVECTION...FOCUSED ACROSS
SOUTHERN IOWA. PWAT VALUES ARE HIGH...WITH PLENTY OF MOISTURE
AVAILABLE COULD SEE POTENTIAL FOR LOCALIZED AREAS OF HEAVY RAIN
AGAIN OVERNIGHT THURSDAY NIGHT...AGAIN HIGHEST LIKELIHOOD APPEARS TO
BE ACROSS SOUTHERN IOWA. OVERNIGHT PRECIPITATION COULD LINGER INTO
EARLY FRIDAY BEFORE AGAIN QUICKLY PUSHING OUT OF THE CWA. HAVE LEFT
SLIGHT CHANCE POPS FOR FRIDAY AFTERNOON WITH POTENTIAL FOR AFTERNOON
DEVELOPMENT WITH ANOTHER APPROACHING FRONTAL SYSTEM...BUT AGAIN
APPEARS MAIN PRECIP CHANCES WILL BE OVERNIGHT.

TEMPERATURES BECOME A BIT TRICKY FOR FRIDAY AND SATURDAY. WAA AHEAD
OF APPROACHING FRONTAL SYSTEM IS STRONG FOR FRIDAY WITH GOOD MIXING
POSSIBLE FRIDAY. IF MIXING IS FULLY REALIZED...OR SKIES CLEAR FOR
LONG ENOUGH COULD EASILY SEE TEMPERATURES POP UP INTO THE UPPER 80S
FOR MUCH OF THE CENTRAL AND SOUTHERN PORTIONS OF THE CWA. HAVE
INCREASED TEMPERATURES FOR FRIDAY AND SATURDAY...BUT MAY STILL HAVE
BEEN TOO COOL...ESPECIALLY FOR FRIDAY. TIMING OF FRONTAL BOUNDARY
WILL HAVE IMPACT ON TEMPS FOR SATURDAY...WITH LITTLE MODEL AGREEMENT
ON PLACING OF FRONT HAVE TRENDED UPWARDS WITH TEMPS.

ACTIVE PATTERN CONTINUES FOR REMAINDER OF EXTENDED WITH AREA OF LOW
PRESSURE EXPECTED TO PUSH ACROSS THE NORTHERN PLAINS/SOUTHERN CANADA
FOR THE END OF EXTENDED. ASSOCIATED FRONTAL BOUNDARYS WILL BRING
CHANCES FOR PRECIPITATION THROUGH THE WEEKEND...WITH LINGERING
PRECIPITATION INTO EARLY NEXT WEEK.


&&

.AVIATION...03/06Z
THUNDERSTORM ACTIVITY CONTINUES TO BE MOSTLY NON-EXISTENT ACROSS THE
CWA...WITH A FEW CELLS PUSHING THROUGH EXTREME NORTHERN CWA. FORCING
FOR THUNDERSTORMS REMAINS STRONGER TO THE WEST OF THE CWA...AND
STILL MAY GET SOME MOVING THROUGH THE AREA LATE TONIGHT TOWARD
SUNRISE OR A LITTLE BEFORE. THEREFORE HAVE GONE MORE PESSIMISTIC
WITH THE TAFS AND ONLY MENTIONED VCSH FOR KDSM AND KOTM WHERE THE
BETTER CHANCES WILL BE VERSUS THE NORTHERN CWA AT THIS TIME.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM 7 PM CDT THIS EVENING THROUGH THURSDAY
MORNING FOR BLACK HAWK-BREMER-BUTLER-CERRO GORDO-FRANKLIN-GRUNDY-
HARDIN.

&&

$$

SHORT TERM...COGIL
LONG TERM...AWB
AVIATION...MJB















AREA FORECAST DISCUSSION

NWS TOPEKA KS

 614 PM CDT FRI MAY 4 2012

...AVIATION UPDATE...

.DISCUSSION...
SEE PREV DISCUSSION.

&&

.AVIATION...
WITH LITTLE OR NO FORCING OR LIFT FOR CONVECTION TO
DEVELOP...THINK THE TERMINALS WILL REMAIN DRY OVERNIGHT. DO NOT
HAVE MUCH CONFIDENCE IN THE MODEL PROGS OF MVFR OR IFR CIGS
DEVELOPING OVERNIGHT. THINK THAT AS LONG AS THERE IS WIND...DRY
AIR SHOULD CONTINUE TO ENTRAIN INTO THE BOUNDARY LAYER. WITH
MODELS KEEPING THE SFC TROUGH TO THE WEST...EXPECT THERE TO BE
SOME WIND THROUGH THE NIGHT. THEREFORE HAVE CONTINUED WITH A VFR
FORECAST.

WOLTERS

&&

.PREV DISCUSSION.../ISSUED 346 PM CDT FRI MAY 4 2012/
AN UPPER LEVEL TROUGH ACROSS THE WESTERN CONUS THIS AFTERNOON
WILL LIFT NORTHEAST INTO THE NORTHERN AND CENTRAL HIGH PLAINS BY
SATURDAY AFTERNOON. A DOWNSTREAM UPPER LEVEL RIDGE WILL AMPLIFY
ACROSS THE EASTERN CENTRAL AND SOUTHERN PLAINS TONIGHT THROUGH
SATURDAY.

A WEAK SOUTHERN STREAM UPPER LEVEL TROUGH WAS LOCATED ACROSS CENTRAL
OK LATE THIS AFTERNOON AND WILL LIFT NORTHEAST INTO SOUTHWEST MO
THIS EVENING. THERE MAY BE ENOUGH ASCENT AHEAD OF THE WEAK H5 TROUGH
TO CAUSE ISOLATED SHOWERS AND THUNDERSTORMS TO DEVELOP THIS
AFTERNOON ACROSS SOUTHEAST KS AND SOUTHWEST MO. FORECAST SOUNDINGS
ACROSS THE CWA SHOW A STRONG CAP...WHICH WILL PREVENT SFC BASED
PARCELS REACHING THEIR LFC...DUE TO AN EML AT 830 MB. THE 16Z RUN OF
THE HRRR IS THE ONLY NUMERICAL MODEL SHOWING ISOLATED THUNDERSTORMS
DEVELOPING ACROSS SOUTHEAST KS AND SOUTHWEST MO...SOUTH AND
SOUTHEAST OF THE CWA THIS AFTERNOON. I KEPT 14 POPS ACROSS THE
SOUTHEAST COUNTIES OF THE CWA THIS AFTERNOON AND TONIGHT...JUST IN
CASE THERE WAS ENOUGH ASCENT FOR PARCELS ABOVE THE CAPPING INVERSION
TO REACH THEIR LFC. IF THESE ELEVATED STORMS DEVELOP THEY WILL NOT
BE SEVERE ACROSS THE SOUTHEAST COUNTIES OF THE CWA.

TONIGHT...THERE MAY BE SOME WEAK ISENTROPIC LIFT AFTER 3Z FOR SCT TO
STRATUS TO DEVELOP BUT AFTER 10Z...850MB WINDS VEER MORE TO THE
SOUTHWEST...THUS ANY STRATUS MAY DISSIPATE AFTER 10Z SAT. OVERNIGHT
LOWS WILL ONLY DROP INTO THE UPPER 60S TO LOWER 70S.

SATURDAY...850MB WINDS WILL BACK TO THE SOUTH DURING THE MID AND
LATE MORNING HOURS. DEEP MOISTURE ADVECTION WILL CAUSE SFC DEWPOINTS
TO BE IN THE UPPER 60S TO LOWER 70S DURING THE AFTERNOON HOURS.
FORECAST SOUNDINGS CONTINUE TO SHOW THE EML KEEPING A MODERATELY
STRONG CAP IN PLACE ACROSS THE CWA. THE H5 TROUGH OVER THE WESTERN
CONUS WILL LIFT NORTHEAST INTO THE NORTHERN HIGH PLAINS DURING THE
LATE AFTERNOON HOURS. THE ONLY SFC CONVERGENCE AND ASCENT WILL BE
ALONG AND NORTH OF THE SFC BOUNDARY ACROSS NORTHERN AND WESTERN NE
DURING THE LATE AFTERNOON HOURS...WHERE SCATTERED THUNDERSTORMS WILL
DEVELOP. EXPECT A WARM AND HUMID DAY WITH HIGHS IN THE UPPER 80S TO
LOWER 90S...AND AFTERNOON HEAT INDICES IN MID TO UPPER 90S.

GARGAN

MODELS CONTINUE TO DIFFER ON FRONTAL POSITION/SPEED OF MOVEMENT
ACROSS THE CWA THROUGH SUNDAY. THE NAM CONTINUES TO BE THE FASTER
AMONG THE MODELS WITH THE SPEED OF THE FRONT...AND GFS THE SLOWER.
WENT WITH A COMPROMISE AMONG MODELS BRINGING THE FRONT INTO THE FAR
NORTHWEST CORNER SUNDAY MORNING AND EXITING THE SOUTHEAST CORNER
SUNDAY EVENING. STILL EXPECTED THE DEVELOPMENT OF THUNDERSTORM
COMPLEX WELL NORTH OF THE CWA SATURDAY EVENING...BUT APPEARS ONLY A
LOW END CHC/SCHC POPS WARRANTED ACROSS AREAS NORTH OF I 70 THROUGH
SUNRISE SUNDAY. THE REMAINDER OF THE CWA SHOULD BE DRY. AS THE FRONT
MOVES INTO AND ACROSS THE CWA SUNDAY/SUNDAY EVENING...THE CHANCE FOR
THUNDERSTORMS WILL INCREASE...MAINLY ACROSS AREAS ALONG AND EAST OF
HIGHWAY 99 FROM MID AFTERNOON INTO THE EVENING. ALTHOUGH SHEAR WILL
BE WEAK...MLCAPE WILL BE VERY HIGH TO EXTREME WITH VALUES IN
ACROSS THE SOUTHEAST 1/2 OF THE CWA COMMONLY IN THE RANGE OF
3500-4500 J/KG. THEREFORE...STILL A THREAT FOR LARGE HAIL AND
STRONG GUSTY WINDS ALONG AND AHEAD OF THE FRONT FROM MID AFTERNOON
INTO THE EARLY EVENING OVER THE NORTHEAST AND EAST CENTRAL
COUNTIES. THE FRONT WILL BEGIN TO BRING IN COOLER AND DRIER AIR
INTO THE NORTHWEST CWA SUNDAY WITH HIGHS IN THE MIDDLE 70S
NORTHWEST TO STILL THE MIDDLE 80S SOUTHEAST AHEAD OF THE FRONT AT
PEAK HEATING.

CHANCES FOR SHOWERS AND THUNDERSTORMS WILL STEADILY DECREASE WEST TO
EAST ACROSS THE CWA SUNDAY EVENING...WITH DRY CONDITIONS ALL AREAS
LATER IN THE NIGHT. HAVE LOWERED LOWS INTO THE MIDDLE 50S TO NEAR 60.

THE EXTENDED FORECAST FROM MONDAY INTO THURSDAY STILL LOOKS TO BE
DOMINATED FROM COOLER HIGH PRESSURE WITH PLEASANT HIGHS IN THE 70S
AND LOWS IN THE UPPER 40S AND LOWER 50S EACH DAY. AS THE LARGE SFC
RIDGE SHIFTS FURTHER EAST BY LATE THURSDAY...MOISTURE WHICH WILL BE
POOLING TO THE SOUTH AND WEST OF THE AREA WILL GET ADVECTED
NORTHWARD INTO THE AREA FRIDAY. AS A SHORTWAVE TROUGH APPROACHES
FROM THE SOUTHWEST...THE CHANCES FOR SHOWERS AND THUNDERSTORMS WILL
BE ON INCREASE AT THAT TIME. 63

&&

.TOP WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$






AREA FORECAST DISCUSSION

NWS DODGE CITY KS

 1238 PM CDT THU MAY 3 2012

...UPDATED AVIATION DISCUSSION...

.SYNOPSIS...
ISSUED AT 234 AM CDT THU MAY 3 2012

THE 03.00Z 250 HPA SYNOPTIC MAP SHOWED A SEGMENTED POLAR JET WITH A
90 KT JET PUSHING ASHORE ACROSS THE PACIFIC NORTHWEST. ANOTHER 110
KT JET STREAK WAS LOCATED ACROSS THE NORTHERN PLAINS WITH THE RIGHT
ENTRANCE REGION FAIRLY CLOSE TO KANSAS (AND COULD HAVE BEEN PARTIALLY
RESPONSIBLE FOR CONVECTION EARLIER). ANOTHER 100 KT JET WAS LOCATED
ACROSS NEW ENGLAND. AT 500 HPA, VERY COLD TEMPERATURES OF -25 TO -31
DEG C WERE OBSERVED ACROSS BRITISH COLUMBIA AND EXTENDING EASTWARDS
ACROSS THE CANADIAN PRAIRIES AND AS FAR SOUTH AS NORTHEASTERN MONTANA.
SEVERAL MID LEVEL SHORTWAVE TROUGH WERE ANALYZED ACROSS THE CONUS MID
ATMOSPHERE. CLOSER TO KANSAS AND IN THE LOWER LEVELS, A WARM AND DRY
PLUME (EML) EXTENDED ACROSS THE KANSAS AND SOUTHWARD INTO THE SOONER/LONE
STAR STATES. AT THE SURFACE, A LOW PRESSURE CENTER WAS LOCATED ACROSS
FAR SOUTHWESTERN KANSAS. A DRYLINE ASSOCIATED WITH THIS SURFACE LOW
EXTENDED ACROSS SOUTHWEST KANSAS AND SOUTHWARD INTO TEXAS. DEWPOINTS
IN THE 60S DEG F WERE EAST OF THIS BOUNDARY. A WEAK COLD FRONT WAS PUSHING
ACROSS EAST CENTRAL COLORADO AND INTO NORTHWEST KANSAS.

&&

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 234 AM CDT THU MAY 3 2012

THIS MORNING:

A COLD FRONT IS MOVING ACROSS NORTHWESTERN KANSAS EARLY THIS MORNING.
THIS FRONT WILL MAKE ITS WAY AT LEAST THROUGH 2/3RD`S OF THE REGION
AND STALL ROUGHLY FROM MEADE TO LARNED. HRRR INDICATES SOME POST FRONTAL
STRATUS VIA UPSLOPE FLOW ACROSS INTERSTATE 70 SO HAVE INCREASED CLOUD
COVER AS A RESULT DURING THE MORNING FOR THIS AREA. TODAY WILL START
OUT QUITE MILD AS DEWPOINTS EAST OF THE DRYLINE ARE WELL INTO THE 60S
DEG F. THIS WAS UNDER FORECAST BY SEVERAL OF THE MODELS. NO PRECIPITATION
IS EXPECTED ALONG THE FRONTAL BOUNDARY DUE TO SUBSIDENCE ALOFT/NO UPPER
LEVEL SUPPORT.

TODAY:

THE HOTTEST TEMPERATURES ARE LIKELY SOUTH OF THE FRONTAL WHICH WILL
STALL ACROSS THE AFOREMENTIONED MEADE TO LARNED LINE. LOW TO MID 90S
DEG F ARE POSSIBLE ACROSS SOUTH CENTRAL KANSAS. FURTHER NORTHWEST, THERE
WILL BE ENOUGH INSOLATION AND MIXING TO ALLOW TEMPERATURES TO PEAK INTO
THE MID TO UPPER 80S DEG F.

THIS EVENING:

I HAVE COMPROMISED BETWEEN SEVERAL MODELS AND HAVE SLIGHT POPS ROUGHLY
NORTHWEST FROM A HAYS TO ELKHART LINE. 00Z NAM/WRF/NMM ARE IN FAIRLY
GOOD AGREEMENT WITH THE POSSIBILITY OF UPSLOPE AND FRONTAL RELATED CONVECTION
ACROSS SOUTHEASTERN COLORADO INTO FAR SW/W KANSAS. THE GFS IS A BIT
DIFFERENT WITH BETTER CONVECTIVE CHANCES ALONG INTERSTATE 70. AS A RESULT,
HAVE BLENDED POPS BETWEEN THE MODELS. THERE MAY BE A WEAK MID LEVEL
SHORTWAVE TROUGH AS SEEN ACROSS THE ROCKIES EARLY THIS MORNING THAT
COULD PROVIDE ENOUGH UPPER LEVEL SUPPORT FOR THUNDERSTORMS. OTHERWISE,
UPPER LEVEL SUPPORT TODAY IS QUITE WEAK. FORECAST SOUNDINGS ACROSS
FAR WESTERN KANSAS SHOW ABOUT 1500 J/KG OF CAPE AND A BIT OF VEERING
IN THE WIND PROFILE, ALTHOUGH SPEED SHEAR IS RATHER WEAK. THE THERMODYNAMIC
PROFILE IS WELL MIXED TO ABOUT 600 HPA SO IF CONVECTION DOES FORM, THEN
DAMAGING WIND GUSTS WOULD BE THE MAIN THREAT AND PERHAPS MARGINAL SEVERE
HAIL SINCE 0 TO 6 KM SHEAR IS ONLY FORECAST TO BE ABOUT 25-30 KT. WITH
THIS EXCEPTION OF A VERY MARGINAL CHANCE OF AN ISOLATED THUNDERSTORM,
THE FORECAST WILL REMAIN DRY. OVERNIGHT LOWS HEADING INTO FRIDAY MORNING
WILL BE MILD AGAIN WITH 50S DEG F TOWARDS GARDEN CITY AND 60S DEG F
TOWARDS MEDICINE LODGE DUE TO MODERATE DEWPOINTS AND WEAK LEE TROUGH/RESULTANT
SOUTHERLY WINDS THROUGH THE OVERNIGHT PERIOD.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 309 AM CDT THU MAY 3 2012

BOTH THE NAM AND GFS ARE IN GOOD AGREEMENT WITH A SUBTLE UPPER
LEVEL DISTURBANCE CROSSING SOUTHWEST KANSAS EARLY IN THE DAY ON
FRIDAY. AS THIS SYSTEM CROSSES WESTERN KANSAS A SURFACE BOUNDARY
WILL EXTEND FROM WEST TO EAST NORTH OF INTERSTATE 70 AND A DRYLINE
IS EXPECTED TO STRETCH FROM THIS SURFACE BOUNDARY SOUTH INTO
WESTERN OKLAHOMA. AT THIS TIME BASED ON THE TIMING OF THIS SUBTLE
FEATURE AND WARM MID LEVEL TEMPERATURES FORECAST FRIDAY AFTERNOON
WILL CONTINUE TO FAVOR A DRY FORECAST FRIDAY AND FRIDAY NIGHT
ACROSS WESTERN KANSAS. MODEL SOUNDINGS INDICATING A DECENT MIXING
DEPTH AND BASED ON 850MB TEMPERATURES AT 00Z SATURDAY WILL
CONTINUE TO FAVOR HIGHS AT LEAST IN THE LOW TO MID 90S.

A STRONGER UPPER LEVEL TROUGH WILL BEGIN TO CROSS WESTERN UNITED
STATES LATE FRIDAY. AN UPPER LEVEL JET IS FORECAST TO BEGIN TO
MOVE FROM THE BASE OF THIS TROUGH AND EJECT OUT INTO THE WEST
CENTRAL HIGH PLAINS BY EARLY THIS WEEKEND. AS THIS NEXT SYSTEM
APPROACHES EARLY THIS WEEKEND AN AREA OF LOW PRESSURE IS EXPECTED
TO DEEPEN ACROSS EASTERN COLORADO/WESTERN KANSAS. BY 00Z SUNDAY
700MB TEMPERATURES ACROSS WESTERN KANSAS ARE FORECAST TO RANGE
FROM +10 TO +12C AND THE RIGHT ENTRANCE REGION OF THE UPPER LEVEL
JET IS EXPECTED TO BE LOCATED NEAR NORTHEAST COLORADO. BASED ON
THE LOCATION OF THE UPPER JET, 925-850MB THETA-E RIDGE
AXIS/MOISTURE ADVECTION AND NORTHERN EDGE OF THE WARM 700MB
TEMPERATURES WILL FAVOR LATE DAY AND EARLY SATURDAY NIGHT
CONVECTION STAYING NORTH OF THE AREA. TEMPERATURES SATURDAY WILL
ONCE AGAIN BE WARM AND BASED ON 850MB TEMPERATURES AND THE
FORECAST MIXED LAYER THE HIGHS SATURDAY AFTERNOON SHOULD CLIMB
ONCE AGAIN BACK INTO THE LOW TO MID 90S.

BY EARLY SUNDAY THE UPPER JET WILL MOVE OUT INTO THE NORTHERN
PLAINS AND A COLD FRONT IS FORECAST TO SURGE SOUTH INTO WESTERN
KANSAS. A TIGHT SURFACE PRESSURE GRADIENT AND STRONG BOUNDARY
LAYER TO 850MB WINDS ARE FORECAST BEHIND THIS FRONT WITH A NET 24
HOUR 850MB TEMPERATURE CHANCE FROM 00Z SUNDAY TO 00Z MONDAY
AVERAGING FROM 8-12C DEGREES COOLER. AS A RESULT WILL UNDERCUT MAX
TEMPERATURES ON SUNDAY AND TREND TOWARDS THE COOLER 00Z MONDAY
ECMWF/GFS 850MB MIX DOWN TEMPERATURES. MOISTURE SOMEWHAT LIMITED
WITH THIS FRONT AND UPPER LEVEL DYNAMICS APPEAR TO REMAIN NORTH OF
THE AREA SO PRECIPITATION CHANCES STILL APPEAR SMALL BUT DID
INSERT SOME SMALL POPS EARLY SUNDAY NEAR AND NORTH OF INTERSTATE
70.

ON MONDAY ISENTROPIC LIFT/850-700MB WARM AIR ADVECTION BEGINS TO
IMPROVE ACROSS EASTERN COLORADO AND WESTERN KANSAS. ON MONDAY
NIGHT ANOTHER UPPER LEVEL TROUGH WILL BEGIN TO APPROACH THE WEST
CENTRAL PLAINS WHICH SHOULD PROVIDE THE NEXT DECENT OPPORTUNITY
FOR MEASURABLE PRECIPITATION TO PORTIONS OF WESTERN KANSAS TUESDAY
AND WEDNESDAY AS MOISTURE AND ISENTROPIC LIFT/WARM AIR ADVECTION
CONTINUES ACROSS WESTERN KANSAS. IN ADDITION GIVEN THE CLOUD COVER
EXPECTED TUESDAY AND WEDNESDAY WILL CONTINUE TO FAVOR THE PREVIOUS
FORECAST WITH HIGHS MAINLY IN THE UPPER 60S TO LOWER
70S...ESPECIALLY ON TUESDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1238 PM CDT THU MAY 3 2012

NORTHERLY WINDS AT GARDEN CITY AND DODGE CITY LATE THIS MORNING
WILL DECREASE AND GRADUALLY SWING AROUND TO THE EAST AND SOUTHEAST
LATER THIS AFTERNOON WHILE AT HAYS, WINDS SHOULD REMAIN LIGHT AND
VARIABLE. ISOLATED THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG THE
COLORADO FRONT RANGE THIS AFTERNOON AND COULD MOVE INTO FAR
WESTERN KANSAS THIS EVENING. THE STORMS ARE EXPECTED TO DISSIPATE
BEFORE THEY WOULD HAVE ANY IMPACT ON TAF SITES IN SOUTHWEST
KANSAS. WEAK MOIST UPSLOPE FLOW COULD RESULT IN LOW LEVEL STRATUS
AROUND HAYS LATE TONIGHT INTO EARLY FRIDAY MORNING.

&&

.PRELIMINARY POINT TEMPS/POPS...
DDC  88  56  95  61 /  10  10   0   0
GCK  86  55  94  58 /  10  20   0   0
EHA  89  56  94  59 /  20  20   0   0
LBL  89  58  96  60 /  10  10   0   0
HYS  85  60  93  62 /  10  20   0  10
P28  93  66  93  66 /  10  10   0   0

&&

.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...BURGERT
AVIATION...GERARD







AREA FORECAST DISCUSSION

NWS DODGE CITY KS

 614 AM CDT THU MAY 3 2012

...UPDATED AVIATION DISCUSSION...

.SYNOPSIS...
ISSUED AT 234 AM CDT THU MAY 3 2012

THE 03.00Z 250 HPA SYNOPTIC MAP SHOWED A SEGMENTED POLAR JET WITH A
90 KT JET PUSHING ASHORE ACROSS THE PACIFIC NORTHWEST. ANOTHER 110
KT JET STREAK WAS LOCATED ACROSS THE NORTHERN PLAINS WITH THE RIGHT
ENTRANCE REGION FAIRLY CLOSE TO KANSAS (AND COULD HAVE BEEN PARTIALLY
RESPONSIBLE FOR CONVECTION EARLIER). ANOTHER 100 KT JET WAS LOCATED
ACROSS NEW ENGLAND. AT 500 HPA, VERY COLD TEMPERATURES OF -25 TO -31
DEG C WERE OBSERVED ACROSS BRITISH COLUMBIA AND EXTENDING EASTWARDS
ACROSS THE CANADIAN PRAIRIES AND AS FAR SOUTH AS NORTHEASTERN MONTANA.
SEVERAL MID LEVEL SHORTWAVE TROUGH WERE ANALYZED ACROSS THE CONUS MID
ATMOSPHERE. CLOSER TO KANSAS AND IN THE LOWER LEVELS, A WARM AND DRY
PLUME (EML) EXTENDED ACROSS THE KANSAS AND SOUTHWARD INTO THE SOONER/LONE
STAR STATES. AT THE SURFACE, A LOW PRESSURE CENTER WAS LOCATED ACROSS
FAR SOUTHWESTERN KANSAS. A DRYLINE ASSOCIATED WITH THIS SURFACE LOW
EXTENDED ACROSS SOUTHWEST KANSAS AND SOUTHWARD INTO TEXAS. DEWPOINTS
IN THE 60S DEG F WERE EAST OF THIS BOUNDARY. A WEAK COLD FRONT WAS PUSHING
ACROSS EAST CENTRAL COLORADO AND INTO NORTHWEST KANSAS.

&&

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 234 AM CDT THU MAY 3 2012

THIS MORNING:

A COLD FRONT IS MOVING ACROSS NORTHWESTERN KANSAS EARLY THIS MORNING.
THIS FRONT WILL MAKE ITS WAY AT LEAST THROUGH 2/3RD`S OF THE REGION
AND STALL ROUGHLY FROM MEADE TO LARNED. HRRR INDICATES SOME POST FRONTAL
STRATUS VIA UPSLOPE FLOW ACROSS INTERSTATE 70 SO HAVE INCREASED CLOUD
COVER AS A RESULT DURING THE MORNING FOR THIS AREA. TODAY WILL START
OUT QUITE MILD AS DEWPOINTS EAST OF THE DRYLINE ARE WELL INTO THE 60S
DEG F. THIS WAS UNDER FORECAST BY SEVERAL OF THE MODELS. NO PRECIPITATION
IS EXPECTED ALONG THE FRONTAL BOUNDARY DUE TO SUBSIDENCE ALOFT/NO UPPER
LEVEL SUPPORT.

TODAY:

THE HOTTEST TEMPERATURES ARE LIKELY SOUTH OF THE FRONTAL WHICH WILL
STALL ACROSS THE AFOREMENTIONED MEADE TO LARNED LINE. LOW TO MID 90S
DEG F ARE POSSIBLE ACROSS SOUTH CENTRAL KANSAS. FURTHER NORTHWEST, THERE
WILL BE ENOUGH INSOLATION AND MIXING TO ALLOW TEMPERATURES TO PEAK INTO
THE MID TO UPPER 80S DEG F.

THIS EVENING:

I HAVE COMPROMISED BETWEEN SEVERAL MODELS AND HAVE SLIGHT POPS ROUGHLY
NORTHWEST FROM A HAYS TO ELKHART LINE. 00Z NAM/WRF/NMM ARE IN FAIRLY
GOOD AGREEMENT WITH THE POSSIBILITY OF UPSLOPE AND FRONTAL RELATED CONVECTION
ACROSS SOUTHEASTERN COLORADO INTO FAR SW/W KANSAS. THE GFS IS A BIT
DIFFERENT WITH BETTER CONVECTIVE CHANCES ALONG INTERSTATE 70. AS A RESULT,
HAVE BLENDED POPS BETWEEN THE MODELS. THERE MAY BE A WEAK MID LEVEL
SHORTWAVE TROUGH AS SEEN ACROSS THE ROCKIES EARLY THIS MORNING THAT
COULD PROVIDE ENOUGH UPPER LEVEL SUPPORT FOR THUNDERSTORMS. OTHERWISE,
UPPER LEVEL SUPPORT TODAY IS QUITE WEAK. FORECAST SOUNDINGS ACROSS
FAR WESTERN KANSAS SHOW ABOUT 1500 J/KG OF CAPE AND A BIT OF VEERING
IN THE WIND PROFILE, ALTHOUGH SPEED SHEAR IS RATHER WEAK. THE THERMODYNAMIC
PROFILE IS WELL MIXED TO ABOUT 600 HPA SO IF CONVECTION DOES FORM, THEN
DAMAGING WIND GUSTS WOULD BE THE MAIN THREAT AND PERHAPS MARGINAL SEVERE
HAIL SINCE 0 TO 6 KM SHEAR IS ONLY FORECAST TO BE ABOUT 25-30 KT. WITH
THIS EXCEPTION OF A VERY MARGINAL CHANCE OF AN ISOLATED THUNDERSTORM,
THE FORECAST WILL REMAIN DRY. OVERNIGHT LOWS HEADING INTO FRIDAY MORNING
WILL BE MILD AGAIN WITH 50S DEG F TOWARDS GARDEN CITY AND 60S DEG F
TOWARDS MEDICINE LODGE DUE TO MODERATE DEWPOINTS AND WEAK LEE TROUGH/RESULTANT
SOUTHERLY WINDS THROUGH THE OVERNIGHT PERIOD.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 309 AM CDT THU MAY 3 2012

BOTH THE NAM AND GFS ARE IN GOOD AGREEMENT WITH A SUBTLE UPPER
LEVEL DISTURBANCE CROSSING SOUTHWEST KANSAS EARLY IN THE DAY ON
FRIDAY. AS THIS SYSTEM CROSSES WESTERN KANSAS A SURFACE BOUNDARY
WILL EXTEND FROM WEST TO EAST NORTH OF INTERSTATE 70 AND A DRYLINE
IS EXPECTED TO STRETCH FROM THIS SURFACE BOUNDARY SOUTH INTO
WESTERN OKLAHOMA. AT THIS TIME BASED ON THE TIMING OF THIS SUBTLE
FEATURE AND WARM MID LEVEL TEMPERATURES FORECAST FRIDAY AFTERNOON
WILL CONTINUE TO FAVOR A DRY FORECAST FRIDAY AND FRIDAY NIGHT
ACROSS WESTERN KANSAS. MODEL SOUNDINGS INDICATING A DECENT MIXING
DEPTH AND BASED ON 850MB TEMPERATURES AT 00Z SATURDAY WILL
CONTINUE TO FAVOR HIGHS AT LEAST IN THE LOW TO MID 90S.

A STRONGER UPPER LEVEL TROUGH WILL BEGIN TO CROSS WESTERN UNITED
STATES LATE FRIDAY. AN UPPER LEVEL JET IS FORECAST TO BEGIN TO
MOVE FROM THE BASE OF THIS TROUGH AND EJECT OUT INTO THE WEST
CENTRAL HIGH PLAINS BY EARLY THIS WEEKEND. AS THIS NEXT SYSTEM
APPROACHES EARLY THIS WEEKEND AN AREA OF LOW PRESSURE IS EXPECTED
TO DEEPEN ACROSS EASTERN COLORADO/WESTERN KANSAS. BY 00Z SUNDAY
700MB TEMPERATURES ACROSS WESTERN KANSAS ARE FORECAST TO RANGE
FROM +10 TO +12C AND THE RIGHT ENTRANCE REGION OF THE UPPER LEVEL
JET IS EXPECTED TO BE LOCATED NEAR NORTHEAST COLORADO. BASED ON
THE LOCATION OF THE UPPER JET, 925-850MB THTA-E RIDGE
AXIS/MOISTURE ADVECTION AND NORTHERN EDGE OF THE WARM 700MB
TEMPERATURES WILL FAVOR LATE DAY AND EARLY SATURDAY NIGHT
CONVECTION STAYING NORTH OF THE AREA. TEMPERATURES SATURDAY WILL
ONCE AGAIN BE WARM AND BASED ON 850MB TEMPERATURES AND THE
FORECAST MIXED LAYER THE HIGHS SATURDAY AFTERNOON SHOULD CLIMB
ONCE AGAIN BACK INTO THE LOW TO MID 90S.

BY EARLY SUNDAY THE UPPER JET WILL MOVE OUT INTO THE NORTHERN
PLAINS AND A COLD FRONT IS FORECAST TO SURGE SOUTH INTO WESTERN
KANSAS. A TIGHT SURFACE PRESSURE GRADIENT AND STRONG BOUNDARY
LAYER TO 850MB WINDS ARE FORECAST BEHIND THIS FRONT WITH A NET 24
HOUR 850MB TEMPERATURE CHANCE FROM 00Z SUNDAY TO 00Z MONDAY
AVERAGING FROM 8-12C DEGREES COOLER. AS A RESULT WILL UNDERCUT MAX
TEMPERATURES ON SUNDAY AND TREND TOWARDS THE COOLER 00Z MONDAY
ECMWF/GFS 850MB MIX DOWN TEMPERATURES. MOISTURE SOMEWHAT LIMITED
WITH THIS FRONT AND UPPER LEVEL DYNAMICS APPEAR TO REMAIN NORTH OF
THE AREA SO PRECIPITATION CHANCES STILL APPEAR SMALL BUT DID
INSERT SOME SMALL POPS EARLY SUNDAY NEAR AND NORTH OF INTERSTATE
70.

ON MONDAY ISENTROPIC LIFT/850-700MB WARM AIR ADVECTION BEGINS TO
IMPROVE ACROSS EASTERN COLORADO AND WESTERN KANSAS. ON MONDAY
NIGHT ANOTHER UPPER LEVEL TROUGH WILL BEGIN TO APPROACH THE WEST
CENTRAL PLAINS WHICH SHOULD PROVIDE THE NEXT DECENT OPPORTUNITY
FOR MEASURABLE PRECIPITATION TO PORTIONS OF WESTERN KANSAS TUESDAY
AND WEDNESDAY AS MOISTURE AND ISENTROPIC LIFT/WARM AIR ADVECTION
CONTINUES ACROSS WESTERN KANSAS. IN ADDITION GIVEN THE CLOUD COVER
EXPECTED TUESDAY AND WEDNESDAY WILL CONTINUE TO FAVOR THE PREVIOUS
FORECAST WITH HIGHS MAINLY IN THE UPPER 60S TO LOWER
70S...ESPECIALLY ON TUESDAY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 604 AM CDT THU MAY 3 2012

A WEAK COLD FRONT EXTENDED FROM HAYS TO DODGE CITY AS OF 10Z WITH
LOW CLOUDS DEVELOPING BEHIND THIS FRONT BASED ON THE 11-3.9
SATELLITE LOOP. THE LATEST SATELLITE TRENDS APPEARS TO SUPPORT THE
06Z BUFR SOUNDINGS IN PLACING HAYS IN THE AREA WHERE THE MVFR STATUS
WILL LINGER FOR A COUPLE OF HOURS EARLY THIS MORNING. ELSEWHERE VFR
CONDITIONS ARE ANTICIPATED. THE NORTHERLY WINDS BEHIND THIS FRONT
IS EXPECTED TO GRADUALLY VEER BACK TO THE EAST BY LATE DAY WITH
WIND SPEEDS AVERAGING 10 KNOTS OR LESS.

&&

.PRELIMINARY POINT TEMPS/POPS...
DDC  88  56  95  61 /  10  10   0   0
GCK  86  55  94  58 /  10  20   0   0
EHA  89  56  94  59 /  20  20   0   0
LBL  89  58  96  60 /  10  10   0   0
HYS  85  60  93  62 /  10  20   0  10
P28  93  66  93  66 /  10  10   0   0

&&

.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...BURGERT
AVIATION...BURGERT







AREA FORECAST DISCUSSION

NWS DODGE CITY KS

 314 AM CDT THU MAY 3 2012

...UPDATED LONG TERM DISCUSSION...

.SYNOPSIS...
ISSUED AT 234 AM CDT THU MAY 3 2012

THE 03.00Z 250 HPA SYNOPTIC MAP SHOWED A SEGMENTED POLAR JET WITH A
90 KT JET PUSHING ASHORE ACROSS THE PACIFIC NORTHWEST. ANOTHER 110
KT JET STREAK WAS LOCATED ACROSS THE NORTHERN PLAINS WITH THE RIGHT
ENTRANCE REGION FAIRLY CLOSE TO KANSAS (AND COULD HAVE BEEN PARTIALLY
RESPONSIBLE FOR CONVECTION EARLIER). ANOTHER 100 KT JET WAS LOCATED
ACROSS NEW ENGLAND. AT 500 HPA, VERY COLD TEMPERATURES OF -25 TO -31
DEG C WERE OBSERVED ACROSS BRITISH COLUMBIA AND EXTENDING EASTWARDS
ACROSS THE CANADIAN PRAIRIES AND AS FAR SOUTH AS NORTHEASTERN MONTANA.
SEVERAL MID LEVEL SHORTWAVE TROUGH WERE ANALYZED ACROSS THE CONUS MID
ATMOSPHERE. CLOSER TO KANSAS AND IN THE LOWER LEVELS, A WARM AND DRY
PLUME (EML) EXTENDED ACROSS THE KANSAS AND SOUTHWARD INTO THE SOONER/LONE
STAR STATES. AT THE SURFACE, A LOW PRESSURE CENTER WAS LOCATED ACROSS
FAR SOUTHWESTERN KANSAS. A DRYLINE ASSOCIATED WITH THIS SURFACE LOW
EXTENDED ACROSS SOUTHWEST KANSAS AND SOUTHWARD INTO TEXAS. DEWPOINTS
IN THE 60S DEG F WERE EAST OF THIS BOUNDARY. A WEAK COLD FRONT WAS PUSHING
ACROSS EAST CENTRAL COLORADO AND INTO NORTHWEST KANSAS.

&&

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 234 AM CDT THU MAY 3 2012

THIS MORNING:

A COLD FRONT IS MOVING ACROSS NORTHWESTERN KANSAS EARLY THIS MORNING.
THIS FRONT WILL MAKE ITS WAY AT LEAST THROUGH 2/3RD`S OF THE REGION
AND STALL ROUGHLY FROM MEADE TO LARNED. HRRR INDICATES SOME POST FRONTAL
STRATUS VIA UPSLOPE FLOW ACROSS INTERSTATE 70 SO HAVE INCREASED CLOUD
COVER AS A RESULT DURING THE MORNING FOR THIS AREA. TODAY WILL START
OUT QUITE MILD AS DEWPOINTS EAST OF THE DRYLINE ARE WELL INTO THE 60S
DEG F. THIS WAS UNDER FORECAST BY SEVERAL OF THE MODELS. NO PRECIPITATION
IS EXPECTED ALONG THE FRONTAL BOUNDARY DUE TO SUBSIDENCE ALOFT/NO UPPER
LEVEL SUPPORT.

TODAY:

THE HOTTEST TEMPERATURES ARE LIKELY SOUTH OF THE FRONTAL WHICH WILL
STALL ACROSS THE AFOREMENTIONED MEADE TO LARNED LINE. LOW TO MID 90S
DEG F ARE POSSIBLE ACROSS SOUTH CENTRAL KANSAS. FURTHER NORTHWEST, THERE
WILL BE ENOUGH INSOLATION AND MIXING TO ALLOW TEMPERATURES TO PEAK INTO
THE MID TO UPPER 80S DEG F.

THIS EVENING:

I HAVE COMPROMISED BETWEEN SEVERAL MODELS AND HAVE SLIGHT POPS ROUGHLY
NORTHWEST FROM A HAYS TO ELKHART LINE. 00Z NAM/WRF/NMM ARE IN FAIRLY
GOOD AGREEMENT WITH THE POSSIBILITY OF UPSLOPE AND FRONTAL RELATED CONVECTION
ACROSS SOUTHEASTERN COLORADO INTO FAR SW/W KANSAS. THE GFS IS A BIT
DIFFERENT WITH BETTER CONVECTIVE CHANCES ALONG INTERSTATE 70. AS A RESULT,
HAVE BLENDED POPS BETWEEN THE MODELS. THERE MAY BE A WEAK MID LEVEL
SHORTWAVE TROUGH AS SEEN ACROSS THE ROCKIES EARLY THIS MORNING THAT
COULD PROVIDE ENOUGH UPPER LEVEL SUPPORT FOR THUNDERSTORMS. OTHERWISE,
UPPER LEVEL SUPPORT TODAY IS QUITE WEAK. FORECAST SOUNDINGS ACROSS
FAR WESTERN KANSAS SHOW ABOUT 1500 J/KG OF CAPE AND A BIT OF VEERING
IN THE WIND PROFILE, ALTHOUGH SPEED SHEAR IS RATHER WEAK. THE THERMODYNAMIC
PROFILE IS WELL MIXED TO ABOUT 600 HPA SO IF CONVECTION DOES FORM, THEN
DAMAGING WIND GUSTS WOULD BE THE MAIN THREAT AND PERHAPS MARGINAL SEVERE
HAIL SINCE 0 TO 6 KM SHEAR IS ONLY FORECAST TO BE ABOUT 25-30 KT. WITH
THIS EXCEPTION OF A VERY MARGINAL CHANCE OF AN ISOLATED THUNDERSTORM,
THE FORECAST WILL REMAIN DRY. OVERNIGHT LOWS HEADING INTO FRIDAY MORNING
WILL BE MILD AGAIN WITH 50S DEG F TOWARDS GARDEN CITY AND 60S DEG F
TOWARDS MEDICINE LODGE DUE TO MODERATE DEWPOINTS AND WEAK LEE TROUGH/RESULTANT
SOUTHERLY WINDS THROUGH THE OVERNIGHT PERIOD.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 309 AM CDT THU MAY 3 2012

BOTH THE NAM AND GFS ARE IN GOOD AGREEMENT WITH A SUBTLE UPPER
LEVEL DISTURBANCE CROSSING SOUTHWEST KANSAS EARLY DAY ON FRIDAY.
AS THIS SYSTEM CROSSES WESTERN KANSAS A SURFACE BOUNDARY WILL
EXTEND FROM WEST TO EAST NORTH OF INTERSTATE 70 AND A DRYLINE IS
EXPECTED TO STRETCH FROM THIS SURFACE BOUNDARY SOUTH INTO WESTERN
OKLAHOMA. AT THIS TIME BASED ON THE TIMING OF THIS SUBTLE FEATURE
AND WARM MID LEVEL TEMPERATURES FORECAST FRIDAY AFTERNOON WILL
CONTINUE TO FAVOR A DRY FORECAST FRIDAY AND FRIDAY NIGHT ACROSS
WESTERN KANSAS. MODEL SOUNDINGS INDICATING A DECENT MIXING DEPTH
AND BASED ON 850MB TEMPERATURES AT 00Z SATURDAY WILL CONTINUE TO
FAVOR HIGHS AT LEAST IN THE LOW TO MID 90S.

A STRONGER UPPER LEVEL TROUGH WILL BEGIN TO CROSS WESTERN UNITED
STATES LATE FRIDAY. AN UPPER LEVEL JET IS FORECAST TO BEGIN TO
MOVE FROM THE BASE OF THIS TROUGH AND EJECT OUT INTO THE WEST
CENTRAL HIGH PLAINS BY EARLY THIS WEEKEND. AS THIS NEXT SYSTEM
APPROACHES EARLY THIS WEEKEND AN AREA OF LOW PRESSURE IS EXPECTED
TO DEEPEN ACROSS EASTERN COLORADO/WESTERN KANSAS. BY 00Z SUNDAY
700MB TEMPERATURES ACROSS WESTERN KANSAS ARE FORECAST TO RANGE
FROM +10 TO +12C AND THE RIGHT ENTRANCE REGION OF THE UPPER LEVEL
JET IS EXPECTED TO BE LOCATED NEAR NORTHEAST COLORADO. BASED ON
THE LOCATION OF THE UPPER JET, 925-850MB THTA-E RIDGE
AXIS/MOISTURE ADVECTION AND NORTHERN EDGE OF THE WARM 700MB
TEMPERATURES WILL FAVOR LATE DAY AND EARLY SATURDAY NIGHT
CONVECTION STAYING NORTH OF THE AREA. TEMPERATURES SATURDAY WILL
ONCE AGAIN BE WARM AND BASED ON 850MB TEMPERATURES AND THE
FORECAST MIXED LAYER THE HIGHS SATURDAY AFTERNOON SHOULD CLIMB
ONCE AGAIN BACK INTO THE LOW TO MID 90S.

BY EARLY SUNDAY THE UPPER JET WILL MOVE OUT INTO THE NORTHERN
PLAINS AND A COLD FRONT IS FORECAST TO SURGE SOUTH INTO WESTERN
KANSAS. A TIGHT SURFACE PRESSURE GRADIENT AND STRONG BOUNDARY
LAYER TO 850MB WINDS ARE FORECAST BEHIND THIS FRONT WITH A NET 24
HOUR 850MB TEMPERATURE CHANCE FROM 00Z SUNDAY TO 00Z MONDAY
AVERAGING FROM 8-12C DEGREES COOLER. AS A RESULT WILL UNDERCUT MAX
TEMPERATURES ON SUNDAY AND TREND TOWARDS THE COOLER 00Z MONDAY
ECMWF/GFS 850MB MIX DOWN TEMPERATURES. MOISTURE SOMEWHAT LIMITED
WITH THIS FRONT AND UPPER LEVEL DYNAMICS APPEAR TO REMAIN NORTH OF
THE AREA SO PRECIPITATION CHANCES STILL APPEAR SMALL BUT DID
INSERT SOME SMALL POPS EARLY SUNDAY NEAR AND NORTH OF INTERSTATE
70.

ON MONDAY ISENTROPIC LIFT/850-700MB WARM AIR ADVECTION BEGINS TO
IMPROVE ACROSS EASTERN COLORADO AND WESTERN KANSAS. ON MONDAY
NIGHT ANOTHER UPPER LEVEL TROUGH WILL BEGIN TO APPROACH THE WEST
CENTRAL PLAINS WHICH SHOULD PROVIDE THE NEXT DECENT OPPORTUNITY
FOR MEASURABLE PRECIPITATION TO PORTIONS OF WESTERN KANSAS TUESDAY
AND WEDNESDAY AS MOISTURE AND ISENTROPIC LIFT/WARM AIR ADVECTION
CONTINUES ACROSS WESTERN KANSAS. IN ADDITION GIVEN THE CLOUD COVER
EXPECTED TUESDAY AND WEDNESDAY WILL CONTINUE TO FAVOR THE PREVIOUS
FORECAST WITH HIGHS MAINLY IN THE UPPER 60S TO LOWER
70S...ESPECIALLY ON TUESDAY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1200 AM CDT THU MAY 3 2012

MVFR CIGS ARE INDICATED BY MOS GUIDANCE AS WELL AS THE 01Z HRRR FOR
KHYS IN ASSOCIATION WITH WITH POST FRONTAL UPSLOPE STRATUS. THE RELATED
FRONT WILL MOVE THROUGH KGCK AND KDDC EARLY IN THE MORNING AS WELL,
HOWEVER, ENOUGH MIXING LOOKS TO KEEP CIGS AT VFR. THIS FRONT WILL STALL
OUT THROUGH THE DAY AND RETURN NORTH AS A WARM FRONT BY EVENING. WINDS
SHOULD GENERALLY BE LIGHT (8 TO 13 KT) WITH A GRADUAL VEERING IN DIRECTION
WITH THE RETURN OF THE WARM FRONT.


&&

.PRELIMINARY POINT TEMPS/POPS...
DDC  88  56  95  61 /  10  10   0   0
GCK  86  55  94  58 /  10  20   0   0
EHA  89  56  93  59 /  20  20   0   0
LBL  89  58  96  60 /  10  10   0   0
HYS  85  60  93  62 /  10  20   0  10
P28  93  66  92  66 /  10  10   0   0

&&

.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...BURGERT
AVIATION...SUGDEN







AREA FORECAST DISCUSSION

NWS DODGE CITY KS

 234 AM CDT THU MAY 3 2012

...UPDATE TO SYNOPSIS AND SHORT TERM DISCUSSIONS...

.SYNOPSIS...
ISSUED AT 234 AM CDT THU MAY 3 2012

THE 03.00Z 250 HPA SYNOPTIC MAP SHOWED A SEGMENTED POLAR JET WITH A
90 KT JET PUSHING ASHORE ACROSS THE PACIFIC NORTHWEST. ANOTHER 110
KT JET STREAK WAS LOCATED ACROSS THE NORTHERN PLAINS WITH THE RIGHT
ENTRANCE REGION FAIRLY CLOSE TO KANSAS (AND COULD HAVE BEEN PARTIALLY
RESPONSIBLE FOR CONVECTION EARLIER). ANOTHER 100 KT JET WAS LOCATED
ACROSS NEW ENGLAND. AT 500 HPA, VERY COLD TEMPERATURES OF -25 TO -31
DEG C WERE OBSERVED ACROSS BRITISH COLUMBIA AND EXTENDING EASTWARDS
ACROSS THE CANADIAN PRAIRIES AND AS FAR SOUTH AS NORTHEASTERN MONTANA.
SEVERAL MID LEVEL SHORTWAVE TROUGH WERE ANALYZED ACROSS THE CONUS MID
ATMOSPHERE. CLOSER TO KANSAS AND IN THE LOWER LEVELS, A WARM AND DRY
PLUME (EML) EXTENDED ACROSS THE KANSAS AND SOUTHWARD INTO THE SOONER/LONE
STAR STATES. AT THE SURFACE, A LOW PRESSURE CENTER WAS LOCATED ACROSS
FAR SOUTHWESTERN KANSAS. A DRYLINE ASSOCIATED WITH THIS SURFACE LOW
EXTENDED ACROSS SOUTHWEST KANSAS AND SOUTHWARD INTO TEXAS. DEWPOINTS
IN THE 60S DEG F WERE EAST OF THIS BOUNDARY. A WEAK COLD FRONT WAS PUSHING
ACROSS EAST CENTRAL COLORADO AND INTO NORTHWEST KANSAS.

&&

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 234 AM CDT THU MAY 3 2012

THIS MORNING:

A COLD FRONT IS MOVING ACROSS NORTHWESTERN KANSAS EARLY THIS MORNING.
THIS FRONT WILL MAKE ITS WAY AT LEAST THROUGH 2/3RD`S OF THE REGION
AND STALL ROUGHLY FROM MEADE TO LARNED. HRRR INDICATES SOME POST FRONTAL
STRATUS VIA UPSLOPE FLOW ACROSS INTERSTATE 70 SO HAVE INCREASED CLOUD
COVER AS A RESULT DURING THE MORNING FOR THIS AREA. TODAY WILL START
OUT QUITE MILD AS DEWPOINTS EAST OF THE DRYLINE ARE WELL INTO THE 60S
DEG F. THIS WAS UNDER FORECAST BY SEVERAL OF THE MODELS. NO PRECIPITATION
IS EXPECTED ALONG THE FRONTAL BOUNDARY DUE TO SUBSIDENCE ALOFT/NO UPPER
LEVEL SUPPORT.

TODAY:

THE HOTTEST TEMPERATURES ARE LIKELY SOUTH OF THE FRONTAL WHICH WILL
STALL ACROSS THE AFOREMENTIONED MEADE TO LARNED LINE. LOW TO MID 90S
DEG F ARE POSSIBLE ACROSS SOUTH CENTRAL KANSAS. FURTHER NORTHWEST, THERE
WILL BE ENOUGH INSOLATION AND MIXING TO ALLOW TEMPERATURES TO PEAK INTO
THE MID TO UPPER 80S DEG F.

THIS EVENING:

I HAVE COMPROMISED BETWEEN SEVERAL MODELS AND HAVE SLIGHT POPS ROUGHLY
NORTHWEST FROM A HAYS TO ELKHART LINE. 00Z NAM/WRF/NMM ARE IN FAIRLY
GOOD AGREEMENT WITH THE POSSIBILITY OF UPSLOPE AND FRONTAL RELATED CONVECTION
ACROSS SOUTHEASTERN COLORADO INTO FAR SW/W KANSAS. THE GFS IS A BIT
DIFFERENT WITH BETTER CONVECTIVE CHANCES ALONG INTERSTATE 70. AS A RESULT,
HAVE BLENDED POPS BETWEEN THE MODELS. THERE MAY BE A WEAK MID LEVEL
SHORTWAVE TROUGH AS SEEN ACROSS THE ROCKIES EARLY THIS MORNING THAT
COULD PROVIDE ENOUGH UPPER LEVEL SUPPORT FOR THUNDERSTORMS. OTHERWISE,
UPPER LEVEL SUPPORT TODAY IS QUITE WEAK. FORECAST SOUNDINGS ACROSS
FAR WESTERN KANSAS SHOW ABOUT 1500 J/KG OF CAPE AND A BIT OF VEERING
IN THE WIND PROFILE, ALTHOUGH SPEED SHEAR IS RATHER WEAK. THE THERMODYNAMIC
PROFILE IS WELL MIXED TO ABOUT 600 HPA SO IF CONVECTION DOES FORM, THEN
DAMAGING WIND GUSTS WOULD BE THE MAIN THREAT AND PERHAPS MARGINAL SEVERE
HAIL SINCE 0 TO 6 KM SHEAR IS ONLY FORECAST TO BE ABOUT 25-30 KT. WITH
THIS EXCEPTION OF A VERY MARGINAL CHANCE OF AN ISOLATED THUNDERSTORM,
THE FORECAST WILL REMAIN DRY. OVERNIGHT LOWS HEADING INTO FRIDAY MORNING
WILL BE MILD AGAIN WITH 50S DEG F TOWARDS GARDEN CITY AND 60S DEG F
TOWARDS MEDICINE LODGE DUE TO MODERATE DEWPOINTS AND WEAK LEE TROUGH/RESULTANT
SOUTHERLY WINDS THROUGH THE OVERNIGHT PERIOD.

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 320 PM CDT WED MAY 2 2012

MEDIUM RANGE MODELS INDICATE AN UPPER LEVEL TROUGH OF LOW PRESSURE
PUSHING ASHORE INTO THE PACIFIC NORTHWEST FRIDAY THEN CONTINUING TO
TRACK EASTWARD ACROSS THE NORTHERN ROCKIES SATURDAY, AND INTO THE
NORTHERN PLAINS ALONG THE CANADIAN BORDER BY THE END OF THE WEEKEND.
THIS SYSTEM WILL BRING THE POSSIBILITY FOR SHOWERS AND THUNDERSTORMS
FROM THE NORTHERN PLAINS SOUTHWARD INTO PORTIONS OF NEBRASKA AND
KANSAS THROUGHOUT THE WEEKEND. AN ATTENDANT COLD FRONT TO THE UPPER
LEVEL SYSTEM IS PROGGED TO PUSH SOUTHEAST INTO WESTERN KANSAS
SOMETIME EARLY SUNDAY SETTING UP THE CHANCE FOR PRECIP ACROSS
PORTIONS OF WESTERN KANSAS BY LATE SUNDAY INTO EARLY MONDAY.
ALTHOUGH MODELS BEGIN TO DIVERGE EARLY NEXT WEEK, ALL SHOW UPPER
LEVEL TROUGHING DEEPENING ACROSS THE INTERMOUNTAIN WEST SETTING UP A
SOUTHWESTERLY FLOW ALOFT ACROSS THE WESTERN HIGH PLAINS. MEANWHILE,
A SERIES OF H5 VORT MAXES ARE LIKELY TO EJECT NORTHEAST OUT OF THE
TROUGH, AND ALONG WITH PLENTY OF LOW LEVEL MOISTURE AVAILABLE,
INCREASE CHANCES FOR PRECIP VIRTUALLY EACH DAY THROUGH THE END OF
THE PERIOD.

TEMPERATURES ARE EXPECTED TO BE ABOVE NORMAL FRIDAY AS UPPER LEVEL
TROUGHING BEGINS TO PUSH EAST ACROSS THE INTERMOUNTAIN WEST. AS THE
UPPER LEVEL SYSTEM APPROACHES FROM THE WEST, A SURFACE TROUGH LEE OF
THE ROCKIES WILL HELP INFLUENCE A LOW LEVEL SOUTH TO SOUTHWESTERLY
FLOW ACROSS WESTERN KANSAS. THIS WILL ENHANCE WARM AIR ADVECTION
INTO THE AREA WITH H85 TEMPERATURES RANGING FROM THE MID 20S(C)
ACROSS CENTRAL KANSAS TO THE UPPER 20S(C) NEAR THE COLORADO BORDER.
SO, WITH THE NAM, GFS, AND GEM SHOWING DRY LAPSE RATES IN THE LOWER
LEVELS, LOOK FOR HIGHS UP INTO THE LOWER TO MID 90S(F) FRIDAY
AFTERNOON. SIMILAR HIGHS ARE LIKELY SATURDAY WITH LEE SIDE TROUGHING
PERSISTING NEAR THE COLORADO BORDER AND H85 TEMPERATURES CHANGING
VERY LITTLE. GENERALLY COOLER TEMPERATURES ARE THEN EXPECTED SUNDAY
AS A COLD FRONT IS PROJECTED TO PUSH INTO WESTERN KANSAS SOMETIME
DURING THE DAY ALLOWING COOLER AIR TO FILTER SOUTH INTO WESTERN
KANSAS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1200 AM CDT THU MAY 3 2012

MVFR CIGS ARE INDICATED BY MOS GUIDANCE AS WELL AS THE 01Z HRRR FOR
KHYS IN ASSOCIATION WITH WITH POST FRONTAL UPSLOPE STRATUS. THE RELATED
FRONT WILL MOVE THROUGH KGCK AND KDDC EARLY IN THE MORNING AS WELL,
HOWEVER, ENOUGH MIXING LOOKS TO KEEP CIGS AT VFR. THIS FRONT WILL STALL
OUT THROUGH THE DAY AND RETURN NORTH AS A WARM FRONT BY EVENING. WINDS
SHOULD GENERALLY BE LIGHT (8 TO 13 KT) WITH A GRADUAL VEERING IN DIRECTION
WITH THE RETURN OF THE WARM FRONT.

&&

.PRELIMINARY POINT TEMPS/POPS...
DDC  88  56  95  61 /  10  10   0   0
GCK  86  55  94  58 /  10  20   0   0
EHA  89  56  93  59 /  20  20   0   0
LBL  89  58  96  60 /  10  10   0   0
HYS  85  60  93  62 /  10  20   0   0
P28  93  66  92  66 /  10  10   0   0

&&

.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...JJOHNSON
AVIATION...SUGDEN







AREA FORECAST DISCUSSION

NWS DODGE CITY KS

 1200 AM CDT THU MAY 3 2012

...UPDATE TO AVIATION FOR 06Z TAFS...

.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 250 PM CDT WED MAY 2 2012

THE 12Z UPPER AIR ANALYSIS WAS SHOWING A SHORTWAVE TROUGH OVER IDAHO
AND NORTHERN NEVADA. AN ASSOCIATED 110 KNOT JET STREAK AT THE 250
MILLIBAR LEVEL WAS CENTERED OVER RAPID CITY, SOUTH DAKOTA. FARTHER
SOUTH THE MID AND UPPER LEVEL FLOW WAS FAIRLY WEAK OVER WESTERN
KANSAS. AT THE SURFACE...A WEAK COOL FRONT HAD PUSHED SOUTH ACROSS
WESTERN KANSAS EARLY THIS MORNING. THE FRONT WAS SLOW TO ERODE
THIS AFTERNOON BUT LIGHT AND VARIABLE SURFACE WINDS ARE BEGINNING
TO SWITCH AROUND TO A SOUTHERLY DIRECTION OVER PARTS OF SOUTHWEST
KANSAS.

AS THE NORTHERN PLAINS SHORTWAVE TROUGH MOVES EAST TONIGHT...WEAK
LOW PRESSURE OVER EASTERN COLORADO WILL TRACK OUT ACROSS KANSAS
WITH THE WEAK COLD FRONT PUSHING SOUTH THROUGH WESTERN KANSAS
AGAIN LATE TONIGHT. A FAIR AMOUNT OF SURFACE BASED INSTABILITY IS
IN PLACE OVER WESTERN KANSAS BUT IS BEING CAPPED OFF BY WARM MID
LEVEL TEMPERATURES. THINK THAT ANY THUNDERSTORMS LATE THIS
AFTERNOON WOULD BE CONFINED TO THE AREA ALONG AND NORTH OF I-70.
WILL CARRY A SLIGHT CHANCE FOR EVENING STORMS IN THAT AREA BUT
KEEP IT DRY FARTHER SOUTH.

ON THURSDAY THE MODELS SHOW THE FRONTAL BOUNDARY WASHING OUT
ACROSS SOUTHWEST KANSAS. TEMPERATURES ALONG AND NORTH OF THE
OKLAHOMA BORDER SHOULD BE ABLE TO CLIMB TO AROUND 90 OR EVEN INTO
THE LOWER 90S BUT FARTHER NORTH EXPECT HIGHS TO STAY IN THE MID TO
UPPER 80S TOWARD I-70. A FEW THUNDERSTORMS COULD DEVELOP OR MOVE
INTO WEST CENTRAL KANSAS LATE THURSDAY AFTERNOON OR EVENING. NOT
REAL CONFIDENT IN THIS YET SO WILL JUST GO WITH LESS THAN 15
PERCENT POPS FOR THAT AREA AT THIS TIME.

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 320 PM CDT WED MAY 2 2012

MEDIUM RANGE MODELS INDICATE AN UPPER LEVEL TROUGH OF LOW PRESSURE
PUSHING ASHORE INTO THE PACIFIC NORTHWEST FRIDAY THEN CONTINUING TO
TRACK EASTWARD ACROSS THE NORTHERN ROCKIES SATURDAY, AND INTO THE
NORTHERN PLAINS ALONG THE CANADIAN BORDER BY THE END OF THE WEEKEND.
THIS SYSTEM WILL BRING THE POSSIBILITY FOR SHOWERS AND THUNDERSTORMS
FROM THE NORTHERN PLAINS SOUTHWARD INTO PORTIONS OF NEBRASKA AND
KANSAS THROUGHOUT THE WEEKEND. AN ATTENDANT COLD FRONT TO THE UPPER
LEVEL SYSTEM IS PROGGED TO PUSH SOUTHEAST INTO WESTERN KANSAS
SOMETIME EARLY SUNDAY SETTING UP THE CHANCE FOR PRECIP ACROSS
PORTIONS OF WESTERN KANSAS BY LATE SUNDAY INTO EARLY MONDAY.
ALTHOUGH MODELS BEGIN TO DIVERGE EARLY NEXT WEEK, ALL SHOW UPPER
LEVEL TROUGHING DEEPENING ACROSS THE INTERMOUNTAIN WEST SETTING UP A
SOUTHWESTERLY FLOW ALOFT ACROSS THE WESTERN HIGH PLAINS. MEANWHILE,
A SERIES OF H5 VORT MAXES ARE LIKELY TO EJECT NORTHEAST OUT OF THE
TROUGH, AND ALONG WITH PLENTY OF LOW LEVEL MOISTURE AVAILABLE,
INCREASE CHANCES FOR PRECIP VIRTUALLY EACH DAY THROUGH THE END OF
THE PERIOD.

TEMPERATURES ARE EXPECTED TO BE ABOVE NORMAL FRIDAY AS UPPER LEVEL
TROUGHING BEGINS TO PUSH EAST ACROSS THE INTERMOUNTAIN WEST. AS THE
UPPER LEVEL SYSTEM APPROACHES FROM THE WEST, A SURFACE TROUGH LEE OF
THE ROCKIES WILL HELP INFLUENCE A LOW LEVEL SOUTH TO SOUTHWESTERLY
FLOW ACROSS WESTERN KANSAS. THIS WILL ENHANCE WARM AIR ADVECTION
INTO THE AREA WITH H85 TEMPERATURES RANGING FROM THE MID 20S(C)
ACROSS CENTRAL KANSAS TO THE UPPER 20S(C) NEAR THE COLORADO BORDER.
SO, WITH THE NAM, GFS, AND GEM SHOWING DRY LAPSE RATES IN THE LOWER
LEVELS, LOOK FOR HIGHS UP INTO THE LOWER TO MID 90S(F) FRIDAY
AFTERNOON. SIMILAR HIGHS ARE LIKELY SATURDAY WITH LEE SIDE TROUGHING
PERSISTING NEAR THE COLORADO BORDER AND H85 TEMPERATURES CHANGING
VERY LITTLE. GENERALLY COOLER TEMPERATURES ARE THEN EXPECTED SUNDAY
AS A COLD FRONT IS PROJECTED TO PUSH INTO WESTERN KANSAS SOMETIME
DURING THE DAY ALLOWING COOLER AIR TO FILTER SOUTH INTO WESTERN
KANSAS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1200 AM CDT THU MAY 3 2012

MVFR CIGS ARE INDICATED BY MOS GUIDANCE AS WELL AS THE 01Z HRRR FOR
KHYS IN ASSOCIATION WITH WITH POST FRONTAL UPSLOPE STRATUS. THE RELATED
FRONT WILL MOVE THROUGH KGCK AND KDDC EARLY IN THE MORNING AS WELL,
HOWEVER, ENOUGH MIXING LOOKS TO KEEP CIGS AT VFR. THIS FRONT WILL STALL
OUT THROUGH THE DAY AND RETURN NORTH AS A WARM FRONT BY EVENING. WINDS
SHOULD GENERALLY BE LIGHT (8 TO 13 KT) WITH A GRADUAL VEERING IN DIRECTION
WITH THE RETURN OF THE WARM FRONT.

&&

.PRELIMINARY POINT TEMPS/POPS...
DDC  60  91  60  95 /   0  10  10   0
GCK  55  89  56  94 /   0  10  10   0
EHA  54  90  57  93 /   0   0   0   0
LBL  56  92  58  96 /   0  10   0   0
HYS  61  85  60  93 /   0  10  10   0
P28  66  92  64  92 /   0  10  10   0

&&

.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...GERARD
LONG TERM...JJOHNSON
AVIATION...SUGDEN







AREA FORECAST DISCUSSION...UPDATED

NWS JACKSON KY

 1051 PM EDT FRI MAY 4 2012

.UPDATE...
ISSUED AT 1049 PM EDT FRI MAY 4 2012

THE CWA HAS BEEN RATHER VOID OF CONVECTION OVER THE PAST COUPLE OF
HOURS. THE CURRENT CONVECTION ACROSS THE OH VALLEY REGION IS CLOSE TO
IF NOT NORTH OF THE OH RIVER. EXTRAPOLATION AND RECENT RUC AND NAM
RUNS AS WELL AS 21Z SREF GENERALLY DROP THIS CONVECTION SOUTH INTO
THE AREA OVERNIGHT. THE GUIDANCE MAY BE A BIT TO FAR SW WITH ITS
TRACK INTO THE CWA LATER ON TONIGHT. IF NOT...THEN THE HEAVIEST RAIN
MAY FALL OUTSIDE OF THE FFA. CONFIDENCE IN THE EXACT CONVECTIVE
EVOLUTION IS NOT THAT HIGH FOR THE OVERNIGHT AS INSTABILITY IS RATHER
MEAGER AS MUCH OF CENTRAL KY HAS BEEN WORKED OVER OR HAS HAD AN
OUTFLOW PASS.

UPDATE ISSUED AT 740 PM EDT FRI MAY 4 2012

MODELS OTHER THAN THE MOST RECENT RUN SEEM TO BE HAVING TROUBLE WITH
THE CONVECTION CURRENTLY ONGOING ACROSS THE OH VALLEY REGION. THE
FORECAST FOR THE REMAINDER OF THE NIGHT IS HIGHLY DEPENDENT ON THE
CONVECTIVE EVOLUTION CLOSER TO THE BOUNDARY TO OUR NORTH AND
NORTHWEST AND IF THIS CONVECTION CAN HOLD TOGETHER ACROSS THE AREAS
THAT HAVE BEEN RECENTLY WORKED OVER. EARLIER STRONGER CONVECTION
THAT WAS OVER CENTRAL KY HAS FIZZLED AND CONVECTION OVER OH AND FAR
NE KY SEEMS DESTINED TO HEAD TO OUR EAST IN THE IMMEDIATE FUTURE.
HOWEVER...OUTFLOWS FROM THIS CONVECTION OR FURTHER DEVELOPMENT TO OUR
NW SHOULD REACH THE CWA SOMETIME OVERNIGHT...BUT THIS IS A LOW
CONFIDENCE FORECAST AT THIS TIME. IF/WHEN CONVECTION AFFECTS THE CWA
THERE WOULD BE SOME POTENTIAL FOR IT TO TRAIN ACROSS SOME OF THE
AREAS THAT HAVE BEEN WET IN THE LAST 24 HOURS. OVERALL...IT APPEARS
THAT WITH THE LOSS OF DAYTIME HEATING THE THREAT FOR SEVERE
CONVECTION IS DIMINISHING...UNLESS AN MCS DEVELOPS A STRONG COLD POOL
AND MOVES INTO THE AREA. WE WILL CONTINUE TO MONITOR CONVECTIVE
DEVELOPMENT AND EVALUATE THE NEED FOR THE FLASH FLOOD WATCH A BIT
LATER THIS EVENING.

UPDATE ISSUED AT 508 PM EDT FRI MAY 4 2012

SKY AND POPS WERE UPDATED TO BETTER REFLECT TIMING OF THE CONVECTION
APPROACHING FROM THE WEST NOW NEAR THE I 65 CORRIDOR/KSDF VICINITY
AND MORE ISOLATED CONVECTION OVER THE BLUEGRASS REGION. RECENT
ANALYSIS INDICATES HIGHER INSTABILITY ML CAPE NEAR 2000 J/KG AND LI
-6C OR LOWER ACROSS THE NORTHERN CWA. DEWPOINTS ARE ALSO HIGHER IN
THIS REGION COMPARED TO THE SW. HOWEVER...LAPSE RATES IN THE LOW AND
MID LEVELS ARE MORE MARGINAL WITH SOME MID LEVEL CAPPING CURRENTLY
OVER THE CWA. HOWEVER...THIS SHOULD ERODE PER MODEL GUIDANCE AS THE
CONVECTION AND ASSOCIATED MID LEVEL WAVE TO OUR NW APPROACHES. AT THIS
POINT...IT STILL APPEARS THAT THE BEST CHANCE FOR THUNDERSTORMS WITH
HEAVY RAIN WILL BE ACROSS THE NORTHERN CWA WHERE CURRENT FFA IS IN
PLACE. EXTRAPOLATION AND INSTABILITY AND SHEAR PARAMETERS POINT TO
THE POSSIBILITY OF DAMAGING WINDS OR MARGINALLY SEVERE HAIL POSSIBLE
WITH ANY CONVECTION THIS EVENING ACROSS THE NORTHERN TWO THIRDS OF
THE CWA BETWEEN ABOUT 22Z AND 3Z.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 300 PM EDT FRI MAY 4 2012

EXTENSIVE CLOUDINESS AND A MID LEVEL CAP HAS INHIBITED CONVECTIVE
INITIATION ACROSS OUR AREA EARLY THIS AFTERNOON. THE FEW CELLS THAT
HAVE MANAGED TO DEVELOP IN THE NORTHWESTERN PART OF THE FORECAST AREA
HAVE REMAINED RELATIVELY WEAK. THE CONVECTIVE COMPLEX NOW CROSSING IL
INTO INDIANA SHOULD MAINTAIN ITSELF AS IT MOVES ACROSS THE SEVERE
THUNDERSTORM WATCH TO OUR WEST. BASED ON CURRENT MOVEMENT THIS
COMPLEX WILL REACH THE NORTHWEST PART OF OUR FORECAST AREA AROUND 7
PM. SHORT RANGE GUIDANCE HAS BEEN POINTING TOWARDS FAIRLY WIDESPREAD
THUNDERSTORMS ACROSS OUR AREA TONIGHT.

UP TO TWO INCHES OF RAIN FELL IN A FEW SPOTS ACROSS THE NORTHERN PART
OF THE FORECAST AREA OVER THE PAST 24 HOURS. WHERE HEAVIEST RAIN FELL
LAST NIGHT 1 HOUR FLASH FLOOD GUIDANCE IS AS LOW AS 1 INCH...WITH 3
HOUR GUIDANCE AS LOW AS 1.3 INCHES. BASED ON THIS AND QPF HAVE ISSUED
A FLASH FLOOD WATCH FOR THE NORTHEAST TWO THIRDS OF THE FORECAST AREA
FOR TONIGHT. THIS HAS BEEN COORDINATED WITH WFO CHARLESTON AND ALL OF
NE KY IS IN THE WATCH.

UNSETTLED WEATHER WILL CONTINUE INTO SATURDAY AS THE FRONT CURRENTLY
TO OUR NORTH SAGS SOUTH. ADDITIONAL SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE ON SATURDAY. WILL TAPER OFF PRECIPITATION CHANCES SATURDAY
NIGHT. TEMPERATURES AND DEWPOINTS WILL REMAIN MORE LIKE SUMMER TIME
VALUES INTO SATURDAY.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 300 PM EDT FRI MAY 4 2012

THE MODELS ARE IN GOOD AGREEMENT WITH THE LONG WAVE PATTERN THROUGH
THE PERIOD...WITH THE FLOW AMPLIFYING AND BECOMING MORE SPLIT WITH
TIME. THE MAIN UPPER LEVEL FEATURE OF INTEREST WILL BE A NORTHERN
STREAM TROUGH THAT WILL GRADUALLY SHIFT EAST WITH TIME AND
EVENTUALLY CUTOFF AND RIDE THE US/CANADIAN BORDER THROUGH THE END OF
THE NEXT WORK WEEK. THIS WILL BE BRINGING MORE UNSETTLED WEATHER TO
THE AREA FROM MONDAY THROUGH WEDNESDAY. OF COURSE...THE MODELS
HANDLE THE DETAILS WITH THE EVOLUTION OF THIS TROUGH QUITE A BIT
DIFFERENTLY. THE LAST 00Z ECMWF RUN HAS BECOME TOO AMPLIFIED AND
SLOW COMPARED TO THE REST OF THE GUIDANCE. AS SUCH...HAVE DISCOUNTED
THE OPERATIONAL RUN...AND ALLOWED BLENDING FROM ITS ENSEMBLE MEAN
WHICH SEEMS TO JIVE BETTER WITH THE REST OF THE CONSENSUS SOLUTION.

WARM AND HUMID CONDITIONS WITH ISOLATED SHOWERS AND THUNDERSTORMS
POSSIBLE ARE EXPECTED ON SUNDAY. AS WE HEAD INTO MONDAY...THE
TROUGH AND ASSOCIATED SURFACE COLD FRONT WILL BE MOVING IN FROM THE
WEST. POPS WILL BE ON THE INCREASE...WITH MONDAY NIGHT INTO EARLY
TUESDAY MORNING STILL LOOKING LIKE THE BEST CHANCE...AND HAVE STUCK
WITH THE GIVEN HIGH LIKELY. ON TUESDAY...THE FRONT WILL BE SHIFTING
EAST...WITH LIKELY POPS HANGING ON FOR MOST THROUGH AT LEAST THE
FIRST PART OF THE DAY...BEFORE DIMINISHING IN THE EVENING. THE
TROUGH AXIS WILL LINGER THROUGH WEDNESDAY...ALLOWING FOR SOME
ADDITIONAL SCATTERED SHOWER ACTIVITY. BY THURSDAY AND FRIDAY...THE
TROUGH AXIS WILL HAVE EXITED EAST...WITH RIDGING BUILDING
IN...BRINGING DRIER AND COOLER WEATHER TO CONCLUDE THE REST OF THE
PERIOD.

FOR TEMPERATURES...ABOVE NORMAL READINGS AND HUMID CONDITIONS WILL
COOL OFF TO NEAR NORMAL VALUES WITH LESS HUMIDITY THROUGH THE PERIOD.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 745 PM EDT FRI MAY 4 2012

OVER THE NEXT SEVERAL HOURS...CONVECTION SHOULD BE CONFINED TO AREAS
NORTH OF THE MTN PARKWAY AND GENERALLY IN LOCATIONS MUCH CLOSER TO THE
OH RIVER IF NOT IN OH AND WV. CONDITIONS OUTSIDE OF CONVECTION...AT
THE TAF SITES SHOULD REMAIN VFR FOR MOST OF THE FIRST 6 HOURS OF THE
PERIOD. IF/WHEN CONVECTION MOVES INTO THE REGION OVERNIGHT...POSSIBLY
AFTER 3Z...CONDITIONS WOULD DETERIORATE TO MVFR OR LOWER...ESPECIALLY
IN THUNDERSTORMS. IF THESE PERSISTED...PREVAILING CONDITIONS IN THE
MVFR OR IFR RANGE WOULD BE POSSIBLE. AT LEAST SCATTERED CONVECTION
SHOULD PERSIST INTO THE SECOND 12 HOURS OF THE PERIOD...WITH MVFR
CIGS POSSIBLE IN OR NEAR ANY SHRA/TSRA.


&&

.JKL WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 6 AM EDT SATURDAY FOR KYZ044-050>052-
058>060-104-106>115-118>120.

&&

$$

UPDATE...JP
SHORT TERM...SBH
LONG TERM....GEOGERIAN
AVIATION...JP







AREA FORECAST DISCUSSION

NWS PITTSBURGH PA

 1007 PM EDT FRI MAY 4 2012

.SYNOPSIS...
A SOUTHWARD MOVING COLD FRONT CAN STILL BRING SOME THUNDERSTORMS
OVERNIGHT, ALONG WITH PATCHY FOG. CANADIAN HIGH PRESSURE WILL FOLLOW
TO PROVIDE DRY, SEASONABLE CONDITIONS FOR SATURDAY AND SUNDAY.

&&

.NEAR TERM /THROUGH SATURDAY/...
BLEND OF RECENT RADAR DATA AND RAP/HRRR/MODEL OUTPUT SHOW
PREFRONTAL BANDS OF NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS
WILL CONTINUE TO MOVE SOUTHEASTWARD THROUGH THE UPPER OHIO VALLE
OVERNIGHT. EARLIER SOME STORMS HAD WIND GUSTS TO 35 MPH, NOW THEY
MAINLY FEATURE HEAVY RAIN. EXPECT SOME LATE NIGHT FOG DUE TO RAIN
EVAPORATION AND RADIATIONAL COOLING. SURFACE WIND SPEEDS CAN
REMAIN OVER 5 MPH WHICH SHOULD LIMIT FOG COVERAGE AND DURATION.

THE LAST OF THE SHOWERS SHOULD EXIT INTO CENTRAL WEST
VIRGINIA AROUND DAYBREAK SATURDAY. THE REST OF SATURDAY WILL BE
DRY WITH SOME SUNSHINE. FORECASTED TEMPERATURES TO BE NOT AS WARM
AS THE THURSDAY AND FRIDAY, BUT STILL MORE THAN 5 DEGREES WARMER
THAN NORMAL.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
RECENT SREF MODEL OUTPUT SHOWS CANADIAN HIGH PRESSURE WILL
MAINTAIN DRY CONDITIONS WITH NO MORE THAN SCATTERED CLOUDS MOST OF
THE TIME THROUGH DAYTIME SUNDAY.

OPTED FOR SLOWER GFS SOLUTION SUNDAY NIGHT AND MONDAY, WITH
NORTHWARD RETURN OF A WARM FRONTAL BOUNDARY AND MOISTURE AHEAD OF
A FAIRLY STRONG SURFACE LOW AND COLD FRONT FOR MONDAY. THIS IS
MORE IN LINE WITH 12Z ECMWF AND A BLEND OF GFS/ECMWF USED.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
12Z GFS SHOWS A CLOSED UPPER LOW AND ASSOCIATED SURFACE LOW TRACKING
NORTH OF THE GREAT LAKES EARLY IN THE WEEK AND REACHING SOUTHERN
QUEBEC LATE WEDNESDAY. OLD 00Z ECMWF TRACK DIGS THE UPPER LOW MUCH
FURTHER SOUTHWARD INTO THE APPALACHIANS BY THURSDAY. LEANED TOWARD
HPC PROGS WHICH ARE CLOSER TO GFS SOLUTION.

FORECAST LIKELY POPS FOR SHOWERS AND THUNDER MONDAY NIGHT INTO
TUESDAY WITH FRONTAL PASSAGE. TAPERED POPS TO SCATTERED COVERAGE
TUESDAY NIGHT INTO THURSDAY AS SYSTEM MAKES SLOW EASTWARD PROGRESS.
DRY CONDITIONS ARE FORECAST BY FRIDAY AS SURFACE HIGH BUILDS IN
FROM THE WEST.

&&

.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
BLEND OF RECENT RADAR DATA AND HRRR MODEL OUTPUT SHOWS PREFRONTAL BANDS
OF MVFR SHOWERS AND SCATTERED IFR THUNDERSTORMS, WITH HEAVY RAIN, WILL
MOVE SOUTHEASTWARD THROUGH THE UPPER OHIO VALLEY THROUGH ABOUT
08Z.

AREAS OF POST-FRONTAL POST-RAIN IFR FOG AND STRATUS CAN DEVELOP
LATE TONIGHT AND LINGER UNTIL ABOUT 13Z.

HIGH PRESSURE SUBSIDENCE AND DRYING, COUPLED WITH DAYTIME
VERTICAL MIXING, WILL PROVIDE IMPROVING CONDITIONS TO VFR CUMULUS
CEILINGS BY SATURDAY AFTERNOON.

SURFACE WINDS WILL BECOME NORTHWEST 6-10 KTS LATE TONIGHT AND
SATURDAY. HIGHER GUSTS ARE POSSIBLE WITH THUNDERSTORMS THROUGH
08Z.

.OUTLOOK...SATURDAY NIGHT THROUGH WEDNESDAY...
HIGH PRESSURE WILL PROVIDE VFR CONDITIONS SATURDAY NIGHT THROUGH
EARLY MONDAY. RESTRICTIONS WILL BE POSSIBLE MONDAY THROUGH
WEDNESDAY DUE TO SHOWERS AND POSSIBLE THUNDERSTORMS ASSOCIATED
WITH THE EASTBOUND PASSAGE OF A LOW PRESSURE SYSTEM.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

$$







AREA FORECAST DISCUSSION

NWS BALTIMORE MD/WASHINGTON DC

 253 PM EDT THU MAY 3 2012

.SYNOPSIS...

AN UPPER-LEVEL DISTURBANCE WILL PASS THROUGH THE REGION TONIGHT
INTO FRIDAY BEFORE A BACKDOOR COLD FRONT WILL MOVE THROUGH THE
REGION FRIDAY NIGHT. CANADIAN HIGH PRESSURE BUILDS SOUTHWARD THIS
WEEKEND BEFORE MOVING OFF THE MID-ATLANTIC COAST MONDAY.

&&

.NEAR TERM /TONIGHT/...

A SPL 18Z BALLOON WAS LAUNCHED - ONLY AS A TEST BUT THERE IS UPPER
AIR DATA.

AFTR A MRNG WHERE MUCH OF THE MID ATLC RGN WAS OVC IN LOW CLDS A
RAPID CLRG TOOK PLACE DURG LATE MRNG LVG CWA UNDER M SUN SKIES.
TEMPS NOW RISING...AND MUCH OF CWA SHOULD REACH THE 80S DURG THE
NEXT FEW HRS.

A FEW RW HV BEGUN TO SPRING UP OVR THE HIGHER TERRAIN. HRRR RUC
SHOWS A MORE DVLPD LN OF CNVCTN DVLPG OVR THE MTNS OF PA/MD/VA
DURG THE LATE AFTN BUT WEAKENING AS IT MOVES E. I CAN`T CLAIM TO
HV GREAT CONFIDENCE THAT THE SCENARIO WL UNFOLD EXACTLY LK THIS-
18Z SNDG SHOWS A WEAK WIND FIELD. MDL SNDGS ARE VARYING WIDELY ON
THE AMT OF CAPE THAT WL BE AVBL. SVR THREAT APPEARS MARGINAL AT
BEST...BUT OF COURSE WE HV A RDR OPERATOR KEEPING AN EYE ON
THINGS.

BY LATE EVE CNVCTN SHOULD BE DYING DOWN. IF ANY CNVCTV THREAT
RMNS IT SHOULD BE W OF THE BLUE RDG.

LATE TNGT THERE COULD BE ANOTHER RESURGENCE OF LO LVL
MOISTURE...BRINGING LOW CLDS BACK TO THE NERN PART OF THE CWA.
BOTH NAM AND GFS DEPICT A LOW LVL INVERSION SETTING UP AT BWI
TNGT...AS THESE DID LAST NGT. HOWEVER DO NOT FEEL TNGT`S LOW CLD
XPRNC WL BE AS WIDESPREAD AS LAST NGTS.

LOWS TEMPS MAINLY IN THE L60S...XCPT MU50S IN NERN MD AND OVR THE HIGHLANDS.

&&

.SHORT TERM /FRIDAY/...

A COLD FNT WL MOVE TO A POSN NEAR THE ERN GRT LKS FRI MRNG. THE SWD
PROGRESSION WL BE VERY SLOW...SO MID ATLC LOOKS TO BE IN THE WARM
SECTOR THRUT FRI. TEMPS SHOULD MAKE IT INTO THE MU80S DURG THE
AFTN. MUCH LK THIS AFTN WIND FIELD IS NOT THAT STRONG. GFS IMPLIES
A SHORT WV TRACKING E OF THE APLCHS LATE TMRW WHICH WOULD HELP
INITIATE CNVCTN. THE NERN PART OF THE CWA IS OUTLOOKED W/ A SLT
RISK. BLV LARGE/GUSTY WINDS WOULD BE THE PRIMARY CONSIDERATIONS.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...

BACKDOOR COLD FRONT OVER PA WILL SAG SWD THRU THE CWA FRI NGT.
ONGOING CONVECTIVE ACTIVITY FROM FRI AFTN WILL LIKELY CONTINUE INTO
THE EVE UNTIL DAYTIME INSTABILITY WANES AROUND SUNSET. IF THE WRN
SECTOR OF FRONT BECOMES HELD UP NEAR THE MTS...WHICH SEEMS PLAUSIBLE
GIVEN SHALLOW NATURE OF THE BOUNDARY...SHOWERS ACTIVITY MAY LINGER
NEAR THE ALLEGHENY FRONT DURING THE OVNGT.

THE FRONT IS EXPECTED TO BE JUST SOUTH OF THE AREA BY SAT MRNG.
THERE ARE STILL MODEL DIFFERENCES WITH ARRIVAL OF THE DRIER/COLDER
AIR IN WAKE OF FROPA...BUT DIFFERENCES ARE CONSIDERABLY SMALLER THAN
24-HR AGO. APPRECIABLE DRY ADVECTION MAY BE DELAYED 6-12 HR POST SFC
FROPA... WHICH COULD KEEP SHOWERS/STORMS IN THE FCST DURING THE DAY
ON SAT AS A MID-LVL SHORTWAVE TROUGH MOVES THRU. THE BEST CHANCE FOR
SHOWERS WILL BE ACROSS CENTRAL VA AND SRN MD...WHILE NRN LOCALES
NEAR THE MASON-DIXON LINE MAY DRY OUT IN THE AFTN.

CANADIAN HIPRES NOSES SWD INTO THE MID-ATLANTIC STATES SAT NGT AND
SUN BEFORE SHIFTING OFF THE COAST MON. THE DRIEST PERIOD DURING THE
ENTIRE 7-DAY FCST APPEARS TO BE THE LATE WEEKEND AND BEGINNING OF
NEXT WEEK. HOWEVER...ELY/UPSLOPE FLOW AROUND THE HIGH MAY PRODUCE
ENOUGH LIFT FOR ISO SHOWERS ACROSS THE SRN POTOMAC HIGHLANDS SUN.

WX PATTERN BECOMES INCREASINGLY UNSETTLED BY MON NGT OR TUE AS A
SHORTWAVE TROUGH APPROACHES FROM THE OH VLY. A MORE POTENT NR-
STREAM TROUGH IS FCST TO DIG SWD INTO THE GREAT LAKES/OH VLY
MIDWEEK. WITH THE MID-ATLANTIC SITUATED IN UNSTABLE WARM SECTOR...
SCT SHOWERS AND STORMS LIKELY THRU WED.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...

VFR CONDS THIS EVE. LOW ST COULD AGN DVLP LATE TNGT...ALTHO NOT AS
WIDESPREAD AS LAST NGT. MVFR CIGS MOST LKLY AT BWI/MTN.

TSTMS PSBL FRI AFTN. ALL XCPT CHO COULD SEE STORMS BY LATE FRI AFTN.

COLD FRONT MOVING SWD WILL CROSS THE TERMINALS FRI NGT. SCT SHOWERS
AND STORMS CONTINUE ERY FRI EVE WILL DIMINISH AFTER SUNSET. ENOUGH
SFC INSTABILITY MAY DEVELOP ON SAT FOR ISO-SCT SHOWERS/TSTMS TO
DEVELOP ON SAT. SLIGHTLY BETTER CHANCES FOR CONVECTIVE ACTIVITY WILL
BE NEAR CHO.

NELY COMPONENT TO THE FLOW MAY ADVECT MARINE LAYER INLAND SUN AS
HIPRES BUILDS SEWD. A FASTER PROGRESSION OF THE HIGH WOULD FAVOR A
MORE ELY COMPONENT TO THE FLOW AND INLAND ADVECTION OF LOW STRATUS
SUN MRNG.

&&

.MARINE...

WINDS TO RMN BLO SCA VALUES TNGT AND FRI. XCPTN WOULD BE IF TSTMS
DVLP FRI AFTN.

COLD FRONT WILL MOVE SWD THRU THE WATERS FRI NGT. THREAT OF STRONG
TSTMS WILL CONTINUE ACROSS THE WATERS FRI EVE BEFORE STORMS WEAKEN
AFTER SUNSET. WINDS WILL BE LGT THRU THE WEEKEND.

SLY FLOW INCREASES ERY NEXT WEEK AS HIPRES SHIFTS OFF THE EAST
COAST. WINDS MAY INCREASE TO SCA LVLS LATE MON INTO TUE...BUT STILL
CONSIDERABLE UNCERTAINTY THIS FAR OUT.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.

&&

$$
PRODUCTS...WOODY!/JRK








AREA FORECAST DISCUSSION...UPDATED

NWS TWIN CITIES/CHANHASSEN MN

 911 PM CDT FRI MAY 4 2012

.UPDATE...

MADE CHANGES TO THE OVERNIGHT FORECAST TO DIMINISH THE CHANCES ON
THE SHOWERS AND THUNDERSTORMS IN THE WAKE OF THE CONVECTIVE
COMPLEX THAT MOVED ALONG THE I-90 CORRIDOR THIS AFTERNOON. MODEL
GUIDANCE DIDN`T HANDLE THIS WELL WITH THE MID AFTERNOON HRRR
CATCHING ON. USING THE HRRR OVERNIGHT WOULD INDICATE ONLY MINOR
SHOWER AND THUNDERSTORM ACTIVITY AT BOTH THE EAST AND WEST ENDS OF
OUR CWA. IN ADDITION...A WAKE LOW HAS DEVELOPED ACROSS SOUTH
CENTRAL MN. THIS WILL CAUSE STRONG EAST WINDS (30-45 MPH) THROUGH THE
LATE EVENING HOURS.

&&

.DISCUSSION... /ISSUED 417 PM CDT FRI MAY 4 2012/

TONIGHT AND SATURDAY...QUASI-STATIONARY SFC FRONT EXTENDING FROM
ERN WY THRU NRN NE AND NRN IA INTO THE OH VALLEY ACTING TO ENHANCE
LOW- AND MID- LEVEL SHEAR ALONG WITH ADDING MUCH DEEPER MOISTURE
TO THE AREA...PARTICULARLY SRN MN. SOUTHERLY FLOW S OF THE BNDRY
WITHE E-NE FLOW N OF IT CREATING A DISTINCT CORRIDOR OF ENHANCED
SHEAR CAPABLE OF PRODUCING TORNADIC SUPERCELLS IN FAR SRN MN FOR
LATE THIS AFTN INTO EARLY THIS EVE. GOING N FROM THERE...MORE
PRONOUNCED E-NE WINDS AND AN ENVIRONMENT OF MUCH LOWER CAPE/SHEAR
WILL MEAN RAIN WITH A FEW WEAK TSTMS FROM MANKATO ON NORTH.
LOOKING AT THE BIGGER PICTURE...A LARGE UPPER LEVEL TROUGH WILL
PUSH ONSHORE THE PACIFIC COAST TONIGHT INTO TOMORROW...AMPLIFYING
THE LARGE RIDGE SHIFTING FROM THE MISSISSIPPI RIVER VALLEY EWD
THROUGH SATURDAY. THIS WILL MAKE FOR DEEP SWLY FLOW ALOFT...
FORCING WARM AIR AND HIGHER MOISTURE AIR ADVECTION FOR THE
WEEKEND. AS THE UPPER FLOW PIVOTS TONIGHT INTO SATURDAY...THIS
WILL NUDGE THE SFC BOUNDARY NWD AS A WMFNT... BRINGING HIGHS ARND
80 OVER FAR SRN MN AND HIGHS IN THE UPR 60S THROUGH THE 70S TO THE
REMAINDER OF THE AREA FOR SATURDAY. RAIN CHANCES DIMINISH A BIT
SATURDAY AS THE AREA GETS WORKED OVER FROM CONVECTION TONIGHT...SO
POPS HAVE BEEN HELD BACK INTO THE CHC RANGE.

SATURDAY NIGHT THROUGH MONDAY...TANDEM AREAS OF LOW PRESSURE...
ONE IN NRN MT AND ANOTHER IN WRN KS/NE...WILL SHIFT ENE SAT NIGHT
INTO SUN WHILE THE WMFNT WOBBLES OVER SRN MN. THE WMFNT WILL
GRADUALLY LIFT N BY EARLY SUN IN ADVANCE OF A CDFNT THAT WILL
GRADUALLY SHIFT E ACRS THE AREA SUN INTO SUN NIGHT. STRONG
MOISTURE ADVECTION WITH THIS SYSTEM ALONG WITH GREATLY ENHANCED
OMEGA LIFT WILL PRODUCE QPFS IN THE ONE HALF TO ONE INCH RANGE FOR
MUCH OF THE AREA WITH ISOLATED HIGHER AMOUNTS. IN ADDITION...
THERE IS STILL A SMALL SHOT AT STRONG TO SEVERE STORMS BUT WITH
A MORE EASTERLY FLOW AND LACK OF STRONG INSTABILITY AS COMPARED TO
S OF THE WMFNT...THE BULK OF SEVERE ACTIVITY SHOULD REMAIN S OF
THE MPX CWFA. THAT SAID...POPS SAT NIGHT INTO SUN ARE IN THE
LIKELY TO CATEGORICAL RANGE. AS THE CDFNT SHIFTS INTO WI AND
POINTS E SUN NIGHT INTO MON...PRECIP CHCS DROP OFF STRONGLY AND
WILL LOOK TO HAVE A DRYING OUT PERIOD ON MONDAY ALONG WITH COOLER
TEMPERATURES. HIGHS WILL DROP OUT OF THE 60S/70S SUNDAY TO JUST
THE 60S ON MONDAY.

TUESDAY THROUGH THURSDAY...GENERALLY DRIER AND COOLER TEMPERATURES
ARE EXPECTED THROUGH THE MIDWEEK PERIOD AS PRONOUNCED NW UPPER
LEVEL FLOW COMBINED WITH MODIFIED CANADIAN HIGH PRESSURE DROPS
INTO THE REGION. A WEAK MIDLVL DISTURBANCE MAY BE ABLE TO SPARK
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ON TUESDAY BUT
MOISTURE ADVECTION IS NOT IMPRESSIVE. FURTHER DRYING OUT IS
EXPECTED WEDNESDAY INTO THURSDAY. THE COLD AIR ADVECTION
ANTICIPATED FOR THE MIDWEEK PERIOD WILL DROP HIGHS INTO THE
50S/60S ON TUESDAY...THE PEAK OF COOLING. THIS WILL BE FOLLOWED BY
HIGHS IN THE 60S ON WEDNESDAY AND A RETURN TO THE 70S ON THURSDAY.

&&

.AVIATION... /00Z TAF ISSUANCE/

TOUGH FORECAST. LOW CONFIDENCE ON OVERALL CLOUDS TREND OVERNIGHT.
SOME CONVECTIVE POTENTIAL INTO SOUTHERN METRO INTO WESTERN WISCONSIN
THIS EVENING.  WILL LEAVE THUNDER OUT OF KMSP AND STATIONS EAST FOR
NOW.  SHOWERS SHOULD END OVER EASTERN MN THROUGH 04Z AND INTO
WISCONSIN THEREAFTER.  SOME INDICATION OF REDEVELOPMENT
FARTHER EAST DURING THE NIGHT AND WILL CONTINUE TO MENTION SOME SHRA
INTO WISCONSIN LATE.  OTHERWISE...CEILINGS EXPECTED TO LOWER TO IFR
AT KRWF AND LOWER MVFR CEILINGS MOST OTHER AREAS OVERNIGHT.  EXPECT
CEILINGS TO LIFT TO VFR INTO THE AFTERNOON...WITH MAYBE SOME
CONVECTION MOVING INTO WESTERN MN LATE AFTERNOON.  SHOULD HOLD OFF
INTO EASTERN AREAS UNTIL 00Z SUN OR LATER.  SURFACE WINDS WILL
REMAIN NORTHEAST/EAST THROUGH THE PERIOD.  MAY SEE WINDS INCREASE
AGAIN SATURDAY AFTERNOON IF SUNSHINE DOES DEVELOP.

KMSP...SHRA OVER THE FIELD FOR A FEW HOURS THIS EVENING.  ISOLATED
THUNDER POSSIBLE FOR A COUPLE HOURS BUT LEFT IT OUT OF THE TAF.
SHOULD SEE ACTIVITY SHIFT EAST INTO WESTERN WISCONSIN THROUGH 04Z
EXPECT MAINLY DRY THEREAFTER UNTIL PERHAPS AFTER 00Z SUNDAY.
CEILING SHOULD STILL DECREASE TO MVFR NEXT SEVERAL HOURS AND THEN
REMAIN  SO THROUGH SATURDAY MORNING.  VFR POSSIBLE INTO SATURDAY
AFTERNOON BEFORE NEXT SYSTEM APPROACHES FROM TH WEST MAINLY  SATURDAY
NIGHT.  SURFACE WIND MAY TURN A BIT MORE NORTHEAST AS RAIN MOVES
THROUGH EARLY...THEN EXPECT MORE EASTERLY WIND FLOW THROUGH THE DAY
SATURDAY.

SUNDAY...MVFR/VFR WITH -SHRA POSSIBLE.
MONDAY...VFR WITH NORTHWEST WINDS 15-20KTS.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&

$$

RAH/JPC/DWE






AREA FORECAST DISCUSSION

NWS TWIN CITIES/CHANHASSEN MN

 704 AM CDT THU MAY 3 2012

...UPDATE...

UPDATED FOR 12Z AVIATION DISCUSSION BELOW

&&

.DISCUSSION...

NUMEROUS THUNDERSTORM COMPLEXES TRACKED ACROSS THE MIDWEST AND THEIR
OUTFLOW BOUNDARIES HAVE POLLUTED ANY ATTEMPT AT A CLEAN SURFACE
ANALYSIS. JUST LOOKING AT THE DEWPOINTS AND WIND FIELD ON THE LARGE
SCALE...IT APPEARS THE PARENT BOUNDARY REMAINS ACROSS THE NORTHERN
HALF OF THE CWA. THIS BOUNDARY WILL ONCE AGAIN BE THE FOCUS FOR
SHOWERS AND THUNDERSTORMS LATER TODAY.

TODAY...THE TWO OBVIOUS MCS PER IR SATELLITE IMAGERY ARE LOCATED TO
THE EAST AND SOUTH OF THE CWA. MEANWHILE A SMALLER LESS ORGANIZED
COMPLEX OF SHOWERS AND THUNDERSTORMS WILL BE EXITING EASTERN
MINNESOTA AND ENTERING WESTERN WISCONSIN. THERE SHOULD BE SOME
CLEARING FROM WEST TO EAST AND A DRY START TO THE DAY TODAY AS THESE
SHOWERS AND THUNDERSTORMS EXIT THE REGION. LATEST WV IMAGERY WITH
500MB HEIGHTS SHOWS ELONGATED SHORTWAVE TROUGH ACROSS THE
MONTANA/DAKOTA BORDER. NUMERICAL MODELS TRACK THIS SHORTWAVE NORTH
OF LAKE SUPERIOR TODAY...AND WEAK RIDGING/SUBSIDENCE IN THE WAKE OF
THIS WAVE WILL DEVELOP A SURFACE HIGH THAT WILL ATTEMPT TO PUSH THE
STATIONARY BOUNDARY SOUTH OF THE REGION THROUGHOUT THE DAY TOWARD
THE EVENING HOURS. HAVE A LITTLE TROUBLE BUYING THE SOUTHERN EXTEND OF
THE BOUNDARY PROGRESSION...ESPECIALLY WITH ZONAL FLOW ALOFT. IF THE
BOUNDARY DOES FAIL TO SLIDE SOUTHEAST OF THE REGION AS CURRENTLY
FORECAST...THE PROBABILITY OF LATE AFTERNOON THUNDERSTORMS WOULD
INCREASE. THE AIRMASS ALONG AND SOUTH OF THE BOUNDARY IS
CHARACTERIZED BY ABUNDANT LOW LEVEL MOISTURE...AND WILL QUICKLY
DESTABILIZE WITH AND AMOUNT OF SOLAR INSOLATION TODAY. LOW LEVEL
WIND FIELDS ARE LESS IMPRESSIVE THAN WEDNESDAYS....BUT EVEN
MARGINAL DEEP LAYER SHEAR OF 30-40KTS WITH 2000J/KG OF CAPE WOULD
SUPPORT SUPERCELLS CAPABLE OF PRODUCING SEVERE HAIL AND POSSIBLY
DAMAGING WINDS. LATEST SPC DAY 1 OUTLOOK SLIGHT RISK AREA JUST
CLIPS THE FAR SOUTHERN PORTION OF THE CWA. HOWEVER...BOTTOM LINE
IS THE PROGRESSION OF THE BOUNDARY WILL HAVE TO BE MONITORED TO
ADD CONFIDENCE TO THE TIMING AND PLACEMENT OF PRECIP/SEVERE THREAT
LATER THIS AFTERNOON. FLASH FLOODING WILL ALSO HAVE TO MONITORED
IF TRAINING THUNDERSTORMS DEVELOP.

FRIDAY THROUGH WEDNESDAY...ASSUMING THE BULK OF THE PRECIP REMAINS
SOUTHEAST OF THE REGION THURSDAY NIGHT...WILL START OFF DRY FOR
FRIDAY BEFORE ANOTHER WAVE DEVELOPS SOME SHOWERS AND THUNDERSTORMS
AND SPREADS THEM ACROSS THE REGION FROM WEST TO EAST. LOOKS LIKE
CHANCES FOR PRECIP WILL LAST THROUGH SUNDAY...WITH THE HIGHEST CHANCE
SATURDAY NIGHT INTO SUNDAY MORNING AS THE MOST POTENT WAVE IN THIS
SHORTWAVE-TRAIN MOVES ACROSS THE REGION. AS THIS POSITIVELY TILTED
WAVE PASSES THROUGH...THE PATTERN WILL AMPLIFY AND WE WILL
TRANSITION FORM ZONAL WEST/EAST FLOW...TO MORE OF A NORTHWEST FLOW.
THIS WILL BRING DRIER WEATHER AND COOLER TEMPERATURES THROUGH THE
MIDDLE OF NEXT WEEK.

&&



.AVIATION.../12Z TAF ISSUANCE/

WEAK BOUNDARY CONTINUES TO MAKE THIS A FORECASTING CHALLENGE.
OVERNIGHT CONVECTION HAS MADE IDENTIFYING THE WEAK BOUNDARY A TAD
MORE DIFFICULT.

A WEAK LOW PRESSURE AREA LOCATED ALONG THE MN/SD
BORDER HAS A BOUNDARY EXTENDING EAST TOWARD NORTHERN WISCONSIN.
THIS BOUNDARY HAS BEEN THE FOCUS OF PAST AND ONGOING CONVECTION.
THE OVERALL SOLUTION TODAY WILL BE TO SLOWLY PUSH THE BOUNDARY
SOUTH TOWARD THE MN/IA BORDER BY TONIGHT. VARIOUS SOLUTIONS PUSH
THE BOUNDARY SOUTH SOONER AND HAVE DIFFERENT PRECIPITATION
SCENARIOS. THIS WILL MAKE FOR A CHALLENGING CONVECTION AND WIND
FORECAST. THE RAP IS FASTER AND MORE AGGRESSIVE THAN THE NAM. BOTH
OF WHICH BRING DRIER AIR INTO MUCH OF THE AREA LATER THIS
AFTERNOON. THE 03Z HRRR HAD A GOOD HANDLE ON THE CONVECTION
HOWEVER SUBSEQUENT RUNS HAVE BEEN CHALLENGED. AS A RESULT I AM NOT
OVERLY CONFIDENT OF THE FORECAST. AS A RESULT HAVE FAIRLY
OPTIMISTIC TAFS AND THEY WILL HAVE TO BE WATCHED CLOSELY. REALLY
BELIEVE MOST OF THE CONVECTION WILL BE IN THE SOUTHERN PART OF OUR
AREA AND WILL NOT IMPACT ANY OF THE MN TERMINALS. COULD SEE MORE OF
AN IMPACT AT KEAU LATE THIS AFTERNOON.

KMSP...BOUNDARY APPEARS TO BE JUST NORTH OF THE AIRFIELD AND
WILL MOVE SOUTH OF THE AIRFIELD LATER THIS AFTERNOON. DEPENDING ON
TIMING OF THE BOUNDARY PASSAGE IT IS POSSIBLE THAT THE AIRPORT
WILL SEE NO THUNDERSTORM ACTIVITY. THIS WILL BE MONITORED CLOSELY.


OUTLOOK...EVEN AFTER THE BOUNDARY MOVES TOWARD IOWA WE HAVE SOME
RESIDUAL MOISTURE IN PLACE WITH SOME PERIODS OF INSTABILITY
THEREFORE CAN EXPECT TO SEE CHANCES OF CONVECTION FOR THE NEXT FEW DAYS.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&

$$

JRB/DRL






AREA FORECAST DISCUSSION

NWS KANSAS CITY/PLEASANT HILL MO

 626 PM CDT Fri May 4 2012


...UPDATED AVIATION DISCUSSION...


.DISCUSSION...

Main concerns continue to be thunderstorm chances with a multitude of
outflow boundaries to be concerned about.

This Evening and Tonight:

The strongest outflow boundary and the one that seems to have the
best chance of initiating convection is still residing from near
Paola to south of Clinton, MO. There has been some deeper cloud
development in the vicinity of the boundary and given the extreme
instability, MUCAPE approaching 5,000 J/kg, if something could
develop it would likely become severe. But limited deep layer shear
would inhibit much organization so more multicell clusters would be
the most likely convective mode. Forecast soundings offer a mixed
scenario. The NAM maintains a fairly strong cap and inhibits
convection. The RUC weakens the cap to the point that mixed layer
parcel would be uninhibited and we`d be off to the races. Something
in between is probably the best scenario in which case a little
better forcing would be needed to break the cap. That said the
presence of the boundary within the extreme instability warrants at
least a small mention of thunderstorms. Forecast soundings in the
southern portions of the forecast area also show some mid level dry
air. All that said, should any storm get going they could easily
become severe with damaging winds and large hail possible. Also,
with ample amounts of moisture available any storm could drop
copious amounts of rainfall over a localized area.

During the overnight hours, storms may fire again in far northern MO
or southern IA and NE and move into northern MO. This area is not as
unstable as it is still recovering from morning convection but
3-4,000 J/kg could still be realized by late this afternoon. Shear
looks weak in this area so if any storms can get going and/or move
into northern MO they would likely be disorganized. There is still
ample moisture in this area and some areas received heavy rain so
any storm could easily produce additional flooding problems.

Saturday:

Hot and humid conditions will persist with heat indices in the mid
90s. This is very unseasonal and could pose problems for those who
are most sensitive to heat. Otherwise, it looks like the area should
be capped for most of the day inhibiting convective chances until
closer to sunset. By the evening and overnight hours we may see some
storms move into or develop in northern MO. Instability should be
around 3,000 J/kg but again shear looks marginal at best for storm
organization. So a more disorganized storm mode would be expected
with hail and damaging winds possible should storms impact the area.

Sunday:

Extreme instability is expected to build back into the forecast area
by Sunday afternoon and evening with potential 4-5,000 J/kg MUCAPE to
work with. Models differ a little with the timing of the frontal
boundary with the NAM bringing the boundary into NW MO late Sunday
morning. The GFS is little slower, holding it up until the evening
hours. Shear continues to looks rather weak in the warm sector of
the system which would limit storm organization. But with the
extreme instability and front to act as a trigger thunderstorms are
expected to develop during the afternoon hours and could easily
become severe. It looks like the biggest hazards with this system
will be large hail and damaging winds as well locally heavy rainfall
given the copious amounts of moisture available.

CDB

Medium Range (Monday through Friday)...

Medium range models are in very good agreement on the overall
pattern aloft which is marked by a dry airmass with seasonal
temperatures. Except for the possibility of some lingering post
frontal showers over the eastern CWA Monday morning as high pressure
builds in from the Rockies.

The first portion of this forecast period will be dominated by an
upper trough which will deepen as it digs southeast from south
central Canada through the Great Lakes and Upper MS Valley. The
ECMWF and GEM are in closer agreement on the depth of the system/
timing and thus get a slight nod over the more progressive GFS. This
allows a bit more cold air advection to work its way southward out
of southern Canada but temperatures through mid week will still be
near seasonal averages. Could see some light instability showers
sneak across the IA/MO border Tuesday afternoon but have low
confidence this far out.

By the end of the work week expect to see warm air advection move
back in as the surface high departs and an upper ridge builds into
the Northern Plains. GFS/ECMWF similarly address the issue of a closed
upper low over either northern Mexico or the far southwestern U.S.
opening up and being lifted northeast by the developing
southwesterly mid/upper level flow. Both models lift this feature
into the Central Plains by Friday and interact with an approaching
cold front to generate convection. Despite both models being on the
same page with this feature have limited confidence in them as they
both tend to have issues in handling closed upper lows this far out.
So, best option is to use a blend of models and await the next
couple of model runs.


MJ

&&

.AVIATION...
For 00z TAFs, TAF sites should remain VFR through much of the evening
hours, however short range MOS guidance continues to advertise lower
ceilings and visibility overnight down into MVFR and in some cases
IFR categories. Will continue with this general trend however will
push timing back a bit from previous TAFs, and will only take
ceilings into the MVFR category. Slight possibility that convection
over central Nebraska could make it into the vicinity of the
terminals overnight, particularly STJ, however confidence in this
scenario is low, so will not introduce thunder into TAF at this time.


MJM

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&

$$

WFO EAX







AREA FORECAST DISCUSSION

NWS GLASGOW MT

 834 PM MDT FRI MAY 4 2012

.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT...
MOIST AND UNSTABLE SW FLOW ALOFT PATTERN...ASSOCIATED WITH THE
UPPER TROUGH OVER W COAST STATES MOVING SLOWLY E. BROAD SURFACE
TROUGH OVER CENTRAL MT ZONES AND INTO OUR W ZONES. THIS EVE THOUGH
WE ARE IN A DRY SLOT WHICH IS WELL SHOWN ON SATELLITE
CHANNELS...AS WELL AS THE 00Z SOUNDING. THIS LIMITING CONVECTION
TO VERY ISOLATED...WITH ONE NEAR-SEVERE STORM OVER SHERIDAN
COUNTY.

LATER TONIGHT THOUGH...INCREASED CONVECTION ON OVER ID/WT
WILL SHIFT E INTO OUR AREA...INCREASING THE CHANCES OF SHOWERS AS
INDICATED BY MODELS. HRRR REFLECTIVITY LOOP INDICATES THIS TOO.
THIS WILL INITIALLY TEND TO FOCUS OVER THE SURFACE TROUGH OVER
OUR W ZONES. CURRENT FORECAST COVERS THIS VERY WELL...NO UPDATE. SIMONSEN

PREVIOUS SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH
SUNDAY...WEST FLOW ALOFT WILL PREVAIL AHEAD OF AN UPPER TROUGH
THAT WILL MOVE ACROSS CENTRAL MONTANA ON SATURDAY ENDING UP IN
SOUTHERN SASKATCHEWAN BY SUNDAY. IT WILL DRAG A COLD FRONT ACROSS
EASTERN MONTANA ON SATURDAY WHICH WILL LEAD TO WIDESPREAD SHOWERS
AND EVEN SOME EMBEDDED THUNDERSTORMS ON SATURDAY AFTERNOON.

THIS EVENING AND OVERNIGHT EASTERN MONTANA WILL BE AHEAD OF THE
APPROACHING UPPER TROUGH SO EXPECT A CHANCE OF SHOWERS WITH A
SLIGHT CHANCE OF THUNDERSTORMS. THIS APPROACHING SYSTEM HAS PLENTY
OF PACIFIC MOISTURE TO USE AND THE ATMOSPHERE IS UNSTABLE ENOUGH
TO SEE EMBEDDED THUNDERSTORMS TONIGHT THROUGH SATURDAY AFTERNOON.
LEFT POPS IN THE CHANCE RANGE BUT AS WE HEAD TOWARDS SATURDAY
MORNING WE WILL SEE THE CHANCE OF SHOWERS INCREASE ACROSS CENTRAL
MONTANA. MODELS ALL ARE IN PRETTY GOOD AGREEMENT WITH THE COVERAGE
AND AMOUNT OF PRECIPITATION ACROSS EASTERN MONTANA SATURDAY
AFTERNOON AHEAD OF THE COLD FRONT. RAISED POPS UP TO 80% AND
STUCK WITH THE EMBEDDED THUNDERSTORMS POSSIBILITY FOR SATURDAY
AFTERNOON. I STILL FEEL MODELS ARE ALL A LITTLE HIGH ON QPF AS
THEY ALL SIT WITH SWATHS OF 1/2 TO 3/4 OF AN INCH QPF ACROSS
EASTERN MONTANA. DECIDED TO LOWER THAT A BIT AND WENT WITH A MORE
MODEST QPF TOTAL BETWEEN 1/3 TO 1/2 AN INCH.

AS THE UPPER TROUGH MOVES OVER SASKATCHEWAN ON SATURDAY EVENING
IT BECOMES A STACKED AND CLOSED FEATURE. DRY AIR WILL WRAP INTO
SYSTEM FROM CENTRAL MONTANA WHICH WILL BRING AN END TO THE SHOWERS
ACROSS EASTERN MONTANA FROM WEST TO EAST. THE UPPER LOW WILL
LINGER OVER SOUTHERN SASKATCHEWAN THROUGH SUNDAY THEN SLOWLY MOVE
EAST OVER MANITOBA SUNDAY NIGHT.

THE UPPER FEATURE IS STILL CLOSE ENOUGH TO NORTHEAST MONTANA AS
IT BEGINS TO MOVE EASTWARD IT WILL WRAP SOME SCATTERED SHOWERS
AROUND THE BACK SIDE OF THE SYSTEM. I DECIDED TO LEAVE CHANCE
POPS IN THE FORECAST FOR THIS THING ALTHOUGH MOST OF ACTIVITY WILL
BE NORTH OF THE MISSOURI RIVER. ANOTHER THING TO WORRY ABOUT IS
THE STRONGER NORTHWEST WINDS WRAPPING AROUND THIS SYSTEM. WE WILL
LIKELY NEED A LAKE WIND ADVISORY FOR SUNDAY WHICH MAY REMAIN IN
PLACE THOUGH MONDAY MORNING. ANY WRAP AROUND PRECIPITATIONS WILL
COME TO AN END BEFORE SUNDAY NIGHT. RSMITH

.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...
NOT TOO MANY CHANGES WERE MADE TODAY WITH THE MAJORITY OF THE
CHANGES COMING TO ASSIST WITH INTER-OFFICE COORDINATION. JAMBA

PREVIOUS DISCUSSION...
THE PERIOD BEGINS WITH NE MT STILL IN THE CYCLONIC UPPER
CIRCULATION PATTERN FROM THE WEEKEND SYSTEM. THAT MAY KEEP A FEW
LINGERING SHOWERS INTO MONDAY. ECMWF IS QUITE CHILLY AT THIS TIME
WITH 850 MB TEMPS BELOW 0C IN OUR NE MONDAY MORN. THE OTHER
MODELS NOT THAT COLD. CLEARING SKIES WITH CANADIAN HIGH MOVING IN
ABOUT THIS TIME.

AN UPPER RIDGE THEN BRINGS SUNNY AND WARMER WEATHER FOR TUE/WED.
MOST MODELS HAVE A SHORTWAVE SYSTEM ARRIVING FROM THE W THU/THU
NIGHT. THIS SHOULD GIVE AT LEAST A SLIGHT CHANCE OF SHOWERS FOR A
PERIOD OR TWO. MODELS ARE IN REASONABLE AGREEMENT WITH THIS
SYSTEM. SIMONSEN

&&

.AVIATION...
MOSTLY VFR CONDITIONS ARE EXPECTED THROUGH THE TAF CYCLE. SOME
ISOLATED THUNDERSTORM ACTIVITY SHOULD TAPER OFF AFTER DARK LEAVING
MOSTLY CLEAR SKIES UNTIL EARLY SATURDAY MORNING WHEN MORE SHOWER
ACTIVITY IS EXPECTED. SHOWER ACTIVITY ON SATURDAY COULD BE LOCALLY
HEAVY AT TIMES. WINDS ARE EXPECTED TO TURN TO THE WEST AND NORTH
SATURDAY AFTERNOON AND INCREASE IN STRENGTH TO 20 KTS. AES/WJM

&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

WEATHER.GOV/GLASGOW






AREA FORECAST DISCUSSION

NWS GREAT FALLS MT

 1145 AM MDT THU MAY 3 2012

UPDATED AVIATION

.UPDATE...
NO SIGNIFICANT CHANGES TO THE FORECAST FOR THIS MORNING. HAVE
UPDATED POPS ACROSS CENTRAL MONTANA FOR THE AFTERNOON
HOURS...SLIGHTLY RAISING POPS WHERE THE RUC AND HRRR MODELS HAVE
BOTH EMPHASIZED A BETTER CHANE OF AFTERNOON SHOWERS. OTHERWISE
FORECAST REMAINS ON TRACK. SUK


&&

.AVIATION...
UPDATED 1800Z.
SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP THIS AFTERNOON
AFTER 20Z AS MOIST AND UNSTABLE SOUTHWEST FLOW SPREADS INTO THE
AREA. THESE SHOWERS AND THUNDERSTORMS MAY PRODUCED LOCALIZED MVFR
CONDITIONS IN HEAVIER RAINFALL. GUSTY ERRATIC WINDS AND SMALL HAIL
ARE ALSO POSSIBLE WITH SOME STRONGER STORMS. THIS ACTIVITY WILL
DECREASE AFTER SUNSET. BREEZY SOUTHEAST WINDS THIS AFTERNOON WILL
SHIFT MORE SOUTHWESTERLY AS AN UPPER-LEVEL TROUGH OF LOW PRESSURE
MOVES TOWARDS THE AREA. MLV

&&

.HYDROLOGY...
THE SCATTERED SHOWERS AND THUNDERSTORMS EXPECTED ACROSS THE AREA
THROUGH FRIDAY MAY PRODUCE BRIEF HEAVY RAINFALL AT TIMES...WHICH
MAY CAUSE BRIEF LOCALIZED FLOODING CONCERNS FOR SMALL STREAMS AND
CREEKS. TEMPERATURES ARE NOT EXPECTED TO BECOME UNUSUALLY WARM
FOR THIS TIME OF YEAR...SO RAPID AND SIGNIFICANT MELTING OF
MOUNTAIN SNOWPACK IS UNLIKELY. STEADY SNOWMELT WILL KEEP WATERWAYS
RUNNING HIGH...BUT FLOODING OF MAIN STEM RIVERS IS NOT FORECAST AT
THIS TIME. A LARGER SCALE SYSTEM WILL LIKELY BRING MORE
WIDESPREAD PRECIPITATION TO THE AREA FOR SATURDAY AND
SUNDAY...WHICH MAY CAUSE RIVERS TO RISE FURTHER. WILL THEREFORE
CONTINUE TO MONITOR THE SITUATION FOR THE NEXT SEVERAL DAYS FOR
POTENTIAL HYDROLOGIC HIGHLIGHTS.  COULSTON

&&

.PREV DISCUSSION...
/ISSUED 550 AM MDT THU MAY 3 2012/

TODAY THROUGH SATURDAY...THE UPPER LEVEL TROUGH OF LOW PRESSURE
POSITIONED ALONG THE PACIFIC COAST WILL CONTINUE THE MOIST AND
UNSTABLE SOUTHWESTERLY FLOW ALOFT OVER THE TFX CWA THROUGH
FRIDAY. ONE WEAK SHORTWAVE TROUGH WILL BRING A GOOD CHANCE OF
SHOWERS AND THUNDERSTORMS TO THE AREA ONCE AGAIN FOR LATER THIS
AFTERNOON THROUGH THE EVENING HOURS. THE UPPER LEVEL TROUGH WILL
THEN MOVE INTO THE PACIFIC NORTHWEST ON FRIDAY...AS MOISTURE AND
ENERGY AHEAD OF THE TROUGH COMBINE TO BRING ANOTHER GOOD CHANCE
OF SHOWERS AND THUNDERSTORMS TO THE AREA. THE AIRMASS WILL BE
SLIGHTLY MORE UNSTABLE ACROSS SOUTHWEST MONTANA ON FRIDAY THAN
WHAT IS EXPECTED TODAY...SO THE THREAT FOR SMALL HAIL AND GUSTY
WINDS THERE WILL BE SLIGHTLY GREATER ON FRIDAY.
OVERALL...THOUGH...THE MAIN THREAT FROM THUNDERSTORMS BOTH DAYS
WILL BE BRIEF HEAVY RAINFALL. TEMPERATURES BOTH DAYS WILL BE NEAR
TO SLIGHTLY ABOVE NORMAL AS AN INVERTED SURFACE TROUGH BUILDS
OVER THE AREA...ADVECTING WARMER AIR INTO THE AREA. THE UPPER
LEVEL TROUGH WILL THEN MOVE THROUGH AREA ON SATURDAY...PRODUCING A
BETTER CHANCE OF WIDESPREAD PRECIPITATION. THE INVERTED SURFACE
TROUGH WILL MOVE EAST OF THE AREA AS A COLD FRONT FRIDAY NIGHT
INTO SATURDAY...AND THE COOLER CANADIAN AIRMASS IN ITS WAKE WILL
COOL TEMPERATURES TO BETWEEN 10 AND 15 DEGREES COOLER THAN NORMAL.
THIS COOLER AIR WILL ALSO WEAKEN THE INSTABILITY OVER THE AREA
FOR LESS OF A CHANCE FOR THUNDERSTORMS. THIS SYSTEM WILL ALSO
LOWER SNOW LEVELS DOWN TO BETWEEN 5500 AND 6500 FEET ACROSS THE
AREA...FOR A BETTER CHANCE OF MEASURABLE SNOWFALL IN THE
MOUNTAINS AS WELL. THIS SITUATION WILL CONTINUE TO BE MONITORED
FOR POSSIBLE WINTER WEATHER HIGHLIGHTS...MAINLY FOR THE
MOUNTAINS.  COULSTON

SATURDAY NIGHT THROUGH THURSDAY...MEDIUM RANGE MODELS CONTINUE TO
HAVE QUITE SUBSTANTIAL DIFFERENCES IN THEIR SOLUTIONS FOR
SATURDAY NIGHT AND SUNDAY. AS BEFORE...THE GFS IS SLOWER...DEEPER
AND WETTER WITH THE UPPER LEVEL SYSTEM THAN THE ECMWF. THE MOST
RECENT RUN OF THE GFS HAS SLOWED THE SYSTEM EVEN MORE THAN
EARLIER RUNS AND KEEPS THE INFLUENCE OF THE UPPER TROUGH OVER THE
FORECAST AREA CLEAR INTO TUESDAY. AT THIS TIME I FEEL COMFORTABLE
KEEPING THE EARLY PART OF THE MEDIUM RANGE PERIOD COOL AND WET IN
KEEPING WITH THE GFS. HOWEVER...BELIEVE THIS LATEST RUN IS
KEEPING THE LOW IN THE REGION TOO LONG SO HAVE TRENDED MORE
TOWARD THE ECMWF FOR TUESDAY AND BEYOND WITH AN UPPER LEVEL RIDGE
EXPECTED TO BUILD OVER THE NORTHERN ROCKIES FOR WARMER AND DRIER
CONDITIONS. MPJ

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  61  39  61  37 /  30  40  30  50
CTB  58  34  58  34 /  20  60  20  20
HLN  61  37  60  35 /  40  30  50  50
BZN  62  35  61  33 /  40  30  50  40
WEY  50  28  51  26 /  60  40  40  30
DLN  58  33  58  30 /  50  30  50  50
HVR  65  37  65  37 /  10  60  20  40
LWT  58  35  59  34 /  20  60  40  40

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS









AREA FORECAST DISCUSSION

NWS GREAT FALLS MT

 1045 AM MDT THU MAY 3 2012

.UPDATE...
NO SIGNIFICANT CHANGES TO THE FORECAST FOR THIS MORNING. HAVE
UPDATED POPS ACROSS CENTRAL MONTANA FOR THE AFTERNOON
HOURS...SLIGHTLY RAISING POPS WHERE THE RUC AND HRRR MODELS HAVE
BOTH EMPHASIZED A BETTER CHANE OF AFTERNOON SHOWERS. OTHERWISE
FORECAST REMAINS ON TRACK. SUK


&&

.AVIATION...
UPDATED 1150Z.
VFR CONDITIONS ARE GENERALLY EXPECTED ACROSS THE AREA THROUGH AT
LEAST 12Z FRIDAY...UNLESS OTHERWISE SPECIFIED. A DISTURBANCE IN THE
MOIST AND UNSTABLE SOUTHWEST FLOW ALOFT WILL SPREAD SCATTERED
SHOWERS AND THUNDERSTORMS ACROSS THE AREA FROM THE
SOUTHWEST...BEGINNING AFTER 16Z IN SOUTHWEST MONTANA (KBZN). THESE
SHOWERS AND THUNDERSTORMS MAY PRODUCE LOCALIZED MVFR CONDITIONS IN
HEAVIER RAINFALL. THE SHOWERS/STORMS WILL THEN DECREASE FROM THE
SOUTHWEST AFTER 00Z AS THE DISTURBANCE BEGINS EXITING THE
AREA...WITH MOST ACTIVITY OUT OF THE AREA BY 04Z. A SURFACE TROUGH
WILL ALSO MOVE WEST THROUGH THE AREA AFTER 21Z...CAUSING BREEZY
SOUTHEAST WINDS TO SHIFT MORE SOUTHWESTERLY THROUGH AROUND
06Z...WITH DECREASING WINDS OVERNIGHT.  COULSTON

&&

.HYDROLOGY...
THE SCATTERED SHOWERS AND THUNDERSTORMS EXPECTED ACROSS THE AREA
THROUGH FRIDAY MAY PRODUCE BRIEF HEAVY RAINFALL AT TIMES...WHICH
MAY CAUSE BRIEF LOCALIZED FLOODING CONCERNS FOR SMALL STREAMS AND
CREEKS. TEMPERATURES ARE NOT EXPECTED TO BECOME UNUSUALLY WARM
FOR THIS TIME OF YEAR...SO RAPID AND SIGNIFICANT MELTING OF
MOUNTAIN SNOWPACK IS UNLIKELY. STEADY SNOWMELT WILL KEEP WATERWAYS
RUNNING HIGH...BUT FLOODING OF MAIN STEM RIVERS IS NOT FORECAST AT
THIS TIME. A LARGER SCALE SYSTEM WILL LIKELY BRING MORE
WIDESPREAD PRECIPITATION TO THE AREA FOR SATURDAY AND
SUNDAY...WHICH MAY CAUSE RIVERS TO RISE FURTHER. WILL THEREFORE
CONTINUE TO MONITOR THE SITUATION FOR THE NEXT SEVERAL DAYS FOR
POTENTIAL HYDROLOGIC HIGHLIGHTS.  COULSTON

&&

.PREV DISCUSSION...
/ISSUED 550 AM MDT THU MAY 3 2012/

TODAY THROUGH SATURDAY...THE UPPER LEVEL TROUGH OF LOW PRESSURE
POSITIONED ALONG THE PACIFIC COAST WILL CONTINUE THE MOIST AND
UNSTABLE SOUTHWESTERLY FLOW ALOFT OVER THE TFX CWA THROUGH
FRIDAY. ONE WEAK SHORTWAVE TROUGH WILL BRING A GOOD CHANCE OF
SHOWERS AND THUNDERSTORMS TO THE AREA ONCE AGAIN FOR LATER THIS
AFTERNOON THROUGH THE EVENING HOURS. THE UPPER LEVEL TROUGH WILL
THEN MOVE INTO THE PACIFIC NORTHWEST ON FRIDAY...AS MOISTURE AND
ENERGY AHEAD OF THE TROUGH COMBINE TO BRING ANOTHER GOOD CHANCE
OF SHOWERS AND THUNDERSTORMS TO THE AREA. THE AIRMASS WILL BE
SLIGHTLY MORE UNSTABLE ACROSS SOUTHWEST MONTANA ON FRIDAY THAN
WHAT IS EXPECTED TODAY...SO THE THREAT FOR SMALL HAIL AND GUSTY
WINDS THERE WILL BE SLIGHTLY GREATER ON FRIDAY.
OVERALL...THOUGH...THE MAIN THREAT FROM THUNDERSTORMS BOTH DAYS
WILL BE BRIEF HEAVY RAINFALL. TEMPERATURES BOTH DAYS WILL BE NEAR
TO SLIGHTLY ABOVE NORMAL AS AN INVERTED SURFACE TROUGH BUILDS
OVER THE AREA...ADVECTING WARMER AIR INTO THE AREA. THE UPPER
LEVEL TROUGH WILL THEN MOVE THROUGH AREA ON SATURDAY...PRODUCING A
BETTER CHANCE OF WIDESPREAD PRECIPITATION. THE INVERTED SURFACE
TROUGH WILL MOVE EAST OF THE AREA AS A COLD FRONT FRIDAY NIGHT
INTO SATURDAY...AND THE COOLER CANADIAN AIRMASS IN ITS WAKE WILL
COOL TEMPERATURES TO BETWEEN 10 AND 15 DEGREES COOLER THAN NORMAL.
THIS COOLER AIR WILL ALSO WEAKEN THE INSTABILITY OVER THE AREA
FOR LESS OF A CHANCE FOR THUNDERSTORMS. THIS SYSTEM WILL ALSO
LOWER SNOW LEVELS DOWN TO BETWEEN 5500 AND 6500 FEET ACROSS THE
AREA...FOR A BETTER CHANCE OF MEASURABLE SNOWFALL IN THE
MOUNTAINS AS WELL. THIS SITUATION WILL CONTINUE TO BE MONITORED
FOR POSSIBLE WINTER WEATHER HIGHLIGHTS...MAINLY FOR THE
MOUNTAINS.  COULSTON

SATURDAY NIGHT THROUGH THURSDAY...MEDIUM RANGE MODELS CONTINUE TO
HAVE QUITE SUBSTANTIAL DIFFERENCES IN THEIR SOLUTIONS FOR
SATURDAY NIGHT AND SUNDAY. AS BEFORE...THE GFS IS SLOWER...DEEPER
AND WETTER WITH THE UPPER LEVEL SYSTEM THAN THE ECMWF. THE MOST
RECENT RUN OF THE GFS HAS SLOWED THE SYSTEM EVEN MORE THAN
EARLIER RUNS AND KEEPS THE INFLUENCE OF THE UPPER TROUGH OVER THE
FORECAST AREA CLEAR INTO TUESDAY. AT THIS TIME I FEEL COMFORTABLE
KEEPING THE EARLY PART OF THE MEDIUM RANGE PERIOD COOL AND WET IN
KEEPING WITH THE GFS. HOWEVER...BELIEVE THIS LATEST RUN IS
KEEPING THE LOW IN THE REGION TOO LONG SO HAVE TRENDED MORE
TOWARD THE ECMWF FOR TUESDAY AND BEYOND WITH AN UPPER LEVEL RIDGE
EXPECTED TO BUILD OVER THE NORTHERN ROCKIES FOR WARMER AND DRIER
CONDITIONS. MPJ

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  61  39  61  37 /  30  40  30  50
CTB  58  34  58  34 /  20  60  20  20
HLN  61  37  60  35 /  40  30  50  50
BZN  62  35  61  33 /  40  30  50  40
WEY  50  28  51  26 /  60  40  40  30
DLN  58  33  58  30 /  50  30  50  50
HVR  65  37  65  37 /  10  60  20  40
LWT  58  35  59  34 /  20  60  40  40

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...SUK
LONG TERM...MPJ
AVIATION...MPJ

WEATHER.GOV/GREATFALLS






AREA FORECAST DISCUSSION

NWS BILLINGS MT

 924 AM MDT THU MAY 3 2012

.SHORT TERM...VALID FOR TDY AND FRI...

WEAK SHORTWAVE MOVING THROUGH THE AREA NOW DID PRODUCE SOME LIGHT
PCPN OVER THE MOUNTAINS BUT NOTHING MORE THAN SOME MID CLOUD
ACROSS LOWER ELEVATIONS. THIS AREA OF MID CLOUD IS SPREADING TO
SOUTHEAST MONTANA NOW AND WILL EXIT OVER THE COMING HOURS...
ALLOWING FOR INCREASED SUNSHINE IN ITS WAKE. NEXT APPROACHING
SHORTWAVE ALONG THE PAC NW COAST IS SOMEWHAT STRONGER AND FORCING
FROM THIS FEATURE WILL INCREASE THIS AFTERNOON. IT APPEARS THAT
JET DIVERGENCE WILL BE GREATEST IN OUR NW SO HIGHEST POPS THERE
LOOK GOOD THIS AFTERNOON. ONSET OF LOW LEVEL EAST THEN SOUTHEAST
FLOW WILL RESULT IN VERY MODEST MOISTURE RETURN AS THE DAY WEARS
ON. EVEN WITH THIS...CAPE VALUES WILL REMAIN MEAGER AT 100-200
JOULES OR LESS...SO NOT SEEING MUCH LIGHTNING POTENTIAL TODAY.
LATEST NAM AND HRRR DO SHOW SOME WEAK CONVECTION IN OUR FAR
SOUTHEAST BY THIS EVENING...IN LINE WITH THE INCREASED MOISTURE
AND WEAK SFC TROF...SO SCATTERED POPS EXTENDING ACROSS OUR
SOUTHEAST THIS EVENING ALSO LOOK GOOD. SHOWER CHANCES WILL
DIMINISH LATE TONIGHT AS WAVE PASSES. TEMPS TODAY WILL TURN A FEW
DEGREES WARMER THAN YESTERDAY WITH SOME PREFRONTAL HEATING AHEAD
OF THIS EVENINGS WAVE. LOOKING FOR HIGHS INTO THE 60S TO NEAR 70.

JKL

.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...

EXTENDED MODELS LOOK TO BE IN GOOD AGREEMENT OVERALL THROUGH THE
FIRST PORTION OF THE EXTENDED PERIOD. BOTH THE GFS AND ECMWF
SWING AN UPPER LEVEL TROUGH ACROSS MONTANA ON SATURDAY WITH THE
UPPER LOW MOVING ACROSS THE NORTHERN PORTIONS OF THE STATE. AT
THE SAME TIME...A SURFACE LOW ACROSS EASTERN COLORADO WILL EXTEND
NORTHWARD INTO WESTERN NORTH DAKOTA. THE NORTHERN PORTION OF THIS
AREA OF LOW PRESSURE WILL CUT OFF AND STRENGTHEN OVER SOUTHERN
CANADA WHILE THE UPPER LOW CUTS OFF AND DEEPENS OVER THE SAME AREA.
THIS ALL RESULTS IN AN OVERALL COOL AND SHOWERY WEEKEND. PRESSURE
GRADIENTS WILL BE TIGHT ACROSS THE EASTERN HALF OF THE STATE SO
EXPECT GUSTY NORTHWEST WINDS SATURDAY AND SUNDAY AS WELL. THE
STRONGEST WIND GUSTS WILL BE EAST OF BILLINGS...ESPECIALLY TOWARD
THE DAKOTA BORDER. BEST CHANCES FOR SHOWERS WILL BE THE FAVORED
AREAS WITH NORTHWEST SURFACE WINDS...MAINLY FROM BILLINGS
EASTWARD. TEMPERATURES WILL BE AT OR SLIGHTLY BELOW NORMAL FOR THE
WEEKEND...AND GIVEN COOL TEMPERATURES...NOT EXPECTING MUCH IN THE
WAY OF THUNDERSTORM ACTIVITY AT THIS TIME.

NORTHWEST FLOW ALOFT CONTINUES MONDAY WITH LINGERING SHOWER
CHANCES...ALTHOUGH LESS CHANCES THAN SATURDAY AND SUNDAY. BOTH
THE GFS AND ECMWF SHOW HIGH PRESSURE RIDGING RETURNING TOWARD THE
MIDDLE TO END OF NEXT WEEK RESULTING IN WARMER AND DRIER
CONDITIONS. HOWEVER...TIMING IS OFF WITH MODELS AS TO HOW QUICKLY
THIS RIDGE BUILDS OVER OUR FORECAST AREA. HOOLEY

&&

.AVIATION...

EXPECT PARTLY TO MOSTLY CLOUDY SKIES TODAY. A FEW SHOWERS WILL BE
POSSIBLE OVER THE MOUNTAINS THIS MORNING BUT THE LOWER ELEVATIONS
ARE EXPECTED TO BE DRY. HOWEVER...SHOWER AND ISOLATED
THUNDERSTORM CHANCES INCREASE THIS AFTERNOON FROM KBIL WESTWARD
WITH THE BEST CHANCES OVER THE MOUNTAIN LOCATIONS. VFR CONDITIONS
WILL PREVAIL TODAY WITH MVFR CONDITIONS IN ANY SHOWER ACTIVITY.
THE MOUNTAINS WILL BE OBSCURED AT TIMES THROUGHOUT THE DAY.
HOOLEY

&&

.PRELIMINARY POINT TEMP/POPS...

    TDY FRI     SAT     SUN     MON     TUE     WED
-------------------------------------------------------
BIL 066 044/069 045/063 042/059 040/058 038/062 039/067
    2/W 33/T    34/T    33/W    23/W    22/W    21/B
LVM 063 039/063 036/059 034/055 032/054 030/059 031/064
    4/T 34/T    44/T    33/W    34/W    22/W    21/B
HDN 069 043/073 044/065 042/062 041/060 038/064 039/068
    1/B 33/T    34/T    33/W    23/W    22/W    21/B
MLS 070 047/073 046/065 042/061 040/060 040/065 040/068
    1/B 43/T    34/T    43/W    23/W    22/W    11/B
4BQ 069 045/072 044/065 042/061 039/059 037/063 040/066
    1/B 33/T    44/T    43/W    13/W    22/W    11/B
BHK 067 047/072 046/065 042/060 040/058 040/062 040/066
    0/B 42/T    34/T    43/W    22/W    22/W    11/B
SHR 067 041/070 041/062 037/058 037/055 033/058 036/063
    1/B 33/T    24/T    42/W    24/W    22/W    21/B

&&

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.

&&

$$
WEATHER.GOV/BILLINGS







AREA FORECAST DISCUSSION...UPDATED

NWS NORTH PLATTE NE

 618 PM CDT FRI MAY 4 2012

.UPDATE...

.AVIATION...
VFR IS EXPECTED MOST AREAS THROUGH 06Z. MVFR/IFR/LIFR COULD BECOME
WIDESPREAD BETWEEN 09Z AND 15Z. VFR IS EXPECTED MOST AREAS THEREAFTER.

ISOLATED SEVERE STORMS SHOULD DISSIPATE BETWEEN 03Z AND 04Z
TONIGHT. NEW STORM DEVELOPMENT IS EXPECTED SATURDAY AFTERNOON FROM
AROUND 20Z ONWARD.

THE RUC IS AGAIN FCSTING STRATUS AND VERY LOW CIGS TONIGHT.
BURNOFF SHOULD BE BETWEEN 15Z AND 16Z SATURDAY. VFR IS EXPECTED
THEREAFTER.

&&

.PREV DISCUSSION... /ISSUED 325 PM CDT FRI MAY 4 2012/

SYNOPSIS...

FOR THE MOST PART...THE H5 PATTERN IS SIMILAR TO YESTERDAYS AT THIS
TIME. A BROAD TROUGH OF LOW PRESSURE EXTENDED ACROSS THE ALASKA
PANHANDLE SSEWD TO THE NRN CA COAST. LOW AMPLITUDE RIDGING WAS
PRESENT ACROSS CENTRAL CANADA...WHILE THE WRN HALF OF THE CONUS WAS
UNDER THE INFLUENCE OF WEST SOUTHWESTERLY FLOW WITH SEVERAL WEAK
DISTURBANCES NOTED ACROSS THE SWRN CONUS. AT THE SURFACE...LOW
PRESSURE WAS NOTED OVER NRN COLORADO. A DRY LINE WAS NOTED FROM WEST
OF OGALLALA TO THE EASTERN OK PANHANDLE. A WARM FRONT EXTENDED
ACROSS SWRN AND SRN NEBRASKA WITH AN OUTFLOW BOUNDARY NOTED ACROSS
NRN NEBRASKA. TEMPERATURES AS OF 2 PM CDT RANGED FROM 67 AT KVTN AND
KANW...TO 85 AT KLBF.

DISCUSSION...

NEAR TERM...TONIGHT THROUGH MONDAY...MAIN FORECASTING CHALLENGES ARE
PRECIPITATION CHANCES AND SEVERE POTENTIAL FOR TONIGHT THROUGH
SUNDAY. THE FORECAST FOCUS SHIFTS TO TEMPERATURES MONDAY...IN
PARTICULAR...MONDAY MORNING WITH THE THREAT FOR LOWS POSSIBLY IN THE
30S.

FOR TONIGHT...THUNDERSTORMS THIS EVENING...FOLLOWED BY FOG POTENTIAL
ARE THE MAIN FORECASTING CONCERNS OVER THE NEXT 12 HRS.

THUNDERSTORMS...APART FROM WHAT IS ONGOING IN THE NERN ZONES...ARE
EXPECTED TO INITIATE ACROSS PORTIONS OF WEST CENTRAL NEBRASKA OVER
THE NEXT 1 TO 3 HRS AS A DRYLINE BULGE WORKS INTO THE WESTERN SAND
HILLS. ANY STORMS WHICH DO DEVELOP HAVE THE POTENTIAL TO BE SEVERE.
VERY STEEP MID LEVEL LAPSE RATES AND BULK SHEAR OF 45 TO 55 KTS WILL
BE CONDUCIVE FOR VERY LARGE HAIL...ESPECIALLY ALONG AND NORTH OF
HIGHWAY 2 AND 91 FROM HYANNIS TO ERICSON. CONVECTION IS EXPECTED TO
SHIFT EAST OF THE AREA BY 06Z TONIGHT. ATTM...THE THREAT FOR
REDEVELOPMENT OVERNIGHT APPEARS MINIMAL GIVEN THE ABSENCE OF A LOW
LEVEL JET OVERNIGHT.

FOG IS EXPECTED TO DEVELOP OVERNIGHT AS A WARM FRONTAL BOUNDARY IS
FORCED SOUTH INTO SRN NEBRASKA CONVECTION ACROSS NRN NEBRASKA. ERLY
UPSLOPE WINDS WILL TRANSPORT BOUNDARY LAYER MOISTURE INTO WRN AND
NORTH CENTRAL NEBRASKA OVERNIGHT FROM ERN NEBRASKA ALONG AND NORTH
OF THE WARM FRONT. WITH COOLING TEMPERATURES OVERNIGHT AND LIGHT
WINDS...A STRONG SETUP FOR FOG EXISTS AND HAVE PLACED IT IN THE
ENTIRE FORECAST FROM 09Z THROUGH 15Z SATURDAY.

ON SATURDAY MORNING...A FRONTAL BOUNDARY WILL BE ANCHORED ACROSS SRN
NEBRASKA. WITH SURFACE HEATING AND DEEPENING LOW PRESSURE OVER WRN
KS...THIS FEATURE WILL TRACK NORTH AS A WARM FRONT ON SATURDAY.
ATTM...THE MODELS BEGIN SATURDAY WITH THIS FEATURE SOUTH OF
INTERSTATE 80. A WORD OF CAUTION HERE. IF CONVECTION TONIGHT IS
STRONGER THAN WHAT THE MODELS DEPICT...THIS FRONT WOULD BE ACROSS
NRN KS...WHICH WOULD INCREASE THE SVR THREAT FURTHER SOUTH. AS IT
STANDS RIGHT NOW...THE FRONTAL BOUNDARY WILL LIFT INTO CENTRAL AND
EASTERN SANDHILLS BY SATURDAY AFTERNOON. THIS WOULD FACILITATE THE
GREATEST SVR THREAT ACROSS THE CENTRAL AND NORTHERN FORECAST
AREA...OR ALONG AND NORTH OF INTERSTATE 80. LIKE TODAY...THE
GREATEST SEVERE THREAT WILL BE FROM LARGE DAMAGING HAIL GIVEN THE
VERY STEEP MID LEVEL LAPSE RATES...3000-4000 CAPES...AND EFFECTIVE
BULK SHEAR OF 45 TO 55 KTS. COVERAGE WILL INCREASE SATURDAY EVENING
AS A POWERFUL COLD FRONT TRACKS ACROSS WESTERN AND NORTH CENTRAL
NEBRASKA THROUGH SUNDAY MORNING. ATTM...THE BEST CHANCES FOR
MEASURABLE PRECIPITATION WILL BE ACROSS NRN NEBRASKA WHERE JET
DYNAMICS ARE MOST FAVORABLE. FURTHER SOUTH...PRECIPITATION WILL BE
CONFINED TO THE FROPA WHICH WILL BE BRIEF IN COMPARISON TO WHAT IS
EXPECTED OVER NRN NEBRASKA. ONE FINAL NOTE ON WINDS ALONG AND BEHIND
THE FROPA. FOR THE FIRST 72 HRS OF THE FORECAST...WE UTILIZED THE
GFS SOLN AS THE NAM FRONTAL TIMING APPEARED WAY TOO FAST. THE NAM
PUSHED THE FRONTAL BOUNDARY THROUGH THE ENTIRE FORECAST AREA BY
SATURDAY EVENING. THIS APPEARED WAY TOO FAST AS THE FRONT WOULD BE
PUSHING INTO UPPER 80S AND LWR 90S TEMPERATURES EXPECTED ACROSS
CENTRAL AND SWRN NEBRASKA SAT AFTN. THE GFS WAS MUCH
SLOWER...PUSHING THE FRONT THROUGH THE CWA BY SUNDAY MORNING WHICH
SEEMED MUCH MORE PLAUSIBLE.

SHOWERS WILL LINGER SUNDAY MORNING IN EASTERN AREAS AS THE FRONT
CLEARS THE FORECAST AREA. MUCH COOLER TEMPERATURES AND DRIER AIR
WILL PUSH INTO WRN AND NORTH CENTRAL NEBRASKA. HIGHS SUNDAY WILL BE
IN THE 60S WITH DRY CONDS EXPECTED SUNDAY AND SUNDAY NIGHT.

EARLY MONDAY...TEMPERATURE TRENDS WILL NEED TO BE MONITORED CLOSELY
AS THE MET GUIDANCE HAS WIDESPREAD 30S ACROSS THE FORECAST AREA.
THIS SEEMS PLAUSIBLE WITH COOL HIGH PRESSURE BUILDING INTO THE
CENTRAL AND NRN ROCKIES AND THE DEVELOPMENT OF LIGHT WESTERLY WINDS
THROUGH MONDAY MORNING. THERE ARE STILL SOME SIGNIFICANT DIFFERENCES
BETWEEN THE NAM AND GFS WITH RESPECT TO WIND SPEEDS...SURFACE DEW
POINTS...AND ULTIMATELY LOW TEMPS. LOWS WERE TRENDED DOWNWARD SOME
FOR MONDAY MORNING...BUT NOT AS FAR AS THE MET GUIDANCE WOULD
SUGGEST.

LONG TERM...MONDAY THROUGH FRIDAY...A BENIGN WEATHER PATTERN WILL
SET UP NEXT WEEK AS A CLOSED LOW TRACKS FROM THE GREAT LAKES INTO
ERN CANADA. THIS WILL PLACE THE FORECAST AREA IN DRY NWRLY
FLOW...TRANSITIONING TO RIDGING ACROSS THE CENTRAL CONUS THROUGH THE
END OF THE WEEK. THE NEXT MINIMAL PRECIPITATION CHANCE WILL ARRIVE
ON THURSDAY NIGHT INTO FRIDAY AS THE RIDGE BREAKS DOWN AND SWRLY
FLOW TRANSITIONS EAST ACROSS THE CENTRAL PLAINS.

AVIATION...

SHOWERS AND ISOLATED THUNDERSTORMS WILL CONTINUE INTO
THE EVENING HOURS ACROSS FAR NORTH CENTRAL NEBRASKA WITH THE
POTENTIAL OF GUSTY ERRATIC WIND...FREQUENT LIGHTNING AND LARGE
HAIL.  THUNDERSTORM COVERAGE IS EXPECTED TO BE HIGHEST EAST AND
NORTH OF A KANW TO KONL LINE.  FURTHER SOUTH AND WEST...CONFIDENCE
IN CONVECTION IS SLIGHT...BUT WILL GO AHEAD AN PUT PREVAILING
MENTION OF -TSRA AFTER 01Z TONIGHT FOR VTN AS ALL THE MODEL GUIDANCE
POINTS TO THE ADDITIONAL DEVELOPMENT.  THEREAFTER...SREF PROBS
INDICATE THE POTENTIAL FOR FOG AFTER 09Z TOMORROW AT BOTH THE VTN
AND LBF TERMINAL.  TO ACCOUNT FOR THIS...WILL LOWER PREVAILING
CEILINGS TO 100 FT AND VISIBILITY TO 2SM.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&

$$

SHORT TERM/EXTENDED...CDC
AVIATION...CDC






AREA FORECAST DISCUSSION

NWS OMAHA/VALLEY NE

 124 PM CDT THU MAY 3 2012

.UPDATE...

EARLY AFTERNOON UPDATE TO REDUCE POPS A BIT THIS AFTERNOON.

&&

.DISCUSSION...

COMPLEXITY OF AFTERNOON/THIS EVENING CONVECTIVE FORECAST REMAINS
HIGH WITH SEVERAL WEAK BOUNDARIES EXTENDING ACROSS THE REGION. A
FEW BOUNDARIES STICK OUT...THE FIRST OF WHICH IS THE MAIN
SYNOPTIC BOUNDARY EXTENDING FM LOW PRESURE OVER SOUTH CENTRAL
KANSAS TOWARD KOFK...KLCG AND JUST NORTH OF KSUX. SOUTH OF
THIS...VERY MOIST AIRMASS REMAINS IN PLACE ALLOWING FOR AN
UNSTABLE AIRMASS WITH SFC TEMPS INTO THE MID TO UPPER 70S. HAVE
HAD TO ADJUST SKY GRIDS THIS AFTERNOON FOR EXPANDING STRATUS DECK
OVER OUR FAR SOUTHWESTERN COUNTIES BUT DO EXPECT THIS TO SCATTER
OUT AS WAS THE CASE YESTERDAY WITH INCREASED AFTERNOON HEATING.
SECOND BOUNDARY TO MENTION IS LEFT OVER OUTFLOW BOUNDARY ACROSS
ERN KS/WRN MO WHICH SHOULD PUSH NORTH. MILLION DOLLAR
QUESTION...LIKE YESTERDAY...IS WHETHER OR NOT IF/WHEN ANY
CONVECTION WILL BE ABLE TO FORM ALONG THE OUTFLOW BOUNDARY AS
SHORT TERM MODELS CONTINUE TO INDICATE...LIKE WAS THE CASE YESTERDAY.
WEAK UPPER LEVEL SUPPORT IS FORECAST TO PROGRESS INTO SOUTHEAST
NEB AROUND 00Z AND COULD BE THE FOCUS TIME FOR CONVECTIVE
INITIATION ACROSS SOUTHEAST NEB. AGAIN...FORECAST CONFIDENCE IS
LOW REGARDING THE LATE AFTERNOON/EVENING CONVECTION.

&&

.AVIATION...18Z TAFS FOR KOFK...KOMA AND KLNK.

VFR TO MVFR CONDITIONS WILL CONTINUE THRU THE TAF PERIOD WITH
TSTMS MOST PROBABLE THIS EVENING AT KLNK AND KOMA. SFC WINDS WILL
REMAIN LIGHT WITH SEVERAL LITTLE BOUNDARIES OVER THE AREA.


&&

.PREV DISCUSSION... /ISSUED 405 AM CDT THU MAY 3 2012/

DISCUSSION...

STRENGTH AND COVERAGE OF CONVECTION SHOULD BE THE PRIMARY FORECAST
CONCERNS THE NEXT FEW DAYS.

UPPER AIR CHARTS FROM LAST EVENING SHOWED THE FOLLOWING. A 300 MB
JET MAX OF AROUND 110 KNOTS EXTENDED FROM NORTH DAKOTA INTO NORTHERN
MINNESOTA AND THEN INTO ONTARIO CANADA. A STRONGER JET CORE OF
AROUND 140 KNOTS WAS PUNCHING TOWARD THE CALIFORNIA COAST. AT 500 MB
SOUTHWESTERLY FLOW WAS IN PLACE FROM THE ROCKIES INTO THE NORTHERN
AND CENTRAL PLAINS. SEVERAL WEAK DISTURBANCES WERE NOTED IN THE FLOW.
PLENTY OF LOW LEVEL MOISTURE WAS IN PLACE FROM THE GULF COAST
NORTHWARD INTO IOWA AND EASTERN NEBRASKA...WITH 850 MB DEWPOINTS
AS HIGH AS THE MID TEENS CELSIUS AT KTOP AND KOAX. SURFACE
ANALYSIS EARLY THIS MORNING WAS SOMEWHAT COMPLEX DUE TO OUTFLOW
BOUNDARIES BUT LOW PRESSURE CENTERS WERE NOTED OVER EASTERN SOUTH
DAKOTA AND WESTERN KANSAS. A DRYLINE EXTENDED SOUTH FROM THE
KANSAS LOW AND A WEAKLY ORGANIZED STATIONARY FRONT APPEARED TO
STRETCH FROM NORTHEAST NEW MEXICO INTO NORTHERN WISCONSIN. SURFACE
DEWPOINTS WERE MOSTLY IN THE 60S SOUTH/EAST OF THE FRONT AND EAST
OF THE DRYLINE.

ONGOING CONVECTIVE COMPLEX WILL LIKELY LINGER INTO MID MORNING FOR
PARTS OF THE AREA...AS SUPPORTED BY RECENT RUNS OF THE HRRR MODEL.
LATER TODAY...HAVE A DRY PERIOD GOING FOR A WHILE...THEN INCREASED
THUNDERSTORM CHANCES FOR THE MID AND LATE AFTERNOON...SIMILAR TO
THE PREVIOUS FORECAST. SOUTHWEST MID LEVEL FLOW WILL BE IN PLACE
AND IT APPEARS SURFACE BOUNDARY MAY PROVIDE SOME FOCUS AS THE
ATMOSPHERE DESTABILIZES THIS AFTERNOON. 00Z GFS RUN FROM LAST
EVENING SHOWED SURFACE BASED CAPES REACHING OVER 3000 J/KG OVER
SOUTHEAST NEBRASKA AND SOUTHWEST IOWA. INTERESTINGLY THOUGH THE
4 KM WRF RUN FROM 00Z DID NOT DEVELOP MUCH OVER OUR AREA THIS
AFTERNOON OR EVENING. THAT MODEL (4 KM WRF-NMM RUN FOR SPC) DID A
DECENT JOB THE PAST TWO NIGHTS. SO CONFIDENCE IN CONVECTION LATER
TODAY IS NOT OVERLY HIGH. DID GO WITH LOWER THUNDERSTORM CHANCES BY
LATE EVENING AND CONFINED CHANCES TO JUST THE FAR SOUTHEAST PART
OF THE FORECAST AREA AFTER MIDNIGHT TONIGHT.

THE NEXT MAIN THUNDERSTORM CHANCE WILL START FRIDAY AFTERNOON...BUT
SHOULD INCREASE DRAMATICALLY FRIDAY NIGHT FOR AT LEAST THE NORTHERN
2/3 OF THE AREA. KEPT LOW CHANCES GOING SATURDAY...BUT THINK STORM
CHANCES ARE HIGH SATURDAY EVENING INTO SATURDAY NIGHT. KEPT POPS AT
40-60 PERCENT AS A COLD FRONT PUSHES THROUGH. GENERALLY WENT WITH
FRONTAL TIMING DEPICTED BY THE GFS. GENERALLY LOWERED THUNDERSTORM
CHANCES AFTER TUESDAY AS LARGE SCALE PATTERN CHANGES SOMEWHAT.

MILLER

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&

$$




AREA FORECAST DISCUSSION

NWS HASTINGS NE

 1226 AM CDT THU MAY 3 2012

.AVIATION...06Z KGRI TAF. THUNDERSTORM CHANCES REMAIN A CONCERN
FOR THE TAF PERIOD THROUGH THE NEXT FEW HOURS. THUNDERSTORMS HAVE
BEEN DEVELOPING ALONG AND NORTH OF AN OUTFLOW BOUNDARY. THESE
STORMS HAVE BEEN CAPABLE OF PRODUCING HAIL UP TO 2 INCHES IN
DIAMETER. WHILE SOUTH SOUTHEAST WINDS ARE EXPECTED DURING THE
OVERNIGHT HOURS...ANY THUNDERSTORMS THAT DEVELOP COULD PROVIDE THE
POTENTIAL FOR STRONG GUSTS OVER THE TAF SITE. BY THE EARLY MORNING
HOURS...WINDS WILL BECOME LIGHT AND VARIABLE.

&&

PREV DISCUSSION... /ISSUED 345 PM CDT WED MAY 2 2012/

SHORT TERM...THROUGH 00Z FRIDAY. MORNING UPPER AIR ANALYSIS INDICATES
QUASI-ZONAL MID AND UPPER LEVEL FLOW ACROSS MUCH OF THE CENTRAL
CONUS...WITH A MID LEVEL SHORTWAVE TROUGH NOTED OVER THE
NORTHWESTERN CONUS. MID AND UPPER LEVEL JET ENERGY REMAINS
RELEGATED TO THE WEST/NORTHWESTERN CONUS...WITH TROPOSPHERIC FLOW
REMAINING FAIRLY LIGHT OVER OUR AREA. WATER VAPOR IMAGERY
INDICATES A PLUME OF MID LEVEL MOISTURE ADVANCING FROM THE PACIFIC
INTO THE SOUTHWESTERN CONUS...ONWARD INTO THE MIDDLE ROCKY
MOUNTAIN RANGE AS WELL AS PORTIONS OF THE CENTRAL AND NORTHERN
PLAINS. EARLY AFTERNOON SURFACE ANALYSIS SHOWS AN AREA OF LOW
PRESSURE OVER SOUTHWESTERN KANSAS...WITH A WARM FRONT EXTENDING
NORTHEASTWARD FROM THE LOW INTO PORTIONS OF NORTH CENTRAL KANSAS
AS WELL AS PORTIONS OF SOUTH CENTRAL AND SOUTHEAST NEBRASKA. AS OF
18Z THIS WARM FRONT WAS NOTED EXTENDING FROM NEAR KHYS...TO NEAR
KK82...TO NEAR KJYR AND KOLU. EARLY AFTERNOON TEMPERATURES ARE
GENERALLY IN THE UPPER 70S AND LOWER 80S ACROSS THE CWA...WITH DEW
POINTS RANGING FROM THE MID 40S AT KLXN...TO THE UPPER 50S THROUGH
THE TRI-CITIES...TO THE MID AND UPPER 60S ACROSS OUR SOUTHEAST
WHERE THE SURFACE WARM FRONT HAS ALREADY CLEARED. EARLY AFTERNOON
VISIBLE SATELLITE IMAGERY SHOWS MOSTLY CLEAR SKIES ACROSS OUR
NORTHWESTERN CWA...WITH THE INCREASED LOW LEVEL MOISTURE VALUES
HELPING PROMOTE INCREASED INSTABILITY AND A RESULTANT EXPANSIVE CU
FIELD.

FOR THE REST OF THIS AFTERNOON AND EARLY THIS EVENING...CONFIDENCE
IS LOW REGARDING CONVECTIVE DEVELOPMENT ACROSS OUR AREA AS FORECAST
PROXIMITY SOUNDINGS FROM THE NAM AND OPERATIONAL GFS SUGGEST
CONVECTIVE INHIBITION SHOULD HOLD FOR THE MOST PART. THAT BEING
SAID...FORECAST PROXIMITY SOUNDINGS FROM THE NAM DO SUGGEST CIN WILL
DECREASE TO ALMOST NOTHING ACROSS OUR EXTREME SOUTHEAST BY 00Z THIS
EVENING...AND WITH THE LOW LEVEL BAROCLINIC ZONE MEANDERING ACROSS
THE AREA THUS PROMOTING LOW LEVEL CONVERGENCE AND RESULTANT
FORCING...FELT IT PRUDENT TO GO WITH A SLIGHT CHANCE POP ACROSS THE
ENTIRE CWA LATE THIS AFTERNOON THROUGH THIS EVENING. THE NAM AND
OPERATIONAL GFS SUGGEST 0-1KM MLCAPE VALUES OF 2000-3500J/KG WILL BE
OBSERVED ACROSS OUR CWA LATE THIS AFTERNOON AND EVENING...WITH THE
GREATEST INSTABILITY LOCATED ACROSS OUR SOUTHEAST WITHIN THE LOW
LEVEL MOISTURE PLUME. WITH MID AND UPPER LEVEL JET ENERGY REMAINING
RELEGATED TO THE WEST/NORTHWEST OF OUR AREA...DEEP LAYER BULK SHEAR IS
NOT OVERLY IMPRESSIVE...BUT GUIDANCE DOES SUGGEST DEEP LAYER BULK
SHEAR VALUES NEAR 30KTS WILL STILL BE POSSIBLE THUS PRESENTING THE
POSSIBILITY FOR ROTATING UPDRAFTS. ALL THAT BEING SAID...SHOULD
CONVECTIVE INITIATION BE REALIZED LATE THIS AFTERNOON OR EARLY THIS
EVENING...SEVERE WEATHER WILL MOST LIKELY BE OBSERVED WITH LARGE
HAIL BEING THE PRIMARY THREAT...AND ISOLATED THUNDERSTORM WIND GUSTS
ALSO POSSIBLE ALONG OUTFLOW. FINALLY...0-1KM SRH IS NOT OVERLY
IMPRESSIVE...WITH THE NAM AND OPERATIONAL GFS SUGGESTING VALUES
SOMEWHERE AROUND 100 M^2/S^2 ACROSS OUR AREA AT 00Z...BUT WITH
LOCALLY ENHANCED LOW LEVEL HORIZONTAL VORTICITY EXISTING IN THE
VICINITY OF LOW LEVEL BAROCLINIC ZONE...ISOLATED TORNADOES ALSO
CANNOT BE RULED OUT.

ATTENTION THEN TURNS TO THE SEVERE POTENTIAL OVERNIGHT TONIGHT. THE
NAM...OPERATIONAL GFS...EC...SREF-MEAN AND HRRR ALL SUGGEST
AFTERNOON AND EVENING HIGH PLAINS CONVECTION WILL MORPH INTO A MCS
AND PUSH EAST INTO PORTIONS OF SOUTH CENTRAL NEBRASKA AND NORTH
CENTRAL KANSAS. AS THE MCS PUSHES EAST IT SHOULD BEGIN INTERACTING
WITH A 40-50KT LOW LEVEL JET WHICH SHOULD HELP SUSTAIN THE MCS IF
NOT HELP IT INTENSIFY THROUGH INCREASED LOW LEVEL MOISTURE FLUX.
GIVEN ALL THIS...A WIDESPREAD SEVERE STRAIGHT LINE WIND EVENT
SOMEWHERE ACROSS OUR CWA IS APPEARING MORE AND MORE LIKELY OVERNIGHT
TONIGHT. AS IS USUALLY THE CASE...EXACT DETAILS REGARDING PLACEMENT AND
TRACK OF THIS MCS WILL NOT LIKELY BE KNOWN UNTIL LATER THIS
EVENING...BUT GIVEN THE LATEST DATA WILL GO AHEAD AND HIGHLIGHT MOST
ALL OF THE CWA FOR SEVERE OVERNIGHT TONIGHT...WITH STRAIGHT LINE
WINDS BEING THE PRIMARY SEVERE WEATHER THREAT. ONE ADDITIONAL
NOTE...THE AFOREMENTIONED MID LEVEL MOISTURE PLUME NOTED ON WATER
VAPOR IMAGERY SHOULD PUSH OVERHEAD TONIGHT THUS HELPING TO INCREASE
PRECIPITABLE WATER VALUES. THESE INCREASING MID LEVEL MOISTURE
VALUES...ALONG WITH THE STRONG CONVECTION CURRENTLY FORECAST...WILL
HAVE THE CAPABILITY TO PROMOTE HEAVY RAINFALL AND PERHAPS LOCALIZED
FLASH FLOODING.

PRECIPITATION CHANCES FOR THURSDAY REMAIN UNCERTAIN AT THIS
POINT...ESPECIALLY WITH THE POTENTIAL FOR A SIGNIFICANT MESO-HIGH
SETTING UP OVER THE AREA DUE TO OVERNIGHT RAIN. ASSUMING THE MESO-HIGH
CAN FULLY DISSIPATE BY MID TO LATE AFTERNOON...AND ASSUMING THERE
IS ENOUGH OMEGA WITH ONE OF THE MANY MID LEVEL PERTURBATIONS WHICH
WILL BE PUSHING OVER THE AREA ALONG THE APPROACHING MID LEVEL JET
AXIS...THURSDAY AFTERNOON 0-1KM MLCAPE VALUES ON THE ORDER OF
1000-2500J/KG COULD CERTAINLY PROMOTE A SEVERE HAIL THREAT. AT
THIS TIME IT APPEARS THE BEST POTENTIAL FOR OBSERVING SEVERE
WEATHER ON THURSDAY WILL BE RELEGATED TO OUR EAST WITHIN THE
BETTER LOW LEVEL MOISTURE...AND WILL GO AHEAD AND HIGHLIGHT OUR
EAST FOR SEVERE WEATHER ON THURSDAY AS A RESULT.

LONG TERM...STARTING WITH THE MID-TERM THURSDAY EVENING THROUGH
SATURDAY PERIOD...THE RISK OF THUNDERSTORMS...OR LACK
THEREOF...CONTINUES TO BE THE ULTIMATE DILEMMA DURING THESE 48
HOURS AND CONFIDENCE IN THE DETAILS CONTINUES TO RUN BELOW
AVERAGE. ALOFT...A BLEND OF SOLUTIONS FROM THE 12Z NAM/GFS AND 00Z
ECMWF CONTINUE TO ADVERTISE A RATHER PERSISTENT PATTERN...AS
MODESTLY STRONG...BROAD WEST-SOUTHWEST FLOW REMAINS IN
PLACE...DOWNSTREAM FROM A LARGER SCALE SHORTWAVE TROUGH THAT
CARVES OUT ACROSS THE PACIFIC NORTHWEST/NORTHERN ROCKIES. THE
PRIMARY 300MB JET AXIS WILL THUS REMAIN OFF TO THE NORTH AND WEST
OF THE REGION. HOWEVER...CONSIDERABLE CONVECTIVE INSTABILITY WILL
REMAIN FIRMLY IN PLACE IN OR NEAR THE CWA...AS A QUASI-STATIONARY
FRONT WAVERS BACK AND FORTH ACROSS THE GENERAL REGION. BEFORE
CONTINUING...WILL AGAIN STATE THAT CONFIDENCE IN THE DETAILS IS
LOW REGARDING POPS/THUNDER/SEVERE CHANCES...WITH A BIT HIGHER
CONFIDENCE IN TEMPS. HOWEVER...WAS NO LONGER WILLING TO LEAVE THE
FRIDAY THROUGH SATURDAY TIME FRAME COMPLETELY VOID OF ANY
THUNDERSTORM MENTION.

STARTING WITH THURSDAY EVENING/NIGHT...DECIDED TO BLANKET A GENERIC
20 PERCENT CHANCE OF STORMS CWA-WIDE...AS JUST CANNOT GUARANTEE A
STORM-FREE NIGHT ANYWHERE. DETERMINISTIC MODELS ARE ALL OVER THE
PLACE ON QPF PLACEMENT...WITH THE ECWMF ROLLING STORMS IN FROM THE
WEST MAINLY IN THE EVENING...WHILE THE NAM/GFS AFFECT AT LEAST
SOUTHWEST PORTIONS OF THE AREA MAINLY AFTER 06Z. LEANING ON THE 12Z
NAM...ONLY A MODEST LOW LEVEL JET IS PRESENT OVERNIGHT...BUT WITH
SUBTLE SHORTWAVES MOVING THROUGH AND HEALTHY ELEVATED MUCAPE IN
EXCESS OF 2500 J/KG HANGING OUT ACROSS MOST OF THE CWA THROUGH THE
NIGHT...JUST FEEL BETTER HAVING A TOKEN 20 PERCENT CHANCE
EVERYWHERE. HOWEVER...IT IS LIKELY THAT MOST OF THE AREA WILL IN
FACT REMAIN STORM FREE...WITH THE MOST LIKELY SCENARIO FOR POSSIBLE
CONVECTION BEING HIGH PLAINS ACTIVITY DRIFTING IN FROM THE WEST. AS
FOR SEVERE CHANCES THURSDAY NIGHT...DEEP LAYER SHEAR IS NOT ALL THAT
STRONG...20-30 KNOTS AT MOST...BUT OBVIOUSLY WITH HIGH CAPE LEVELS
HANGING AROUND CANNOT RULE OUT AT LEAST MARGINALLY SEVERE HAIL AND
WIND. AS FOR LOW TEMPS...NUDGED UP SLIGHTLY FROM PREVIOUS
FORECAST...WITH MOST OF SOUTHEAST 1/2 OF CWA HOLDING UP IN THE
LOW-MID 60S.

FOR FRIDAY...MUCH OF THE SAME...AS FORCING ALOFT REMAINS
SUBTLE...BUT INSTABILITY REMAINS HIGH WITH AFTERNOON MLCAPE VALUES
AGAIN BUILDING TO AROUND 3000 J/KG OR HIGHER PER THE NAM...ALTHOUGH
THIS MODEL MAY BE OVERDOING DEWPOINTS AND RESULTANT CAPE A BIT.
ALTHOUGH ODDS ARE REASONABLY HIGH THAT MOST OF THE AREA WILL REMAIN
STORM FREE...OPTED TO INTRODUCE A SLIGHT 20 POP ACROSS SEVERAL
COUNTIES NORTH OF I-80...AS HINTED AT BY THE 12Z GFS AND TO A LESSER
EXTENT THE 12Z NAM. AGAIN...ANYTHING THAT HAPPENS TO FIRE IN THIS
AREA BEFORE DARK COULD POTENTIALLY BE SEVERE. TEMP WISE...ASSUMING
THAT SOUTHERLY BREEZES ARE PRESENT AND CLOUDS ARE NOT
WIDESPREAD...THIS HAS THE POTENTIAL TO BE A RATHER WARM DAY.
ALTHOUGH STILL NOT AIMING QUITE AS HIGH AS THE NAM SUGGESTS...NUDGED
UP A FEW DEGREES...NOW PUTTING MOST OF THE CWA IN THE 87-90 RANGE.

FRIDAY NIGHT...INTRODUCED MORE SLIGHT THUNDERSTORM CHANCES MAINLY
NORTH OF I-80 IN CLOSEST PROXIMITY TO TRACK OF SUBTLE
SHORTWAVES...AND IN THE PRESENCE OF CONTINUED HEALTHY ELEVATED
INSTABILITY. FOR THE DAYTIME HOURS SATURDAY...JUST CONTINUED WITH
MORE OF THE SAME...KEEPING THE SAME AREAS NORTH OF INTERSTATE 80 IN
A SLIGHT CHANCE OF STORMS...BUT WITH BETTER FOCUS LIKELY TARGETING
AREAS JUST TO THE NORTH. BY THIS TIME...THE PRIMARY MID LEVEL TROUGH
TO THE WEST WILL BE CENTERED ROUGHLY ALONG A MT-UT AXIS...BUT STILL
WELL TO THE WEST. TEMP WISE SATURDAY...KEPT SUMMER-LIKE READINGS
GOING AND EVEN NUDGED UP A FEW DEGREES FROM PREVIOUS PER MODEL
CONSENSUS...WITH MID-UPPER 80S MOST AREAS...AND SOME LOW 90S MOST
FAVORED IN KS ZONES.

FOCUSING NOW ON THE LONGER TERM PERIODS SATURDAY NIGHT THROUGH
NEXT WEDNESDAY: IN SHORT...EACH AND EVERY PERIOD FEATURES AT LEAST
20-30 PERCENT RAIN CHANCES FOR NOW...ALTHOUGH WILL STATE THE OBVIOUS
THAT SOME OF THESE PERIODS WILL LIKELY END UP BEING DRY...WITH
PLENTY OF TWEAKING LIKELY OVER THE NEXT SEVERAL DAYS. LOOKING AT THE
BIG PICTURE AND LEANING TOWARD A BLEND OF THE 12Z ECMWF/GFS...THERE
IS ACTUALLY REASONABLY HIGH AGREEMENT THAT ON SATURDAY NIGHT AND
SUNDAY NIGHT A FAIRLY WELL DEFINED SURFACE COLD FRONT WILL CROSS THE
AREA...DRIVEN SOUTHWARD IN RESPONSE TO THE AFOREMENTIONED MID LEVEL
SHORTWAVE TROUGH RIDING UP ACROSS THE NORTHERN PLAINS INTO SOUTH
CENTRAL CANADA. AS A RESULT OF THIS FRONTAL PASSAGE...THE HIGHEST
POPS IN THE EXTENDED PERIOD...40S-50S PERCENTS ACROSS MAINLY NEB
ZONES FOR NOW...ARE FOCUSED ON SATURDAY NIGHT. ALTHOUGH DEEP LAYER
WIND SHEAR DOES NOT LOOK OVERLY IMPRESSIVE WITH THIS FRONTAL
PASSAGE...THE GFS HAS MUCAPE VALUES OF AT LEAST 2000-3000 J/KG IN
PLACE DURING THIS TIME FRAME...SO CERTAINLY A SLIGHT RISK OF SEVERE
NOT OUT OF THE QUESTION. IN THE WAKE OF THIS BOUNDARY...TEMPS SUNDAY
ARE CURRENTLY FORECAST ABOUT 10 DEGREES COOLER THAN
SATURDAY...RANGING FROM LOW 70S NORTHWEST TO LOW 80S SOUTHEAST.
BEYOND SUNDAY...THE CURRENTLY ADVERTISED POPS WOULD SEEM TO COME
MORE AND MORE UNDER QUESTION...BUT WILL STICK WITH THEM PER NOW
ACCORDING TO THE ALLBLEND CONSENSUS INITIALIZATION. THE BASIC STORY
INVOLVES A GRADUAL CARVING OUT OF A MID LEVEL TROUGH ACROSS THE
NORTH CENTRAL CONUS...RESULTING IN A NOTICEABLY COOLER TEMP REGIME
THAN THE CURRENT PATTERN. NUDGED DOWN HIGHS SLIGHTLY FOR MONDAY WITH
UPPER 60S-LOW 70S...WHILE TUESDAY CONTINUES TO LOOK LIKE THE COOLEST
DAY OF THE PERIOD WITH HIGHS ONLY MID-UPPER 60S ALL AREAS AND MAYBE
A REBOUND TO NEAR 70 WEDNESDAY. EVEN IF RAIN WERE TO MATERIALIZE
DURING THE MONDAY NIGHT-WEDNESDAY TIME FRAME...HAVE DROPPED THUNDER
MENTION IN THE FORECAST IN FAVOR OF PLAIN SHOWERS...AS MUCAPE PROGS
FROM BOTH THE ECMWF/GFS ADVERTISE VERY LIMITED IF ANY CONVECTIVE
INSTABILITY. IN CLOSING...WANT TO REITERATE THAT ALTHOUGH POPS IN
THE SAT NIGHT-SUNDAY TIME FRAME LOOK QUITE WARRANTED...WOULD EXPECT
TO SEE AN EVENTUAL TRIMMING OF SOME OF THE RAIN CHANCES DURING THE
SUNDAY NIGHT-WEDNESDAY TIME FRAME.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&

$$








AREA FORECAST DISCUSSION

NWS RALEIGH NC

 248 PM EDT THU MAY 3 2012

.SYNOPSIS...
STRONG UPPER LEVEL HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH
THE WEEK. A COLD FRONT WILL DROP SOUTH THROUGH THE AREA LATE
SATURDAY AND INTO SUNDAY.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 1045 AM THURSDAY...

HAVE BEEN MONITORING THE SOUTHWEST ADVANCEMENT OF A LOW STRATUS/FOG
SHIELD ACROSS SOUTHEAST AND SOUTHERN VIRGINIA INTO NORTHEAST NC.
THIS FEATURE HAD BEEN MAKING STEADY PROGRESS TO THE SOUTHWEST FOR
SEVERAL HOURS AND HAS REACHED HALIFAX AND WARREN COUNTIES. RECENT
SAT TRENDS SUGGEST THAT THE SW PUSH HAS SLOWED AND THE CLOUDS/FOG
MAY HAVE REACHED THEIR FURTHEST SOUTHWARD EXTENT. THIS FEATURE WAS
NOT WELL PROGGED BY THE NAM/GFS BUT RECENT RUNS OF THE RAHWRFARW AND
ESPECIALLY THE HRRR PICKED UP ON THIS FEATURE. EXPECT THE CLOUDS TO
HOLD FOR A FEW MORE HOURS WHERE THEY HAVE REACHED BUT NOT MOVE TOO
MUCH FURTHER SW.

THE 12Z KGSO RAOB PROVIDES A 1000-850 THICKNESS OF 1408M OR 4M
GREATER THAN 12Z WED. 850MB TEMPS WARMED 3DEG C FROM 12Z WED.
700MB HEIGHTS AT KGSO REACHED 3205M WHICH ALL SUPPORT VERY WARM
AFTERNOON HIGHS ABOUT 2 DEGREES WARMER THAN WED. THIS SHOULD RESULT
IN NEAR RECORD HIGHS OF 90-93 DEGREES TODAY.

THREAT OF CONVECTION TODAY IS RATHER LIMITED WITH THE LACK OF
FORCING MECHANISMS. ONE DISTURBANCE OVER SOUTHEAST VA WHICH SHOWS UP
WELL IN THE 1.5PV ANALYSIS SHOULD REMAIN NORTHEAST OF OUR AREA
THROUGH THE AFTERNOON. ANOTHER DISTURBANCE ELONGATED NORTH-SOUTH
ACROSS THE TN VALLEY WILL SHIFT TOWARD THE MOUNTAINS THIS EVENING.
THE BEST FORCING FOR ASCENT WITH THIS FEATURE SHOULD REMAIN ACROSS
THE MOUNTAINS. DIFFERENTIAL HEATING BOUNDARY ASSOCIATED WITH THE
PREVIOUSLY NOTED CLOUD SHIELD COULD ALSO FOCUS CONVECTION. WOULD NOT
BE SURPRISED TO SEE AN ISOLATED STORM MOVE FROM THE FOOTHILLS INTO
THE NORTHERN PIEDMONT OR OTHER ISOLATED ACTIVITY LATE THIS AFTERNOON
IN THE NORTHERN TIER BUT THE COVERAGE IS EXPECTED TO BE SO LIMITED
WE WILL OMIT POPS.


THE PASSAGE OF THE MID-UPPER LEVEL SHEAR AXIS WILL BRING A SLIGHT
REPRIEVE ON FRIDAY AND FRIDAY NIGHT WITH H7 HEIGHTS FALLING 60-70
METERS WITH H8 TEMPS COOLING OFF TO 15 TO 16C. ADDITIONALLY...AS
PLUME OF TROPICAL MOISTURE SURGES NORTHWARD INTO THE AREA(PWATS +2SD
ABOVE NORMAL...1.5-1.7")...EXPECT CLOUDY TO MOSTLY CLOUDY SKIES AND
THE PROSPECTS OF CONVECTION TO GREATLY LIMIT HEATING. WILL LOWER
FORECAST HIGHS INTO THE MID TO UPPER 80S...BUT COULD CONCEIVABLY BE
COOLER...MORE IN THE WAY IN THE LOWER TO MID 80S IF THE CONVECTION
MOVES/DEVELOPS EARLY ENOUGH. MILD OVERNIGHT LOWS GENERALLY IN THE
MID 60S.

WILL KEEP A DRY FORECAST FOR TONIGHT WITH BROAD ANTICYCLONIC FLOW
AND ASSOCIATED SUBSIDENCE THE RULE. RAIN CHANCES RETURN ON FRIDAY
WITH THE PASSAGE OF THE MID-UPPER LEVEL SHEAR AXIS MOVING THROUGH
THE AREA DURING PEAK AFTERNOON HEATING PROVIDING THE FOCUS FOR
SCATTERED SHOWERS AND THUNDERSTORM FRIDAY AFTERNOON AND INTO THE
EARLY EVENING BEFORE THE WAVE SHIFTS EAST OF THE AFTER MIDNIGHT.
WHILE MODELS SHOW MODERATE INSTABILITY ACROSS THE AREA FRIDAY
AFTERNOON...WIND SHEAR IS VERY WEAK...10 TO 15KTS. THUS DO NOT
EXPECT MUCH IN THE WAY OF SEVERE. HOWEVER...DUE TO HIGH
PWATS...LOCALLY HEAVY RAIN IS POSSIBLE.

BLAES/CBL

&&

.SHORT TERM /6 AM SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 220 PM...

SATURDAY FORECAST HINGES ON THE TIMING AND STRENGTH OF A FRONT
DROPPING SOUTH FROM VIRGINIA DURING THE DAY. THE MAJORITY OF
MODELS INDICATE A SURFACE FRONT NEAR THE VIRGINIA BORDER AT
SUNRISE... WITH THE NAM A FASTER OUTLIER. THE MAJORITY OF
SOLUTIONS HAVE THE FRONT NEAR HIGHWAY 64 BY EARLY AFTERNOON AND TO
THE FAYETTEVILLE VICINITY BY DARK. LOW LEVEL FLOW IS WEAK AHEAD OF
THE FRONT AND FROM THE WEST BY LATE FRIDAY NIGHT. CONVERGENCE
ALONG THE FRONT IS WEAK. HOWEVER INSTABILITY AND POTENTIAL ENERGY
IS AT LEAST MODERATE AND THERE IS AGREEMENT ON A SHORT WAVE
PASSAGE ALOFT WITH THE FRONT. ONLY WEAK LOW LEVEL FLOW PREVENTS
MOVING POPS TO LIKELY... AND WILL HOLD POPS AT 40 PERCENT. THE
SEVERE THREAT LOOKS SMALL BUT NONZERO.

TEMPERATURES FOR THE DAY WERE LOWERED... AND COULD YET BE TOO
HIGH... ESPECIALLY IN THE NORTH. HIGH TEMPERATURES IN THE MID 80S
WITH A FEW UPPER 80S SOUTH. MORE EXTENSIVE CLOUDS... PRECIPITATION
OR THE FASTER TIMING OF THE NAM COULD KNOCK TEN DEGREES OFF THESE
FORECAST TEMPERATURES.

LINGERING RAIN CHANCES IN THE SOUTH WITH THE FRONT SATURDAY EVENING.
PRECIPITATION WITH VORTICITY CENTERS ON THE MODELS UNRELIABLE AND
WILL PUT FAITH IN WEAK NORTH SURFACE FLOW AND LACK OF SURFACE
TRIGGERS TO LEAVE THE REST OF THE NIGHT DRY. LITTLE ADVECTION IN
THE WEAK NORTH FLOW... AND LOW TEMPERATURES IN THE LOW TO MID 60S.

NORTH FLOW SUNDAY SHIFTING TO EAST FOR THE EVENING AND SUNDAY NIGHT.
WILL KEEP THIS PERIOD DRY. SOME MARINE STRATUS LIKELY SATURDAY NIGHT
IN THE EAST FLOW... PERSISTING INTO THE AFTERNOON... THOUGH LIFTING.
HIGH TEMPERATURES UPPER 70S NORTHEAST TO MID 80S SUNDAY WITH LOW
TEMPERATURES UPPER 50S TO LOWER 60S.

&&

.LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 245 PM...

THE WEATHER IS LIKELY DRY INTO TUESDAY MORNING. SURFACE HIGH
PRESSURE MOVING INTO THE ATLANTIC WITH FLOW OVER CENTRAL NORTH
CAROLINA BECOMING SOUTHEAST... THEN SOUTH MONDAY NIGHT. MODELS IN
ROUGH AGREEMENT IN BRINGING A FRONT TO THE MOUNTAINS BEFORE SUNSET
TUESDAY. THE UPPER LEVEL SUPPORT OF A MINOR SHORT WAVE IN SOME OF
THE MODELS APPEARS TO ORIGINATE WITH CONVECTION IN THE MIDWEST
DURING THE WEEKEND AND COULD DISAPPEAR WITH LATER MODEL RUNS. LOW
CHANCE POPS IN THE NORTHWEST TUESDAY AFTERNOON... SPREADING EAST
OVERNIGHT. AN UPPER LEVEL WAVE MOVING THROUGH THE GREAT LAKES IS
SIGNIFICANTLY STRONGER... PUSHING THE FRONT THROUGH CENTRAL NORTH
CAROLINA WEDNESDAY INTO THE LATE EVENING. LIMITING POPS TO FORTY
PERCENT WITH AN EVENT THIS FAR OUT IN TIME. THE UPPER WAVE CLOSES
OFF AND LINGERS OVER NEW ENGLAND INTO THURSDAY NIGHT. WILL HAVE LATE
WEDNESDAY NIGHT INTO THURSDAY DRY IN NORTHWEST TO WEST FLOW.

HIGH TEMPERATURES MID 70S TO LOWER 80S AS LOW LEVEL THICKNESSES AT
GREENSBORO SETTLE IN NEAR CLIMATOLOGY. LOW TEMPERATURES UPPER 50S TO
LOWER 60S.

&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
AS OF 140 PM THURSDAY...

WEAK HIGH PRESSURE AND A RIDGE ALOFT SHOULD RESULT IN MAINLY VFR
CONDITIONS THROUGH THE 24 HOUR TAF PERIOD. INCREASING CIRRUS TONIGHT
WILL LEAD TO SOME ALTOSTRATUS/ALTOCUMULUS LATE TONIGHT/FRIDAY.
LITTLE CUMULUS EXPECTED TODAY WITH SCT CUMULUS EXPECTED EARLY
FRIDAY AFTERNOON. LIGHT SOUTHWESTERLY WINDS AT 8KTS OR LESS WILL
BECOME MORE WESTERLY AND INCREASE TO AROUND 10 KTS ON FRIDAY.

LOOKING FURTHER AHEAD...
ISOLATED TO SCATTERED AFTERNOON AND EARLY EVENING SHOWERS AND
THUNDERSTORMS WILL BE THE MAIN CONCERN DURING THE EXTENDED RANGE
WITH THE BEST CHANCE OF CONVECTION ASSOCIATED WITH FRONTS THAT WILL
BE IN THE AREA ON SATURDAY AND WEDNESDAY. PATCHY PREDAWN FOG/STRATUS
WILL ALSO BE POSSIBLE EACH MORNING. -BLAES

&&

.CLIMATE...
THE FOLLOWING ARE RECORD HIGH TEMPERATURES FOR THE REMAINDER OF THE
WEEK:
                    RDU            GSO            FAY
THU MAY 3RD:     93 IN 1959     92 IN 1959     95 IN 1913
FRI MAY 4TH:     94 IN 1938     94 IN 1928     97 IN 1938

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

NEAR TERM...BLAES/CBL
AVIATION...BLAES






AREA FORECAST DISCUSSION

NWS RALEIGH NC

 225 PM EDT THU MAY 3 2012

.SYNOPSIS...
STRONG UPPER LEVEL HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH
THE WEEK. A COLD FRONT WILL DROP SOUTH THROUGH THE AREA LATE
SATURDAY AND INTO SUNDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 AM THURSDAY...

HAVE BEEN MONITORING THE SOUTHWEST ADVANCEMENT OF A LOW STRATUS/FOG
SHIELD ACROSS SOUTHEAST AND SOUTHERN VIRGINIA INTO NORTHEAST NC.
THIS FEATURE HAD BEEN MAKING STEADY PROGRESS TO THE SOUTHWEST FOR
SEVERAL HOURS AND HAS REACHED HALIFAX AND WARREN COUNTIES. RECENT
SAT TRENDS SUGGEST THAT THE SW PUSH HAS SLOWED AND THE CLOUDS/FOG
MAY HAVE REACHED THEIR FURTHEST SOUTHWARD EXTENT. THIS FEATURE WAS
NOT WELL PROGGED BY THE NAM/GFS BUT RECENT RUNS OF THE RAHWRFARW AND
ESPECIALLY THE HRRR PICKED UP ON THIS FEATURE. EXPECT THE CLOUDS TO
HOLD FOR A FEW MORE HOURS WHERE THEY HAVE REACHED BUT NOT MOVE TOO
MUCH FURTHER SW.

THE 12Z KGSO RAOB PROVIDES A 1000-850 THICKNESS OF 1408M OR 4M
GREATER THAN 12Z WED. 850MB TEMPS WARMED 3DEG C FROM 12Z WED.
700MB HEIGHTS AT KGSO REACHED 3205M WHICH ALL SUPPORT VERY WARM
AFTERNOON HIGHS ABOUT 2 DEGREES WARMER THAN WED. THIS SHOULD RESULT
IN NEAR RECORD HIGHS OF 90-93 DEGREES TODAY.

THREAT OF CONVECTION TODAY IS RATHER LIMITED WITH THE LACK OF
FORCING MECHANISMS. ONE DISTURBANCE OVER SOUTHEAST VA WHICH SHOWS UP
WELL IN THE 1.5PV ANALYSIS SHOULD REMAIN NORTHEAST OF OUR AREA
THROUGH THE AFTERNOON. ANOTHER DISTURBANCE ELONGATED NORTH-SOUTH
ACROSS THE TN VALLEY WILL SHIFT TOWARD THE MOUNTAINS THIS EVENING.
THE BEST FORCING FOR ASCENT WITH THIS FEATURE SHOULD REMAIN ACROSS
THE MOUNTAINS. DIFFERENTIAL HEATING BOUNDARY ASSOCIATED WITH THE
PREVIOUSLY NOTED CLOUD SHIELD COULD ALSO FOCUS CONVECTION. WOULD NOT
BE SURPRISED TO SEE AN ISOLATED STORM MOVE FROM THE FOOTHILLS INTO
THE NORTHERN PIEDMONT OR OTHER ISOLATED ACTIVITY LATE THIS AFTERNOON
IN THE NORTHERN TIER BUT THE COVERAGE IS EXPECTED TO BE SO LIMITED
WE WILL OMIT POPS.


THE PASSAGE OF THE MID-UPPER LEVEL SHEAR AXIS WILL BRING A SLIGHT
REPRIEVE ON FRIDAY AND FRIDAY NIGHT WITH H7 HEIGHTS FALLING 60-70
METERS WITH H8 TEMPS COOLING OFF TO 15 TO 16C. ADDITIONALLY...AS
PLUME OF TROPICAL MOISTURE SURGES NORTHWARD INTO THE AREA(PWATS +2SD
ABOVE NORMAL...1.5-1.7")...EXPECT CLOUDY TO MOSTLY CLOUDY SKIES AND
THE PROSPECTS OF CONVECTION TO GREATLY LIMIT HEATING. WILL LOWER
FORECAST HIGHS INTO THE MID TO UPPER 80S...BUT COULD CONCEIVABLY BE
COOLER...MORE IN THE WAY IN THE LOWER TO MID 80S IF THE CONVECTION
MOVES/DEVELOPS EARLY ENOUGH. MILD OVERNIGHT LOWS GENERALLY IN THE
MID 60S.

WILL KEEP A DRY FORECAST FOR TONIGHT WITH BROAD ANTICYCLONIC FLOW
AND ASSOCIATED SUBSIDENCE THE RULE. RAIN CHANCES RETURN ON FRIDAY
WITH THE PASSAGE OF THE MID-UPPER LEVEL SHEAR AXIS MOVING THROUGH
THE AREA DURING PEAK AFTERNOON HEATING PROVIDING THE FOCUS FOR
SCATTERED SHOWERS AND THUNDERSTORM FRIDAY AFTERNOON AND INTO THE
EARLY EVENING BEFORE THE WAVE SHIFTS EAST OF THE AFTER MIDNIGHT.
WHILE MODELS SHOW MODERATE INSTABILITY ACROSS THE AREA FRIDAY
AFTERNOON...WIND SHEAR IS VERY WEAK...10 TO 15KTS. THUS DO NOT
EXPECT MUCH IN THE WAY OF SEVERE. HOWEVER...DUE TO HIGH
PWATS...LOCALLY HEAVY RAIN IS POSSIBLE.

BLAES/CBL

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 220 PM...

SATURDAY FORECAST HINGES ON THE TIMING AND STRENGTH OF A FRONT
DROPPING SOUTH FROM VIRGINIA DURING THE DAY. THE MAJORITY OF
MODELS INDICATE A SURFACE FRONT NEAR THE VIRGINIA BORDER AT
SUNRISE... WITH THE NAM A FASTER OUTLIER. THE MAJORITY OF
SOLUTIONS HAVE THE FRONT NEAR HIGHWAY 64 BY EARLY AFTERNOON AND TO
THE FAYETTEVILLE VICINITY BY DARK. LOW LEVEL FLOW IS WEAK AHEAD OF
THE FRONT AND FROM THE WEST BY LATE FRIDAY NIGHT. CONVERGENCE
ALONG THE FRONT IS WEAK. HOWEVER INSTABILITY AND POTENTIAL ENERGY
IS AT LEAST MODERATE AND THERE IS AGREEMENT ON A SHORT WAVE
PASSAGE ALOFT WITH THE FRONT. ONLY WEAK LOW LEVEL FLOW PREVENTS
MOVING POPS TO LIKELY... AND WILL HOLD POPS AT 40 PERCENT. THE
SEVERE THREAT LOOKS SMALL BUT NONZERO.

TEMPERATURES FOR THE DAY WERE LOWERED... AND COULD YET BE TOO
HIGH... ESPECIALLY IN THE NORTH. HIGH TEMPERATURES IN THE MID 80S
WITH A FEW UPPER 80S SOUTH. MORE EXTENSIVE CLOUDS... PRECIPITATION
OR THE FASTER TIMING OF THE NAM COULD KNOCK TEN DEGREES OFF THESE
FORECAST TEMPERATURES.

LINGERING RAIN CHANCES IN THE SOUTH WITH THE FRONT SATURDAY EVENING.
PRECIPITATION WITH VORTICITY CENTERS ON THE MODELS UNRELIABLE AND
WILL PUT FAITH IN WEAK NORTH SURFACE FLOW AND LACK OF SURFACE
TRIGGERS TO LEAVE THE REST OF THE NIGHT DRY. LITTLE ADVECTION IN
THE WEAK NORTH FLOW... AND LOW TEMPERATURES IN THE LOW TO MID 60S.

NORTH FLOW SUNDAY SHIFTING TO EAST FOR THE EVENING AND SUNDAY NIGHT.
WILL KEEP THIS PERIOD DRY. SOME MARINE STRATUS LIKELY SATURDAY NIGHT
IN THE EAST FLOW... PERSISTING INTO THE AFTERNOON... THOUGH LIFTING.
HIGH TEMPERATURES UPPER 70S NORTHEAST TO MID 80S SUNDAY WITH LOW
TEMPERATURES UPPER 50S TO LOWER 60S.

&&

.LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...

THE BEGINNING OF THE LONG TERM PERIOD SHOULD START MOSTLY DRY...WITH
SEASONAL TEMPS AS HIGH PRESSURE CONTINUES TO RIDGE INTO THE AREA
FROM THE NORTH. THERE WILL BE A SLIGHT CHANCE OF DIURNAL CONVECTION
ON MONDAY...ESPECIALLY ACROSS THE SOUTHWESTERN/WESTERN PORTIONS OF
THE FORECAST AREA DUE TO PROXIMITY OF A STALLED FRONT. THEN THE
SURFACE HIGH RIDGING WILL SHIFT OFFSHORE BY TUESDAY AS THE NEXT
SYSTEM APPROACHES FROM THE NORTHWEST. PRECIP CHANCES WILL INCREASE
TUESDAY INTO THE WEDNESDAY AS THE FRONT SHIFTS BACK NORTH ACROSS THE
REGION AND WARM...MOIST SOUTHERLY FLOW RETURNS TO THE AREA. ALSO...
AS THE AFOREMENTIONED SURFACE LOW PRESSURE SYSTEM TRACKS TO THE
NORTH OF THE AREA...IT TRIES TO PUSH A COLD FRONT TOWARDS THE REGION
BY MID WEEK...WHICH MAY ALSO HELP TO INCREASE PRECIP CHANCES.
HOWEVER...AS CAN BE EXPECTED DURING THIS PART OF THE FORECAST...
THERE IS TIMING AND STRENGTH DIFFERENCES IN THE MODELS...THEREFORE
WILL GO NO HIGH THAN LOW END CHANCE POPS AT THIS TIME. TEMPS WILL
GRADUALLY WARM THROUGH THE PERIOD AS RETURN FLOW SETS UP OVER THE
REGION...BUT SHOULD STAY JUST ABOVE NORMAL VALUES...GENERALLY IN THE
LOW TO MID 80S BY WEDNESDAY.

&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
AS OF 140 PM THURSDAY...

WEAK HIGH PRESSURE AND A RIDGE ALOFT SHOULD RESULT IN MAINLY VFR
CONDITIONS THROUGH THE 24 HOUR TAF PERIOD. INCREASING CIRRUS TONIGHT
WILL LEAD TO SOME ALTOSTRATUS/ALTOSTRATUS LATE TONIGHT/FRIDAY.
LITTLE CUMULUS EXPECTED TODAY WITH SCT CUMULUS EXPECTED EARLY FRIDAY
AFTERNOON. LIGHT SOUTHWESTERLY WINDS AT 8KTS OR LESS WILL BECOME
MORE WESTERLY AND INCREASE TO AROUND 10 KTS ON FRIDAY.

LOOKING FURTHER AHEAD...
ISOLATED TO SCATTERED AFTERNOON AND EARLY EVENING SHOWERS AND
THUNDERSTORMS WILL BE THE MAIN CONCERN DURING THE EXTENDED RANGE
WITH THE BEST CHANCE OF CONVECTION ASSOCIATED WITH FRONTS THAT WILL
BE IN THE AREA ON SATURDAY AND WEDNESDAY. PATCHY PREDAWN FOG/STRATUS
WILL ALSO BE POSSIBLE EACH MORNING. -BLAES

&&

.CLIMATE...
THE FOLLOWING ARE RECORD HIGH TEMPERATURES FOR THE REMAINDER OF THE
WEEK:
                    RDU            GSO            FAY
THU MAY 3RD:     93 IN 1959     92 IN 1959     95 IN 1913
FRI MAY 4TH:     94 IN 1938     94 IN 1928     97 IN 1938

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

NEAR TERM...BLAES/CBL
LONG TERM...KRR
AVIATION...BLAES






AREA FORECAST DISCUSSION

NWS RALEIGH NC

 140 PM EDT THU MAY 3 2012

.SYNOPSIS...
STRONG UPPER LEVEL HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH
THE WEEK. A COLD FRONT WILL DROP SOUTH THROUGH THE AREA LATE
SATURDAY AND INTO SUNDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 AM THURSDAY...

HAVE BEEN MONITORING THE SOUTHWEST ADVANCEMENT OF A LOW STRATUS/FOG
SHIELD ACROSS SOUTHEAST AND SOUTHERN VIRGINIA INTO NORTHEAST NC.
THIS FEATURE HAD BEEN MAKING STEADY PROGRESS TO THE SOUTHWEST FOR
SEVERAL HOURS AND HAS REACHED HALIFAX AND WARREN COUNTIES. RECENT
SAT TRENDS SUGGEST THAT THE SW PUSH HAS SLOWED AND THE CLOUDS/FOG
MAY HAVE REACHED THEIR FURTHEST SOUTHWARD EXTENT. THIS FEATURE WAS
NOT WELL PROGGED BY THE NAM/GFS BUT RECENT RUNS OF THE RAHWRFARW AND
ESPECIALLY THE HRRR PICKED UP ON THIS FEATURE. EXPECT THE CLOUDS TO
HOLD FOR A FEW MORE HOURS WHERE THEY HAVE REACHED BUT NOT MOVE TOO
MUCH FURTHER SW.

THE 12Z KGSO RAOB PROVIDES A 1000-850 THICKNESS OF 1408M OR 4M
GREATER THAN 12Z WED. 850MB TEMPS WARMED 3DEG C FROM 12Z WED.
700MB HEIGHTS AT KGSO REACHED 3205M WHICH ALL SUPPORT VERY WARM
AFTERNOON HIGHS ABOUT 2 DEGREES WARMER THAN WED. THIS SHOULD RESULT
IN NEAR RECORD HIGHS OF 90-93 DEGREES TODAY.

THREAT OF CONVECTION TODAY IS RATHER LIMITED WITH THE LACK OF
FORCING MECHANISMS. ONE DISTURBANCE OVER SOUTHEAST VA WHICH SHOWS UP
WELL IN THE 1.5PV ANALYSIS SHOULD REMAIN NORTHEAST OF OUR AREA
THROUGH THE AFTERNOON. ANOTHER DISTURBANCE ELONGATED NORTH-SOUTH
ACROSS THE TN VALLEY WILL SHIFT TOWARD THE MOUNTAINS THIS EVENING.
THE BEST FORCING FOR ASCENT WITH THIS FEATURE SHOULD REMAIN ACROSS
THE MOUNTAINS. DIFFERENTIAL HEATING BOUNDARY ASSOCIATED WITH THE
PREVIOUSLY NOTED CLOUD SHIELD COULD ALSO FOCUS CONVECTION. WOULD NOT
BE SURPRISED TO SEE AN ISOLATED STORM MOVE FROM THE FOOTHILLS INTO
THE NORTHERN PIEDMONT OR OTHER ISOLATED ACTIVITY LATE THIS AFTERNOON
IN THE NORTHERN TIER BUT THE COVERAGE IS EXPECTED TO BE SO LIMITED
WE WILL OMIT POPS.


THE PASSAGE OF THE MID-UPPER LEVEL SHEAR AXIS WILL BRING A SLIGHT
REPRIEVE ON FRIDAY AND FRIDAY NIGHT WITH H7 HEIGHTS FALLING 60-70
METERS WITH H8 TEMPS COOLING OFF TO 15 TO 16C. ADDITIONALLY...AS
PLUME OF TROPICAL MOISTURE SURGES NORTHWARD INTO THE AREA(PWATS +2SD
ABOVE NORMAL...1.5-1.7")...EXPECT CLOUDY TO MOSTLY CLOUDY SKIES AND
THE PROSPECTS OF CONVECTION TO GREATLY LIMIT HEATING. WILL LOWER
FORECAST HIGHS INTO THE MID TO UPPER 80S...BUT COULD CONCEIVABLY BE
COOLER...MORE IN THE WAY IN THE LOWER TO MID 80S IF THE CONVECTION
MOVES/DEVELOPS EARLY ENOUGH. MILD OVERNIGHT LOWS GENERALLY IN THE
MID 60S.

WILL KEEP A DRY FORECAST FOR TONIGHT WITH BROAD ANTICYCLONIC FLOW
AND ASSOCIATED SUBSIDENCE THE RULE. RAIN CHANCES RETURN ON FRIDAY
WITH THE PASSAGE OF THE MID-UPPER LEVEL SHEAR AXIS MOVING THROUGH
THE AREA DURING PEAK AFTERNOON HEATING PROVIDING THE FOCUS FOR
SCATTERED SHOWERS AND THUNDERSTORM FRIDAY AFTERNOON AND INTO THE
EARLY EVENING BEFORE THE WAVE SHIFTS EAST OF THE AFTER MIDNIGHT.
WHILE MODELS SHOW MODERATE INSTABILITY ACROSS THE AREA FRIDAY
AFTERNOON...WIND SHEAR IS VERY WEAK...10 TO 15KTS. THUS DO NOT
EXPECT MUCH IN THE WAY OF SEVERE. HOWEVER...DUE TO HIGH
PWATS...LOCALLY HEAVY RAIN IS POSSIBLE.

BLAES/CBL

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM THURSDAY...

A SURFACE LOW OVER NEW ENGLAND WILL GRADUALLY SHIFT SOUTHEAST
SATURDAY INTO SUNDAY...BRINGING A COLD FRONT AND ASSOCIATED PRECIP
CHANCES TOWARDS THE REGION. MODELS HAVE COME INTO A LITTLE BETTER
AGREEMENT WITH THEIR HANDLING OF THIS FRONT OVER THE AREA FOR THE
WEEKEND. AT THIS TIME...IT APPEARS THE FRONT SHOULD CROSS THE AREA
LATE SATURDAY INTO SUNDAY AND THEN STALL NEAR THE SOUTHWESTERN
PORTIONS OF THE FORECAST AREA BY LATE SUNDAY...WITH HIGH PRESSURE
BUILDING IN FROM THE NORTH. THEREFORE...PRECIP CHANCES SHOULD
INCREASE THROUGH THE DAY ON SATURDAY...BEFORE DECREASING FROM
NORTHEAST TO SOUTHWEST LATE SUNDAY. WE SHOULD SEE ONE MORE DAY OF
HIGHS IN THE UPPER 80S TO NEAR 90 DEGREES ON SATURDAY...BEFORE
SLIGHTLY COOLER MAX TEMPS ON SUNDAY BEHIND THE FRONT...GENERALLY LOW
TO MID 80S. SIMILAR TREND IS EXPECTED FOR OVERNIGHT LOWS...WITH
GENERALLY MID 60S EXPECTED SATURDAY NIGHT AND UPPER 50S TO LOWER 60S
EXPECTED BY SUNDAY NIGHT.

&&

.LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...

THE BEGINNING OF THE LONG TERM PERIOD SHOULD START MOSTLY DRY...WITH
SEASONAL TEMPS AS HIGH PRESSURE CONTINUES TO RIDGE INTO THE AREA
FROM THE NORTH. THERE WILL BE A SLIGHT CHANCE OF DIURNAL CONVECTION
ON MONDAY...ESPECIALLY ACROSS THE SOUTHWESTERN/WESTERN PORTIONS OF
THE FORECAST AREA DUE TO PROXIMITY OF A STALLED FRONT. THEN THE
SURFACE HIGH RIDGING WILL SHIFT OFFSHORE BY TUESDAY AS THE NEXT
SYSTEM APPROACHES FROM THE NORTHWEST. PRECIP CHANCES WILL INCREASE
TUESDAY INTO THE WEDNESDAY AS THE FRONT SHIFTS BACK NORTH ACROSS THE
REGION AND WARM...MOIST SOUTHERLY FLOW RETURNS TO THE AREA. ALSO...
AS THE AFOREMENTIONED SURFACE LOW PRESSURE SYSTEM TRACKS TO THE
NORTH OF THE AREA...IT TRIES TO PUSH A COLD FRONT TOWARDS THE REGION
BY MID WEEK...WHICH MAY ALSO HELP TO INCREASE PRECIP CHANCES.
HOWEVER...AS CAN BE EXPECTED DURING THIS PART OF THE FORECAST...
THERE IS TIMING AND STRENGTH DIFFERENCES IN THE MODELS...THEREFORE
WILL GO NO HIGH THAN LOW END CHANCE POPS AT THIS TIME. TEMPS WILL
GRADUALLY WARM THROUGH THE PERIOD AS RETURN FLOW SETS UP OVER THE
REGION...BUT SHOULD STAY JUST ABOVE NORMAL VALUES...GENERALLY IN THE
LOW TO MID 80S BY WEDNESDAY.

&&

.AVIATION /18Z THURSDAY THROUGH MONDAY/...
AS OF 140 PM THURSDAY...

WEAK HIGH PRESSURE AND A RIDGE ALOFT SHOULD RESULT IN MAINLY VFR
CONDITIONS THROUGH THE 24 HOUR TAF PERIOD. INCREASING CIRRUS TONIGHT
WILL LEAD TO SOME ALTOSTRATUS/ALTOSTRATUS LATE TONIGHT/FRIDAY.
LITTLE CUMULUS EXPECTED TODAY WITH SCT CUMULUS EXPECTED EARLY FRIDAY
AFTERNOON. LIGHT SOUTHWESTERLY WINDS AT 8KTS OR LESS WILL BECOME
MORE WESTERLY AND INCREASE TO AROUND 10 KTS ON FRIDAY.

LOOKING FURTHER AHEAD...
ISOLATED TO SCATTERED AFTERNOON AND EARLY EVENING SHOWERS AND
THUNDERSTORMS WILL BE THE MAIN CONCERN DURING THE EXTENDED RANGE
WITH THE BEST CHANCE OF CONVECTION ASSOCIATED WITH FRONTS THAT WILL
BE IN THE AREA ON SATURDAY AND WEDNESDAY. PATCHY PREDAWN FOG/STRATUS
WILL ALSO BE POSSIBLE EACH MORNING. -BLAES

&&

.CLIMATE...

THE FOLLOWING ARE RECORD HIGH TEMPERATURES FOR THE REMAINDER OF THE
WEEK:
                    RDU            GSO            FAY
THU MAY 3RD:     93 IN 1959     92 IN 1959     95 IN 1913
FRI MAY 4TH:     94 IN 1938     94 IN 1928     97 IN 1938
&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...CBL
NEAR TERM...BLAES/CBL
SHORT TERM...KRR
LONG TERM...KRR
AVIATION...BLAES
CLIMATE...RAH


















AREA FORECAST DISCUSSION

NWS RALEIGH NC

 1045 AM EDT THU MAY 3 2012

.SYNOPSIS...
STRONG UPPER LEVEL HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH
THE WEEK. A COLD FRONT WILL DROP SOUTH THROUGH THE AREA LATE
SATURDAY AND INTO SUNDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 AM THURSDAY...

HAVE BEEN MONITORING THE SOUTHWEST ADVANCEMENT OF A LOW STRATUS/FOG
SHIELD ACROSS SOUTHEAST AND SOUTHERN VIRGINIA INTO NORTHEAT NC. THIS
FEATURE HAD BEEN MAKING STEADY PROGRESS TO THE SOUTHWEST FOR SEVERAL
HOURS AND HAS REACHED HALIFAX AND WARREN COUNTIES. RECENT SAT TRENDS
SUGGEST THAT THE SW PUSH HAS SLOWED AND THE CLOUDS/FOG MAY HAVE
REACHED THEIR FURTHEST SOUTHWARD EXTENT. THIS FEATURE WAS NOT WELL
PROGGED BY THE NAM/GFS BUT RECENT RUNS OF THE RAHWRFARW AND
ESPECIALLY THE HRRR PICKED UP ON THIS FEATURE. EXPECT THE CLOUDS TO
HOLD FOR A FEW MORE HOURS WHERE THEY HAVE REACHED BUT NOT MOVE TOO
MUCH FURTHER SW.

THE 12Z KGSO RAOB PROVIDES A 1000-850 THICKNESS OF 1408M OR 4M
GREATER THAN 12Z WED. 850MB TEMPS WARMED 3DEG C FROM 12Z WED.
700MB HEIGHTS AT KGSO REACHED 3205M WHICH ALL SUPPORT VERY WARM
AFTERNOON HIGHS ABOUT 2 DEGREES WARMER THAN WED. THIS SHOULD RESULT
IN NEAR RECORD HIGHS OF 90-93 DEGREES TODAY.

THREAT OF CONVECTION TODAY IS RATHER LIMITED WITH THE LACK OF
FORCING MECHANISMS. ONE DISTURBANCE OVER SOUTHEAST VA WHICH SHOWS UP
WELL IN THE 1.5PV ANALYSIS SHOULD REMAIN NORTHEAST OF OUR AREA
THROUGH THE AFTERNOON. ANOTHER DISTURBANCE ELONGATED NORTH-SOUTH
ACROSS THE TN VALLEY WILL SHIFT TOWARD THE MOUNTAINS THIS EVENING.
THE BEST FORCING FOR ASCENT WITH THIS FEATURE SHOULD REMAIN ACROSS
THE MOUNTAINS. DIFFERENTIAL HEATING BOUNDARY ASSOCIATED WITH THE
PREVIOUSLY NOTED CLOUD SHIELD COULD ALSO FOCUS CONVECTION. WOULD NOT
BE SURPRISED TO SEE AN ISOLATED STORM MOVE FROM THE FOOTHILLS INTO
THE NORTHERN PIEDMONT OR OTHER ISOLATED ACTIVITY LATE THIS AFTERNOON
IN THE NORTHERN TIER BUT THE COVERAGE IS EXPECTED TO BE SO LIMITED
WE WILL OMIT POPS.


THE PASSAGE OF THE MID-UPPER LEVEL SHEAR AXIS WILL BRING A SLIGHT
REPRIEVE ON FRIDAY AND FRIDAY NIGHT WITH H7 HEIGHTS FALLING 60-70
METERS WITH H8 TEMPS COOLING OFF TO 15 TO 16C. ADDITIONALLY...AS
PLUME OF TROPICAL MOISTURE SURGES NORTHWARD INTO THE AREA(PWATS +2SD
ABOVE NORMAL...1.5-1.7")...EXPECT CLOUDY TO MOSTLY CLOUDY SKIES AND
THE PROSPECTS OF CONVECTION TO GREATLY LIMIT HEATING. WILL LOWER
FORECAST HIGHS INTO THE MID TO UPPER 80S...BUT COULD CONCEIVABLY BE
COOLER...MORE IN THE WAY IN THE LOWER TO MID 80S IF THE CONVECTION
MOVES/DEVELOPS EARLY ENOUGH. MILD OVERNIGHT LOWS GENERALLY IN THE
MID 60S.

WILL KEEP A DRY FORECAST FOR TONIGHT WITH BROAD ANTICYCLONIC FLOW
AND ASSOCIATED SUBSIDENCE THE RULE. RAIN CHANCES RETURN ON FRIDAY
WITH THE PASSAGE OF THE MID-UPPER LEVEL SHEAR AXIS MOVING THROUGH
THE AREA DURING PEAK AFTERNOON HEATING PROVIDING THE FOCUS FOR
SCATTERED SHOWERS AND THUNDERSTORM FRIDAY AFTERNOON AND INTO THE
EARLY EVENING BEFORE THE WAVE SHIFTS EAST OF THE AFTER MIDNIGHT.
WHILE MODELS SHOW MODERATE INSTABILITY ACROSS THE AREA FRIDAY
AFTERNOON...WIND SHEAR IS VERY WEAK...10 TO 15KTS. THUS DO NOT
EXPECT MUCH IN THE WAY OF SEVERE. HOWEVER...DUE TO HIGH
PWATS...LOCALLY HEAVY RAIN IS POSSIBLE.

BLAES/CBL

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM THURSDAY...

A SURFACE LOW OVER NEW ENGLAND WILL GRADUALLY SHIFT SOUTHEAST
SATURDAY INTO SUNDAY...BRINGING A COLD FRONT AND ASSOCIATED PRECIP
CHANCES TOWARDS THE REGION. MODELS HAVE COME INTO A LITTLE BETTER
AGREEMENT WITH THEIR HANDLING OF THIS FRONT OVER THE AREA FOR THE
WEEKEND. AT THIS TIME...IT APPEARS THE FRONT SHOULD CROSS THE AREA
LATE SATURDAY INTO SUNDAY AND THEN STALL NEAR THE SOUTHWESTERN
PORTIONS OF THE FORECAST AREA BY LATE SUNDAY...WITH HIGH PRESSURE
BUILDING IN FROM THE NORTH. THEREFORE...PRECIP CHANCES SHOULD
INCREASE THROUGH THE DAY ON SATURDAY...BEFORE DECREASING FROM
NORTHEAST TO SOUTHWEST LATE SUNDAY. WE SHOULD SEE ONE MORE DAY OF
HIGHS IN THE UPPER 80S TO NEAR 90 DEGREES ON SATURDAY...BEFORE
SLIGHTLY COOLER MAX TEMPS ON SUNDAY BEHIND THE FRONT...GENERALLY LOW
TO MID 80S. SIMILAR TREND IS EXPECTED FOR OVERNIGHT LOWS...WITH
GENERALLY MID 60S EXPECTED SATURDAY NIGHT AND UPPER 50S TO LOWER 60S
EXPECTED BY SUNDAY NIGHT.

&&

.LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...

THE BEGINNING OF THE LONG TERM PERIOD SHOULD START MOSTLY DRY...WITH
SEASONAL TEMPS AS HIGH PRESSURE CONTINUES TO RIDGE INTO THE AREA
FROM THE NORTH. THERE WILL BE A SLIGHT CHANCE OF DIURNAL CONVECTION
ON MONDAY...ESPECIALLY ACROSS THE SOUTHWESTERN/WESTERN PORTIONS OF
THE FORECAST AREA DUE TO PROXIMITY OF A STALLED FRONT. THEN THE
SURFACE HIGH RIDGING WILL SHIFT OFFSHORE BY TUESDAY AS THE NEXT
SYSTEM APPROACHES FROM THE NORTHWEST. PRECIP CHANCES WILL INCREASE
TUESDAY INTO THE WEDNESDAY AS THE FRONT SHIFTS BACK NORTH ACROSS THE
REGION AND WARM...MOIST SOUTHERLY FLOW RETURNS TO THE AREA. ALSO...
AS THE AFOREMENTIONED SURFACE LOW PRESSURE SYSTEM TRACKS TO THE
NORTH OF THE AREA...IT TRIES TO PUSH A COLD FRONT TOWARDS THE REGION
BY MID WEEK...WHICH MAY ALSO HELP TO INCREASE PRECIP CHANCES.
HOWEVER...AS CAN BE EXPECTED DURING THIS PART OF THE FORECAST...
THERE IS TIMING AND STRENGTH DIFFERENCES IN THE MODELS...THEREFORE
WILL GO NO HIGH THAN LOW END CHANCE POPS AT THIS TIME. TEMPS WILL
GRADUALLY WARM THROUGH THE PERIOD AS RETURN FLOW SETS UP OVER THE
REGION...BUT SHOULD STAY JUST ABOVE NORMAL VALUES...GENERALLY IN THE
LOW TO MID 80S BY WEDNESDAY.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 720 AM THURSDAY...

OUTSIDE OF SOME BRIEF PATCHY FOG/STRATUS THIS MORNING...STRONG HIGH
PRESSURE ALOFT WILL RESULT IN VFR CONDITIONS THROUGH THE 24 HOUR TAF
PERIOD ENDING AT 06Z FRIDAY. WINDS WILL REMAIN LIGHT AND VARIABLE.

OUTLOOK...UPPER LEVEL ISOLD TO SCATTERED AFTERNOON AND EARLY EVENING
SHOWERS AND THUNDERSTORMS WILL BE THE MAIN CONCERN THE NEXT COUPLE
OF DAYS WITH INCREASING CHANCES FOR CONVECTION INTO THE WEEKEND WITH
THE PASSAGE OF A COLD FRONT. PATCHY PREDAWN FOG/STRATUS WILL ALSO BE
POSSIBLE EACH MORNING...OTHERWISE VFR CONDITIONS

&&

.CLIMATE...

THE FOLLOWING ARE RECORD HIGH TEMPERATURES FOR THE REMAINDER OF THE
WEEK:
                    RDU            GSO            FAY
THU MAY 3RD:     93 IN 1959     92 IN 1959     95 IN 1913
FRI MAY 4TH:     94 IN 1938     94 IN 1928     97 IN 1938
&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...CBL
NEAR TERM...BLAES/CBL
SHORT TERM...KRR
LONG TERM...KRR
AVIATION...CBL
CLIMATE...RAH















AREA FORECAST DISCUSSION

NWS CLEVELAND OH

 138 PM EDT THU MAY 3 2012

.SYNOPSIS...
A FRONT JUST NORTH OF LAKE ERIE WILL REMAIN NEARLY STATIONARY INTO
FRIDAY AS WAVES OF LOW PRESSURE MOVE ALONG THE FRONT. THE FRONT WILL
DROP SOUTHEAST ACROSS THE AREA LATER FRIDAY AND STALL NEAR THE OHIO
RIVER UNTIL A LOW SLOWLY MOVES ACROSS OHIO MONDAY NIGHT.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE...BOOSTED TEMPS A BIT IN PLACES BASED ON LATEST HRRR OUTPUT.


FOR 630 AM UPDATE...ONLY CHANGE WILL BE TO LOWER POPS FOR MORNING
SINCE NOTHING OF NOTE CURRENTLY OCCURRING. ALSO WILL ADD SOME PATCHY
FOG FOR NEXT FEW HOURS.

THE AIRMASS WILL REMAIN UNSTABLE TODAY. A LOW LEVEL JET WILL
CONTINUE TO BRING MOISTURE INTO THE CWA FROM THE SW WHILE WIND SHEAR
REMAINS RELATIVELY WEAK. THE SHORT TERM HI RES MODELS SEEM TO WANT
TO PRODUCE THE MOST CONVECTION INTO THE MORNING THEN THE NAM AND GFS
TAPER BACK THE THREAT INTO THE AFTERNOON AS THE FRONTAL CONVERGENCE
LIFTS NE OF THE AREA. WILL CONTINUE CHANCE POPS FOR TODAY WITH THE
BEST CHANCE IN THE NORTH. DUE TO THE LIMITED RISK FOR SEVERE WILL
NOT MENTION AT THIS TIME.

A VERY WARM DAY IS IN STORE WITH RECORD OR NEAR RECORD HIGHS
POSSIBLE.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
THE WEAK FRONTAL BOUNDARY WILL GET PUSHED SOUTH ACROSS THE CWA FRI.
ABUNDANT MOISTURE PRESENT WITH PW`S AROUND 1.5 INCHES. EXPECT FAIRLY
WIDESPREAD SHRA/TSRA TO SPREAD SE ACROSS THE REGION WITH THE FRONT.
CLOUD COVER WILL BE MORE EXTENSIVE SO THIS SHOULD HELP TO LIMIT HIGH
TEMPS/INSTABILITY AND THUS THE SEVERE THREAT.

FRI NIGHT...THE BETTER THREAT FOR CONVECTION SHOULD BE SHIFTING INTO
THE SOUTHERN HALF OF THE CWA WITH A LINGERING CHANCE INTO SAT FOR
MAINLY THE SOUTH. EVEN THOUGH OVERALL AIRMASS REMAINS QUITE WARM ON
SAT...NE FLOW OFF OF A CHILLY LAKE ERIE WILL LIKELY KEEP TEMPS IN
THE LOW TO MID 60S DOWNWIND OF THE LAKE.

THE HIGH TO THE NORTH SHOULD PUSH ENOUGH OF A RIDGE SOUTH INTO THE
AREA TO HOLD OFF THE PRECIP THREAT FOR SAT NIGHT AND SUN BUT
OVERRUNNING IN THE SW WILL BEGIN ON SUN AND COULD ALLOW SOME
CONVECTION TO RETURN.

THE APPROACH OF A LOW WEST OF THE AREA BY DAYBREAK MON WILL PROBABLY
LEAD TO MORE CONVECTION PUSHING INTO AT LEAST THE WEST HALF OF THE
AREA SUN NIGHT.

&&

.LONG TERM /MONDAY THROUGH WEDNESDAY/...
LOW PRESSURE WILL BE MOVING INTO THE REGION ON MONDAY WITH INCREASED
CHANCES OF RAIN BY AFTERNOON. THIS RAIN WILL CONTINUE INTO MONDAY
NIGHT AND MAY ACTUALLY LINGER INTO TUESDAY MORNING. MODELS ARE
DIFFERING ON HOW FAST THIS LOW WILL CLEAR THE AREA. A FRONTAL
BOUNDARY WILL NOT BE ALL THAT FAR FROM THE SOUTHERN COUNTY WARNING
AREA ON TUESDAY NIGHT BUT IT APPEARS THAT MUCH OF THE AREA WILL BE
DRY. MODELS ARE STRUGGLING ON HOW TO DIG THE NEXT TROUGH INTO THE
CENTRAL LAKES ON WEDNESDAY. THE DIFFERING SCENARIOS WOULD BE SHOWERS
RETURNING EITHER EARLY WEDNESDAY OR MAYBE HOLDING OFF UNTIL
AFTERNOON OR EVENING.

HIGHS WILL LIKELY BE ABOVE AVERAGE ON MONDAY BUT WE WILL COOL BACK
TO SEASONAL LEVELS FOR TUESDAY INTO WEDNESDAY.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
SITES DOMINATED BY HIGH PRESSURE AND SOUTHERLY FLOW THIS
AFTERNOON. SOME THUNDERSTORM DEVELOPMENT IS EXPECTED TO CONTINUE
ACROSS NE OH AND NW PA ALONG LAKE BREEZE BOUNDARY. HOWEVER...WITH
ERI NORTH OF THE BOUNDARY WITH ONSHORE FLOW EXPECTING STORMS TO
PASS JUST SOUTH OF THE FIELD SO DIDN/T INCLUDE VCTS. WILL WATCH
THIS AREA THOUGH IF STORMS DO COME CLOSER TO THE AIRPORT.
ELSEWHERE EXPECTING SOUTHWEST FLOW THROUGH THE AFTERNOON WITH VFR
CONDITIONS AND SCT-BKN CLOUDS AROUND 040-070. COLD FRONT EXPECTED
TO DROP SOUTH INTO NW OH IMPACTING TOL FIRST FRI MORNING. HAVE
SOME SHRA MENTIONED THERE. SITES FURTHER EAST WILL SEE SHRA/TS
NEAR OR AFTER 18Z FRI.

.OUTLOOK...NON-VFR CONDITIONS POSSIBLE IN CONVECTION FRIDAY
AFTERNOON/EVENING. NON-VFR POSSIBLE ON MONDAY.

&&

.MARINE...
WARM FRONT WILL BE IN THE VICINITY OF THE NORTH SHORE OF LAKE ERIE
TODAY. THIS SHOULD ALLOW FOR A SOUTH TO SOUTHWEST WIND ACROSS THE
ENTIRE LAKE. THE STRONGEST WINDS WILL LIKELY BE ACROSS THE WESTERN
BASIN BUT SHOULD NOT EXCEED 20 KNOTS. SOUTHWESTERLY WINDS WILL
CONTINUE INTO FRIDAY NIGHT WITH A WIND SHIFT EXPECTED BY SATURDAY
MORNING AS A COLD FRONT PASSES. HIGH PRESSURE IN THE WAKE OF THE
FRONT WILL REMAIN IN CONTROL INTO SUNDAY WITH NORTHEAST TO EAST
WINDS EXPECTED. THIS WILL LIKELY CAUSE WAVES TO BUILD BUT WITH WINDS
NOT EXPECTED TO BE HIGHER THAN 15 KNOTS WE SHOULD SEE 2 TO 4 FOOT
WAVES. WE WILL HAVE TO WATCH THE WESTERN HALF OF THE LAKE CLOSELY IF
WIND SPEEDS ARE A BIT STRONGER THAN ANTICIPATED. AS LOW PRESSURE
APPROACHES THE CENTRAL LAKES ON MONDAY WINDS SHOULD GRADUALLY SWING
AROUND TO THE SOUTH.

&&

.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...ADAMS
NEAR TERM...ADAMS/TK
SHORT TERM...ADAMS
LONG TERM...MULLEN
AVIATION...ABE
MARINE...MULLEN







AREA FORECAST DISCUSSION

NWS CLEVELAND OH

 1133 AM EDT THU MAY 3 2012

.SYNOPSIS...
A FRONT JUST NORTH OF LAKE ERIE WILL REMAIN NEARLY STATIONARY INTO
FRIDAY AS WAVES OF LOW PRESSURE MOVE ALONG THE FRONT. THE FRONT WILL
DROP SOUTHEAST ACROSS THE AREA LATER FRIDAY AND STALL NEAR THE OHIO
RIVER UNTIL A LOW SLOWLY MOVES ACROSS OHIO MONDAY NIGHT.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE...BOOSTED TEMPS A BIT IN PLACES BASED ON LATEST HRRR OUTPUT.


FOR 630 AM UPDATE...ONLY CHANGE WILL BE TO LOWER POPS FOR MORNING
SINCE NOTHING OF NOTE CURRENTLY OCCURRING. ALSO WILL ADD SOME PATCHY
FOG FOR NEXT FEW HOURS.

THE AIRMASS WILL REMAIN UNSTABLE TODAY. A LOW LEVEL JET WILL
CONTINUE TO BRING MOISTURE INTO THE CWA FROM THE SW WHILE WIND SHEAR
REMAINS RELATIVELY WEAK. THE SHORT TERM HI RES MODELS SEEM TO WANT
TO PRODUCE THE MOST CONVECTION INTO THE MORNING THEN THE NAM AND GFS
TAPER BACK THE THREAT INTO THE AFTERNOON AS THE FRONTAL CONVERGENCE
LIFTS NE OF THE AREA. WILL CONTINUE CHANCE POPS FOR TODAY WITH THE
BEST CHANCE IN THE NORTH. DUE TO THE LIMITED RISK FOR SEVERE WILL
NOT MENTION AT THIS TIME.

A VERY WARM DAY IS IN STORE WITH RECORD OR NEAR RECORD HIGHS
POSSIBLE.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
THE WEAK FRONTAL BOUNDARY WILL GET PUSHED SOUTH ACROSS THE CWA FRI.
ABUNDANT MOISTURE PRESENT WITH PW`S AROUND 1.5 INCHES. EXPECT FAIRLY
WIDESPREAD SHRA/TSRA TO SPREAD SE ACROSS THE REGION WITH THE FRONT.
CLOUD COVER WILL BE MORE EXTENSIVE SO THIS SHOULD HELP TO LIMIT HIGH
TEMPS/INSTABILITY AND THUS THE SEVERE THREAT.

FRI NIGHT...THE BETTER THREAT FOR CONVECTION SHOULD BE SHIFTING INTO
THE SOUTHERN HALF OF THE CWA WITH A LINGERING CHANCE INTO SAT FOR
MAINLY THE SOUTH. EVEN THOUGH OVERALL AIRMASS REMAINS QUITE WARM ON
SAT...NE FLOW OFF OF A CHILLY LAKE ERIE WILL LIKELY KEEP TEMPS IN
THE LOW TO MID 60S DOWNWIND OF THE LAKE.

THE HIGH TO THE NORTH SHOULD PUSH ENOUGH OF A RIDGE SOUTH INTO THE
AREA TO HOLD OFF THE PRECIP THREAT FOR SAT NIGHT AND SUN BUT
OVERRUNNING IN THE SW WILL BEGIN ON SUN AND COULD ALLOW SOME
CONVECTION TO RETURN.

THE APPROACH OF A LOW WEST OF THE AREA BY DAYBREAK MON WILL PROBABLY
LEAD TO MORE CONVECTION PUSHING INTO AT LEAST THE WEST HALF OF THE
AREA SUN NIGHT.

&&

.LONG TERM /MONDAY THROUGH WEDNESDAY/...
LOW PRESSURE WILL BE MOVING INTO THE REGION ON MONDAY WITH INCREASED
CHANCES OF RAIN BY AFTERNOON. THIS RAIN WILL CONTINUE INTO MONDAY
NIGHT AND MAY ACTUALLY LINGER INTO TUESDAY MORNING. MODELS ARE
DIFFERING ON HOW FAST THIS LOW WILL CLEAR THE AREA. A FRONTAL
BOUNDARY WILL NOT BE ALL THAT FAR FROM THE SOUTHERN COUNTY WARNING
AREA ON TUESDAY NIGHT BUT IT APPEARS THAT MUCH OF THE AREA WILL BE
DRY. MODELS ARE STRUGGLING ON HOW TO DIG THE NEXT TROUGH INTO THE
CENTRAL LAKES ON WEDNESDAY. THE DIFFERING SCENARIOS WOULD BE SHOWERS
RETURNING EITHER EARLY WEDNESDAY OR MAYBE HOLDING OFF UNTIL
AFTERNOON OR EVENING.

HIGHS WILL LIKELY BE ABOVE AVERAGE ON MONDAY BUT WE WILL COOL BACK
TO SEASONAL LEVELS FOR TUESDAY INTO WEDNESDAY.

&&

.AVIATION /16Z THURSDAY THROUGH MONDAY/...
EXPECT SOME MIDDLE AND HIGH LEVEL CLOUD COVER TO VARY IN
THICKNESS THROUGH THE MORNING. BELIEVE THERE WILL AT LEAST BE A
FEW PATCHES OF MVFR FOG...ESPECIALLY WHERE IT RAINED OVERNIGHT.
CANT COMPLETELY RULE OUT A SHOWER OR TWO DEVELOPING WITH THE
MORNING MIX. IF THESE DO OCCUR THEY WILL BE VERY BRIEF. SOUTHWEST
WINDS WILL BECOME GUSTY BY AFTERNOON. GUSTS IN THE 25 KNOT RANGE
WILL BE COMMON WITH A FEW LOCATIONS ACROSS NW OHIO AROUND 30
KNOTS.

THE ATMOSPHERE WILL BE UNSTABLE AGAIN THIS AFTERNOON BUT THERE
MAY NOT BE ANY BOUNDARIES TO GET THE CONVECTION STARTED. CANT RULE
OUT AN ISOLATED STORM ANYWHERE ACROSS THE REGION. HOWEVER IT
APPEARS THAT THE KERI AREA MAY HAVE THE BEST CHANCE BUT STILL
NOTHING HIGHER THAN 30 PERCENT.

.OUTLOOK...NON-VFR CONDITIONS POSSIBLE IN CONVECTION THURSDAY
EVENING AND AGAIN FRIDAY AFTERNOON/EVENING. NON-VFR POSSIBLE ON
MONDAY.

&&

.MARINE...
WARM FRONT WILL BE IN THE VICINITY OF THE NORTH SHORE OF LAKE ERIE
TODAY. THIS SHOULD ALLOW FOR A SOUTH TO SOUTHWEST WIND ACROSS THE
ENTIRE LAKE. THE STRONGEST WINDS WILL LIKELY BE ACROSS THE WESTERN
BASIN BUT SHOULD NOT EXCEED 20 KNOTS. SOUTHWESTERLY WINDS WILL
CONTINUE INTO FRIDAY NIGHT WITH A WIND SHIFT EXPECTED BY SATURDAY
MORNING AS A COLD FRONT PASSES. HIGH PRESSURE IN THE WAKE OF THE
FRONT WILL REMAIN IN CONTROL INTO SUNDAY WITH NORTHEAST TO EAST
WINDS EXPECTED. THIS WILL LIKELY CAUSE WAVES TO BUILD BUT WITH WINDS
NOT EXPECTED TO BE HIGHER THAN 15 KNOTS WE SHOULD SEE 2 TO 4 FOOT
WAVES. WE WILL HAVE TO WATCH THE WESTERN HALF OF THE LAKE CLOSELY IF
WIND SPEEDS ARE A BIT STRONGER THAN ANTICIPATED. AS LOW PRESSURE
APPROACHES THE CENTRAL LAKES ON MONDAY WINDS SHOULD GRADUALLY SWING
AROUND TO THE SOUTH.

&&

.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...ADAMS
NEAR TERM...ADAMS/TK
SHORT TERM...ADAMS
LONG TERM...MULLEN
AVIATION...MULLEN
MARINE...MULLEN







AREA FORECAST DISCUSSION

NWS WILMINGTON OH

 140 AM EDT THU MAY 3 2012

.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE WILL PASS THROUGH THE GREAT LAKES
TONIGHT. HIGH PRESSURE WILL STRENGTHEN ON THURSDAY...LEADING TO
MAINLY DRY WEATHER AND CONTINUED MUCH ABOVE NORMAL TEMPERATURES. A
COLD FRONT WILL SLOWLY SINK SOUTH INTO THE REGION THROUGH THE
WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
UPDATED THE FORECAST TO DECREASE PRECIPITATION CHANCES FOR THE
OVERNIGHT TIME FRAME. THE HRRR IS STILL TRYING TO SHOW A FEW
STORMS DEVELOPING AND MOVING ACROSS EXTREME NORTHERN PORTIONS OF
THE FA. MODELS HAVE BEEN OVERDOING PRECIPITATION TONIGHT AND
CURRENTLY DRY CONDITIONS ARE PRESENT ACROSS THE REGION. ONLY LEFT
A SLIGHT CHANCE OF THUNDERSTORMS IN ACROSS THE EXTREME NORTHERN
LOCATION OF THE FA HOWEVER BELIEVE THE CHANCE FOR PRECIPITATION
WILL BE LOW. MADE MINOR ADJUSTMENTS TO TEMPERATURES TO ACCOUNT FOR
CURRENT TRENDS.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM FRIDAY/...
UPPER LEVEL RIDGING WILL STRENGTHEN ON THURSDAY WHICH SHOULD PUT A
MORE SUBSIDENT ATMOSPHERE IN PLACE...ALTHOUGH A DECENT AMOUNT OF
INSTBY WILL CONTINUE TO BE PRESENT. SOME MODELS TRY TO POP A FEW
STORMS BUT THINK THIS THREAT IS PRETTY MINIMAL. WITH GOOD
MIXING...THERE WILL BE SOME CUMULUS DEVELOPMENT BUT STILL PLENTY
OF SUN AND WAA...SO EXPECT ANOTHER DAY OF TEMPERATURES IN THE MID
80S AND PERHAPS UPPER 80S IN THE SE. RECORD HIGHS ARE 87 AT
CVG...89 AT CMH...AND 90 AT DAY. IT WILL BE A LITTLE BREEZY AS
WELL...PARTICULARLY THE NW WHERE A TIGHTER PRESSURE GRADIENT WILL
BE DUE TO LOW PRESSURE OVER THE UPPER GREAT LAKES.

THERE IS SOME MODEL DISAGREEMENT ON WHAT TO DO WITH AN EMBEDDED
VORT MAX OVER THE GULF COAST. THE NAM/GFS TRY TO LIFT THIS ALL THE
WAY INTO WEST VIRGINIA BY THURSDAY EVENING AND OVERNIGHT...WHICH
COULD PROVIDE SOME PCPN TO OUR FAR SE COUNTIES. OTHER MODELS ARE
WEAKER WITH THIS FEATURE AND MAINLY KEEP ITS INFLUENCE OUT OF OUR
AREA. FOR NOW JUST INTRODUCED LOW END POPS IN THE SE DURING
THIS PERIOD. OTHERWISE ANOTHER NIGHT WITH LOWS IN THE MID 60S IS
IN STORE.

HEIGHTS BEGIN TO FALL ON FRIDAY. MODELS ARE IN PRETTY GOOD
AGREEMENT ON BRINGING A SHORTWAVE TROUGH THROUGH THE GREAT LAKES
DURING THE DAY...WHILE A SFC BOUNDARY SLOWLY SINKS SOUTH AS WELL.
DEEP MOISTURE WILL BE ON THE INCREASE...SO EXPECT MORE CLOUDS AND
SHOWERS AND THUNDERSTORMS GRADUALLY WORKING THEIR WAY SOUTH INTO
THE AREA. SHEAR PROFILES WILL ALSO BECOME MORE FAVORABLE WHICH
COULD LEAD TO SOME SEVERE STORMS. THIS IS HIGHLIGHTED IN THE HWO
AND SPC DAY 3 OUTLOOK. ABOVE FACTORS WILL LIMIT DAYTIME HIGHS TO
THE LOWER TO MID 80S. THE NORTH COULD BE COOLER IF STORMS MOVE IN
EARLY.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
SATURDAY STARTS OUT WITH THE PREDAWN HOURS AND A FRONT DRAPED W-E
OVER THE OHIO VALLEY PROVIDING A FOCUS FOR EXPECTED SHOWER AND
THUNDERSTORMS. THESE STORMS MAY CONTINUE INTO SATURDAY DAYLIGHT
HOURS AS THE FRONT CONTINUES TO SAG SOUTHWARD TOWARDS THE LOWER OHIO
VALLEY OR NORTHERN TENNESSEE VALLEY. THIS PUSH IS DUE TO BUILDING
HIGH PRESSURE OVER CANADA NORTH OF THE GREAT LAKES.

MODELS DIFFER IN THEIR RESULTS ON SUNDAY BUT THE EUROPEAN DEVELOPS A
WARM FRONT OVER CWA WHILE CANADIEN AND GFS CONTINUE TO BUILD THE
HIGH TO THE NORTHEAST...KEEPING A MORE DRY EASTERLY FLOW OVER CWA
THROUGH SUNDAY AND SUN NIGHT. LOW PRESSURE WILL DEVELOP OVER THE
MIDWEST ON MONDAY AND TRACK TOWARDS THE OHIO VALLEY DURING THE
DAY...COMBINING WITH THE BREAKDOWN OF THE UPPER RIDGE TO INCREASE
THE CHANCE FOR ANOTHER ROUND OF STORMS MONDAY AND MONDAY NIGHT.

THE RESULTANT COLD FRONT CROSSES EARLY TUESDAY AND DRIER AIR SHOULD
REPLACE IT THROUGH MID WEEK AS HIGH PRESSURE BUILDS BEHIND IT WITH
COOLER AND DRIER AIR.

TEMPERATURES THROUGH TUESDAY WILL CONTINUE TO BE UNSEASONABLY WARM
IN THE UPPER 70S TO LOWER 80S WITH MILD NIGHTTIME LOWS IN 55-60
RANGE. AFTER TUESDAY THERE SHOULD BE A BIT COOLER AIR FILTERING
IN...MAKING READINGS MORE TOWARDS SEASONAL NORMALS.

CONFIDENCE IN THE EXTENDED BEYOND SATURDAY REMAINS LOW DUE TO THE
LARGE VARIABILITY IN MODEL GUIDANCE AND RUN TO RUN INCONSISTENCY.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AN UPPER LEVEL LOW OVER THE SOUTHERN STATES WILL DRIFT NORTHWARD
TOWARD THE TENNESSEE VALLEY THIS AFTERNOON. IT WILL THEN WEAKEN AS
IT SHIFTS NE INTO THE MID/UPPER OHIO VALLEY TONIGHT.
MEANWHILE...THE WESTERN GREAT LAKES WILL REMAIN UNDER A BROAD SW
FLOW ALOFT WITH EMBEDDED DISTURBANCES RIPPLING THROUGH IT FROM
TIME TO TIME. OUR REGION WILL BE WEDGED BETWEEN THESE TWO WEATHER
FEATURES AND SHOULD REMAIN DRY THROUGH THE TAF PERIOD AS
CONVECTION IS EXPECTED TO REMAIN NW AND SE OF THE TAF SITES.

THIS PATTERN WILL RESULT IN VFR CONDITIONS...EXCEPT KLUK...WHERE
SOME RIVER FOG MAY RESULT IN SOME MVFR VSBYS UNTIL 13Z. SOUTH TO
SOUTHWEST WINDS WILL BECOME LOCALLY GUSTY UP TO 25 KNOTS BETWEEN
16Z AND 00Z...DIMINSIHING THIS EVENING AS THE LOW LEVELS DECOUPLE.

OUTLOOK...THUNDERSTORMS POSSIBLE FRIDAY...SATURDAY AND AGAIN ON
MONDAY.

&&

.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.

&&

$$
SYNOPSIS...SNYDER
NEAR TERM...NOVAK
SHORT TERM...SNYDER
LONG TERM...FRANKS
AVIATION...HICKMAN







AREA FORECAST DISCUSSION

NWS NASHVILLE TN

 939 AM CDT THU MAY 3 2012

.UPDATE...UPDATED ZONE PACKAGE TO FRESHEN IT UP A BIT. NO REAL
SUBSTANTATIVE CHANGES...MOST LOOKS ON TRACK. MODELS INDICATE THAT
THE UPPER LOW OVER WEST TN WILL MOVE A BIT FURTHER NORTH AND THEN
BE PUSHED EWD INTO EAST TN/KY BY THIS EVENING. AREA OF SCATTERED
TO NUMEROUS SHOWERS SHOULD MOVE INTO THE DAVIDSON COUNTY AREA SHORTLY
BUT PROBABLY START TO FRAGMENT A BIT AS DAYTIME HEATING TAKES
HOLD. LIGHTNING DATA HAS NO STRIKES IN THE AREA CURRENTLY...BUT
SOME TSTM DEVELOPMENT IS POSSIBLE...MAINLY TO THE EAST OF THE
CURRENT RAIN AREA. HI TEMPS IN THE LOWER 80S STILL LOOK FINE.


&&

.PREV DISCUSSION... /ISSUED 750 AM CDT THU MAY 3 2012/

UPDATE...

LATEST RADAR IMAGERY SHOWS LARGE AREA OF LIGHT TO MODERATE RAIN
SPREADING ACROSS SOUTHWEST MIDDLE TENNESSEE THIS MORNING.
CIRCULATION ASSOCIATED WITH UPPER LEVEL LOW APPEARS TO BE MOVING
MORE NORTHWARD THAN EARLIER MODEL RUNS INDICATED...MORE IN LINE
WITH 06Z GFS AND LOCAL WRF MODEL. THIS SHOULD HELP SPREAD
SOME BENEFICIAL RAIN ACROSS MUCH OF THE MID STATE TODAY.
ADDITIONAL SHOWERS AND THUNDERSTORMS SHOULD ALSO DEVELOP THIS
MORNING WITHIN AND TO THE EAST OF THE MAIN RAIN SHIELD WITH
ADDITIONAL DAYTIME HEATING. HAVE ADJUSTED POPS UPWARD ACROSS THE
BOARD AND RAISED TO CATEGORICAL ACROSS SOUTHERN COUNTIES ALONG THE
ALABAMA BORDER WHERE RAIN SHOULD CONTINUE THROUGH MUCH OF THE
MORNING HOURS AT LEAST. MADE OTHER MINOR ADJUSTMENTS TO GRIDS AND
ZONES AS WELL WITH UPDATED PRODUCTS OUT SHORTLY.

PREV DISCUSSION... /ISSUED 633 AM CDT THU MAY 3 2012/

UPDATE...FOR 12Z AVIATION FORECAST

AVIATION...
MESOCONVECTIVE VORTICITY FEATURE PUNCHING NORTHWARD THROUGH NORTHERN
ALABAMA AT 11Z WITH RAIN FIELD BEGINNING TO CURL MORE TOWARD THE
WEST AS IT HEADS NORTHWARD INTO SOUTHERN MIDDLE TENNESSEE. MODELS
DIFFER ON WHAT HAPPENS WITH RAIN AREA TODAY IN MID STATE. LATEST
RADAR LOOP MORE IN LINE WITH LATEST RUC RUN AND H-TRIPLE-R 08Z RUN
WHICH HAS THE RAIN REACHING NASHVILLE TERMINAL AROUND 16Z AND THEN
SPREADS EASTWARD ONTO PLATEAU AROUND 18Z. AS THE RAIN MOVED OVER
NORTH ALABAMA HUNTSVILLE MEASURED A TOTAL OF 0.05 INCH WITH VSBYS
NEVER GOING < P6SM AND CEILINGS REMAINING VFR...WITH SIMILAR
CONDITIONS AT MUSCLE SHOALS. MY GUT FEELING IS THAT THE RAIN AREA WILL
BECOME MORE WEST TO EAST ORIENTED RATHER THAN NORTH TO SOUTH AS
MODELS WANT TO DEPICT AND THEN SHIFT EASTWARD WHILE KEEPING AREAS
NORTH OF INTERSTATE 40 BASICALLY RAIN-FREE. ALL IN ALL NOT MUCH
CONFIDENCE IN FORECAST SO AVIATORS SHOULD LOOK FOR UPDATES AS WE
GO THROUGH THE MORNING.

BOYD

PREV DISCUSSION... /ISSUED 320 AM CDT THU MAY 3 2012/

DISCUSSION...

WATER VAPOR IMAGERY SHOWS A WEAK UPPER LEVEL LOW OVER MISSISSIPPI
THIS MORNING WITH A DEEP FEED OF TROPICAL MOISTURE SPREADING
NORTHWARD AHEAD OF THE LOW FROM THE GULF OF MEXICO THROUGH ALABAMA
INTO SOUTHERN MIDDLE TENNESSEE. THIS FEATURE WILL MOVE ACROSS THE
MID STATE TODAY...AND THE DEEPER MOISTURE COMBINED WITH THE LIFT
FROM THE UPPER LOW SHOULD PRODUCE SCATTERED TO NUMEROUS SHOWERS
AND THUNDERSTORMS ACROSS THE MID STATE. HIGHEST RAIN CHANCES WILL
BE ACROSS SOUTHERN ZONES AND THE PLATEAU...AND RADAR IMAGERY
ALREADY SHOWS LIGHT RAIN INCREASING ACROSS NORTHERN ALABAMA THIS
MORNING AND MOVING NORTHWARD INTO WAYNE/LAWRENCE/GILES COUNTIES.
COULD ALSO SEE A FEW STRONG STORMS TODAY AS MODERATE INSTABILITY
DEVELOPS AND 925-500MB SOUTHERLY WIND FIELDS INTENSIFY UP TO 40
KNOTS...WITH STRONG WIND GUSTS THE MAIN THREAT. DUE TO THE
EXPECTED PRECIPITATION AND CLOUD COVER...HIGH TEMPERATURES WILL
BE QUITE A BIT COOLER THAN THE RECORD/NEAR RECORD HIGHS SEEN
YESTERDAY.

UPPER LEVEL LOW WILL MOVE OUT OF THE MID STATE OVERNIGHT WITH
NORTHWEST FLOW DEVELOPING ALOFT FROM FRIDAY INTO THE WEEKEND.
GUIDANCE INDICATES A WEAK SHORTWAVE WILL MOVE ACROSS THE CWA ON
FRIDAY...WITH SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING BY
AFTERNOON AND CONTINUING THROUGH FRIDAY NIGHT. BULK SHEAR VALUES
INCREASING UP TO 40 KNOTS AND MODERATE INSTABILITY MAY LEAD TO A
FEW STRONG OR SEVERE THUNDERSTORMS...AND SPC HAS PLACED NORTHERN
PARTS OF THE MID STATE IN A SLIGHT RISK FOR SEVERE STORMS FOR
FRIDAY/FRIDAY NIGHT. AT LEAST LOW PRECIP CHANCES TO REMAIN IN THE
FORECAST THROUGH THE REMAINDER OF THE FORECAST PERIOD AS NORTHWEST
FLOW CONTINUES AND HEIGHTS GRADUALLY FALL INTO EARLY NEXT
WEEK...WITH TEMPERATURES SLOWLY COOLING DOWN CLOSER TO NORMAL
LEVELS.

&&

.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

18






AREA FORECAST DISCUSSION

NWS NASHVILLE TN

 750 AM CDT THU MAY 3 2012

.UPDATE...

LATEST RADAR IMAGERY SHOWS LARGE AREA OF LIGHT TO MODERATE RAIN
SPREADING ACROSS SOUTHWEST MIDDLE TENNESSEE THIS MORNING.
CIRCULATION ASSOCIATED WITH UPPER LEVEL LOW APPEARS TO BE MOVING
MORE NORTHWARD THAN EARLIER MODEL RUNS INDICATED...MORE IN LINE
WITH 06Z GFS AND LOCAL WRF MODEL. THIS SHOULD HELP SPREAD
SOME BENEFICIAL RAIN ACROSS MUCH OF THE MID STATE TODAY.
ADDITIONAL SHOWERS AND THUNDERSTORMS SHOULD ALSO DEVELOP THIS
MORNING WITHIN AND TO THE EAST OF THE MAIN RAIN SHIELD WITH
ADDITIONAL DAYTIME HEATING. HAVE ADJUSTED POPS UPWARD ACROSS THE
BOARD AND RAISED TO CATEGORICAL ACROSS SOUTHERN COUNTIES ALONG THE
ALABAMA BORDER WHERE RAIN SHOULD CONTINUE THROUGH MUCH OF THE
MORNING HOURS AT LEAST. MADE OTHER MINOR ADJUSTMENTS TO GRIDS AND
ZONES AS WELL WITH UPDATED PRODUCTS OUT SHORTLY.


&&

.PREV DISCUSSION... /ISSUED 633 AM CDT THU MAY 3 2012/

UPDATE...FOR 12Z AVIATION FORECAST

AVIATION...
MESOCONVECTIVE VORTICITY FEATURE PUNCHING NORTHWARD THROUGH NORTHERN
ALABAMA AT 11Z WITH RAIN FIELD BEGINNING TO CURL MORE TOWARD THE
WEST AS IT HEADS NORTHWARD INTO SOUTHERN MIDDLE TENNESSEE. MODELS
DIFFER ON WHAT HAPPENS WITH RAIN AREA TODAY IN MID STATE. LATEST
RADAR LOOP MORE IN LINE WITH LATEST RUC RUN AND H-TRIPLE-R 08Z RUN
WHICH HAS THE RAIN REACHING NASHVILLE TERMINAL AROUND 16Z AND THEN
SPREADS EASTWARD ONTO PLATEAU AROUND 18Z. AS THE RAIN MOVED OVER
NORTH ALABAMA HUNTSVILLE MEASURED A TOTAL OF 0.05 INCH WITH VSBYS
NEVER GOING < P6SM AND CEILINGS REMAINING VFR...WITH SIMILAR
CONDITIONS AT MUSCLE SHOALS. MY GUT FEELING IS THAT THE RAIN AREA WILL
BECOME MORE WEST TO EAST ORIENTED RATHER THAN NORTH TO SOUTH AS
MODELS WANT TO DEPICT AND THEN SHIFT EASTWARD WHILE KEEPING AREAS
NORTH OF INTERSTATE 40 BASICALLY RAIN-FREE. ALL IN ALL NOT MUCH
CONFIDENCE IN FORECAST SO AVIATORS SHOULD LOOK FOR UPDATES AS WE
GO THROUGH THE MORNING.

BOYD

PREV DISCUSSION... /ISSUED 320 AM CDT THU MAY 3 2012/

DISCUSSION...

WATER VAPOR IMAGERY SHOWS A WEAK UPPER LEVEL LOW OVER MISSISSIPPI
THIS MORNING WITH A DEEP FEED OF TROPICAL MOISTURE SPREADING
NORTHWARD AHEAD OF THE LOW FROM THE GULF OF MEXICO THROUGH ALABAMA
INTO SOUTHERN MIDDLE TENNESSEE. THIS FEATURE WILL MOVE ACROSS THE
MID STATE TODAY...AND THE DEEPER MOISTURE COMBINED WITH THE LIFT
FROM THE UPPER LOW SHOULD PRODUCE SCATTERED TO NUMEROUS SHOWERS
AND THUNDERSTORMS ACROSS THE MID STATE. HIGHEST RAIN CHANCES WILL
BE ACROSS SOUTHERN ZONES AND THE PLATEAU...AND RADAR IMAGERY
ALREADY SHOWS LIGHT RAIN INCREASING ACROSS NORTHERN ALABAMA THIS
MORNING AND MOVING NORTHWARD INTO WAYNE/LAWRENCE/GILES COUNTIES.
COULD ALSO SEE A FEW STRONG STORMS TODAY AS MODERATE INSTABILITY
DEVELOPS AND 925-500MB SOUTHERLY WIND FIELDS INTENSIFY UP TO 40
KNOTS...WITH STRONG WIND GUSTS THE MAIN THREAT. DUE TO THE
EXPECTED PRECIPITATION AND CLOUD COVER...HIGH TEMPERATURES WILL
BE QUITE A BIT COOLER THAN THE RECORD/NEAR RECORD HIGHS SEEN
YESTERDAY.

UPPER LEVEL LOW WILL MOVE OUT OF THE MID STATE OVERNIGHT WITH
NORTHWEST FLOW DEVELOPING ALOFT FROM FRIDAY INTO THE WEEKEND.
GUIDANCE INDICATES A WEAK SHORTWAVE WILL MOVE ACROSS THE CWA ON
FRIDAY...WITH SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING BY
AFTERNOON AND CONTINUING THROUGH FRIDAY NIGHT. BULK SHEAR VALUES
INCREASING UP TO 40 KNOTS AND MODERATE INSTABILITY MAY LEAD TO A
FEW STRONG OR SEVERE THUNDERSTORMS...AND SPC HAS PLACED NORTHERN
PARTS OF THE MID STATE IN A SLIGHT RISK FOR SEVERE STORMS FOR
FRIDAY/FRIDAY NIGHT. AT LEAST LOW PRECIP CHANCES TO REMAIN IN THE
FORECAST THROUGH THE REMAINDER OF THE FORECAST PERIOD AS NORTHWEST
FLOW CONTINUES AND HEIGHTS GRADUALLY FALL INTO EARLY NEXT
WEEK...WITH TEMPERATURES SLOWLY COOLING DOWN CLOSER TO NORMAL
LEVELS.

&&

.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHAMBURGER






AREA FORECAST DISCUSSION

NWS NASHVILLE TN

 633 AM CDT THU MAY 3 2012

.UPDATE...FOR 12Z AVIATION FORECASST

&&

.AVIATION...
MESOCONVECTIVE VORTICITY FEATURE PUNCHING NORTHWARD THROUGH NORTHERN
ALABAMA AT 11Z WITH RAIN FIELD BEGINNING TO CURL MORE TOWARD THE
WEST AS IT HEADS NORTHWARD INTO SOUTHERN MIDDLE TENNESSEE. MODELS
DIFFER ON WHAT HAPPENS WITH RAIN AREA TODAY IN MID STATE. LATEST
RADAR LOOP MORE IN LINE WITH LATEST RUC RUN AND H-TRIPLE-R 08Z RUN
WHICH HAS THE RAIN REACHING NASHVILLE TERMINAL AROUND 16Z AND THEN
SPREADS EASTWARD ONTO PLATEAU AROUND 18Z. AS THE RAIN MOVED OVER
NORTH ALABAMA HUNTSVILLE MEASURED A TOTAL OF 0.05 INCH WITH VSBYS
NEVER GOING < P6SM AND CEILINGS REMAINING VFR...WITH SIMILAR
CONDITIONS AT MUSCLE SHOALS. MY GUT FEELING IS THAT THE RAIN AREA WILL
BECOME MORE WEST TO EAST ORIENTED RATHER THAN NORTH TO SOUTH AS
MODELS WANT TO DEPICT AND THEN SHIFT EASTWARD WHILE KEEPING AREAS
NORTH OF INTERSTATE 40 BASICALLY RAIN-FREE. ALL IN ALL NOT MUCH
CONFIDENCE IN FORECAST SO AVIATORS SHOULD LOOK FOR UPDATES AS WE
GO THROUGH THE MORNING.


BOYD
&&

.PREV DISCUSSION... /ISSUED 320 AM CDT THU MAY 3 2012/

DISCUSSION...

WATER VAPOR IMAGERY SHOWS A WEAK UPPER LEVEL LOW OVER MISSISSIPPI
THIS MORNING WITH A DEEP FEED OF TROPICAL MOISTURE SPREADING
NORTHWARD AHEAD OF THE LOW FROM THE GULF OF MEXICO THROUGH ALABAMA
INTO SOUTHERN MIDDLE TENNESSEE. THIS FEATURE WILL MOVE ACROSS THE
MID STATE TODAY...AND THE DEEPER MOISTURE COMBINED WITH THE LIFT
FROM THE UPPER LOW SHOULD PRODUCE SCATTERED TO NUMEROUS SHOWERS
AND THUNDERSTORMS ACROSS THE MID STATE. HIGHEST RAIN CHANCES WILL
BE ACROSS SOUTHERN ZONES AND THE PLATEAU...AND RADAR IMAGERY
ALREADY SHOWS LIGHT RAIN INCREASING ACROSS NORTHERN ALABAMA THIS
MORNING AND MOVING NORTHWARD INTO WAYNE/LAWRENCE/GILES COUNTIES.
COULD ALSO SEE A FEW STRONG STORMS TODAY AS MODERATE INSTABILITY
DEVELOPS AND 925-500MB SOUTHERLY WIND FIELDS INTENSIFY UP TO 40
KNOTS...WITH STRONG WIND GUSTS THE MAIN THREAT. DUE TO THE
EXPECTED PRECIPITATION AND CLOUD COVER...HIGH TEMPERATURES WILL
BE QUITE A BIT COOLER THAN THE RECORD/NEAR RECORD HIGHS SEEN
YESTERDAY.

UPPER LEVEL LOW WILL MOVE OUT OF THE MID STATE OVERNIGHT WITH
NORTHWEST FLOW DEVELOPING ALOFT FROM FRIDAY INTO THE WEEKEND.
GUIDANCE INDICATES A WEAK SHORTWAVE WILL MOVE ACROSS THE CWA ON
FRIDAY...WITH SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING BY
AFTERNOON AND CONTINUING THROUGH FRIDAY NIGHT. BULK SHEAR VALUES
INCREASING UP TO 40 KNOTS AND MODERATE INSTABILITY MAY LEAD TO A
FEW STRONG OR SEVERE THUNDERSTORMS...AND SPC HAS PLACED NORTHERN
PARTS OF THE MID STATE IN A SLIGHT RISK FOR SEVERE STORMS FOR
FRIDAY/FRIDAY NIGHT. AT LEAST LOW PRECIP CHANCES TO REMAIN IN THE
FORECAST THROUGH THE REMAINDER OF THE FORECAST PERIOD AS NORTHWEST
FLOW CONTINUES AND HEIGHTS GRADUALLY FALL INTO EARLY NEXT
WEEK...WITH TEMPERATURES SLOWLY COOLING DOWN CLOSER TO NORMAL
LEVELS.

&&

.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

01






AREA FORECAST DISCUSSION

NWS GREEN BAY WI

 701 PM CDT FRI MAY 4 2012

UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE

.SHORT TERM...TONIGHT AND SATURDAY.

LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LAST NIGHTS
COLD FRONT DRIFTING SOUTH OVER NORTHERN ILLINOIS/INDIANA WHILE
HUDSON BAY HIGH PRESSURE IS BUILDING SOUTHWARD INTO THE WESTERN
GREAT LAKES.  LOW CLOUDS HAVE STUCK AROUND ALL DAY OVER CENTRAL
WISCONSIN WHERE MOISTURE REMAINS PLENTIFUL...BUT NORTHERN WISCONSIN
HAS CLEARED OUT NICELY.  LOOKING UPSTREAM...SHORTWAVE TROUGH OVER
SOUTH-CENTRAL CANADA HAS HELPED RETURN FLOW KICK OFF SHOWERS AND
THUNDERSTORMS OVER WESTERN MINNESOTA AND EASTERN SOUTH DAKOTA.
THESE STORMS HAVE BEEN RIDING ALONG THE MOST UNSTABLE CAPE
GRADIENT...WHICH STRETCHES FROM SOUTHERN MINNESOTA INTO SW
WISCONSIN.  AS THE RETURN FLOW SHIFTS EAST TONIGHT...SHOWER AND
THUNDERSTORM CHANCES ARE THE MAIN FORECAST CONCERN.

TONIGHT...WEAK SHORTWAVE ACTIVITY WILL CLIMB OVER TOP THE MID-LEVEL
RIDGE INTO FAR SOUTH-CENTRAL CANADA TONIGHT.  RETURN FLOW OVER THE
NORTHERN PLAINS WILL MOVE EAST INTO WESTERN WISCONSIN BY 06Z AND
CENTRAL WISCONSIN BY 12Z.  CLUSTER OF SHOWERS AND STORMS WILL SPREAD
EAST WITH THE ISENTROPIC ASCENT ON THE 300-305K SURFACES IN A REGION
OF GOOD MOISTURE ADVECTION.  HAVE NOT SEEN ANY SIGNS YET THAT THE
DRY AIR ON MPX/S SOUNDING IS ERODING THIS CLUSTER OF STORMS...SO THE
LATEST TIMING WOULD HAVE PRECIP ARRIVING LATE IN THE EVENING INTO
CENTRAL WISCONSIN.  WILL INCREASE POPS AND BRING THEM FARTHER SOUTH.  LIKE
THE PREVIOUS SHIFT...COULDNT FIND MUCH INSTABILITY...BUT CANT ARGUE
WITH THE CURRENT THUNDERSTORM ACTIVITY ONGOING...SO WILL ADD TO THE
FORECAST AS WELL.  PRECIP WILL SPREAD EAST OVERNIGHT...BUT WILL
ENCOUNTER DRIER AIR OVER THE NORTH-CENTRAL GREAT LAKES...WHICH AM
COUNTING ON TO FINALLY SLOW ITS FORWARD PROGRESSION.  SO WILL KEEP
THE LOWEST CHANCES OVER THE EAST.  LOWS MAINLY IN THE 40S.

SATURDAY...300-305K ISENTROPIC ASCENT WILL CONTINUE TO SPREAD EAST
DURING THE MORNING...WHILE THE 850MB BAROCLINIC ZONE STALLS OVER
NORTHEAST WISCONSIN.  FORCING LOOKS THE BEST DURING THE MORNING WHEN
WILL HAVE THE HIGHEST CHANCES OF POPS.  IN THE AFTERNOON...WE LOSE
SOME OF THE LOWER CONDENSATION PRESSURE DEFICITS AND DRIER AIR
ARRIVES IN THE MID AND UPPER LEVELS.  SEEMS REASONABLE TO THINK THAT
MOST OF THE PRECIP WILL FALL DURING THE MORNING AND ONLY SPOTTY
SHOWERS OR MAYBE EVEN DRIZZLE LEFT FOR THE AFTERNOON.  PLENTY OF
SATURATION BELOW 800MB...SO HAVE A TOUGH TIME SEEING CLEARING
OCCURRING.  LOTS OF CLOUDS...PRECIP...AND AN EAST WIND DOES NOT BODE
WELL FOR WARM TEMPS TOMORROW.  WILL MAYBE DROP THE PREV SHIFT/S
TEMPS BY A DEGREE IN SPOTS.

.LONG TERM...SATURDAY NIGHT THROUGH NEXT FRIDAY. SATURDAY NIGHT
INTO SUNDAY NIGHT WILL BE DOMINATED BY THE UPPER DIFFLUENCE
REGION AHEAD OF A DEEPENING UPPER LOW DRIFTING OVER THE NORTHERN
PLAINS. A SURFACE TROUGH IS PROGGED TO TRACK OVER THE WESTERN
GREAT LAKES REGION WITH RESPECT TO THIS SYSTEM. TWO SURFACE LOWS
PRESSURE REGIONS OF NOTE...ONE NEAR THE UPPER LOW OVER THE
NORTHERN PLAINS AND A SECOND NEAR THE MORE UNSTABLE AND DEEPER
MOISTURE REGION OVER THE CENTRAL PLAINS AND MID MISSISSIPPI VALLEY
REGION. THIS SOURCE OF MOIST UNSTABLE AIR IN THE RETURN FLOW IS
THE FOCUS OF POTENTIALLY ANOTHER ROUND OF HEAVY RAIN FALL FOR
SOMEWHERE IN THE STATE. AT THIS TIME BEST AMOUNTS COULD BE OVER
NORTHERN OR NORTHEAST THIRD OF THE STATE WHERE THE H8 BAROCLINIC
ZONE EXTENDS DURING THE PERIOD. NORTHERN WISCONSIN IS ALSO CLOSER
TO THE UPPER JET DYNAMICS. WHEREAS THE AIR MASS A LITTLE MORE
UNSTABLE TOWARD SOUTHERN WISCONSIN. GOING FORECAST OF THE EVENT
LOOKS GOOD...AND ANTICIPATE ONLY MINOR CHANGES WITH RESPECT TO
TIMING. 12Z RUNS INDICATED THE GFS IS MUCH SLOWER WITH DEPARTING
THE SOUTHERN STREAM SURFACE LOW ON MONDAY.

WHILE A DIMINISHED PCPN TREND IS EXPECTED LATER MONDAY INTO MONDAY
NIGHT AS THE SURFACE FRONTAL SYSTEM SHIFTS EAST AND HIGH PRESSURE
SLIDES INTO THE CENTRAL PLAINS...THE UPPER LOW IS PROGGED TO PIVOT
OVER THE GREAT LAKES REGION ON TUESDAY FOR A PERIOD OF CLOUDS AND
PERHAPS DIURNAL TYPE PCPN.

MEDIUM RAIN PROGS BUILD A SURFACE AND UPPER RIDGE INTO THE AREA
FOR MID WEEK BEFORE THE NEXT NORTHERN STREAM SYSTEM APPROACHES
FROM THE NORTHERN PLAINS.
&&

.AVIATION...HIGH PRESSURE CENTERED NORTH OF THE GREAT LAKES WILL
CIRCULATE DRY AIR IN THE LOW LEVELS INTO NORTHERN AND CENTRAL
WISCONSIN TONIGHT WHILE AN UPPER LEVEL DISTURBANCE CAUSES AN
INCREASE IN HUMIDITY ABOVE THE GROUND. THE RESULT WILL BE A
GRADUAL INCREASE IN CLOUDINESS AND LOWERING OF CEILINGS LATE
TONIGHT AND SATURDAY MORNING ALONG WITH PERIODS OF RAIN. THE
LOWEST CEILINGS AND GREATEST CHANCES OF RAIN WILL BE WEST OF AN
IMT TO OSH LINE.

RDM
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$







AREA FORECAST DISCUSSION

NWS GREEN BAY WI

 250 PM CDT THU MAY 3 2012

.SHORT TERM...TONIGHT AND FRIDAY.

LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW MULTIPLE AREAS
OF LOW PRESSURE RANGING FROM THE UPPER PENINSULA TO CENTRAL KANSAS
EARLY THIS AFTERNOON.  ATTACHED TO ONE OF THE LOWS OVER SOUTHERN
MINNESOTA IS A WARM FRONT WHICH HAS MOVED VERY LITTLE FROM MSP TO
MTW.  EARLIER MCV HAS DEPARTED THE REGION WHILE WE AWAIT FOR ANOTHER
SMALLER CLUSTER OF STORMS TO PUSH INTO CENTRAL WISCONSIN. IN
GENERAL...THE WIDESPREAD CONVECTION FROM EARLIER TODAY AS WORKED
OVER THE ATMOSPHERE...WHILE CLOUD COVER HAS PREVENTED FULL
SURFACE-BASED HEATING.  BETTER HEATING HAS OCCURRED OVER SOUTHERN
WISCONSIN WHERE TEMPS HAVE WARMED INTO THE UPPER 70S TO LOWER 80S.
WILL HAVE TO REACH INTO THE MID TO UPPER 70S FOR A CHANCE OF
ADDITIONAL STORM DEVELOPMENT THROUGH THE REST OF THE AFTERNOON.
WITH ADDITIONAL SHOWERS AND STORMS PUSHING IN FROM THE WEST AND
AMPLE CLOUD COVER OVERHEAD...THINK CHANCES OF THIS OCCURRING IS
FAIRLY LOW.  MEANWHILE...A COLD FRONT IS DROPPING SOUTH ACROSS LAKE
SUPERIOR AND NORTHERN MINNESOTA WHERE TEMPS FALL BACK INTO THE 50S.
THE MAIN FORECAST CONCERNS INCLUDE THUNDER AND SEVERE WEATHER
CHANCES TONIGHT.

TONIGHT...THE PESKY SURFACE WARM FRONT WILL CONTINUED TO BE DRAPED
ACROSS CENTRAL WISCONSIN EARLY IN THE EVENING.  MODEL GUIDANCE SHOWS
THE RIGHT REAR QUAD OF A JET STREAK BUILDING BACK INTO SOUTHERN AND
CENTRAL WISCONSIN THROUGH THE EVENING.  AS A RESULT...THERE IS
ENOUGH SUPPORT ALOFT TO KEEP A HIGH CHANCE OF SHOWERS AND
THUNDERSTORMS IN THE FORECAST FROM CENTRAL TO NORTHEAST WISCONSIN.
THE LLJ WILL BE DEVELOPING WELL SOUTH AND EAST OF THE REGION...SO
WILL NOT HAVE THE GOOD MASS CONVERGENCE FOR SEVERE STORMS...BUT
PERHAPS ENOUGH FOR ISOLATED TO SCT COVERAGE.  A COLD FRONT WILL DROP
INTO NORTHERN WISCONSIN IN THE EVENING...THEN DRIVE INTO CENTRAL
WISCONSIN OVERNIGHT.  THIS FRONT WILL END THE SHOWER AND
THUNDERSTORM THREAT...AS WELL AS BRING A RETURN OF NORTHEAST WINDS
AND LESS HUMID CONDITIONS.  QUITE A BIT OF LOW STRATO-CU UPSTREAM
BEHIND THE FRONT...AND THINK WILL HAVE A PROBLEM CLEARING ESPECIALLY
WITH THE AMPLE LOW LEVEL MOISTURE LEFT BEHIND FROM THE EXCESSIVE
RAINFALL.  LOWS BACK INTO THE 40S NORTH TO THE UPPER 50S SOUTH.

FRIDAY...SURFACE COLD FRONT WILL MOVE FROM CENTRAL WISCONSIN INTO
NORTHERN ILLINOIS AND NORTHEAST IOWA IN THE AFTERNOON.  BEHIND THE
FRONT...CANADIAN HIGH PRESSURE WILL BUILD SOUTH ACROSS THE STATE
THROUGH THE DAY.  WILL SEE COOLER AND NOTICEABLY DRIER CONDITIONS
ARRIVE...BROUGHT IN BY BRISK NE WINDS.  LOOKING UPSTREAM...PLENTY OF
LOW CLOUDS BEHIND THE FRONT OVER SOUTHERN MANITOBA AND ONTARIO...SO
THINK WILL SEE A MOSTLY CLOUDY MORNING...FOLLOWED BY PARTLY SUNNY
CONDITIONS IN THE AFTERNOON. NEXT SYSTEM LOOKS LIKE IT WILL STAY TO
THE WEST AT THIS POINT.  HIGHS IN THE 50S NEAR LAKE MICHIGAN...TO
AROUND 70 OVER CENTRAL WISCONSIN.

.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY.
MAIN CONCERN FOR THIS PACKAGE WILL BE THE PERIODIC CHANCES FOR
SHOWERS OR THUNDERSTORMS INTO EARLY NEXT WEEK. SOME MODEL DIFFERENCES
NOTED IN TIMING OF THESE SYSTEMS. FIRST SYSTEM EXPECTED TO PUSH
INTO THE AREA LATE FRIDAY NIGHT AND SATURDAY. WILL HAVE A SMALL
CHANCE OF SHOWERS ACROSS THE WEST LATE FRIDAY NIGHT...THEN A
CHANCE ACROSS THE ENTIRE AREA SATURDAY. DRY AIR FROM A CANADIAN
HIGH PRESSURE SHOULD LIMIT THE THUNDER POTENTIAL. DID KEEP ISOLATED
THUNDER ACROSS THE FAR WEST AND SOUTH TO MATCH UP WITH LA CROSSE
AND MILWAUKEE.

FOR SATURDAY NIGHT...THERE MAY BE A LINGERING SHOWER SATURDAY
EVENING...THEN THERE WILL BE A CHANCE OF SHOWERS AGAIN LATE
SATURDAY NIGHT ACROSS THE FAR WEST. STRONGER SYSTEM WORKING ACROSS
THE AREA WILL BRING LIKELY CHANCES FOR SHOWERS AND THUNDERSTORMS
SUNDAY INTO SUNDAY NIGHT. WILL CONTINUE TO KEEP A SMALL CHANCES OF
SHOWERS DUE TO DEPARTING SYSTEM...THEN MONDAY NIGHT SHOULD BE MAINLY
DRY.

AN UPPER TROUGH IS THEN EXPECTED TO SWING ACROSS THE AREA TUESDAY
AFTERNOON AND TUESDAY NIGHT...BRINGING ANOTHER CHANCE FOR SHOWERS
AND ISOLATED THUNDERSTORMS. FOR WEDNESDAY...CYCLONIC FLOW WILL GRADUALLY
PUSH EAST. WILL CONTINUE THE SMALL CHANCE FOR SHOWERS. HIGH PRESSURE
THEN BUILDS INTO THE REGION FOR WEDNESDAY NIGHT AND THURSDAY. TEMPERATURES
WILL RUN AT OR BELOW NORMAL DURING THE PERIOD.
&&

.AVIATION...FORECAST UNCERTAINTY IS SPILLING OVER INTO THE TAF
DEPARTMENT.  ISOLATED TO SCATTERED SHOWERS AND STORMS REMAIN
POSSIBLE THROUGH EARLY THIS EVENING ACROSS NORTH-CENTRAL AND
NORTHEAST WISCONSIN.  STRONGEST STORMS MAY IMPACT THE FOX VALLEY IF
TEMPERATURES CAN WARM INTO THE MIDDLE TO UPPER 70S.
OTHERWISE...PARTIAL CLEARING THIS AFTERNOON WILL LEAD TO VFR
CONDITIONS OUTSIDE OF THUNDERSTORMS.  A COLD FRONT WILL PASS ACROSS
THE AREA FROM NORTH TO SOUTH TONIGHT.  AMPLE MOISTURE FROM THE
RAINFALL AND THE ARRIVAL OF COOLER AIR WILL LEAD TO THE POSSIBILITY
OF LOWERING MVFR CIGS TO POSSIBLY IFR LATE TONIGHT.  CLOUDS TO STICK
AROUND IN THE MORNING...THOUGH CIGS WILL BE IMPROVING AS A RESULT OF
DAYTIME HEATING.

MPC
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$
MPC/ECKBERG







AREA FORECAST DISCUSSION

NWS GREEN BAY WI

 1229 PM CDT THU MAY 3 2012

UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE

.UPDATE...LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A
BROAD AREA OF LOW PRESSURE CENTERED OVER SOUTHERN MINNESOTA AND
NORTHERN IOWA...WITH A WARM FRONT EXTENDING ACROSS CENTRAL
WISCONSIN TO AROUND MANITOWOC. AN MCV IS TRACKING ALONG THE WARM
FRONT OVER CENTRAL WISCONSIN...WHICH HAS IGNITED ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS. WITH CLOUD TOPS COOLING...POTENTIAL
WILL REMAIN FOR AN ISOLATED SEVERE WEATHER THREAT UNTIL ABOUT
MIDDAY...WHEN THE MCV DEPARTS. HAVE HAD WIND GUSTS UP TO 40 KTS
AND NICKEL SIZED HAIL WITH THE STORMS PROGRESSING ACROSS EAST-
CENTRAL WISCONSIN SO FAR.

WITH THE WARM FRONT EXTENDING BACK TOWARDS MINNEAPOLIS WHERE
ANOTHER NEAR SEVERE CLUSTER OF STORMS EXISTS...POTENTIAL WILL BE
THERE FOR SCATTERED THUNDERSTORM ACTIVITY THROUGH THE AFTERNOON.
THOUGH DID PLACE THE HIGHEST POPS OVER NE WISCONSIN WITHIN THE
COMMA HEAD OF THE MCV THAT WILL BE DEPARTING EARLY THIS AFTERNOON.
AS FOR THE SEVERE THREAT...THE ATMOSPHERE HAS BEEN WORKED OVER
CONTINUOUSLY SINCE THE OVERNIGHT HOURS...AND WILL NEED TO SEE SOME
HEATING IN ORDER TO GET A SURFACE BASED THREAT. CONFIDENCE IS LOW
THAT THIS WILL OCCUR...DO TO THE ONGOING CONVECTION...AND CLOUD
COVER UPSTREAM. WOULD THINK OUTFLOW BOUNDARIES SOUTH OF THE
CONVECTION OVER SOUTHERN WISCONSIN WOULD STAND A BETTER CHANCE.
WILL KEEP AN EYE ON IT...AND WILL SEE IF THE CLUSTER NEAR MSP CAN
STAY ALIVE INTO CENTRAL WISCONSIN LATER THIS AFTERNOON.

MPC
&&

.PREV DISCUSSION...ISSUED AT 339 AM CDT THU MAY 3 2012...

SYNOPSIS...WARM AND HUMID WITH SHOWERS AND THUNDERSTORMS
TODAY...THEN TURNING COOLER AND LESS HUMID.

BROAD UPR TROF PRESENTLY COVERS THE WRN 3/4 OF THE CONUS...WITH
RIDGING OVER THE FAR E. DEVELOPING BLOCKING PATTERN OVER FAR ERN
CANADA AND THE NW ATL WL FORCE ERN CONUS RIDGE TO REFORM WEST OVER
THE GREAT LAKES RGN DURING THE WEEKEND...THEN THE REMNANTS OF THE
WRN TROF WL PROGRESS EWD ACRS THE RGN DURING THE EARLY TO MIDDLE
PART OF NEXT WK.

HAVING THE UPR PATTERN IN A STATE OF FLUX WL RESULT IN A VARIETY
OF WX ACRS THE FCST AREA. WARM AND WET PATTERN WL PREVAIL EARLY...
WITH FLOODING NOW ONGOING ACRS THE FAR SRN PART OF THE FCST AREA.
A SWD SURGE OF COOLER CANADIAN AIR WL PUSH THE BULK OF THE PCPN S
AND ALLOW COOLER AIR TO DOMINATE FOR A DAY OR TWO. THEN CHCS FOR
PCPN WL RETURN AS REMNANTS OF THE WRN TROF HEAD TOWARD THE AREA.
PCPN AMNTS FOR THE 7 DAY PERIOD SHOULD END UP ABV NORMAL.
TEMPS WL START OUT ABV NORMAL THEN FALL BACK CLOSER TO NORMAL.

SHORT TERM...TDA/TNGT/FRI. MAIN CONCERN IS ONGOING FLASH
FLOODING ACRS THE FAR SRN PART OF THE FCST AREA. LINE OF
CONVECTION PRODUCING THE FLOODING WAS BEING FED BY SWLY LLJ OF
40-45 KTS... WHICH WAS FEEDING INSTABILITY IN FM THE SW. MESO
PLOTS THE LAST COUPLE HRS SHOWED THE STRONGEST LOW-LEVEL MOISTURE
CONVERGENCE STARTING TO SHIFT OFF TO THE E IN RESPONSE TO GRADUAL
VEERING OF THE LLJ. SO THINK THE AMNT OF BACKBUILDING AND TRAINING
INTO THE FLOOD ZONE WL DECR. SCHEDULED 10Z/11Z EXPIRATION TIMES OF
THE WARNINGS MIGHT BE CUTTING IT CLOSE...ESP SINCE FLOODING WL
LINGER EVEN AFTER RAIN DIMINISHES. WL NEED TO RE-EVALUATE THAT AS
WE GET CLOSE TO THE EXPIRATION TIMES.

PCPN TRENDS LATER TDA NOT VERY CLEAR CUT. GIVEN MID-LVL SHRTWV
HEADED INTO THE AREA...POSN OF FCST AREA NR RRQ OF UPR JET...AND
COLD FRONT SET TO SAG INTO THE N THIS AFTN...ADDITIONAL TSRA
DEVELOPMENT SEEMS A GOOD BET. BUT SUSPECT IT WON/T BE QUITE AS
FOCUSED/ORGAINZED AS CURRENT BATCH. WL CARRY FAIRLY HIGH
POPS...BUT DON/T FEEL MUCH IN THE WAY OF SPECIFICS/DETAILS CAN BE
ADDED AT THIS POINT. SPC SLGT RISK COVERS ABOUT THE SRN 1/2 OF THE
FCST AREA. ALTHOUGH A SVR STORM CAN/T BE RULED OUT...RIGHT NOW
THERE WOULD SEEM TO BE TOO MANY CLDS AND NOT ENOUGH FOCUSED
FORCING FOR MORE THAN A MARGINAL SVR EVENT.

FRONT WL CONT TO SAG SWD TNGT. SLOWLY EDGED POPS SWD DURING THE
NIGHT...DRYING OUT THE N AFTER MIDNIGHT. LINGERED LOW POPS OVER
THE FAR S EARLY FRI...AND BROUGHT LOW POPS BACK INTO THE FAR NW
LATE IN THE DAY. ADJUSTED TEMPS DOWN AS INCRG NELY FLOW WILL BRING
COOLER AND DRIER AIR INTO THE RGN...AND ACRS THE COLD WATERS OF
THE GREAT LAKES.

LONG TERM...FRI NGT THRU NXT WED. MAIN FCST FOCUS TO BE THE
MOVEMENT OF AN EWD MOVING...POSITIVELY-TILTED UPR TROF WHICH
EVENTUALLY SPLITS INTO A SW CONUS CUT-OFF UPR LOW AND NEARLY
CUT-OFF UPR LOW OVER THE GREAT LKS. INITIALLY...STILL DEALING
WITH ACTIVE W-SW FLOW THRU THE WEEKEND WITH SMALL PCPN CHCS AND
THEN INSTABILITY PCPN TOWARD MID-WEEK WITH THE UPR LOW. TEMPS ARE
EXPECTED TO AVERAGE BLO NORMAL THRU THE MIDDLE OF NXT WEEK.

MDLS ARE STILL AT ODDS WITH THE TIMING OF THE NXT PROMINENT
SHORTWAVE TOPPING THE RELATIVELY FLAT UPR RDG SITUATED OVER THE
CNTRL CONUS. LATEST THINKING IS FOR BETTER PCPN CHCS TO ARRIVE
LATER FRI NGT (AFTER MIDNGT) AND FOCUSED MORE TOWARD CNTRL WI.
HAVE ADDED MORE CLOUDS TOWARD CNTRL WI AND KEPT POPS IN THE CHC
CATEGORY. FARTHER EAST...ENUF DRY AIR MAY KEEP MOST OF THE PCPN AT
BAY FOR MOST OF THE NGT SO HAVE KEPT POPS THERE AT A MINIMUM.

THIS SHORTWAVE PULLS AWAY FROM THE AREA BY SAT MORNING LEAVING AN
EASTERLY FLOW OVER NE WI AND WAITING FOR THE NXT SHORTWAVE TO
APPROACH. IT APPEARS THAT THERE IS A GAP LARGE ENUF SUCH THAT ANY
PCPN CHCS COULD HOLD OFF TIL AFTER SUNSET. SINCE THERE IS NO
TRIGGER EVIDENT AT THE SFC OR ALOFT...MAY BE ABLE TO GET BY MOST
OF THE DAY WITHOUT SEEING MEASURABLE PCPN. STILL EXPECT TO SEE
ENUF CLOUDS AROUND TO KEEP TEMPS IN CHECK WITH READINGS RANGING
FROM THE UPPER 50S LAKESIDE TO THE MIDDLE 60S OVER THE WARMER
SPOTS OF CNTRL WI.

HI PRES DROPPING SE INTO ERN ONTARIO WL CONT TO FUNNEL DRY AIR
INTO NE WI SAT NGT WHILE THE NEARLY CLOSED UPR LOW MOVES TOWARD
ND/SRN MANITOBA. THE NXT SHORTWAVE IS FCST TO RIDE INTO THE UPR MS
VALLEY...BUT AGAIN MDLS DISAGREE ON ITS LOCATION. THIS BRINGS A
SIGNIFICANT TIMING ISSUE TO WHEN TO BRING THE NXT CHC OF SHWRS/
TSTMS TO THE FCST AREA. ONCE AGAIN...IT WOULD SEEM CNTRL WI WOULD
HAVE THE BETTER CHC OF SEEING MEASURABLE PCPN AS THE EAST IS
SOMEWHAT PROTECTED BY THE DRY EASTERLY WINDS. THE HI PRES BEGINS
TO LOSE ITS INFLUENCE OVER ERN WI ON SUNDAY AS THE NEARLY
VERTICALLY STACKED LOW PRES SYSTEM SPINS OVER SRN MANITOBA.
SOMEWHAT OF A BLOCKING PATTERN ALOFT WL SLOW THE ADVANCEMENT OF
BOTH THE SHORTWAVE ALOFT...AS WELL AS A CDFNT THRU THE UPR MS
VALLEY. THEREFORE...WL NEED TO CARRY A HIGHER CHC POP ACROSS CNTRL
WI (CLOSER TO THE SHORTWAVE/CDFNT) WITH ENUF INSTABILITY TO
GENERATE ISOLATED TSTMS. IT IS CONCEIVABLE THAT FAR ERN WI MAY
REMAIN MOSTLY DRY THRU SUNDAY.

THE CDFNT IS PROGGED TO PUSH ACROSS WI SUNDAY NGT AND BRING A GOOD
CHC OF SHWRS/TSTMS TO ALL OF NE WI. COOLER AIR WL SWEEP ACROSS THE
STATE BEHIND THE FNT WITH 8H TEMPS DROPPING INTO THE SINGLE DIGITS
BY MIDDAY MON. MEANWHILE...THE AREA OF LOW PRES SOUTH OF LK
WINNIPEG MAY EASE ITS WAY EWD INTO SW ONTARIO. SOME SHWR ACTIVITY
MAY LINGER INTO MON MORNING PRIMARILY OVER THE EAST...HOWEVER A
DRYING TREND DOES SEEM TO BE AGREED UPON BY THE MDLS FORO THE REST
OF MON. TEMPS WL DROP TO BLO NORMAL LEVELS WITH MAX TEMPS ON MON IN
THE UPR 50S TO LWR 60S.

MDLS EVENTUALLY BRING THIS WEAKENING LOW PRES SYSTEM (SHORTWAVE
TROF ALOFT/WEAK SFC LOW) TOWARD/INTO THE GREAT LKS REGION NXT TUE
AND WED. DAYTIME HEATING COUPLED WITH A COLD POOL ALOFT WL
INCREASE INSTABILITY TO BRING A CHC OF SHWRS/TSTMS TO NE WI
PRIMARILY DURING THE AFTERNOON HOURS.
&&

.AVIATION...FORECAST UNCERTAINTY IS SPILLING OVER INTO THE TAF
DEPARTMENT.  ISOLATED TO SCATTERED SHOWERS AND STORMS REMAIN
POSSIBLE THROUGH EARLY THIS EVENING ACROSS NORTH-CENTRAL AND
NORTHEAST WISCONSIN.  STRONGEST STORMS MAY IMPACT THE FOX VALLEY IF
TEMPERATURES CAN WARM INTO THE MIDDLE TO UPPER 70S.
OTHERWISE...PARTIAL CLEARING THIS AFTERNOON WILL LEAD TO VFR
CONDITIONS OUTSIDE OF THUNDERSTORMS.  A COLD FRONT WILL PASS ACROSS
THE AREA FROM NORTH TO SOUTH TONIGHT.  AMPLE MOISTURE FROM THE
RAINFALL AND THE ARRIVAL OF COOLER AIR WILL LEAD TO THE POSSIBILITY
OF LOWERING MVFR CIGS TO POSSIBLY IFR LATE TONIGHT.  CLOUDS TO STICK
AROUND IN THE MORNING...THOUGH CIGS WILL BE IMPROVING AS A RESULT OF
DAYTIME HEATING.

MPC
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$







AREA FORECAST DISCUSSION

NWS MILWAUKEE/SULLIVAN WI

 1138 AM CDT THU MAY 3 2012

.AVIATION/18Z TAFS/...MAIN CHALLENGE IS RESOLVING CONVECTIVE
TRENDS FOR TAF SITES. DECENT SSW FLOW INTO SRN WI WITH POTENTIAL
INTERACTION WITH OUTFLOW FROM STORMS TO OUR NORTH MAY HELP TO
REGENERATE MORE STORMS AS THE AFTERNOON/EVENING WEARS ALONG. WILL
HAVE CEILINGS PREVAILING AT VFR LEVELS. ONCE SYNOPTIC FRONT PASSES
SOUTH OF THE AREA EARLY FRIDAY...EXPECT WINDS TO SHARPLY SHIFT
NORTHEAST WITH BUFKIT SOUNDINGS SHOWING A GOOD DEAL OF STRATUS
WITH STRONG INVERSION

PC

&&

.MARINE...DECENT MIXING WITH THINNING IN CIRRUS CANOPY HAS ALLOWED
SMALL CRAFT TYPE WINDS TO MIX DOWN. PROBABLY NOT AFFECTING ALL OF
THE AREA DUE TO LIMITED MIXING FURTHER OFFSHORE...BUT WILL PUT OUT
A SHORT DURATION SMALL CRAFT TO COVER THE SITUATION.

PC

&&

.PREV DISCUSSION... /ISSUED 417 AM CDT THU MAY 3 2012/

TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM

TRAINING MULTICELLULAR TSTORMS IS SLOWLY DECREASING IN COVERAGE AND
INTENSITY OVER THE FAR NRN CWA AND SHOULD BE CLOSE TO ENDING BY
SUNRISE OR SHORTLY AFTER AS THE LOW LEVEL JET STREAM FOCUSES MORE TO
THE NORTHEAST. A WEAK MCS OVER IA IS PROGRESSING TOWARD SRN WI
WITHIN THE MEAN FLOW WITH THE HRRR MODEL BRINGING IT ACROSS THE CWA
FROM 14Z TO 19Z. WENT WITH THIS SCENARIO. AFTERWARD BELIEVE THE MAIN
FOCUS FOR CONVECTION WILL BE TOWARD THE IL BORDER AND SWD DUE TO THE
STABILIZING EFFECTS OF THE CONVECTION...AND ALSO WITH THE MAIN FOCUS
OF THE LLJ AND ANY WEAK SHORTWAVE TROUGHS TO OUR SOUTH. THUS ONLY
HAVE CHANCE POPS FOR LATE AFTERNOON THROUGH TNT.

A GOOD PORTION OF MQT...GREEN LAKE COUNTIES HAVE RECEIVED
APPROXIMATELY 3-4 INCHES OF RAIN BUT ONLY MINOR FLOODING HAS BEEN
REPORTED DUE TO THE MANY AREAS OF MARSHES AND LAKES ACTING AS A
SINK. THIS AREA WILL STILL BE MORE SUSCEPTIBLE TO FLOODING BUT
CONFIDENCE FOR FLASH FLOODING IS TOO LOW TO ISSUE A WATCH AND
BELIEVE THIS AREA CAN HANDLE ANOTHER INCH OR LESS OF RAIN WITHOUT
FLASH FLOODING OCCURRING.

FRIDAY...FORECAST CONFIDENCE...MEDIUM

SURFACE FRONT EXPECTED TO GENERALLY BE NEAR THE WI/IL BORDER FRIDAY
MORNING...THOUGH THERE ARE MODEL DIFFERENCES AND THURSDAY NIGHT
CONVECTION WILL PROBABLY HAVE A SAY ON THE LOCATION OF THE
BOUNDARY BY MORNING. KEPT SOME POPS GOING THROUGH THE DAY
FRIDAY...THE BEST CHANCE SOUTH TOWARD THE FRONT. NAM AND GFS
SUPPORT POPS MORE THAN THE ECMWF AND CANADIAN...WITH THE FRONT
FARTHER NORTH THAN THE LATTER MODELS. THE NAM AND GFS WOULD ALSO
BE WARMER...THOUGH TEMPS SEEM A BIT OVERDONE GIVEN SFC FEATURES.
SIZABLE TEMP DIFFERENCES BETWEEN THE TWO SOLUTIONS...SO GENERALLY
SPLIT THE DIFFERENCE. WILL BE COOLER TOWARD THE LAKE UNDER
NORTHEAST WINDS.

SATURDAY THOUGH MONDAY...FORECAST CONFIDENCE...LOW TO MEDIUM

MODELS GENERALLY KEEP THE BAROCLINIC ZONE IN THE AREA FOR SATURDAY
AND SUNDAY...PUSHING LOW PRESSURE THOUGH SUNDAY NIGHT INTO MONDAY.
FELT THE NEED TO KEEP POPS GOING THROUGH THE WEEKEND WITH A COUPLE
IMPULSES RIDING THROUGH THE FLOW. BEST CHANCE FOR PRECIP WILL BE
SUNDAY NIGHT AND MONDAY AS THE LOW SLIDES THOUGH. MODEL SOUNDINGS
CONTINUE TO SHOW SOME CAPE THROUGH MONDAY...SO KEPT THUNDER
MENTION WITH PRECIP. MODELS CONTINUE TO BOUNCE AROUND A BIT WITH
TEMPS FOR THE WEEKEND AND MONDAY...AS THE BAROCLINIC ZONE SHIFTS
SOME FROM RUN TO RUN. THUS GENERALLY WENT WITH CONSENSUS OF MODEL
TEMPS...RESULTING IN NEAR NORMAL VALUES. WILL BE COOLER NEAR LAKE
MICHIGAN WITH PERSISTENT ONSHORE FLOW.

TUESDAY AND WEDNESDAY...FORECAST CONFIDENCE...LOW TO MEDIUM

UPPER TROUGH TO APPROACH TUESDAY...MOVING THROUGH TUESDAY NIGHT OR
WEDNESDAY. THUS MORE SHOWER CHANCES EXPECTED...WITH MAYBE A FEW
RUMBLES OF THUNDER. NEAR NORMAL TEMPS ANTICIPATED TO CONTINUE
THROUGH THE FIRST HALF OF THE WEEK.

AVIATION/12Z TAFS/...MAINLY VFR CONDITIONS ARE EXPECTED TODAY AND
TONIGHT BUT THUNDERSTORMS ARE LIKELY FROM LATE THIS MORNING INTO THE
EARLY AFTERNOON WITH THE POTENTIAL FOR THUNDERSTORMS TO CONTINUE
TONIGHT. MVFR TO IFR CONDITIONS WILL OCCUR WITHIN THE THUNDERSTORMS
AND MAY LINGER IN THEIR WAKE AS WELL.

MARINE...WINDS AND WAVES WILL REMAIN BELOW SMALL CRAFT ADVISORY
CRITERIA BUT MOIST AIR FLOWING OVER THE COLD WATERS OF LAKE MICHIGAN
MAY RESULT IN FOG...AT TIMES DENSE...FOR TODAY AND TONIGHT.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR LMZ645-
     646.

&&

$$
TODAY/TONIGHT AND AVIATION/MARINE...GEHRING
FRIDAY THROUGH WEDNESDAY...DDV







AREA FORECAST DISCUSSION

NWS GREEN BAY WI

 1034 AM CDT THU MAY 3 2012

.UPDATE...LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A
BROAD AREA OF LOW PRESSURE CENTERED OVER SOUTHERN MINNESOTA AND
NORTHERN IOWA...WITH A WARM FRONT EXTENDING ACROSS CENTRAL
WISCONSIN TO AROUND MANITOWOC. AN MCV IS TRACKING ALONG THE WARM
FRONT OVER CENTRAL WISCONSIN...WHICH HAS IGNITED ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS. WITH CLOUD TOPS COOLING...POTENTIAL
WILL REMAIN FOR AN ISOLATED SEVERE WEATHER THREAT UNTIL ABOUT
MIDDAY...WHEN THE MCV DEPARTS. HAVE HAD WIND GUSTS UP TO 40 KTS
AND NICKEL SIZED HAIL WITH THE STORMS PROGRESSING ACROSS EAST-
CENTRAL WISCONSIN SO FAR.

WITH THE WARM FRONT EXTENDING BACK TOWARDS MINNEAPOLIS WHERE
ANOTHER NEAR SEVERE CLUSTER OF STORMS EXISTS...POTENTIAL WILL BE
THERE FOR SCATTERED THUNDERSTORM ACTIVITY THROUGH THE AFTERNOON.
THOUGH DID PLACE THE HIGHEST POPS OVER NE WISCONSIN WITHIN THE
COMMA HEAD OF THE MCV THAT WILL BE DEPARTING EARLY THIS AFTERNOON.
AS FOR THE SEVERE THREAT...THE ATMOSPHERE HAS BEEN WORKED OVER
CONTINUOUSLY SINCE THE OVERNIGHT HOURS...AND WILL NEED TO SEE SOME
HEATING IN ORDER TO GET A SURFACE BASED THREAT. CONFIDENCE IS LOW
THAT THIS WILL OCCUR...DO TO THE ONGOING CONVECTION...AND CLOUD
COVER UPSTREAM. WOULD THINK OUTFLOW BOUNDARIES SOUTH OF THE
CONVECTION OVER SOUTHERN WISCONSIN WOULD STAND A BETTER CHANCE.
WILL KEEP AN EYE ON IT...AND WILL SEE IF THE CLUSTER NEAR MSP CAN
STAY ALIVE INTO CENTRAL WISCONSIN LATER THIS AFTERNOON.

MPC
&&

.PREV DISCUSSION...ISSUED AT 339 AM CDT THU MAY 3 2012...

SYNOPSIS...WARM AND HUMID WITH SHOWERS AND THUNDERSTORMS
TODAY...THEN TURNING COOLER AND LESS HUMID.

BROAD UPR TROF PRESENTLY COVERS THE WRN 3/4 OF THE CONUS...WITH
RIDGING OVER THE FAR E. DEVELOPING BLOCKING PATTERN OVER FAR ERN
CANADA AND THE NW ATL WL FORCE ERN CONUS RIDGE TO REFORM WEST OVER
THE GREAT LAKES RGN DURING THE WEEKEND...THEN THE REMNANTS OF THE
WRN TROF WL PROGRESS EWD ACRS THE RGN DURING THE EARLY TO MIDDLE
PART OF NEXT WK.

HAVING THE UPR PATTERN IN A STATE OF FLUX WL RESULT IN A VARIETY
OF WX ACRS THE FCST AREA. WARM AND WET PATTERN WL PREVAIL EARLY...
WITH FLOODING NOW ONGOING ACRS THE FAR SRN PART OF THE FCST AREA.
A SWD SURGE OF COOLER CANADIAN AIR WL PUSH THE BULK OF THE PCPN S
AND ALLOW COOLER AIR TO DOMINATE FOR A DAY OR TWO. THEN CHCS FOR
PCPN WL RETURN AS REMNANTS OF THE WRN TROF HEAD TOWARD THE AREA.
PCPN AMNTS FOR THE 7 DAY PERIOD SHOULD END UP ABV NORMAL.
TEMPS WL START OUT ABV NORMAL THEN FALL BACK CLOSER TO NORMAL.

SHORT TERM...TDA/TNGT/FRI. MAIN CONCERN IS ONGOING FLASH
FLOODING ACRS THE FAR SRN PART OF THE FCST AREA. LINE OF
CONVECTION PRODUCING THE FLOODING WAS BEING FED BY SWLY LLJ OF
40-45 KTS... WHICH WAS FEEDING INSTABILITY IN FM THE SW. MESO
PLOTS THE LAST COUPLE HRS SHOWED THE STRONGEST LOW-LEVEL MOISTURE
CONVERGENCE STARTING TO SHIFT OFF TO THE E IN RESPONSE TO GRADUAL
VEERING OF THE LLJ. SO THINK THE AMNT OF BACKBUILDING AND TRAINING
INTO THE FLOOD ZONE WL DECR. SCHEDULED 10Z/11Z EXPIRATION TIMES OF
THE WARNINGS MIGHT BE CUTTING IT CLOSE...ESP SINCE FLOODING WL
LINGER EVEN AFTER RAIN DIMINISHES. WL NEED TO RE-EVALUATE THAT AS
WE GET CLOSE TO THE EXPIRATION TIMES.

PCPN TRENDS LATER TDA NOT VERY CLEAR CUT. GIVEN MID-LVL SHRTWV
HEADED INTO THE AREA...POSN OF FCST AREA NR RRQ OF UPR JET...AND
COLD FRONT SET TO SAG INTO THE N THIS AFTN...ADDITIONAL TSRA
DEVELOPMENT SEEMS A GOOD BET. BUT SUSPECT IT WON/T BE QUITE AS
FOCUSED/ORGAINZED AS CURRENT BATCH. WL CARRY FAIRLY HIGH
POPS...BUT DON/T FEEL MUCH IN THE WAY OF SPECIFICS/DETAILS CAN BE
ADDED AT THIS POINT. SPC SLGT RISK COVERS ABOUT THE SRN 1/2 OF THE
FCST AREA. ALTHOUGH A SVR STORM CAN/T BE RULED OUT...RIGHT NOW
THERE WOULD SEEM TO BE TOO MANY CLDS AND NOT ENOUGH FOCUSED
FORCING FOR MORE THAN A MARGINAL SVR EVENT.

FRONT WL CONT TO SAG SWD TNGT. SLOWLY EDGED POPS SWD DURING THE
NIGHT...DRYING OUT THE N AFTER MIDNIGHT. LINGERED LOW POPS OVER
THE FAR S EARLY FRI...AND BROUGHT LOW POPS BACK INTO THE FAR NW
LATE IN THE DAY. ADJUSTED TEMPS DOWN AS INCRG NELY FLOW WILL BRING
COOLER AND DRIER AIR INTO THE RGN...AND ACRS THE COLD WATERS OF
THE GREAT LAKES.

LONG TERM...FRI NGT THRU NXT WED. MAIN FCST FOCUS TO BE THE
MOVEMENT OF AN EWD MOVING...POSITIVELY-TILTED UPR TROF WHICH
EVENTUALLY SPLITS INTO A SW CONUS CUT-OFF UPR LOW AND NEARLY
CUT-OFF UPR LOW OVER THE GREAT LKS. INITIALLY...STILL DEALING
WITH ACTIVE W-SW FLOW THRU THE WEEKEND WITH SMALL PCPN CHCS AND
THEN INSTABILITY PCPN TOWARD MID-WEEK WITH THE UPR LOW. TEMPS ARE
EXPECTED TO AVERAGE BLO NORMAL THRU THE MIDDLE OF NXT WEEK.

MDLS ARE STILL AT ODDS WITH THE TIMING OF THE NXT PROMINENT
SHORTWAVE TOPPING THE RELATIVELY FLAT UPR RDG SITUATED OVER THE
CNTRL CONUS. LATEST THINKING IS FOR BETTER PCPN CHCS TO ARRIVE
LATER FRI NGT (AFTER MIDNGT) AND FOCUSED MORE TOWARD CNTRL WI.
HAVE ADDED MORE CLOUDS TOWARD CNTRL WI AND KEPT POPS IN THE CHC
CATEGORY. FARTHER EAST...ENUF DRY AIR MAY KEEP MOST OF THE PCPN AT
BAY FOR MOST OF THE NGT SO HAVE KEPT POPS THERE AT A MINIMUM.

THIS SHORTWAVE PULLS AWAY FROM THE AREA BY SAT MORNING LEAVING AN
EASTERLY FLOW OVER NE WI AND WAITING FOR THE NXT SHORTWAVE TO
APPROACH. IT APPEARS THAT THERE IS A GAP LARGE ENUF SUCH THAT ANY
PCPN CHCS COULD HOLD OFF TIL AFTER SUNSET. SINCE THERE IS NO
TRIGGER EVIDENT AT THE SFC OR ALOFT...MAY BE ABLE TO GET BY MOST
OF THE DAY WITHOUT SEEING MEASURABLE PCPN. STILL EXPECT TO SEE
ENUF CLOUDS AROUND TO KEEP TEMPS IN CHECK WITH READINGS RANGING
FROM THE UPPER 50S LAKESIDE TO THE MIDDLE 60S OVER THE WARMER
SPOTS OF CNTRL WI.

HI PRES DROPPING SE INTO ERN ONTARIO WL CONT TO FUNNEL DRY AIR
INTO NE WI SAT NGT WHILE THE NEARLY CLOSED UPR LOW MOVES TOWARD
ND/SRN MANITOBA. THE NXT SHORTWAVE IS FCST TO RIDE INTO THE UPR MS
VALLEY...BUT AGAIN MDLS DISAGREE ON ITS LOCATION. THIS BRINGS A
SIGNIFICANT TIMING ISSUE TO WHEN TO BRING THE NXT CHC OF SHWRS/
TSTMS TO THE FCST AREA. ONCE AGAIN...IT WOULD SEEM CNTRL WI WOULD
HAVE THE BETTER CHC OF SEEING MEASURABLE PCPN AS THE EAST IS
SOMEWHAT PROTECTED BY THE DRY EASTERLY WINDS. THE HI PRES BEGINS
TO LOSE ITS INFLUENCE OVER ERN WI ON SUNDAY AS THE NEARLY
VERTICALLY STACKED LOW PRES SYSTEM SPINS OVER SRN MANITOBA.
SOMEWHAT OF A BLOCKING PATTERN ALOFT WL SLOW THE ADVANCEMENT OF
BOTH THE SHORTWAVE ALOFT...AS WELL AS A CDFNT THRU THE UPR MS
VALLEY. THEREFORE...WL NEED TO CARRY A HIGHER CHC POP ACROSS CNTRL
WI (CLOSER TO THE SHORTWAVE/CDFNT) WITH ENUF INSTABILITY TO
GENERATE ISOLATED TSTMS. IT IS CONCEIVABLE THAT FAR ERN WI MAY
REMAIN MOSTLY DRY THRU SUNDAY.

THE CDFNT IS PROGGED TO PUSH ACROSS WI SUNDAY NGT AND BRING A GOOD
CHC OF SHWRS/TSTMS TO ALL OF NE WI. COOLER AIR WL SWEEP ACROSS THE
STATE BEHIND THE FNT WITH 8H TEMPS DROPPING INTO THE SINGLE DIGITS
BY MIDDAY MON. MEANWHILE...THE AREA OF LOW PRES SOUTH OF LK
WINNIPEG MAY EASE ITS WAY EWD INTO SW ONTARIO. SOME SHWR ACTIVITY
MAY LINGER INTO MON MORNING PRIMARILY OVER THE EAST...HOWEVER A
DRYING TREND DOES SEEM TO BE AGREED UPON BY THE MDLS FORO THE REST
OF MON. TEMPS WL DROP TO BLO NORMAL LEVELS WITH MAX TEMPS ON MON IN
THE UPR 50S TO LWR 60S.

MDLS EVENTUALLY BRING THIS WEAKENING LOW PRES SYSTEM (SHORTWAVE
TROF ALOFT/WEAK SFC LOW) TOWARD/INTO THE GREAT LKS REGION NXT TUE
AND WED. DAYTIME HEATING COUPLED WITH A COLD POOL ALOFT WL
INCREASE INSTABILITY TO BRING A CHC OF SHWRS/TSTMS TO NE WI
PRIMARILY DURING THE AFTERNOON HOURS.
&&

.AVIATION...FOR 12Z TAF ISSUANCE...TSRA WL PROBABLY WORK BACK INTO
THE WRN AND NRN TAF SITES...AND KEY WL BE TO HONE IN ON TIMING OF
THAT. KEY TO TNGT WL BE FIGURING OUT POTENTIAL FOR LOW CIGS RIGHT
BEHIND THE FRONT.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$







AREA FORECAST DISCUSSION...UPDATE

NWS MILWAUKEE/SULLIVAN WI

 417 AM CDT THU MAY 3 2012

.TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM

TRAINING MULTICELLULAR TSTORMS IS SLOWLY DECREASING IN COVERAGE AND
INTENSITY OVER THE FAR NRN CWA AND SHOULD BE CLOSE TO ENDING BY
SUNRISE OR SHORTLY AFTER AS THE LOW LEVEL JET STREAM FOCUSES MORE TO
THE NORTHEAST. A WEAK MCS OVER IA IS PROGRESSING TOWARD SRN WI
WITHIN THE MEAN FLOW WITH THE HRRR MODEL BRINGING IT ACROSS THE CWA
FROM 14Z TO 19Z. WENT WITH THIS SCENARIO. AFTERWARD BELIEVE THE MAIN
FOCUS FOR CONVECTION WILL BE TOWARD THE IL BORDER AND SWD DUE TO THE
STABILIZING EFFECTS OF THE CONVECTION...AND ALSO WITH THE MAIN FOCUS
OF THE LLJ AND ANY WEAK SHORTWAVE TROUGHS TO OUR SOUTH. THUS ONLY
HAVE CHANCE POPS FOR LATE AFTERNOON THROUGH TNT.

A GOOD PORTION OF MQT...GREEN LAKE COUNTIES HAVE RECEIVED
APPROXIMATELY 3-4 INCHES OF RAIN BUT ONLY MINOR FLOODING HAS BEEN
REPORTED DUE TO THE MANY AREAS OF MARSHES AND LAKES ACTING AS A
SINK. THIS AREA WILL STILL BE MORE SUSCEPTIBLE TO FLOODING BUT
CONFIDENCE FOR FLASH FLOODING IS TOO LOW TO ISSUE A WATCH AND
BELIEVE THIS AREA CAN HANDLE ANOTHER INCH OR LESS OF RAIN WITHOUT
FLASH FLOODING OCCURRING.


.FRIDAY...FORECAST CONFIDENCE...MEDIUM

SURFACE FRONT EXPECTED TO GENERALLY BE NEAR THE WI/IL BORDER FRIDAY
MORNING...THOUGH THERE ARE MODEL DIFFERENCES AND THURSDAY NIGHT
CONVECTION WILL PROBABLY HAVE A SAY ON THE LOCATION OF THE
BOUNDARY BY MORNING. KEPT SOME POPS GOING THROUGH THE DAY
FRIDAY...THE BEST CHANCE SOUTH TOWARD THE FRONT. NAM AND GFS
SUPPORT POPS MORE THAN THE ECMWF AND CANADIAN...WITH THE FRONT
FARTHER NORTH THAN THE LATTER MODELS. THE NAM AND GFS WOULD ALSO
BE WARMER...THOUGH TEMPS SEEM A BIT OVERDONE GIVEN SFC FEATURES.
SIZABLE TEMP DIFFERENCES BETWEEN THE TWO SOLUTIONS...SO GENERALLY
SPLIT THE DIFFERENCE. WILL BE COOLER TOWARD THE LAKE UNDER
NORTHEAST WINDS.

.SATURDAY THOUGH MONDAY...FORECAST CONFIDENCE...LOW TO MEDIUM

MODELS GENERALLY KEEP THE BAROCLINIC ZONE IN THE AREA FOR SATURDAY
AND SUNDAY...PUSHING LOW PRESSURE THOUGH SUNDAY NIGHT INTO MONDAY.
FELT THE NEED TO KEEP POPS GOING THROUGH THE WEEKEND WITH A COUPLE
IMPULSES RIDING THROUGH THE FLOW. BEST CHANCE FOR PRECIP WILL BE
SUNDAY NIGHT AND MONDAY AS THE LOW SLIDES THOUGH. MODEL SOUNDINGS
CONTINUE TO SHOW SOME CAPE THROUGH MONDAY...SO KEPT THUNDER
MENTION WITH PRECIP. MODELS CONTINUE TO BOUNCE AROUND A BIT WITH
TEMPS FOR THE WEEKEND AND MONDAY...AS THE BAROCLINIC ZONE SHIFTS
SOME FROM RUN TO RUN. THUS GENERALLY WENT WITH CONSENSUS OF MODEL
TEMPS...RESULTING IN NEAR NORMAL VALUES. WILL BE COOLER NEAR LAKE
MICHIGAN WITH PERSISTENT ONSHORE FLOW.

TUESDAY AND WEDNESDAY...FORECAST CONFIDENCE...LOW TO MEDIUM

UPPER TROUGH TO APPROACH TUESDAY...MOVING THROUGH TUESDAY NIGHT OR
WEDNESDAY. THUS MORE SHOWER CHANCES EXPECTED...WITH MAYBE A FEW
RUMBLES OF THUNDER. NEAR NORMAL TEMPS ANTICIPATED TO CONTINUE
THROUGH THE FIRST HALF OF THE WEEK.

&&

.AVIATION/12Z TAFS/...MAINLY VFR CONDITIONS ARE EXPECTED TODAY AND
TONIGHT BUT THUNDERSTORMS ARE LIKELY FROM LATE THIS MORNING INTO THE
EARLY AFTERNOON WITH THE POTENTIAL FOR THUNDERSTORMS TO CONTINUE
TONIGHT. MVFR TO IFR CONDITIONS WILL OCCUR WITHIN THE THUNDERSTORMS
AND MAY LINGER IN THEIR WAKE AS WELL.

.MARINE...WINDS AND WAVES WILL REMAIN BELOW SMALL CRAFT ADVISORY
CRITERIA BUT MOIST AIR FLOWING OVER THE COLD WATERS OF LAKE MICHIGAN
MAY RESULT IN FOG...AT TIMES DENSE...FOR TODAY AND TONIGHT.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&

$$

TODAY/TONIGHT AND AVIATION/MARINE...GEHRING
FRIDAY THROUGH WEDNESDAY...DDV











AREA FORECAST DISCUSSION

NWS LA CROSSE WI

 346 AM CDT THU MAY 3 2012

.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
346 AM CDT THU MAY 3 2012

FORECAST CONCERNS FOR TODAY ARE CENTERED ON SHOWER AND THUNDERSTORM
CHANCES WITH THE POSSIBILITY OF SEVERE THUNDERSTORMS. FOCUS THEN
TURNS TO SHOWER/THUNDERSTORM CHANCES FRIDAY AFTERNOON THROUGH THIS
WEEKEND.

CURRENT RADAR IMAGERY SHOWED A CLUSTER OF SHOWERS AND
THUNDERSTORMS ACROSS ADAMS AND JUNEAU COUNTIES EARLY THIS
MORNING...PRODUCING BRIEF HEAVY DOWNPOURS. AT 330 AM RADAR SHOWED
A LINE OF STRONG TO SEVER THUNDERSTORMS PUSHING INTO FAR NORTHWEST
WISCONSIN...BURNETT AND POLK COUNTIES...MOVING EAST. WILL HAVE TO
KEEP A CLOSE WATCH ON THIS LINE OF STORMS THIS MORNING SINCE THEY
HAVE TO POTENTIAL TO IMPACT CLARK AND TAYLOR COUNTY BETWEEN 6 AM
AND 7 AM.

SCATTERED SHOWERS AND THUNDERSTORMS WILL BE ONGOING EARLY THIS
MORNING. ANOTHER ROUND OF STRONG TO POTENTIALLY SEVERE THUNDERSTORMS
ARE POSSIBLE THIS AFTERNOON....ESPECIALLY ACROSS NORTHEAST IOWA INTO
FAR SOUTHWEST WISCONSIN. AN UNSTABLE AIRMASS WILL REMAIN IN PLACE
ACROSS THE FORECAST AREA TODAY...WITH MUCAPE VALUES OF 1500 TO 2000
J/KG. 0-6 KM BULK SHEAR VALUES WILL RANGE FROM 35 TO 40 KTS THROUGH
THE MID AFTERNOON HOURS...THEN START TO WANE IN THE LATE AFTERNOON
AND EVENING HOURS AS MID LEVEL WINDS DECREASE. THERE THE POTENTIAL
FOR A FEW STRONG TO SEVERE THUNDERSTORMS TODAY WITH THE MAIN THREATS
BEING LARGE HAIL...DAMAGING WINDS...AND HEAVY RAINFALL. AN
OUTFLOW/FRONTAL BOUNDARY JUST NORTH OF THE INTERSTATE 90 CORRIDOR
WILL SHIFT SOUTH INTO NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN
THIS AFTERNOON INTO THIS EVENING. THIS BOUNDARY WILL BE TH FOCUS FOR
THUNDERSTORM DEVELOPMENT LATE THIS AFTERNOON INTO THIS EVENING...WITH
THE POTENTIAL FOR SEEING A FEW ROUNDS OF STORMS ALONG IT. THIS MAY
LEAD TO HEAVY RAIN CONCERNS ACROSS PORTIONS OF NORTHEAST IOWA AND
FAR SOUTHWEST WISCONSIN WITH PRECIPITABLE WATER VALUES AROUND 200
PERCENT OF NORMAL...WARM CLOUD DEPTHS OF 3500 METERS. WILL HAVE TO
KEEP A CLOSE WATCH ON THE PROGRESSION OF THE BOUNDARY TODAY. IF
CONVECTION FIRES THIS AFTERNOON ACROSS SOUTHEAST MINNESOTA INTO WEST
CENTRAL WISCONSIN...THE BOUNDARY MAY END UP BEING PUSHED SOUTH OF
THE FORECAST AREA. THE SHOWERS AND THUNDERSTORMS SHOULD MOVE SOUTH
AND EAST OF THE FORECAST AREA LATE IN THE EVENING WITH A BREAK IN
PRECIPITATION CHANCES FOR MUCH OF THE FORECAST AREA FROM LATE
TONIGHT THROUGH MIDDAY FRIDAY.

A SHORTWAVE TROUGH IS EXPECTED TO MOVE ACROSS SOUTH DAKOTA AND PUSH
INTO CENTRAL/SOUTHERN MINNESOTA FRIDAY AFTERNOON. THIS FEATURE LOOKS
TO MOVE EAST INTO THE UPPER MISSISSIPPI RIVER VALLEY FRIDAY AFTERNOON
INTO FRIDAY NIGHT BRINGING A CHANCE OF SHOWERS AND THUNDERSTORMS TO
THE AREA...SOME WHICH COULD POSSIBLY BE SEVERE. 0-6 KM BULK SHEAR OF
40 TO 50 KTS...AND 0-3KM MUCAPE VALUES OF NEARLY 3000 J/KG WILL MORE
MORE THAN SUFFICIENT TO SUPPORT SEVERE THUNDERSTORMS. SUPERCELLS
WITH LARGE HAIL AND DAMAGING WINDS APPEAR POSSIBLE BUT THERE ARE
STILL SOME DETAILS THAT NEED TO BE WORKED OUT. ONE OF THE MAIN
CONCERNS IS HOW MUCH CLOUD COVER WILL BE AROUND THE REGION WHICH
WILL GREATLY IMPACT THE AMOUNT OF INSTABILITY. PLAN ON HIGHS ON
FRIDAY RANGING FROM THE UPPER 60S ACROSS NORTH CENTRAL WISCONSIN TO
THE UPPER 70S TO AROUND 80 ACROSS NORTHEAST IOWA. SHOWERS AND
THUNDERSTORM CHANCES WILL CONTINUE THROUGH FRIDAY NIGHT. THE ACTIVE
PATTERN IS EXPECTED TO PERSIST SATURDAY INTO SATURDAY NIGHT WITH
CONTINUED CHANCES FOR SHOWERS AND THUNDERSTORMS. THE EASTERN EXTENT
OF THE SHOWER/THUNDERSTORM CHANCES IS IN QUESTION AS HIGH PRESSURE
TRIES TO BUILD SOUTH OUT OF ONTARIO...THROUGH UPPER MICHIGAN INTO
CENTRAL WISCONSIN. THE HIGH MAKES A STRONG PUSH SATURDAY INTO
SUNDAY..WITH DEWPOINTS FALLING INTO THE MID 30S...POSSIBLY
LOWER...ACROSS NORTHERN WISCONSIN. WILL HAVE TO KEEP A CLOSE WATCH
ON THIS LOW LEVEL DRY AIR AS IT WILL GREATLY IMPACT PRECIPITATION
CHANCES.

.LONG TERM...SUNDAY THROUGH WEDNESDAY
346 AM CDT THU MAY 3 2012

03.00 FORECAST MODELS IN GOOD AGREEMENT ON SUNDAY SHOWING A POTENT
TROUGH PUSHING ACROSS THE DAKOTAS EARLY SUNDAY MORNING THEN MOVING
INTO THE UPPER MISSISSIPPI RIVER VALLEY REGION SUNDAY AFTERNOON.
THIS SYSTEM HAS THE POTENTIAL TO BRING ANOTHER ROUND OF SEVERE
WEATHER TO THE REGION...BUT IT IS A LITTLE TOO FAR OUT TO DETERMINE
THE EXACT DETAILS AND TIMING. THE TROUGH IS EXPECTED TO PUSH INTO
THE REGION MONDAY MORNING INTO TUESDAY BRINGING COOLER TEMPERATURES
TO THE AREA ALONG WITH CHANCES FOR SHOWERS AND PERHAPS AN ISOLATED
THUNDERSTORM. PLAN ON HIGHS IN THE 60S TO AROUND 70S ON
SUNDAY...FALLING INTO THE LOWER 60S ON MONDAY THROUGH WEDNESDAY. LOOK
FOR OVERNIGHT LOW TO FALL INTO THE 40S.

&&

.AVIATION...THROUGH 06Z FRIDAY
1212 AM CDT THU MAY 3 2012

RATHER COMPLICATED FORECAST FOR THIS TAF CYCLE WITH LOW
CONFIDENCE. MAIN PRECIPITATION AREA HAS MOVED EAST OF THE TAF
SITES...BUT STILL WARM ADVECTION OVER THE REGION KEEPING SCATTERED
SHOWERS/TSRA AROUND THE AREA THROUGH THE OVERNIGHT HOURS.
SHORTWAVE OVER EASTERN NEBRASKA TO TRANSLATE NORTHEAST OVERNIGHT.
03.00Z HRRR SHOWS CONVECTION WITH THIS WAVE TO LIFT ACROSS IOWA
OVERNIGHT ARRIVING IN THE TAF SITES AROUND DAYBREAK OR A LITTLE
AFTER. IN BETWEEN THIS...CEILINGS WILL LIKELY BE IN THE MVFR/IFR
CATEGORY OVERNIGHT WITH JUST SOME SCATTERED CONVECTION AROUND THE
AREA. DID RAISE CEILINGS LATER THURSDAY AS WAVE MOVES EAST OF THE
AREA. STILL SOME UNCERTAINTY WITH ADDITIONAL CONVECTIVE DEVELOPMENT
IN THE AFTERNOON. FOR NOW LEFT IT OUT AND WILL HAVE TO BE RE-
EVALUATED WITH LATER MODEL RUNS. VFR CONDITIONS THEN EXPECTED
AFTER 00Z.

&&

.HYDROLOGY...TODAY INTO TONIGHT
346 PM CDT WED MAY 2 2012

RAINFALL FROM LAST NIGHT THROUGH EARLY THIS MORNING RANGED FROM 1
TO 3 INCHES OVER NORTHERN WABASHA INTO CENTRAL BUFFALO COUNTY.
THIS ALONG WITH RAINFALL FROM TUESDAY NIGHT INTO WEDNESDAY MORNING
MAY PRODUCE SOME RIVER RISES. ADDITIONAL RAINFALL IS EXPECTED
TODAY WITH SOME LOCATIONS POSSIBLY RECEIVING 1/2 TO 1 INCH...WILL
HAVE TO KEEP A CLOSE EYE ON AREA STREAMS AND RIVERS FOR SOME
LOCALIZED FLOODING POTENTIAL.

HYDROLOGIC STATEMENTS HAVE BEEN ISSUED FOR SEVERAL RIVERS FOR THE
RISES THAT EITHER HAVE OCCURRED OR ARE EXPECTED TO OCCUR. PLEASE
REFERENCE THE LATEST STATEMENTS /MKERVSARX FGUS83/ FOR THE MOST
CURRENT INFORMATION.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
346 AM CDT THU MAY 3 2012

WI...NONE.
MN...NONE.
IA...NONE.

&&

$$

SHORT TERM...WETENKAMP
LONG TERM....WETENKAMP
AVIATION.....RABERDING
HYDROLOGY....WETENKAMP







AREA FORECAST DISCUSSION

NWS LA CROSSE WI

 1212 AM CDT THU MAY 3 2012

.SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT
340 PM CDT WED MAY 2 2012

MAIN FORECAST CONCERNS WILL BE SEVERE WEATHER POTENTIAL THIS EVENING
AND OVERNIGHT/CONTINUING SHOWER AND THUNDERSTORM CHANCES THROUGH THE
REST OF THE PERIOD.

RUC/RAP SURFACE ANALYSIS THIS AFTERNOON HAS AN AREA OF LOW PRESSURE
NEAR GREAT BEND KS WITH A WARM FRONT EXTENDING ALONG I-70 ACROSS MO
INTO CENTRAL IL. MEANWHILE...RUC/RAP 1000-500MB THICKNESS ANALYSIS
SHOWS A FRONTAL BOUNDARY EXISTING ACROSS NORTHERN IA INTO SOUTHERN
WI...ALONG I-90. MEANWHILE...UNDER PARTLY TO MOSTLY SUNNY
SKIES...DESTABILIZATION IS TAKING PLACE MAINLY ALONG/SOUTH OF I-90.
CURRENT LAPS INDICATING 1000-2500J/KG 0-1KM MLCAPE ACROSS NORTHWEST
IA INTO SOUTHERN MN WITH 0-3KM BULK SHEAR IN THE 20-25KT RANGE. VIS
SATELLITE SHOWING INCREASING  CUMULUS ALONG THE AFOREMENTIONED
FRONTAL BOUNDARY IN THIS DESTABILIZATION ZONE.

02.12Z NCEP MODEL SUITE/02.09Z SREF IN GENERALLY GOOD AGREEMENT
THROUGH THE SHORT TERM WITH HANDLING OF OVERALL SYNOPTIC SETUP.

MODELS SHOW INCREASING 925-850MB MOISTURE TRANSPORT INTO THE AREA
THIS EVENING AHEAD OF THE AREA OF LOW PRESSURE OVER THE CENTRAL
PLAINS. THIS MOISTURE TRANSPORT INTO THE FRONTAL BOUNDARY IS
EXPECTED TO TRIGGER A COMPLEX OF THUNDERSTORMS MAINLY ALONG AND
SOUTH OF I-94. WILL HAVE TO WATCH FOR SEVERE POTENTIAL THIS EVENING
AS THE NAM MAINTAINS 1500-2500J/KG 0-3KM MUCAPE AND BULK SHEAR IN
THE 20-35KT RANGE. IT APPEARS THE MAIN SEVERE THREATS GOING INTO
THIS EVENING WILL BE LARGE HAIL AND DAMAGING WINDS. CONVECTION LOOKS
TO WEAKEN SOME AFTER MIDNIGHT AS THE MOISTURE TRANSPORT AXIS BENDS
THE THE EAST OUT OF THE AREA AND CAPE WANES. ANOTHER CONCERN WILL BE
HEAVY RAIN POTENTIAL ACROSS PORTIONS OF NORTHEAST IA INTO FAR
SOUTHWEST WI AS PRECIPITABLE WATER VALUES INCREASE TO AROUND 1.5 TO
1.7 INCHES. WITH RECENT HEAVIER RAINFALL LAST NIGHT/EARLY THIS
MORNING AND LOW FLASH FLOOD GUIDANCE VALUES...WILL BE HOISTING A
FLASH FLOOD WATCH TONIGHT FOR PORTIONS OF NORTHEAST IA. HAVE ALSO
INCLUDED A HYDROLOGY SECTION BELOW TO DISCUSS HEAVY RAIN CONCERNS.

MODELS INDICATE FRONTAL/OUTFLOW BOUNDARY REMAINING NEARLY STATIONARY
ACROSS THE AREA THROUGH THURSDAY. NAM AND GFS SHOWING 0-3KM MUCAPE
INCREASING INTO THE 2000-3500J/KG RANGE BY THURSDAY AFTERNOON WITH
AMPLE BULK SHEAR. THIS CAPE HOWEVER WILL BE HIGHLY DEPENDENT ON HOW
MUCH CLEARING/HEATING CAN BE REALIZED BEHIND THE COMPLEX THAT ROLLS
THROUGH OVERNIGHT. FAIRLY DOUBTFUL WE WILL BE THAT CLEAN FOR THAT
MUCH DESTABILIZATION. WILL HAVE TO CONTINUE TO WATCH THIS CLOSELY
FOR SEVERE POTENTIAL IF WE DO REALIZE HIGHER CAPE.

SHOWER/THUNDERSTORM CHANCES LOOK TO CONTINUE THROUGH THE REST OF THE
PERIOD AS SOUTHWEST FLOW ALOFT BRINGS SEVERAL MID-LEVEL SHORTWAVE
ACROSS THE AREA ALONG WITH A LINGERING SURFACE FRONTAL BOUNDARY IN
THE VICINITY.

TEMPERATURE-WISE...ABOVE NORMAL TEMPERATURES LOOK TO CONTINUE
THROUGH SATURDAY. WILL HAVE TO WATCH SATURDAY AS THE MODELS DEPICT
MORE OF AN EASTERLY FLOW WITH STRATUS. THIS MAY KEEP TEMPERATURES
DOWN MORE THAN EXPECTED.

.LONG TERM...SUNDAY THROUGH WEDNESDAY
340 PM CDT WED MAY 2 2012

02.12Z GFS AND ECMWF IN GOOD AGREEMENT IN BRINGING A LOW PRESSURE
SYSTEM FROM SOUTHERN CANADA AND THE PLAINS...EASTWARD INTO THE AREA
SUNDAY THROUGH SUNDAY NIGHT FOR THE LIKELIHOOD OF SHOWERS AND
THUNDERSTORMS. PATTERN SHIFT THEN OCCURS BEHIND THIS SYSTEM WITH
COOLER CYCLONIC FLOW DOMINATING THROUGH WEDNESDAY. STEEP LAPSE
RATES...ESPECIALLY DURING THE AFTERNOON HOURS UNDER THIS COOLER
CYCLONIC FLOW ALOFT IS EXPECTED TO LEAD TO SCATTERED
SHOWER/THUNDERSTORM ACTIVITY. OTHERWISE...LOOK FOR HIGH TEMPERATURES
THROUGH THE PERIOD IN THE UPPER 50S TO THE MIDDLE 60S.

&&

.AVIATION...THROUGH 06Z FRIDAY
1212 AM CDT THU MAY 3 2012

RATHER COMPLICATED FORECAST FOR THIS TAF CYCLE WITH LOW
CONFIDENCE. MAIN PRECIPITATION AREA HAS MOVED EAST OF THE TAF
SITES...BUT STILL WARM ADVECTION OVER THE REGION KEEPING SCATTERED
SHOWERS/TSRA AROUND THE AREA THROUGH THE OVERNIGHT HOURS.
SHORTWAVE OVER EASTERN NEBRASKA TO TRANSLATE NORTHEAST OVERNIGHT.
03.00Z HRRR SHOWS CONVECTION WITH THIS WAVE TO LIFT ACROSS IOWA
OVERNIGHT ARRIVING IN THE TAF SITES AROUND DAYBREAK OR A LITTLE
AFTER. IN BETWEEN THIS...CEILINGS WILL LIKELY BE IN THE MVFR/IFR
CATEGORY OVERNIGHT WITH JUST SOME SCATTERED CONVECTION AROUND THE
AREA. DID RAISE CEILINGS LATER THURSDAY AS WAVE MOVES EAST OF THE
AREA. STILL SOME UNCERTAINTY WITH ADDITIONAL CONVECTIVE DEVELOPMENT
IN THE AFTERNOON. FOR NOW LEFT IT OUT AND WILL HAVE TO BE RE-
EVALUATED WITH LATER MODEL RUNS. VFR CONDITIONS THEN EXPECTED
AFTER 00Z.

&&

.HYDROLOGY...TONIGHT
340 PM CDT WED MAY 2 2012

RAINFALL FROM LAST NIGHT THROUGH EARLY THIS
MORNING RANGED FROM 0.25 TO 1.50 INCHES. RIVERS SEEMED TO HAVE
HANDLED THIS FAIRLY WELL WITH ONLY SOME WITHIN BANK RISES.
HOWEVER...WITH ANOTHER 1.25-2.00 INCHES POSSIBLE TONIGHT...MAINLY
ALONG/SOUTH OF THE I-94 CORRIDOR...WILL HAVE TO KEEP A CLOSE EYE ON
AREA STREAMS AND RIVERS FOR SOME LOCALIZED FLOODING POTENTIAL.

HYDROLOGIC STATEMENTS HAVE ALREADY BEEN ISSUED FOR SEVERAL RIVERS
FOR THE RISES THAT EITHER HAVE OCCURRED OR ARE EXPECTED TO OCCUR.
PLEASE REFERENCE THE LATEST STATEMENTS /MKERVSARX FGUS83/ FOR THE
MOST CURRENT INFORMATION.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
340 PM CDT WED MAY 2 2012

WI...NONE.
MN...NONE.
IA...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR IAZ018-019-029-
     030.

&&

$$

SHORT TERM...DAS
LONG TERM...DAS
AVIATION...RABERDING
HYDROLOGY...WELVAERT







AREA FORECAST DISCUSSION

NWS GREEN BAY WI

 1121 PM CDT WED MAY 2 2012

UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE

.UPDATE...MADE SOME MINOR ADJUSTMENTS TO PCPN TRENDS AND ADDED A
MENTION OF HEAVY RAINFALL TO PARTS OF C/NE/EC WI OVERNIGHT.

A SMALL CLUSTER OF SVR TSTMS WITH LARGE HAIL HAVE PERSISTED FOR
SEVERAL HOURS OVER SOUTHERN MN...AND ARE NOW MOVG EAST INTO WC WI.
THESE ARE DEVELOPING JUST NORTH OF A WARM FRONT...WHICH EXTENDS
EASTWARD INTO CENTRAL WI. SHOWERS ARE INCREASING RAPIDLY OVER
SOUTHERN WI AND HEADING TOWARD C/EC WI...IN RESPONSE TO MOISTURE
CONVERGENCE AND INCREASING MUCAPE ON THE NOSE OF 30-40 KT LLJ.
OTHER CONVECTION WAS OCCURRING OVER THE EASTERN DAKOTAS...IN
RESPONSE TO A S/W TROF AND THE RRQ OF A STG UPPER LEVEL JET.

THE BIG QUESTION IS HOW ALL OF THIS WILL COME TOGETHER OVERNIGHT.
THE 23Z HRRR SEEMED TO HAVE A PRETTY GOOD HANDLE ON ALL THREE OF
THESE AREAS OF PCPN. THE HRRR GENERALLY WEAKENS THE CURRENT
CLUSTER OF STORMS IN WC WI AS IT MOVES TOWARD C WI. THIS MAY
HAPPEN AS THE DEVELOPING CONVECTION IN SOUTHERN WI TAKES OFF AND
CUTS OFF THE MOISTURE INFLOW. EVEN SO...THERE COULD BE A BRIEF
WINDOW OF OPPORTUNITY FOR LARGE HAIL IN C WI BETWEEN 04Z-06Z.
MODELS GENERALLY AGREE THAT A LARGE AREA OF SHOWERS AND TSTMS
WILL DEVELOP OVER C/EC/FAR NE WI DURING THE OVERNIGHT PERIOD...
WITH A THREAT OF HEAVY RAINFALL AS H8 DEW POINTS INCREASE TO
+10 TO +12 C AND PW SURGES TO NEAR 1.5 INCHES. THE CONVECTION
OVER THE NORTHERN PLAINS MAY BRUSH OUR FAR NORTHWEST COUNTIES
LATE TONIGHT.

KIECKBUSCH
&&

.PREV DISCUSSION...ISSUED AT 655 PM CDT WED MAY 2 2012...

SHORT TERM...TONIGHT AND THURSDAY.

THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW
PRESSURE SITUATED OVER WESTERN KANSAS EARLY THIS AFTERNOON...AND A
COLD FRONT EXTENDING NORTHEAST INTO THE NORTHERN MISSISSIPPI
VALLEY.  AN OUTFLOW BOUNDARY FROM THIS MORNINGS CONVECTION HAS
REACHED INTO NORTHERN MISSOURI AND CENTRAL ILLINOIS...THOUGH
CONVECTION HAS YET TO RE-DEVELOP.  CLOUD COVER HAS BEEN BUILDING
ACROSS IOWA THIS AFTERNOON WHERE THETAE ADVECTION IS ONGOING...BUT
NO SIGN OF PRECIP HERE EITHER.  MEANWHILE...MIXING INTO DRY AIR
ALOFT HAS DISSIPATED THIS MORNINGS CLOUD COVER INTO SCATTERED CU
OVER MUCH OF THE FORECAST AREA.  AS A LOW LEVEL JET DEVELOPS AHEAD
THE LOW PRESSURE AND CONVECTION DEVELOPS UPSTREAM...SEVERE WEATHER
CHANCES AND PRECIP AMOUNTS ARE THE MAIN FORECAST CONCERNS.

TONIGHT...PLENTY OF UNCERTAINTY WITH THE DETAILS CONCERNING
POTENTIAL CONVECTION.  SHORTWAVE TROUGH OVER MONTANA WILL LIFT NE
OVER NORTH DAKOTA AND INTO SOUTH-CENTRAL CANADA.  SW FLOW ALOFT WILL
KEEP LOW PRESSURE OVER THE CENTRAL PLAINS WHILE THE COLD FRONT BECOMES
MORE PERPENDICULAR TO THE LOW LEVEL FLOW OVER IOWA AND INTO
WISCONSIN.  AHEAD OF THE SURFACE LOW...A SOUTH TO SOUTHWEST LLJ WILL
DEVELOP LATE THIS AFTERNOON INTO THIS EVENING POINTING INTO IOWA AND
NORTHERN ILLINOIS.  GOOD MASS CONVERGENCE ON THE NOSE OF THIS LLJ IN
AN AREA OF MU CAPE 1500-2000 J/KG AND MID-LEVEL LAPSE RATES OF 7 TO
7.5 C/KM SHOULD BE SUFFICIENT TO TRIGGER ELEVATED CONVECTION.
FORWARD PROPAGATING CORFIDI VECTORS WOULD TRACK SUBSEQUENT MCS
ENE...THOUGH AM EXPECTING THE STRONGEST THUNDERSTORMS TO FOLLOW THE
GREATEST INSTABILITY OVER THE SOUTHERN 1/3RD OF THE BADGER STATE AND
NORTHERN ILLINOIS.  THE 12Z GFS DOES TRY TO RAM THE LLJ INTO EAST-CENTRAL
WISCONSIN ALONG WITH AMPLE INSTABILITY...BUT THINK THIS IS TOO
AMBITIOUS GIVEN THE WSW FLOW ALOFT AND WITHOUT MUCH MID-LEVEL HEIGHT
RISES.  THE FLOW DOES TURN A BIT MORE SW OVERNIGHT AS THE RIGHT REAR
QUAD OF A JET STREAK SHIFTS INTO NORTHERN WISCONSIN...SO AM
EXPECTING TO SEE A MORE NORTHWARD PUSH OF THE NOCTURNAL CONVECTION
ACROSS THE FORECAST AREA AFTER MIDNIGHT.  WITH THE ELEVATED
INSTABILITY AXIS REMAINING TO OUR SOUTH...HAVE A HARD TIME GETTING
EXCITED ABOUT SEVERE CHANCES...THOUGH ALWAYS TOUGH TO RULE OUT A
MARGINAL SEVERE STORM ADVECTING INTO THE SOUTHERN FORECAST AREA.
WILL KEEP A MENTION OF SEVERE POSSIBILITIES FOR CENTRAL AND
EAST-CENTRAL WISCONSIN...MAINLY FOR LARGE HAIL...AND STRONG WINDS TO
A LESSER EXTENT.  CENTRAL AND EAST-CENTRAL WISCONSIN WILL LIKELY SEE
SUBSTANTIAL RAINFALL...WITH SOME GUIDANCE POINTING TOWARDS WELL OVER
AN INCH OF RAIN.  WILL TRY TO CAP IT AROUND THERE...SINCE THE
GREATER INSTABILITY IS SOUTH OF THE FORECAST AREA.

THURSDAY...MORNING CONVECTION MAY VERY WELL BE ONGOING AT THE START
OF THE PERIOD...AS THE RIGHT REAR QUAD OF THE JET STREAK WILL BE
OVERHEAD WHILE 850MB CONVERGENCE WILL BE DRAPED OVER CENTRAL
WISCONSIN.  THINK THE MORNING MAY TURN OUT TO BE WETTER THAN MODELS
INDICATE AND WILL KEEP THE NEAR CATEGORICAL POPS IN THE FORECAST.
INSTABILITY WILL BE THE QUESTION MARK FOR THE AFTERNOON...AS THE
WARM FRONT WILL REMAIN STALLED ACROSS THE AREA.  THE RIGHT REAR QUAD
OF THE JET STREAK WILL PULL OUT BY THE AFTERNOON...BUT WILL DAYTIME
HEATING LEAD TO CLEARING...DESPITE AMPLE MOISTURE THROUGH THE
COLUMN?  THINK ANY BREAKS WILL JUST LEAD TO CU BUILD-UP...RESULTING
IN A MOSTLY CLOUDY DAY REGARDLESS.  STILL SOME CAPE TO BE HAD...SO
CANNOT RULE OUT SCATTERED COVERAGE OF SHOWERS AND STORMS THROUGH THE
AFTERNOON.  WILL MAKE ONLY COSMETIC CHANGES TO POPS.  HIGHS IN THE
LOW TO MID 70S.

LONG TERM...THURSDAY NIGHT THROUGH NEXT WEDNESDAY. PCPN CHANCES
WILL BE THE PRIMARY FORECAST ISSUE DURING THIS PERIOD. BUSY WSW
FLOW TO CONTINUE INTO FRIDAY BEFORE MEDIUM RANGE MODELS IN
AGREEMENT WITH BRIEFLY BUILDING AN UPPER RIDGE OVER THE WESTERN
GREAT LAKES REGION SATURDAY INTO SUNDAY. THIS UPPER RIDGE BEGINS
TO FLATTEN LATE IN THE WEEKEND WITH A RETURN TO A SOUTH TO
SOUTHWEST FLOW AHEAD OF A SHORT WAVE TROUGH. MEANWHILE THE
SURFACE BOUNDARY WITH BEST INSTABILITY DROPS WELL SOUTH OF THE
FORECAST AREA LATER FRIDAY INTO FRIDAY NIGHT WITH AN EAST TO
NORTHEAST FLOW AROUND A SURFACE HIGH OVER SOUTHERN CANADA.

WOULD NORMALLY BE AGGRESSIVE WITH ENDING POPS IN THIS
SCENARIO...BUT MDM RANGE MODELS ARE CONSISTENTLY LINGERING A WEAK
H8 BOUNDARY OVER WISCONSIN FOR A POSSIBLE FOCUS OF CONVECTION FOR
AT LEAST A CHANCE OF SHOWERS. THIS H8 BOUNDARY WITH WARMER H8 TEMPS WERE
PRODUCING TOTAL TOTAL VALUES IN THE LOWER 50S...ESPECIALLY TOWARD
WESTERN WISCONSIN. IN ADDITION...BEST UPPER JET DYNAMICS LINGER
ACROSS THE NORTHERN GREAT LAKES REGION TO PROVIDE AREAS OF LIFT.

FOR THE NEW WORK WEEK...A PROGGED DEEPENING UPPER TROUGH WITH
FRONTAL SYSTEM WILL PROVIDE MORE EVEN PCPN CHANCES OF PCPN
THROUGH AT LEAST WEDNESDAY BEFORE A HIGH PRESSURE RIDGE TRIES TO
BUILD IN FROM THE NORTHERN PLAINS AND CANADA. BY MID WEEK NEXT
WEEK PCPN CHANCES MAY BE PRIMARILY DIURNAL VARIETY AS THE UPPER
TROUGH SLOWLY DRIFTS OVER.

HYDROLOGY...RAINFALL AMOUNTS OVER CENTRAL AND EAST CENTRAL
WISCOMSIN FROM LAST NIGHS CONVECTION RANGED FROM 0.40 TO 0.80
INCHES. MORE RAIN IS ANTICIPATED TONIGHT INTO THRUSDAY MORNING AS
A WARM FRONT LIFTS INTO SOUTHERN AND CENTRAL WISCONSIN. PWATS
APPROACH 1.50 BY THURSDAY MORNING. AT THIS TIME BETWEEN 1 TO 1.50
INCHES AREAS RAIN IS EXPECTED FROM TONIGHT THROUGH NOON THURSDAY.
DO NOT EXPECT FLOODING AT THESE NUMBERS...BUT IF STORMS BECOME
MORE WIDESPREAD AND CAN TRAIN ALONG THE WARM FRONT...LOCALLY
HIGHER AMOUNTS POSSIBLE. MAIN STEM RIVERS ARE FAIRLY LOW SO
RUNOFF IS NOT EXPECTED TO IMPACT RIVERS...HOWEVER SMALL STREAMS
MAY BEGIN TO BECOME SWOLLEN IF THE HIGHER AMOUNTS VERIFY.
&&

.AVIATION...SHOWERS AND TSTMS WERE DEVELOPING OVER C/EC WI LATE
THIS EVG...AND SHOULD BRING SMALL HAIL...HEAVY RAINFALL AND
MVFR/IFR CONDITIONS TO AREAS SE OF A LINE FROM AUW TO MNM OVERNIGHT.
ADDITIONAL SHOWERS AND STORMS APPROACHING FROM THE NORTHERN PLAINS
AND NORTHERN MN MAY BRUSH THROUGH NC WI LATE TONIGHT INTO EARLY
THURSDAY. THE SHOWERS AND TSTMS ARE EXPECTED TO TAPER OFF BY
THURSDAY MORNING...WITH A MIX OF VFR AND MVFR CONDITIONS EXPECTED
DURING THE DAY. SCT TSTMS MAY REDEVELOP AS A COLD FRONT SAGS SE
ACROSS THE FORECAST AREA THURSDAY AFTERNOON AND EARLY EVG.

KIECKBUSCH
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$







AREA FORECAST DISCUSSION

NWS CHEYENNE WY

 919 PM MDT FRI MAY 4 2012

.UPDATE...
MOIST LOW LEVEL AIR MAKING ITS WAY WESTWARD THIS EVENING. DEW
POINTS NOW IN THE LOW TO MID 50S AND RISING ACROSS NORTHERN
PORTIONS OF THE WESTERN NEBRASKA PANHANDLE. MOIST LOW LEVEL
EASTERLY UPSLOPE FLOW WILL LIKELY PRODUCE FOG ACROSS MOST OF THE
PANHANDLE TONIGHT...REACHING INTO PORTIONS OF SOUTHEAST WYOMING.
FOG MAY BECOME DENSE BY LATE TONIGHT INTO SATURDAY MORNING BEFORE
DISSIPATING.

FOG IS NOT THE ONLY CONCERN TONIGHT. BASED ON LATEST MODEL
RUNS...THERE IS THE POTENTIAL FOR THE DEVELOPMENT OF ELEVATED
THUNDERSTORMS IN FAR EASTERN PORTIONS OF THE FORECAST AREA. STORM
PREDICTION CENTER HAS PUSHED THE SLIGHT RISK FOR SEVERE FARTHER
WEST...AND NOW INCLUDES CHADRON. BASED OFF THE LATEST NAM...THE
SEVERE POTENTIAL MAY BE EVEN FARTHER WEST...POSSIBLY BACK NEAR THE
WYOMING BORDER. MAIN THREAT WOULD BE LARGE HAIL. EFFECTIVE BULK
SHEAR OF 50 KTS OR GREATER COMBINED WITH ELEVATED CAPE 1500-2000
JOULES/KG WILL BE SUPPORTIVE OF LARGE HAIL. STRONG THETAE
ADVECTION SHOULD BE ENOUGH TO POP STORMS OVER THE NORTHERN
PORTIONS OF THE NEBRASKA PANHANDLE MAINLY AFTER
MIDNIGHT...ASSUMING THE 00Z NAM SOLUTION HAS A GOOD HANDLE ON
SYNOPTIC CONDTIONS. THE 23Z HRRR IS LESS BULLISH ON CONVECTION
OVER THE FORECAST AREA AND KEEPS THE STORMS A BIT FARTHER NORTH
INTO WESTERN SOUTH DAKOTA.

NEW FORECAST WILL BE FOLLOW SHORTLY.

&&

.PREV DISCUSSION... /ISSUED 535 PM MDT FRI MAY 4 2012/

AVIATION...00Z TAFS. SCATTERED TO BROKEN LOW AND MID CLOUDS
THIS EVENING. 05Z THROUGH 17Z ACROSS WESTERN NEBRASKA...AREAS
OF IFR AND MVFR CEILINGS AND VISIBILITIES IN LOW CLOUDS AND FOG...
VFR ELSEWHERE. AFTER 18Z...EAST OF A DOUGLAS TO SIDNEY LINE...
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS PRODUCING LOCALIZED
MVFR AND TURBULENCE...VFR ELSEWHERE.  RUBIN

PREV DISCUSSION... /ISSUED 336 PM MDT FRI MAY 4 2012/

SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT...VISIBLE SATELLITE
IMAGERY FROM TODAY SHOWS DEEPER CONVECTION DEVELOPING OFF THE
NORTHERN LARAMIE RANGE WITH SOME SHALLOW CONVECTION ELSEWHERE ACROSS
WYOMING AND NEBRASKA. EXPECT THIS TO BECOME MORE WIDESPREAD THROUGH
THE LATE AFTERNOON...WITH A FEW SHOWERS AND WEAK THUNDERSTORMS STILL
PROGGED IN THAT AREA OF DEEPER CONVECTION COMING OFF THE NORTHERN
LARAMIE RANGE. SIMILAR TO LAST NIGHT...EXPECTING A RETURN OF LOW
CLOUDS TO NORTHERN AND EASTERN PORTIONS OF THE FORECAST AREA
TONIGHT. THE APPROACHING UPPER LEVEL TROUGH WILL INDUCE LEESIDE
TROUGHING WITH SFC WINDS BECOMING NORTHEAST TO EAST ACROSS THE LOWER
ELEVATIONS OF THE EASTERN PLAINS IN RESPONSE. THIS WILL ADVECT
DEWPOINTS FROM THE UPPER 40S TO 50S IN THIS AREA...WHICH WILL
ROUGHLY BE EAST OF A LINE STRETCHING FROM DOUGLAS TO SIDNEY. THESE
EASTERLY WINDS WILL STRENGTHEN SLIGHTLY THIS EVENING AS THE UPPER
WAVE APPROACHES...AND WILL ADD AN ADDITIONAL UPSLOPE COMPONENT ALONG
THE PINE RIDGE FOR SIOUX...DAWES...AND BOX BUTTE COUNTIES TO SEE A
DEEPER SATURATED LAYER IN THE LOW LEVELS. NAM BUFKIT SOUNDINGS SHOW
THIS LAYER TO BE A GOOD 50 TO 100 MB THICK NEAR ALLIANCE AND CHADRON
SO THERE EXISTS A GOOD POTENTIAL FOR DRIZZLE TO OCCUR HERE. OUTSIDE
OF THE NORTHERN PANHANDLE...THINK THAT THE LLVL GRADIENT AND
RESULTANT EASTERLY WINDS WILL BE STRONG ENOUGH TO ADVECT LOW CLOUDS
AND FOG ACROSS MUCH OF THE PANHANDLE AND INTO THE LOWER ELEVATIONS OF
SOUTHEAST WYOMING BUT MOISTURE MAY BE TOO SHALLOW TO PRODUCE DRIZZLE
HERE. THE SATURATED LAYER ALSO DOES NOT LOOK DEEP ENOUGH TO MAKE IT
UP THE CHEYENNE RIDGE SO LEFT THAT AREA AND VCTY OUT OF ANY FOG.
OTHERWISE...WENT AHEAD AND ADDED IN FOG AND DRIZZLE TO
AFOREMENTIONED AREAS FOR TONIGHT. LOW CLOUDS AND FOG SHOULD LAST
THROUGH THE NIGHT AND WILL BURN OFF WITH SUNRISE. THE NORTHERN
PANHANDLE IN THE DEEPER UPSLOPE FLOW MAY LAST A LITTLE LONGER
THROUGH 18Z.

UPPER LEVEL ENERGY WITH SOME MODEST 500 TO 700MB MOISTURE WILL
COMBINE WITH INCREASING LLVL CONVERGENCE AS CYCLOGENESIS OCCURS
OVER EASTERN COLORADO TO BRING A CHANCE FOR SHOWERS AND A FEW
THUNDERSTORMS ACROSS THE EASTERN PLAINS TOMORROW. THE EXCEPTION WILL
BE THE CHEYENNE RIDGE ONCE AGAIN WHERE WESTERLY DOWNSLOPE WINDS
INDUCED BY THE DEVELOPING SURFACE LOW WILL MINIMIZE ANY POTENTIAL
FOR PRECIP HERE. FURTHER WEST...LACK OF GOOD MID LAYER MOISTURE WITH
DRY LOW LEVELS WILL ALSO REDUCE ANY CHANCE FOR ANY PRECIP.
INCREASING WINDS ACROSS THIS AREA WILL MORE INCREASE THE FIRE
WEATHER THREAT...ESPECIALLY IN THE SOUTHERN LARAMIE RANGE AND VCTY
BUT STEADY GREENUP OF FUELS AND MARGINAL WINDS/HUMIDITIES WILL DETER
FROM ISSUING ANY HIGHLIGHTS. COLD FRONT WILL THEN MOVE FROM NORTH TO
SOUTH TOMORROW EVENING AND EARLY OVERNIGHT PERIOD BRINGING GUSTY
NORTHWEST WINDS AND COOLER TEMPS TO THE AREA FOR SATURDAY NIGHT AND
SUNDAY. LOOKS LIKE MODELS ARE TRENDING DOWNWARD WITH WIND SPEEDS IN
THE LLVLS SO WILL MAINTAIN JUST BREEZY CONDITIONS ACROSS THE
PANHANDLE. DO EXPECT A FEW SHOWERS WITH MAYBE A CLAP OF THUNDER TO
ACCOMPANY THE FRONT IN THE FAR EAST WHERE BETTER MOISTURE IS
AVAILABLE SATURDAY AFTERNOON AND EVENING. HIGH PRESSURE BUILDING IN
FROM THE NORTH WILL TURN WINDS TO THE NORTHEAST ALONG THE FRONT
RANGE WITH A BETTER CHANCE FOR LOW CLOUDS TO DEVELOP ALONG THE
SOUTHERN LARAMIE RANGE EARLY SUNDAY MORNING...WITH CHANCES FOR
MAINLY RAIN SHOWERS IN THE LATE AFTERNOON AND EVENING. TEMPS LOOK TO
DROP A GOOD 10 TO 20 DEGREES BEHIND THE FRONT FOR SUNDAY.

LONG TERM...MONDAY THROUGH FRIDAY...
THE NORTHERN STREAM PORTION OF THE SPLIT SYSTEM WILL BE OVER
SOUTHERN MANITOBA ON MONDAY. 12Z ECMWF DATA PROGS A DEEPER SYSTEM
COMPARED TO THE GFS WHICH WOULD RESULT IN CYCLONIC NORTHWEST FLOW
PERSISTING THRU MONDAY. ADDITIONALLY...THE 12Z ECMWF ROTATES A
SHORTWAVE THRU THIS NORTHWEST FLOW. AS A RESULT...WOULD EXPECT AT A
MINIMUM RESIDUAL CLOUD-COVER ON MONDAY WITH PERHAPS SOME LIGHT
SHOWER ACTIVITY IN AND AROUND THE SOUTHERN LARAMIE RANGE. ANY LIGHT
SHOWERS WILL DECREASE THROUGH THE DAY ON MONDAY AS THE SYSTEM
DEPARTS. MONDAYS TEMPERATURES WILL STILL BE COOL WITH H7
TEMPERATURES OF AROUND -2 OR -3C. THIS WILL RESULT IN HIGHS THAT
WILL ONLY CLIMB INTO THE 50S TO NR 60. FOR TUESDAY AND
WEDNESDAY...HEIGHTS WILL BUILD OVER THE NORTHERN ROCKIES AND
NORTHERN PLAINS AS MID/UPPER-LEVEL RIDGING BUILDS IN. SO...DRY AND
WARMING CONDITIONS CAN BE EXPECT BOTH DAYS WITH AFTERNOON HIGHS THAT
WILL CLIMB BACK INTO THE 70S BY WEDNESDAY. FOR THURSDAY...THE UPPER
RIDGE WILL PUSH EAST INTO THE PLAINS ALLOWING MID/UPPER-LEVEL FLOW
TO BACK TO THE SOUTHWEST AHEAD OF ANOTHER SHORTWAVE THAT WILL RACE
ACROSS SOUTHERN CANADA. THIS SHORTWAVE WILL DRAG A COLD FRONT
THROUGH THE CWA LATE THURSDAY BRINGING A CHANCE OF SHOWERS AND
THUNDERSTORMS THAT WILL LINGER INTO FRIDAY. TEMPERATURES WILL BE
COOLER ON FRIDAY AS WELL...WITH HIGHS THAT WILL ONCE AGAIN ONLY
REACH THE 60S.

AVIATION...18Z TAF ISSUANCE...
VFR CONDITIONS WILL PREVAIL AT AREA TERMINALS THROUGH THE
AFTERNOON...WITH JUST SOME AFTERNOON CLOUDS DEVELOPING OVER THE
LARAMIE RANGE AND ACROSS EAST CENTRAL WYOMING. CONDITIONS WILL
DETERIORATE AFT 03Z FOR WESTERN NEBRASKA AIRPORTS IN FOG AND AREAS
OF DRIZZLE AS A FRONT BACKS IN. IFR AND PERHAPS EVEN LIFR
CONDITIONS CAN BE EXPECTED LATE TONIGHT/EARLY SATURDAY FOR WESTERN
NEBRASKA AIRFIELDS. OTHERWISE VFR CONDITIONS CAN BE EXPECTED TO
HOLD THROUGH THE PERIOD FOR SOUTHEAST WYOMING TAF SITES.

FIRE WEATHER...WARM AND BREEZY SOUTHWEST WINDS WILL CONTINUE
THROUGH LATE THIS AFTERNOON ALONG AND WEST OF THE LARAMIE RANGE.
HUMIDITIES WILL REMAIN IN THE LOW TO MID TEENS WITH WIND
SPEEDS QUITE VARIABLE BUT GENERAL GUSTING 20 TO 35 MPH. THE
LOCATIONS WITH CONDITIONS AT OR NEAR CRITICAL STATUS ARE UNDER
GREENUP SO WILL NOT ISSUE ANY SHORT TERM HIGHLIGHTS FOR THIS
AFTERNOON. SIMILAR CONDITIONS ARE EXPECTED TOMORROW SO WILL
HEADLINE THE FORECAST ONCE AGAIN FOR INCREASED FIRE WEATHER THREAT
FOR SATURDAY AFTERNOON IN THE VICINITY OF THE LARAMIE RANGE AND
ALSO IN FAR SOUTHWEST CARBON COUNTY. A COLD FRONT WILL MOVE NORTH TO
SOUTH ACROSS THE DISTRICT LATE SATURDAY AFTERNOON AND EVENING WITH
GUSTY NORTHWEST WINDS BEHIND THE FRONT EXPECTED ACROSS THE EASTERN
PLAINS...ALONG WITH COOLING TEMPS AND A CHANCE FOR SHOWERS AND A FEW
TSTORMS.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.

&&

$$

UPDATE...LIEBL
SHORT TERM/FIRE WEATHER...RJM
LONG TERM/AVIATION...HAHN







AREA FORECAST DISCUSSION

NWS CHICAGO/ROMEOVILLE IL

 252 AM CDT SAT MAY 5 2012

.DISCUSSION...
737 PM CDT

CONCERNS FOR TONIGHT INCLUDE CONVECTIVE CHANCES...ESPECIALLY ACROSS
NORTH CENTRAL ILLINOIS AND AREAS OF FOG ACROSS NORTHEASTERN ILLINOIS
AND NORTHWESTERN INDIANA.

A COLD FRONT HAS PUSHED ACROSS PORTIONS OF NORTH CENTRAL AND
NORTHEASTERN ILLINOIS WITH NORTHEASTERLY FLOW BRINGING COLDER
TEMPERATURES...LOW CLOUDS AND AREAS OF MARINE FOG ONSHORE ACROSS
NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA. AREAS OF DENSE FOG
HAVE BEEN IN PLACE ACROSS SOUTHERN LAKE MICHIGAN FOR MUCH OF THE DAY
AND AS THE WINDS CONTINUE TO VEER TO THE EAST TONIGHT...LOW CLOUDS
AND FOG SHOULD CONTINUE TO PROGRESS INLAND ACROSS THE AREA. MODEL
BUFFER SOUNDINGS AND MODEL ENSEMBLES INDICATE THAT THIS MARINE LAYER
WILL CONTINUE TO PROGRESS INLAND ACROSS MOST OF NORTHEASTERN
ILLINOIS AND NORTHWESTERN INDIANA TONIGHT. WITH THIS IN MIND...I
ADDED FOG TO THE GOING FORECAST TONIGHT. AREAS OF DENSE FOG ARE
POSSIBLE...AND WE WILL MONITOR FOR A POSSIBLE DENSE FOG ADVISORY.

THE OTHER CONCERN TONIGHT IS THE MATURE BOWING MCS CURRENTLY MOVING
EASTWARD ACROSS NORTHERN IA AND SOUTHERN MN. THIS AREA OF CONVECTION
IS ASSOCIATED WITH A MID LEVEL DISTURBANCE PROPAGATING ACROSS FAR
SOUTHERN MN. THIS BOWING MCS WILL ENCOUNTER A MUCH MORE STABLE
ATMOSPHERE AS IT CONTINUES TO MOVE EASTWARD TOWARD SOUTHERN WI AND
NORTHWESTERN IL THIS EVENING. THE LATEST MESOANALYSIS INDICATES ML
CAPES QUICKLY DROPPING UNDER 500 J/KG ACROSS NORTHWESTERN ILLINOIS
WITHIN THE POST COLD FRONTAL AIRMASS. WITH THIS IN MIND...THE MCS
IS EXPECTED TO WEAKEN LATER THIS EVENING AS IT APPROACHES NORTH
CENTRAL ILLINOIS. THEREFORE...ONLY A FEW LEFT OVER SHOWERS ARE
POSSIBLE FROM THIS ACTIVITY ACROSS PORTIONS OF NORTHERN ILLINOIS
LATER THIS EVENING TONIGHT. A FEW SHOWERS HAVE ALSO DEVELOPED
ALONG THE FRONTAL BOUNDARY ACROSS NORTHWESTERN ILLINOIS...THESE
SHOWERS SHOULD DISSIPATE SHORTLY AFTER SUNSET.

KJB

//PREV DISCUSSION...
259 PM CDT

THE MAIN CONCERNS OVER THE COMING DAYS WILL BE THE LOW CHANCES
THUNDERSTORMS ACROSS THE SOUTHWESTERN PORTION OF THE CWA
TONIGHT...AND THEN THE CHANCES FOR THUNDERSTORMS SUNDAY AFTERNOON.

FOR TONIGHT...
THE LATEST SURFACE AND OBSERVED TRENDS SHOW THAT A COOL FRONT LAY
DRAPED ACROSS MUCH OF THE CWA. AS OF THE EARLY AFTERNOON HOURS THE
BOUNDARY STRETCHES FROM KVPZ TO JUST NORTH OF KJOT....THROUGH
NORTHERN DEKALB COUNTY AND INTO WESTERN WINNEBAGO COUNTY. BEHIND
THIS FEATURE WINDS BECAME NORTHERLY TO NORTHEASTERLY...PULLING IN
THE COLD MARINE AIRMASS INTO THE LAND. TEMPS ACROSS CHICAGO PEAKED
THIS MORNING AND HAVE SINCE FALLEN THROUGH THE DAY. TO THROW
INSULT TO INJURY FOR COASTAL LOCATIONS THIS MORNING...THE CHILLY
AIRMASS COLLIDED WITH THE WARM AND HUMID AIRMASS THIS
MORNING...ALLOWING FOG...SOMETIMES THICK AT TIMES TO DEVELOP AND
MEANDER INLAND. GENERALLY SKIES HAVE CLEARED AS OF THIS
AFTERNOON...BUT SOME PATCHY AREAS PERSIST THIS AFTERNOON.

THE SURFACE BOUNDARY IS CLEARLY DENOTED ON VISIBLE IMAGERY THIS
AFTERNOON...AS SURFACE CONVERGENCE IS ALLOWING SOME CU TO POP.
DESPITE THE WARM TEMPERATURES AND HIGH DEWPOINTS PERSISTING...THE
OVERALL ATMOSPHERE IS RATHER WORKED OVER FROM LAST NIGHT AND
OBJECTIVE SPC RAP ANALYSIS CONTINUES TO HIGHLIGHT PERSISTENT CIN
IN PLACE. THE HIGHEST AXIS OF INSTABILITY IS WELL TO THE SOUTH AND
WEST THIS AFTERNOON...AND THAT IS WHERE THE HIGHEST LIKELIHOOD OF
THUNDERSTORM ACTIVITY WILL REMAIN. MODIFIED SOUNDINGS FROM
DAVENPORT SHOW THAT THERE IS MODERATE ELEVATED CAPE /ON THE ORDER
OF 1000 TO 1500 J-KG/. COUPLED WITH THE CONTINUED HIGH PWAT
AIRMASS AND SOME WEAK SURFACE CONVERGENCE ALONG THE
BOUNDARY...WOULDNT BE SURPRISED AT SEEING SOME SHOWERS DEVELOP AND
PERHAPS A CLAP OF THUNDER LATER THIS AFTERNOON AND INTO THE
EVENING HOURS. ONE BIG LACKING INGREDIENT THIS AFTERNOON IS SHEAR
ACROSS OUR AREA. THE BETTER OF THE SHEAR IS WELL TO OUR SOUTH AS A
THE REMNANTS OF A SH/WV IS SHOOTING ACROSS SOUTHERN ILLINOIS AND
SHOWERS AND SOME STRONG STORMS ARE SHOOTING EAST OF ST LOUIS TO
EFFINGHAM. THE SECOND WAVE IS LIFTING THROUGH THE DAKOTAS...AND
WILL MOVE INTO MINNESOTA AND EVENTUALLY NORTHERN
WISCONSIN...LEAVING OUR AREA IN THE VOID OF ANY ORGANIZED
CONVECTION SUPPORTING SHEAR. SO...WHATEVER DOES DECIDE TO POP THIS
AFTERNOON SHOULD GO UP AND COME DOWN IN A QUICK FASHION. WITH THE
HIGH PWATS /ON THE ORDER OF 1.3 TO 1.6 INCHES/ THROUGH THE
COLUMN...ANY OF THESE SHOWERS WILL QUICKLY DROP A GOOD AMOUNT OF
RAIN...BUT OVER A CONFINED AREA. HIGH RESOLUTION GUIDANCE IS
PRETTY CONSISTENT WITH KEEPING THE ACTIVITY FOR OUR AREA GENERALLY
FROM A ROCKFORD TO MENDOTA TO KANKAKEE CORRIDOR. THOUGH THE RAP IS
OVERDONE ACROSS THE SOUTHERN COUNTIES AS OF 20Z...AND THE HRRR IS
TRYING TO SHOW SOME ACTIVITY BEGINNING TO BUBBLE AROUND 02Z.
PRESENT CU FIELD LOOKS ANEMIC...AND GENERALLY THE REST OF THE
AFTERNOON SHOULD REMAIN CALM.

HIGH TEMPERATURES WILL RANGE GREATLY FROM NORTHEAST TO SOUTHWEST
THIS WEEKEND. THE FRONTAL BOUNDARY IS NOT EXPECTED TO MOVE MUCH FROM
ITS PRESENT LOCATION...RATHER MEANDER SLIGHTLY AND WASH OUT. AREAS
NORTH OF THIS WILL REMAIN COLDER WITH A COOL NORTHEAST COMPONENT TO
THE WINDS...WHILE AREAS SOUTH WILL GENERALLY STAY WARMER. AN UPPER
LEVEL RIDGE WILL THEN SWING ACROSS THE AREA AND GUIDANCE STILL
INDICATES A NICE LITTLE RIDGE ROLLER MOVING THROUGH AND BRINGING THE
BETTER CHANCES SHOWERS AND THUNDERSTORMS TO THE REGION OVERNIGHT ON
SUNDAY. PWATS WILL STILL BE FLIRTING WITH THE HIGH SIDE THROUGH
THIS TIME...AND THE CHANCES FOR HEAVY RAINFALL WILL PERSIST
THROUGH THAT EVENT. AS THE RIDGE SLIDES EAST AND A TROUGH MOVES
THROUGH...THE AREA WILL GENERALLY FALL BACK INTO A COOLER
NORTHWESTERLY FLOW REGIME KEEPING DAYTIME HIGHS CLOSER TO SEASONAL
WITH OFF AND ON CHANCES FOR SHOWERS THROUGH THE WEEK.

SHEA

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 06Z...

* IFR CIGS CONTINUING THROUGH DAYBREAK.

* REDUCTION IN VSBY OVERNIGHT INTO THE 3-6SM RANGE.

* CIGS/VSBY EXPECTED TO RETURN TO VFR LATER SATURDAY MORNING.

MDB

//DISCUSSION...UPDATED 06Z...

VARIABLE NORTHEAST WINDS CONTINUE ACROSS THE TERMINALS EARLY
TONIGHT WITH A WEAK HIGH PRESSURE RIDGE EXTENDING ALONG THE
WESTERN SHORE OF LAKE MICHIGAN. LOW LEVEL MOISTURE REMAINS
ABUNDANT WHICH ALLOWED CIGS TO FALL BACK TO IFR ACROSS THE IL
TERMINALS IN THE LAST HOUR OR SO. IFR IS EXPECTED TO CONTINUE
THROUGH DAYBREAK WITH IMPROVEMENT TO MVFR THEN VFR EXPECTED LATER
SATURDAY MORNING. VSBY WILL ALSO START TO FALL ACROSS THE IL
TERMINALS AS COOLING OCCURS AND WILL CONTINUE WITH 3-6SM VSBY
OVERNIGHT WITH IMPROVEMENT SATURDAY MORNING. WILL NEED TO WATCH
FOR POTENTIALLY LOWER VSBY. GYY REMAINS THE EXCEPTION WITH FLOW
OFF THE LAKE CONTINUING TO SUPPORT IFR/LIFR CONDITIONS THROUGH
DAYBREAK WITH IMPROVEMENT EXPECTED LATER SATURDAY MORNING.

EAST TO EAST-NORTHEAST WINDS WILL CONTINUE SATURDAY AFTERNOON WITH
VFR CONDITIONS EXPECTED ACROSS THE TERMINALS. THERE WILL BE A
MINIMAL CHANCE FOR SOME SHOWERS THROUGH THE DAY BUT THE CHANCE IS
TOO LOW TO MENTION IN THE TAFS.

MDB

//ORD AND MDW CONFIDENCE...UPDATED 06Z...

* HIGH CONFIDENCE IN IFR CONTINUING THROUGH AT LEAST
  DAYBREAK...WITH SOME VARIATION IN BASE HEIGHT.

* MEDIUM CONFIDENCE IN VSBY REDUCTION OVERNIGHT.

* MEDIUM CONFIDENCE IN TIMING OF IMPROVEMENT TO MVFR/VFR LATER
  SATURDAY MORNING.

MDB

//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...

SUNDAY THROUGH WEDNESDAY...GENERALLY VFR BUT PERIODIC
CHANCES FOR SHRA/TSRA. THE BEST CHANCE APPEARS TO BE SUNDAY NIGHT
AND MONDAY.

THURSDAY...VFR.

RATZER

&&

.MARINE...
246 AM CDT

HIGH PRESSURE REMAINS CENTERED FROM NORTHERN MANITOBA INTO
SOUTHWESTERN QUEBEC THIS MORNING WHILE LOW PRESSURE IS POSITIONED
OVER THE SOUTHERN HIGH PLAINS. AS A RESULT...LAKE MICHIGAN IS WITHIN
THE GRADIENT BETWEEN THESE TWO SYSTEMS WITH NORTH TO NORTHEAST WINDS
IN PLACE. THE STRONGEST SPEEDS WILL CONTINUE ACROSS NORTHERN
SECTIONS OF THE LAKE TODAY. WINDS WILL THEN TURN MORE EAST AND
SOUTHEAST INTO SUNDAY MORNING AS THE RIDGE STARTS TO SHIFT EASTWARD
AND LOW PRESSURE TRACKS ACROSS THE MID/UPPER MISSISSIPPI RIVER
VALLEY LATER SUNDAY. THE LOW CONSOLIDATES ACROSS CENTRAL ILLINOIS
AND PASSES JUST TO THE SOUTH OF THE LAKE IN MONDAY. WINDS WILL SHIFT
FROM SOUTHEAST TO EAST THEN NORTH MONDAY AS THE FRONT PASSES.
ANOTHER LOW WILL EXTEND BACK TO THE NORTHWEST OF THE INITIAL LOW AND
MOVE ACROSS THE U.P. OF MICHIGAN TUESDAY. WINDS WILL SHIFT FROM THE
NORTH TO WEST AHEAD OF THIS LOW THEN NORTHWEST AS IT PASSES. HIGH
PRESSURE WILL THEN SPREAD INTO THE MID MISSISSIPPI RIVER VALLEY
LATER WEDNESDAY WHICH WILL THEN MOVE EASTWARD ACROSS ILLINOIS AND
INDIANA THURSDAY.

FOG CONTINUES ACROSS THE FAR SOUTHERN SECTIONS OF THE LAKE THIS
MORNING BUT EXPECT THIS TO DIMINISH IN COVERAGE MID/LATE THIS
MORNING. WILL CONTINUE WITH THE FOG ADVISORY FOR THESE AREAS FOR
NOW.

MDB

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ080-LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
     LMZ745-LMZ777-LMZ779-LMZ878 UNTIL 11 AM SATURDAY.

&&

$$






AREA FORECAST DISCUSSION

NWS CHICAGO/ROMEOVILLE IL

 1254 AM CDT SAT MAY 5 2012

.DISCUSSION...
737 PM CDT

CONCERNS FOR TONIGHT INCLUDE CONVECTIVE CHANCES...ESPECIALLY ACROSS
NORTH CENTRAL ILLINOIS AND AREAS OF FOG ACROSS NORTHEASTERN ILLINOIS
AND NORTHWESTERN INDIANA.

A COLD FRONT HAS PUSHED ACROSS PORTIONS OF NORTH CENTRAL AND
NORTHEASTERN ILLINOIS WITH NORTHEASTERLY FLOW BRINGING COLDER
TEMPERATURES...LOW CLOUDS AND AREAS OF MARINE FOG ONSHORE ACROSS
NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA. AREAS OF DENSE FOG
HAVE BEEN IN PLACE ACROSS SOUTHERN LAKE MICHIGAN FOR MUCH OF THE DAY
AND AS THE WINDS CONTINUE TO VEER TO THE EAST TONIGHT...LOW CLOUDS
AND FOG SHOULD CONTINUE TO PROGRESS INLAND ACROSS THE AREA. MODEL
BUFFER SOUNDINGS AND MODEL ENSEMBLES INDICATE THAT THIS MARINE LAYER
WILL CONTINUE TO PROGRESS INLAND ACROSS MOST OF NORTHEASTERN
ILLINOIS AND NORTHWESTERN INDIANA TONIGHT. WITH THIS IN MIND...I
ADDED FOG TO THE GOING FORECAST TONIGHT. AREAS OF DENSE FOG ARE
POSSIBLE...AND WE WILL MONITOR FOR A POSSIBLE DENSE FOG ADVISORY.

THE OTHER CONCERN TONIGHT IS THE MATURE BOWING MCS CURRENTLY MOVING
EASTWARD ACROSS NORTHERN IA AND SOUTHERN MN. THIS AREA OF CONVECTION
IS ASSOCIATED WITH A MID LEVEL DISTURBANCE PROPAGATING ACROSS FAR
SOUTHERN MN. THIS BOWING MCS WILL ENCOUNTER A MUCH MORE STABLE
ATMOSPHERE AS IT CONTINUES TO MOVE EASTWARD TOWARD SOUTHERN WI AND
NORTHWESTERN IL THIS EVENING. THE LATEST MESOANALYSIS INDICATES ML
CAPES QUICKLY DROPPING UNDER 500 J/KG ACROSS NORTHWESTERN ILLINOIS
WITHIN THE POST COLD FRONTAL AIRMASS. WITH THIS IN MIND...THE MCS
IS EXPECTED TO WEAKEN LATER THIS EVENING AS IT APPROACHES NORTH
CENTRAL ILLINOIS. THEREFORE...ONLY A FEW LEFT OVER SHOWERS ARE
POSSIBLE FROM THIS ACTIVITY ACROSS PORTIONS OF NORTHERN ILLINOIS
LATER THIS EVENING TONIGHT. A FEW SHOWERS HAVE ALSO DEVELOPED
ALONG THE FRONTAL BOUNDARY ACROSS NORTHWESTERN ILLINOIS...THESE
SHOWERS SHOULD DISSIPATE SHORTLY AFTER SUNSET.

KJB

//PREV DISCUSSION...
259 PM CDT

THE MAIN CONCERNS OVER THE COMING DAYS WILL BE THE LOW CHANCES
THUNDERSTORMS ACROSS THE SOUTHWESTERN PORTION OF THE CWA
TONIGHT...AND THEN THE CHANCES FOR THUNDERSTORMS SUNDAY AFTERNOON.

FOR TONIGHT...
THE LATEST SURFACE AND OBSERVED TRENDS SHOW THAT A COOL FRONT LAY
DRAPED ACROSS MUCH OF THE CWA. AS OF THE EARLY AFTERNOON HOURS THE
BOUNDARY STRETCHES FROM KVPZ TO JUST NORTH OF KJOT....THROUGH
NORTHERN DEKALB COUNTY AND INTO WESTERN WINNEBAGO COUNTY. BEHIND
THIS FEATURE WINDS BECAME NORTHERLY TO NORTHEASTERLY...PULLING IN
THE COLD MARINE AIRMASS INTO THE LAND. TEMPS ACROSS CHICAGO PEAKED
THIS MORNING AND HAVE SINCE FALLEN THROUGH THE DAY. TO THROW
INSULT TO INJURY FOR COASTAL LOCATIONS THIS MORNING...THE CHILLY
AIRMASS COLLIDED WITH THE WARM AND HUMID AIRMASS THIS
MORNING...ALLOWING FOG...SOMETIMES THICK AT TIMES TO DEVELOP AND
MEANDER INLAND. GENERALLY SKIES HAVE CLEARED AS OF THIS
AFTERNOON...BUT SOME PATCHY AREAS PERSIST THIS AFTERNOON.

THE SURFACE BOUNDARY IS CLEARLY DENOTED ON VISIBLE IMAGERY THIS
AFTERNOON...AS SURFACE CONVERGENCE IS ALLOWING SOME CU TO POP.
DESPITE THE WARM TEMPERATURES AND HIGH DEWPOINTS PERSISTING...THE
OVERALL ATMOSPHERE IS RATHER WORKED OVER FROM LAST NIGHT AND
OBJECTIVE SPC RAP ANALYSIS CONTINUES TO HIGHLIGHT PERSISTENT CIN
IN PLACE. THE HIGHEST AXIS OF INSTABILITY IS WELL TO THE SOUTH AND
WEST THIS AFTERNOON...AND THAT IS WHERE THE HIGHEST LIKELIHOOD OF
THUNDERSTORM ACTIVITY WILL REMAIN. MODIFIED SOUNDINGS FROM
DAVENPORT SHOW THAT THERE IS MODERATE ELEVATED CAPE /ON THE ORDER
OF 1000 TO 1500 J-KG/. COUPLED WITH THE CONTINUED HIGH PWAT
AIRMASS AND SOME WEAK SURFACE CONVERGENCE ALONG THE
BOUNDARY...WOULDNT BE SURPRISED AT SEEING SOME SHOWERS DEVELOP AND
PERHAPS A CLAP OF THUNDER LATER THIS AFTERNOON AND INTO THE
EVENING HOURS. ONE BIG LACKING INGREDIENT THIS AFTERNOON IS SHEAR
ACROSS OUR AREA. THE BETTER OF THE SHEAR IS WELL TO OUR SOUTH AS A
THE REMNANTS OF A SH/WV IS SHOOTING ACROSS SOUTHERN ILLINOIS AND
SHOWERS AND SOME STRONG STORMS ARE SHOOTING EAST OF ST LOUIS TO
EFFINGHAM. THE SECOND WAVE IS LIFTING THROUGH THE DAKOTAS...AND
WILL MOVE INTO MINNESOTA AND EVENTUALLY NORTHERN
WISCONSIN...LEAVING OUR AREA IN THE VOID OF ANY ORGANIZED
CONVECTION SUPPORTING SHEAR. SO...WHATEVER DOES DECIDE TO POP THIS
AFTERNOON SHOULD GO UP AND COME DOWN IN A QUICK FASHION. WITH THE
HIGH PWATS /ON THE ORDER OF 1.3 TO 1.6 INCHES/ THROUGH THE
COLUMN...ANY OF THESE SHOWERS WILL QUICKLY DROP A GOOD AMOUNT OF
RAIN...BUT OVER A CONFINED AREA. HIGH RESOLUTION GUIDANCE IS
PRETTY CONSISTENT WITH KEEPING THE ACTIVITY FOR OUR AREA GENERALLY
FROM A ROCKFORD TO MENDOTA TO KANKAKEE CORRIDOR. THOUGH THE RAP IS
OVERDONE ACROSS THE SOUTHERN COUNTIES AS OF 20Z...AND THE HRRR IS
TRYING TO SHOW SOME ACTIVITY BEGINNING TO BUBBLE AROUND 02Z.
PRESENT CU FIELD LOOKS ANEMIC...AND GENERALLY THE REST OF THE
AFTERNOON SHOULD REMAIN CALM.

HIGH TEMPERATURES WILL RANGE GREATLY FROM NORTHEAST TO SOUTHWEST
THIS WEEKEND. THE FRONTAL BOUNDARY IS NOT EXPECTED TO MOVE MUCH FROM
ITS PRESENT LOCATION...RATHER MEANDER SLIGHTLY AND WASH OUT. AREAS
NORTH OF THIS WILL REMAIN COLDER WITH A COOL NORTHEAST COMPONENT TO
THE WINDS...WHILE AREAS SOUTH WILL GENERALLY STAY WARMER. AN UPPER
LEVEL RIDGE WILL THEN SWING ACROSS THE AREA AND GUIDANCE STILL
INDICATES A NICE LITTLE RIDGE ROLLER MOVING THROUGH AND BRINGING THE
BETTER CHANCES SHOWERS AND THUNDERSTORMS TO THE REGION OVERNIGHT ON
SUNDAY. PWATS WILL STILL BE FLIRTING WITH THE HIGH SIDE THROUGH
THIS TIME...AND THE CHANCES FOR HEAVY RAINFALL WILL PERSIST
THROUGH THAT EVENT. AS THE RIDGE SLIDES EAST AND A TROUGH MOVES
THROUGH...THE AREA WILL GENERALLY FALL BACK INTO A COOLER
NORTHWESTERLY FLOW REGIME KEEPING DAYTIME HIGHS CLOSER TO SEASONAL
WITH OFF AND ON CHANCES FOR SHOWERS THROUGH THE WEEK.

SHEA

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 06Z...

* IFR CIGS CONTINUING THROUGH DAYBREAK.

* REDUCTION IN VSBY OVERNIGHT INTO THE 3-6SM RANGE.

* CIGS/VSBY EXPECTED TO RETURN TO VFR LATER SATURDAY MORNING.

MDB

//DISCUSSION...UPDATED 06Z...

VARIABLE NORTHEAST WINDS CONTINUE ACROSS THE TERMINALS EARLY
TONIGHT WITH A WEAK HIGH PRESSURE RIDGE EXTENDING ALONG THE
WESTERN SHORE OF LAKE MICHIGAN. LOW LEVEL MOISTURE REMAINS
ABUNDANT WHICH ALLOWED CIGS TO FALL BACK TO IFR ACROSS THE IL
TERMINALS IN THE LAST HOUR OR SO. IFR IS EXPECTED TO CONTINUE
THROUGH DAYBREAK WITH IMPROVEMENT TO MVFR THEN VFR EXPECTED LATER
SATURDAY MORNING. VSBY WILL ALSO START TO FALL ACROSS THE IL
TERMINALS AS COOLING OCCURS AND WILL CONTINUE WITH 3-6SM VSBY
OVERNIGHT WITH IMPROVEMENT SATURDAY MORNING. WILL NEED TO WATCH
FOR POTENTIALLY LOWER VSBY. GYY REMAINS THE EXCEPTION WITH FLOW
OFF THE LAKE CONTINUING TO SUPPORT IFR/LIFR CONDITIONS THROUGH
DAYBREAK WITH IMPROVEMENT EXPECTED LATER SATURDAY MORNING.

EAST TO EAST-NORTHEAST WINDS WILL CONTINUE SATURDAY AFTERNOON WITH
VFR CONDITIONS EXPECTED ACROSS THE TERMINALS. THERE WILL BE A
MINIMAL CHANCE FOR SOME SHOWERS THROUGH THE DAY BUT THE CHANCE IS
TOO LOW TO MENTION IN THE TAFS.

MDB


//ORD AND MDW CONFIDENCE...UPDATED 06Z...

* HIGH CONFIDENCE IN IFR CONTINUING THROUGH AT LEAST
  DAYBREAK...WITH SOME VARIATION IN BASE HEIGHT.

* MEDIUM CONFIDENCE IN VSBY REDUCTION OVERNIGHT.

* MEDIUM CONFIDENCE IN TIMING OF IMPROVEMENT TO MVFR/VFR LATER
  SATURDAY MORNING.

MDB

//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...

SUNDAY THROUGH WEDNESDAY...GENERALLY VFR BUT PERIODIC
CHANCES FOR SHRA/TSRA. THE BEST CHANCE APPEARS TO BE SUNDAY NIGHT
AND MONDAY.

THURSDAY...VFR.

RATZER

&&

.MARINE...
229 PM CDT

A COLD FRONT HAS MOVED ACROSS LAKE MICHIGAN TODAY WITH NORTHERLY
WINDS SETTING UP BEHIND THE FRONT. THE FRONTAL BOUNDARY IS FORECAST
TO STALL ACROSS CENTRAL ILLINOIS THIS EVENING WHILE HIGH PRESSURE
BUILDS ACROSS ONTARIO...THEN EVENTUALLY EAST INTO QUEBEC LATE
SATURDAY INTO SUNDAY. NORTHERLY WINDS WILL GRADUALLY VEER TO THE
NORTHEAST AND EAST AS THE HIGH TRANSLATES EAST. ON SUNDAY...THE
FRONTAL BOUNDARY WILL WAVE NORTHWARD WITH WINDS BECOMING
SOUTHEASTERLY...THEN A COLD FRONT SWEEPS ACROSS THE LAKE ON MONDAY
ALLOWING NORTHWEST/NORTH WINDS TO OVERSPREAD THE LAKE. ALL IN
ALL...NOT LOOKING AT ANY HIGH IMPACT WIND SITUATIONS THROUGH THE
FIRST HALF OF NEXT WEEK...WITH THE STRONGEST WINDS EXPECTED OVER THE
NEXT 48 HRS OR SO IN THE 15 TO 25 KT RANGE.

ANOTHER CONCERN FOR TODAY IS THE FOG OVER THE OPEN WATERS. LATEST
VISIBLE SATELLITE IMAGERY STILL PARTLY BLOCKED BY HIGHER
CLOUDS...BUT LOOKING THROUGH THE GAPS IT DOES APPEAR THAT THERE IS
STILL AN EXPANSIVE AREA OF FOG OVER SOUTHERN LAKE MICHIGAN. DRIER
AIR WILL CONTINUE TO ERODE THIS AREA FROM THE NORTH...BUT IN THE
MEANTIME WILL EXTEND THE DENSE FOG ADVISORY THROUGH THIS EVENING.
BMD

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ080-LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
     LMZ745-LMZ777-LMZ779-LMZ878 UNTIL 11 AM SATURDAY.

&&

$$







AREA FORECAST DISCUSSION

NWS DODGE CITY KS

 403 AM CDT SAT MAY 5 2012

...UPDATE TO LONG TERM DISCUSSION...

.SYNOPSIS...
ISSUED AT 127 AM CDT SAT MAY 5 2012

AT 00Z SATURDAY A -26 TO -28C 500MB TROUGH WAS LOCATED FROM
NORTHERN CALIFORNIA TO SOUTHERN BRITISH COLUMBIA. A 250MB +110
KNOT JET STREAK EXTEND FROM THE BASED OF THIS TROUGH NORTHEASTWARD
INTO THE NORTHERN ROCKIES WITH THE RIGHT EXIT REGION OF THIS UPPER
JET POSITIONED NEAR THE FOUR CORNERS REGION. IN THE CENTRAL UNITED
STATES A WEST TO EAST 850MB BAROCLINIC ZONE/SURFACE STATIONARY
FRONT STRETCHED FROM SOUTHEAST WYOMING ACROSS NEBRASKA AND AN AREA
OF LOW PRESSURE AT THE SURFACE EXTENDED SOUTH OF THIS FRONT ACROSS
EASTERN COLORADO. A WARM +10 TO +12C 700MB TEMPERATURES WAS
LOCATED ACROSS EASTERN COLORADO AND WESTERN KANSAS. AT THE SURFACE
TO 850MB LEVEL THE BETTER MOISTURE RETURN FROM THE SOUTH/SOUTHEAST
WINDS WERE LOCATED ACROSS FROM CENTRAL OKLAHOMA, ACROSS CENTRAL
KANSAS AND INTO SOUTHWEST NEBRASKA.

&&

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 127 AM CDT SAT MAY 5 2012

EARLY THIS MORNING AND TODAY...SURFACE PRESSURES WILL CONTINUE TO
FALL ALONG THE LEE OF THE ROCKIES IN RESPONSE TO THE WEST COAST
UPPER LEVEL TROUGH MOVING EASTWARDS TOWARDS THE NORTHERN AND
CENTRAL ROCKIES. SOUTHEASTERLY FLOW NEAR THE SURFACE WILL DRAW
MORE HUMID AIR BACK ACROSS PORTIONS OF NORTH CENTRAL KANSAS BUT AT
THIS TIME BASED ON VARIOUS BUFR SOUNDINGS AND HRRR ANY STATUS OR
FOG THAT MAY DEVELOP EARLY THIS MORNING IS NOT EXPECTED TO BE
WIDESPREAD OR DENSE. BY LATE MORNING A LEE TROUGH/DRYLINE WILL
MOVE EAST ACROSS WESTERN KANSAS ALLOWING DRIER AIR TO RETURN.
THESE LOW DEW POINT BEHIND THIS BOUNDARY COMBINED WITH AFTERNOON
TEMPERATURES TOPPING OUT IN THE MID-UPPER 90S, BASED ON 850-700MB
MIX DOWN TEMPERATURES, WILL ALLOW AFTERNOON RELATIVE HUMIDITIES TO
FALL BACK TO NEAR 10 PERCENT IN A FEW LOCATIONS. WINDS HOWEVER ARE
EXPECTED TO AVERAGE AT LESS THAN 20 MPH AND THE FUEL STATUS PAGE
DOES INDICATE MOST LOCATIONS DO NOT HAVE THE FUELS NEEDED TO
SUPPORT RED FLAG WARNING CONDITIONS. AS A RESULT WILL NOT BE
ISSUING ANY TYPE OF FIRE WEATHER PRODUCTS AT THIS TIME.

TONIGHT...AN UPPER LEVEL JET WILL CROSS THE ROCKIES AND MOVE OUT
INTO THE NORTHERN PLAINS. AS IT DOES THE STATIONARY FRONT ACROSS
NEBRASKA WILL BEGIN TO MOVE SOUTH INTO NORTHWEST KANSAS. BASED ON
THE LOCATION OF THE RIGHT ENTRANCE REGION OF THE UPPER LEVEL JET,
NORTHERN EDGE OF THE WARM 700MB WARM LAYER, AND WHERE THE MOIST
UPSLOPE FLOW WILL BE PRESENT SATURDAY EVENING THE BETTER CHANCES
FOR CONVECTION EARLY TONIGHT WILL STAY WELL NORTH OF INTERSTATE 70
IN NORTHEAST COLORADO AND NORTHWEST KANSAS. THIS AREA OF
CONVECTION WILL MOVE EAST/SOUTHEAST OVERNIGHT AS THE SURFACE COLD
FRONT BEGINS TO WORK ITS WAY INTO WESTERN KANSAS. AT THIS TIME
BASED THE LOCATION OF THE BETTER MOISTURE AND LOW LEVEL FORCING
ALONG WITH THE BETTER MID LEVEL INSTABILITY THE PRECIPITATION
CHANCES STILL APPEARS TO BE IN/NEAR OUR NORTH CENTRAL KANSAS AND
MAINLY AFTER 09Z. AS A RESULT WILL CONTINUE TO LEAN TOWARD LEAVING
THE FORECAST DRY BUT DID INSERT SOME 10-14% CHANCES INTO THE HAYS
AREA. AS FOR TEMPERATURES THE PREVIOUS FORECAST STILL APPEARS TO
HAVE A DECENT HANDLE ON KEEPING LOWS MAINLY IN THE 60S ALONG AND
AHEAD OF THE COLD FRONT WHICH WILL BE LOCATED NEAR SOUTH CENTRAL
KANSAS AT 12Z.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 403 AM CDT SAT MAY 5 2012

SUNDAY:

A STRONG COLD FRONT WILL HAVE CLEARED MUCH OF THE REGION BY SUNDAY MORNING,
EXCEPT AROUND MEDICINE LODGE. THIS FRONT IS BEING USHERED IN BY A 500
HPA SHORTWAVE TROUGH WELL TO THE NORTH. THE RIGHT ENTRANCE REGION OF
A 250 HPA JET WILL SKIRT ACROSS NEBRASKA DURING THE DAY AND AS A RESULT,
I HAVE HIGHEST POPS ACROSS CENTRAL KANSAS DUE TO RESULTANT INCREASING
UPPER LEVEL DYNAMICS/DIVERGENCE ALOFT. THE COLD FRONT WILL HAVE SCOURED
OUT MUCH OF THE BOUNDARY LAYER MOISTURE EXCEPT ACROSS SOUTH CENTRAL
KANSAS. FORECAST SOUNDINGS DO NOT SHOW MUCH IN THE WAY OF CAPE EXCEPT
SOUTHEAST OF A LARNED TO COLDWATER LINE. SO HAVE PUT ISOLATED THUNDERSTORMS,
BUT THE EVENT LOOKS MORE LIKE A SHOWER EVENT IF ANYTHING. THE STRONGER
DYNAMICS WILL BE WELL TO THE NORTHEAST SO AM NOT EXPECTING A HIGH QPF
EVENT. TEMPERATURES WILL COOL DOWN TO WHERE THEY SHOULD BE FOR THIS
TIME OF YEAR (NEAR NORMAL) WITH NEAR 70 DEG F TOWARDS TOWARDS SCOTT
CITY AND WARMER LOWER 80S DEG F SOUTH OF THE FRONT TOWARDS MEDICINE
LODGE. 850 HPA WINDS ARE FORECAST TO BE AROUND 35 TO 40 KT SO SUNDAY
WILL BE WINDY WITH REFRESHING NORTHERLY WINDS 2O TO 30 MPH. A WELCOME
CHANGE FROM THE MID 90S DEG F THE DAY BEFORE.

MONDAY:

HIGH PRESSURE WILL BUILD ACROSS THE CENTRAL PLAINS MONDAY AND A MUCH
DRIER AIRMASS WILL SPREAD ACROSS WESTERN KANSAS. OVERNIGHT LOWS WILL
BE MORE SEASONABLE WITH 40S AND 50S DEG F FORECAST ACROSS MUCH OF THE
REGION. THERE WILL BE A BROAD UPPER LEVEL SHORTWAVE TROUGH ACROSS THE
ROCKIES AND 700 AND 850 HPA TRAJECTORIES WILL BE UPSLOPE ACROSS FAR
WESTERN KANSAS AND INTO COLORADO. AS A RESULT, HAVE SLIGHT POPS IN ACROSS
THE WESTERN HALF AND INTO PORTIONS OF THE SOUTHERN HALF OF THE REGION
DUE TO UPSLOPE CONDITIONS. COOL HIGH PRESSURE WILL PROVIDE TEMPERATURES
IN THE 60S DEG F TOWARDS I 70 AND MID 70S DEG F TOWARDS THE OKLAHOMA
BORDER.

TUESDAY THROUGH THURSDAY:

TEMPERATURES WILL MODERATE THROUGH THE MIDDLE PORTION OF NEXT WEEK AS
THE COOL HIGH PRESSURE CENTER SLIDES OFF TO THE EAST AND WEAK LEE SURFACE
TROUGHING DEVELOPS ACROSS THE HIGH PLAINS. THIS PORTION OF THE FORECAST
PERIOD WILL BE DRY AS A 500 HPA RIDGE AXIS EJECTS OUT FROM THE ROCKIES
AND EVENTUALLY ACROSS THE PLAINS BY THURSDAY AFTERNOON. THE MODELS SHOW
A 500 HPA LOW ACROSS SOUTHWEST TEXAS BUT SW KANSAS LOOKS LIKE TO BE
IN THE COL POINT...MEANING BASICALLY NO IMPACT IN TERMS OF SENSIBLE
WEATHER.

FRIDAY:

THEN NEXT CHANCE FOR PRECIPITATION APPEARS TO BE ON FRIDAY. UNFORTUNATELY
THE AFOREMENTIONED LOW WILL IMPEDE DECENT GULF OF MEXICO MOISTURE FROM
RETURNING NORTHWARD WITH ONLY 50 DEG F DEWPOINTS ADVECTING IN FROM THE
SOUTHERN PLAINS AND MOSTLY LIKELY JUST ACROSS SOUTH CENTRAL KANSAS.
MEANWHILE, AN UPPER LEVEL SHORTWAVE TROUGH SKIRTING ACROSS THE NORTHERN
PLAINS WILL USHER IN A COLD FRONT DURING THE DAY. THE MODELS (EVEN THE
ECMWF WHICH IS A LITTLE MORE CONSERVATIVE ON MOISTURE RETURN) INDICATES
SOME CAPE FORMING SO THERE COULD BE A FEW THUNDERSTORMS AROUND. THE
GFS, AS USUAL, IS TOO AGGRESSIVE WITH WARM AIR/MOISTURE ADVECTION AND
WAS DISREGARDED.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1222 AM CDT SAT MAY 5 2012

SURFACE PRESSURES WILL CONTINUE TO FALL ACROSS EASTERN COLORADO
OVERNIGHT WHICH WILL RESULT IN A PERSISTENT SOUTHEAST FLOW ACROSS
WESTERN KANSAS. THIS WILL DRAW MORE HUMID AIR BACK INTO PORTIONS
OF NORTHERN KANSAS BY DAYBREAK, HOWEVER BASED ON VARIOUS BUFR
SOUNDINGS IT CURRENTLY APPEARS THAT THIS MOISTURE WILL BE VERY
SHALLOW SO WIDESPREAD DENSE FOG IS NOT EXPECTED. VSBYS SHOULD
STAY IN THE MVFR CATEGORY IF FOG DOES DEVELOP AROUND 12Z. THESE
SOUTHEAST WINDS WILL BECOME SOUTH/SOUTHWEST AT DDC AND GCK DURING
THE DAY ON SATURDAY AS A DRYLINE/SURFACE BOUNDARY MOVES EAST
ACROSS WESTERN KANSAS.


&&

.PRELIMINARY POINT TEMPS/POPS...
DDC  95  61  71  52 /   0  10  20  10
GCK  96  58  68  50 /   0  10  20  20
EHA  95  58  72  48 /   0   0  10  20
LBL  97  59  72  50 /   0   0  10  20
HYS  93  63  70  51 /   0  20  30  10
P28  94  68  82  58 /   0  10  20  10

&&

.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...SUGDEN
AVIATION...BURGERT







AREA FORECAST DISCUSSION

NWS DODGE CITY KS

 132 AM CDT SAT MAY 5 2012

...UPDATED SYNOPSIS AND SHORT TERM...

.SYNOPSIS...
ISSUED AT 127 AM CDT SAT MAY 5 2012

AT 00Z SATURDAY A -26 TO -28C 500MB TROUGH WAS LOCATED FROM
NORTHERN CALIFORNIA TO SOUTHERN BRITISH COLUMBIA. A 250MB +110
KNOT JET STREAK EXTEND FROM THE BASED OF THIS TROUGH NORTHEASTWARD
INTO THE NORTHERN ROCKIES WITH THE RIGHT EXIT REGION OF THIS UPPER
JET POSITIONED NEAR THE FOUR CORNERS REGION. IN THE CENTRAL UNITED
STATES A WEST TO EAST 850MB BAROCLINIC ZONE/SURFACE STATIONARY
FRONT STRETCHED FROM SOUTHEAST WYOMING ACROSS NEBRASKA AND AN AREA
OF LOW PRESSURE AT THE SURFACE EXTENDED SOUTH OF THIS FRONT ACROSS
EASTERN COLORADO. A WARM +10 TO +12C 700MB TEMPERATURES WAS
LOCATED ACROSS EASTERN COLORADO AND WESTERN KANSAS. AT THE SURFACE
TO 850MB LEVEL THE BETTER MOISTURE RETURN FROM THE SOUTH/SOUTHEAST
WINDS WERE LOCATED ACROSS FROM CENTRAL OKLAHOMA, ACROSS CENTRAL
KANSAS AND INTO SOUTHWEST NEBRASKA.

&&

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 127 AM CDT SAT MAY 5 2012

EARLY THIS MORNING AND TODAY...SURFACE PRESSURES WILL CONTINUE TO
FALL ALONG THE LEE OF THE ROCKIES IN RESPONSE TO THE WEST COAST
UPPER LEVEL TROUGH MOVING EASTWARDS TOWARDS THE NORTHERN AND
CENTRAL ROCKIES. SOUTHEASTERLY FLOW NEAR THE SURFACE WILL DRAW
MORE HUMID AIR BACK ACROSS PORTIONS OF NORTH CENTRAL KANSAS BUT AT
THIS TIME BASED ON VARIOUS BUFR SOUNDINGS AND HRRR ANY STATUS OR
FOG THAT MAY DEVELOP EARLY THIS MORNING IS NOT EXPECTED TO BE
WIDESPREAD OR DENSE. BY LATE MORNING A LEE TROUGH/DRYLINE WILL
MOVE EAST ACROSS WESTERN KANSAS ALLOWING DRIER AIR TO RETURN.
THESE LOW DEW POINT BEHIND THIS BOUNDARY COMBINED WITH AFTERNOON
TEMPERATURES TOPPING OUT IN THE MID-UPPER 90S, BASED ON 850-700MB
MIX DOWN TEMPERATURES, WILL ALLOW AFTERNOON RELATIVE HUMIDITIES TO
FALL BACK TO NEAR 10 PERCENT IN A FEW LOCATIONS. WINDS HOWEVER ARE
EXPECTED TO AVERAGE AT LESS THAN 20 MPH AND THE FUEL STATUS PAGE
DOES INDICATE MOST LOCATIONS DO NOT HAVE THE FUELS NEEDED TO
SUPPORT RED FLAG WARNING CONDITIONS. AS A RESULT WILL NOT BE
ISSUING ANY TYPE OF FIRE WEATHER PRODUCTS AT THIS TIME.

TONIGHT...AN UPPER LEVEL JET WILL CROSS THE ROCKIES AND MOVE OUT
INTO THE NORTHERN PLAINS. AS IT DOES THE STATIONARY FRONT ACROSS
NEBRASKA WILL BEGIN TO MOVE SOUTH INTO NORTHWEST KANSAS. BASED ON
THE LOCATION OF THE RIGHT ENTRANCE REGION OF THE UPPER LEVEL JET,
NORTHERN EDGE OF THE WARM 700MB WARM LAYER, AND WHERE THE MOIST
UPSLOPE FLOW WILL BE PRESENT SATURDAY EVENING THE BETTER CHANCES
FOR CONVECTION EARLY TONIGHT WILL STAY WELL NORTH OF INTERSTATE 70
IN NORTHEAST COLORADO AND NORTHWEST KANSAS. THIS AREA OF
CONVECTION WILL MOVE EAST/SOUTHEAST OVERNIGHT AS THE SURFACE COLD
FRONT BEGINS TO WORK ITS WAY INTO WESTERN KANSAS. AT THIS TIME
BASED THE LOCATION OF THE BETTER MOISTURE AND LOW LEVEL FORCING
ALONG WITH THE BETTER MID LEVEL INSTABILITY THE PRECIPITATION
CHANCES STILL APPEARS TO BE IN/NEAR OUR NORTH CENTRAL KANSAS AND
MAINLY AFTER 09Z. AS A RESULT WILL CONTINUE TO LEAN TOWARD LEAVING
THE FORECAST DRY BUT DID INSERT SOME 10-14% CHANCES INTO THE HAYS
AREA. AS FOR TEMPERATURES THE PREVIOUS FORECAST STILL APPEARS TO
HAVE A DECENT HANDLE ON KEEPING LOWS MAINLY IN THE 60S ALONG AND
AHEAD OF THE COLD FRONT WHICH WILL BE LOCATED NEAR SOUTH CENTRAL
KANSAS AT 12Z.

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 340 AM CDT FRI MAY 4 2012

MEDIUM RANGE MODELS INDICATE AN UPPER LEVEL TROUGH OF LOW PRESSURE
TRACKING EASTWARD ACROSS THE NORTHERN PLAINS ALONG THE CANADIAN
BORDER SUNDAY BRINGING THE POSSIBILITY FOR SHOWERS AND THUNDERSTORMS
FROM THE NORTHERN PLAINS SOUTHWARD INTO NEBRASKA AND PORTIONS OF
KANSAS AS EARLY AS SUNDAY AFTERNOON. AN ATTENDANT COLD FRONT IS
STILL PROGGED TO PUSH SOUTHEAST INTO WESTERN KANSAS EARLY SUNDAY
SETTING UP THE CHANCE FOR SHOWER AND THUNDERSTORM DEVELOPMENT ACROSS
PORTIONS OF CENTRAL AND POSSIBLY WESTERN KANSAS. THE NAM, GFS, AND
ECMWF CONTINUE TO SHOW A SURFACE LOW SET UP ACROSS SOUTHWESTERN
KANSAS EARLY SUNDAY WITH DRIER AIR NOSING NORTHEASTWARD INTO
SOUTHWEST AND PORTIONS OF SOUTH CENTRAL KANSAS BEHIND A DRYLINE.
THE SURFACE LOW IS THEN PROJECTED TO SHIFT EASTWARD AS THE COLD
FRONT PUSHES SOUTH ACROSS WESTERN KANSAS DURING THE DAY WITH AMPLE
LOW/MID LEVEL MOISTURE WRAPPING AROUND THE LOW BACK INTO WESTERN
KANSAS BEHIND THE FRONT WITH H85 DEWPOINTS AROUND 10C. SHOWERS AND
A FEW ISOLATED THUNDERSTORMS WILL BE POSSIBLE ACROSS SOUTHWEST AND
CENTRAL KANSAS SUNDAY AFTERNOON AND EVENING AS A WEAK BAND OF H7
FRONTOGENESIS MOVES ACROSS THE AREA BEHIND THE FRONT. HOWEVER,
SLIGHT POPS REMAINS REASONABLE WITH A WEAK FLOW ALOFT INDICATED.

THE GFS, GEM, AND ECMWF THEN POINT TO WEAK UPPER LEVEL RIDGING
TRANSITIONING EASTWARD ACROSS THE NORTHERN ROCKIES MONDAY THROUGH
THE MIDDLE OF NEXT WEEK. MEANWHILE, AN UPPER LEVEL LOW WILL CLOSE
OFF AND DROP SOUTH INTO THE DESERT SOUTHWEST CREATING PRECIP CHANCES
FROM THE SOUTHERN ROCKIES INTO THE SOUTH PLAINS OF WEST TEXAS
THROUGH MUCH OF THE WEEK. THERE IS AN OUTSIDE CHANCE FOR SHOWERS
AND EVEN A FEW ISOLATED THUNDERSTORMS ACROSS EXTREME SOUTHWEST
KANSAS EARLY IN THE WEEK IF THE UPPER LEVEL LOW TRACKS CLOSE ENOUGH
AS IT BEGINS TO EDGE EASTWARD LATE IN THE PERIOD.

TEMPERATURES WILL BE COOLER SUNDAY AFTER A COLD FRONT PUSHES THROUGH
WESTERN KANSAS EARLY SUNDAY MORNING. THE NAM, GFS, AND ECWMF SHOW
MUCH COOLER AIR SPILLING SOUTH INTO WESTERN KANSAS WITH H85
TEMPERATURES RANGING FROM THE LOWER TO MID TEENS(C) ACROSS CENTRAL
AND SOUTHWEST KANSAS BY EARLY TO MID AFTERNOON. AS A RESULT, HIGH
TEMPERATURES WILL BE REALIZED A LITTLE EARLIER IN THE DAY WITH HIGHS
EXPECTED ONLY UP INTO THE UPPER 60S(F) AND POSSIBLY THE LOWER TO MID
70S(F) ACROSS WEST CENTRAL KANSAS. THE MID TO UPPER 70S(F) ARE
EXPECTED FURTHER SOUTHEAST WITH THE LOWER 80S(F) STILL POSSIBLE
ACROSS SOUTH CENTRAL KANSAS WHERE THE FRONTAL PASSAGE WILL LAST BE
OBSERVED. A SLIGHT BUT GRADUAL WARM UP IS EXPECTED THROUGH THE END
OF THE WEEK AS A WEAK UPPER LEVEL RIDGE IS PROJECTED TO MOVE EAST
ACROSS THE INTERMOUNTAIN WEST EARLY IN THE WEEK AND PUSH INTO THE
WESTERN HIGH PLAINS BY MID WEEK.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1222 AM CDT SAT MAY 5 2012

SURFACE PRESSURES WILL CONTINUE TO FALL ACROSS EASTERN COLORADO
OVERNIGHT WHICH WILL RESULT IN A PERSISTENT SOUTHEAST FLOW ACROSS
WESTERN KANSAS. THIS WILL DRAW MORE HUMID AIR BACK INTO PORTIONS
OF NORTHERN KANSAS BY DAYBREAK, HOWEVER BASED ON VARIOUS BUFR
SOUNDINGS IT CURRENTLY APPEARS THAT THIS MOISTURE WILL BE VERY
SHALLOW SO WIDESPREAD DENSE FOG IS NOT EXPECTED. VSBYS SHOULD
STAY IN THE MVFR CATEGORY IF FOG DOES DEVELOP AROUND 12Z. THESE
SOUTHEAST WINDS WILL BECOME SOUTH/SOUTHWEST AT DDC AND GCK DURING
THE DAY ON SATURDAY AS A DRYLINE/SURFACE BOUNDARY MOVES EAST
ACROSS WESTERN KANSAS.


&&

.PRELIMINARY POINT TEMPS/POPS...
DDC  96  61  75  51 /   0   0  20  10
GCK  97  58  71  51 /   0   0  20  10
EHA  96  58  71  51 /   0   0  10  20
LBL  98  59  73  52 /   0   0  10  10
HYS  94  63  73  52 /   0  10  20  10
P28  95  68  82  55 /   0  10  20  10

&&

.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...JOHNSON
AVIATION...BURGERT







AREA FORECAST DISCUSSION

NWS TOPEKA KS

 1139 PM CDT FRI MAY 4 2012

...AVIATION UPDATE...

.DISCUSSION...
SEE PREV DISCUSSION.

&&

.AVIATION...
CONFIDENCE IN DEVELOPMENT OF MVFR STRATUS CONTINUES TO BE LOW
SINCE THERE IS NOT EXPECTED TO BE STRONG MOISTURE ADVECTION OR
EVEN STRONG ISENTROPIC LIFT WITHIN THE BOUNDARY LAYER. IT APPEARS
AS THOUGH THE MODELS ARE SATURATING THE BOUNDARY LAYER WITH
DEWPOINTS STILL IN THE MID 60S TO LOWER 70S DUE TO RADIATIONAL
COOLING. THE PROBLEM IS ISENTROPIC SURFACES INDICATED DECENT DRY
AIR JUST ABOVE THE BOUNDARY LAYER. WITH WINDS KEEPING SOME
MIXING...THINK DRY AIR ENTRAINMENT MAY MAKE MVFR CIGS DIFFICULT TO
FORM. NEVERTHELESS THE RAP AND NAM FORECAST SOUNDINGS CONTINUE TO
SHOW LOW CLOUD FORMATION WITH THE OBJECTIVE GUIDANCE FROM THE GFS
AND NAM INDICATING SOME MVFR CIGS. BECAUSE OF THIS WILL INCLUDE A
TEMPO FOR MVFR CONDITIONS BETWEEN 09Z AND 13Z.

WOLTERS

&&

.PREV DISCUSSION... /ISSUED 346 PM CDT FRI MAY 4 2012/
AN UPPER LEVEL TROUGH ACROSS THE WESTERN CONUS THIS AFTERNOON WILL
LIFT NORTHEAST INTO THE NORTHERN AND CENTRAL HIGH PLAINS BY
SATURDAY AFTERNOON. A DOWNSTREAM UPPER LEVEL RIDGE WILL AMPLIFY
ACROSS THE EASTERN CENTRAL AND SOUTHERN PLAINS TONIGHT THROUGH
SATURDAY.

A WEAK SOUTHERN STREAM UPPER LEVEL TROUGH WAS LOCATED ACROSS CENTRAL
OK LATE THIS AFTERNOON AND WILL LIFT NORTHEAST INTO SOUTHWEST MO
THIS EVENING. THERE MAY BE ENOUGH ASCENT AHEAD OF THE WEAK H5 TROUGH
TO CAUSE ISOLATED SHOWERS AND THUNDERSTORMS TO DEVELOP THIS
AFTERNOON ACROSS SOUTHEAST KS AND SOUTHWEST MO. FORECAST SOUNDINGS
ACROSS THE CWA SHOW A STRONG CAP...WHICH WILL PREVENT SFC BASED
PARCELS REACHING THEIR LFC...DUE TO AN EML AT 830 MB. THE 16Z RUN OF
THE HRRR IS THE ONLY NUMERICAL MODEL SHOWING ISOLATED THUNDERSTORMS
DEVELOPING ACROSS SOUTHEAST KS AND SOUTHWEST MO...SOUTH AND
SOUTHEAST OF THE CWA THIS AFTERNOON. I KEPT 14 POPS ACROSS THE
SOUTHEAST COUNTIES OF THE CWA THIS AFTERNOON AND TONIGHT...JUST IN
CASE THERE WAS ENOUGH ASCENT FOR PARCELS ABOVE THE CAPPING INVERSION
TO REACH THEIR LFC. IF THESE ELEVATED STORMS DEVELOP THEY WILL NOT
BE SEVERE ACROSS THE SOUTHEAST COUNTIES OF THE CWA.

TONIGHT...THERE MAY BE SOME WEAK ISENTROPIC LIFT AFTER 3Z FOR SCT TO
STRATUS TO DEVELOP BUT AFTER 10Z...850MB WINDS VEER MORE TO THE
SOUTHWEST...THUS ANY STRATUS MAY DISSIPATE AFTER 10Z SAT. OVERNIGHT
LOWS WILL ONLY DROP INTO THE UPPER 60S TO LOWER 70S.

SATURDAY...850MB WINDS WILL BACK TO THE SOUTH DURING THE MID AND
LATE MORNING HOURS. DEEP MOISTURE ADVECTION WILL CAUSE SFC DEWPOINTS
TO BE IN THE UPPER 60S TO LOWER 70S DURING THE AFTERNOON HOURS.
FORECAST SOUNDINGS CONTINUE TO SHOW THE EML KEEPING A MODERATELY
STRONG CAP IN PLACE ACROSS THE CWA. THE H5 TROUGH OVER THE WESTERN
CONUS WILL LIFT NORTHEAST INTO THE NORTHERN HIGH PLAINS DURING THE
LATE AFTERNOON HOURS. THE ONLY SFC CONVERGENCE AND ASCENT WILL BE
ALONG AND NORTH OF THE SFC BOUNDARY ACROSS NORTHERN AND WESTERN NE
DURING THE LATE AFTERNOON HOURS...WHERE SCATTERED THUNDERSTORMS WILL
DEVELOP. EXPECT A WARM AND HUMID DAY WITH HIGHS IN THE UPPER 80S TO
LOWER 90S...AND AFTERNOON HEAT INDICES IN MID TO UPPER 90S.

GARGAN

MODELS CONTINUE TO DIFFER ON FRONTAL POSITION/SPEED OF MOVEMENT
ACROSS THE CWA THROUGH SUNDAY. THE NAM CONTINUES TO BE THE FASTER
AMONG THE MODELS WITH THE SPEED OF THE FRONT...AND GFS THE SLOWER.
WENT WITH A COMPROMISE AMONG MODELS BRINGING THE FRONT INTO THE FAR
NORTHWEST CORNER SUNDAY MORNING AND EXITING THE SOUTHEAST CORNER
SUNDAY EVENING. STILL EXPECTED THE DEVELOPMENT OF THUNDERSTORM
COMPLEX WELL NORTH OF THE CWA SATURDAY EVENING...BUT APPEARS ONLY A
LOW END CHC/SCHC POPS WARRANTED ACROSS AREAS NORTH OF I 70 THROUGH
SUNRISE SUNDAY. THE REMAINDER OF THE CWA SHOULD BE DRY. AS THE FRONT
MOVES INTO AND ACROSS THE CWA SUNDAY/SUNDAY EVENING...THE CHANCE FOR
THUNDERSTORMS WILL INCREASE...MAINLY ACROSS AREAS ALONG AND EAST OF
HIGHWAY 99 FROM MID AFTERNOON INTO THE EVENING. ALTHOUGH SHEAR WILL
BE WEAK...MLCAPE WILL BE VERY HIGH TO EXTREME WITH VALUES IN
ACROSS THE SOUTHEAST 1/2 OF THE CWA COMMONLY IN THE RANGE OF
3500-4500 J/KG. THEREFORE...STILL A THREAT FOR LARGE HAIL AND
STRONG GUSTY WINDS ALONG AND AHEAD OF THE FRONT FROM MID AFTERNOON
INTO THE EARLY EVENING OVER THE NORTHEAST AND EAST CENTRAL
COUNTIES. THE FRONT WILL BEGIN TO BRING IN COOLER AND DRIER AIR
INTO THE NORTHWEST CWA SUNDAY WITH HIGHS IN THE MIDDLE 70S
NORTHWEST TO STILL THE MIDDLE 80S SOUTHEAST AHEAD OF THE FRONT AT
PEAK HEATING.

CHANCES FOR SHOWERS AND THUNDERSTORMS WILL STEADILY DECREASE WEST TO
EAST ACROSS THE CWA SUNDAY EVENING...WITH DRY CONDITIONS ALL AREAS
LATER IN THE NIGHT. HAVE LOWERED LOWS INTO THE MIDDLE 50S TO NEAR 60.

THE EXTENDED FORECAST FROM MONDAY INTO THURSDAY STILL LOOKS TO BE
DOMINATED FROM COOLER HIGH PRESSURE WITH PLEASANT HIGHS IN THE 70S
AND LOWS IN THE UPPER 40S AND LOWER 50S EACH DAY. AS THE LARGE SFC
RIDGE SHIFTS FURTHER EAST BY LATE THURSDAY...MOISTURE WHICH WILL BE
POOLING TO THE SOUTH AND WEST OF THE AREA WILL GET ADVECTED
NORTHWARD INTO THE AREA FRIDAY. AS A SHORTWAVE TROUGH APPROACHES
FROM THE SOUTHWEST...THE CHANCES FOR SHOWERS AND THUNDERSTORMS WILL
BE ON INCREASE AT THAT TIME. 63

&&

.TOP WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$








AREA FORECAST DISCUSSION

NWS JACKSON KY

 327 AM EDT SAT MAY 5 2012

.UPDATE...
ISSUED AT 205 AM EDT SAT MAY 5 2012

LINE OF SHOWERS AND TSTMS HAS FINALLY ARRIVED AND IS STILL SHOWING
SOME SIGNS OF HEALTHY CONVECTION...PARTICULARLY ALONG THE WRN HALF OF
THE LINE...WHICH IS UNFORTUNATELY HEADING STRAIGHT FOR OUR COUNTIES
OUTSIDE OF THE CURRENT FFA. RECENT OBS UPSTREAM SUGGEST PRECIP RATES
AROUND 1 TO 1.5 IN/HR...WHICH IS CLOSE TO OUR 1 HR FFG AND WITH
PRECIP EXPECTED OVER THE NEXT FEW HRS AT LEAST...SEVERAL LOCALS HAVE
A GOOD POTENTIAL OF REACHING 3 HR...IF NOT 1 HR FFG VALUES.
ALSO...CONVECTION ALONG THE WRN FLANK OF THE LINE IS CURRENTLY SHOWING
SOME SEVERE POTENTIAL WITH HAIL REPORTS IN THE LAST HOUR OF PENNY TO
NICKLE SIZE HAIL. NO DOUBT...A BUSY NIGHT AHEAD AND WILL CONTINUE TO
MONITOR HYDRO CLOSELY OVER THE NEXT FEW HOURS. UPDATED ZONES WILL BE
ISSUED SHORTLY.

UPDATE ISSUED AT 1049 PM EDT FRI MAY 4 2012

THE CWA HAS BEEN RATHER VOID OF CONVECTION OVER THE PAST COUPLE OF
HOURS. THE CURRENT CONVECTION ACROSS THE OH VALLEY REGION IS CLOSE TO
IF NOT NORTH OF THE OH RIVER. EXTRAPOLATION AND RECENT RUC AND NAM
RUNS AS WELL AS 21Z SREF GENERALLY DROP THIS CONVECTION SOUTH INTO
THE AREA OVERNIGHT. THE GUIDANCE MAY BE A BIT TO FAR SW WITH ITS
TRACK INTO THE CWA LATER ON TONIGHT. IF NOT...THEN THE HEAVIEST RAIN
MAY FALL OUTSIDE OF THE FFA. CONFIDENCE IN THE EXACT CONVECTIVE
EVOLUTION IS NOT THAT HIGH FOR THE OVERNIGHT AS INSTABILITY IS RATHER
MEAGER AS MUCH OF CENTRAL KY HAS BEEN WORKED OVER OR HAS HAD AN
OUTFLOW PASS.

UPDATE ISSUED AT 740 PM EDT FRI MAY 4 2012

MODELS OTHER THAN THE MOST RECENT RUN SEEM TO BE HAVING TROUBLE WITH
THE CONVECTION CURRENTLY ONGOING ACROSS THE OH VALLEY REGION. THE
FORECAST FOR THE REMAINDER OF THE NIGHT IS HIGHLY DEPENDENT ON THE
CONVECTIVE EVOLUTION CLOSER TO THE BOUNDARY TO OUR NORTH AND
NORTHWEST AND IF THIS CONVECTION CAN HOLD TOGETHER ACROSS THE AREAS
THAT HAVE BEEN RECENTLY WORKED OVER. EARLIER STRONGER CONVECTION
THAT WAS OVER CENTRAL KY HAS FIZZLED AND CONVECTION OVER OH AND FAR
NE KY SEEMS DESTINED TO HEAD TO OUR EAST IN THE IMMEDIATE FUTURE.
HOWEVER...OUTFLOWS FROM THIS CONVECTION OR FURTHER DEVELOPMENT TO OUR
NW SHOULD REACH THE CWA SOMETIME OVERNIGHT...BUT THIS IS A LOW
CONFIDENCE FORECAST AT THIS TIME. IF/WHEN CONVECTION AFFECTS THE CWA
THERE WOULD BE SOME POTENTIAL FOR IT TO TRAIN ACROSS SOME OF THE
AREAS THAT HAVE BEEN WET IN THE LAST 24 HOURS. OVERALL...IT APPEARS
THAT WITH THE LOSS OF DAYTIME HEATING THE THREAT FOR SEVERE
CONVECTION IS DIMINISHING...UNLESS AN MCS DEVELOPS A STRONG COLD POOL
AND MOVES INTO THE AREA. WE WILL CONTINUE TO MONITOR CONVECTIVE
DEVELOPMENT AND EVALUATE THE NEED FOR THE FLASH FLOOD WATCH A BIT
LATER THIS EVENING.

UPDATE ISSUED AT 508 PM EDT FRI MAY 4 2012

SKY AND POPS WERE UPDATED TO BETTER REFLECT TIMING OF THE CONVECTION
APPROACHING FROM THE WEST NOW NEAR THE I 65 CORRIDOR/KSDF VICINITY
AND MORE ISOLATED CONVECTION OVER THE BLUEGRASS REGION. RECENT
ANALYSIS INDICATES HIGHER INSTABILITY ML CAPE NEAR 2000 J/KG AND LI
-6C OR LOWER ACROSS THE NORTHERN CWA. DEWPOINTS ARE ALSO HIGHER IN
THIS REGION COMPARED TO THE SW. HOWEVER...LAPSE RATES IN THE LOW AND
MID LEVELS ARE MORE MARGINAL WITH SOME MID LEVEL CAPPING CURRENTLY
OVER THE CWA. HOWEVER...THIS SHOULD ERODE PER MODEL GUIDANCE AS THE
CONVECTION AND ASSOCIATED MID LEVEL WAVE TO OUR NW APPROACHES. AT THIS
POINT...IT STILL APPEARS THAT THE BEST CHANCE FOR THUNDERSTORMS WITH
HEAVY RAIN WILL BE ACROSS THE NORTHERN CWA WHERE CURRENT FFA IS IN
PLACE. EXTRAPOLATION AND INSTABILITY AND SHEAR PARAMETERS POINT TO
THE POSSIBILITY OF DAMAGING WINDS OR MARGINALLY SEVERE HAIL POSSIBLE
WITH ANY CONVECTION THIS EVENING ACROSS THE NORTHERN TWO THIRDS OF
THE CWA BETWEEN ABOUT 22Z AND 3Z.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 300 PM EDT FRI MAY 4 2012

EXTENSIVE CLOUDINESS AND A MID LEVEL CAP HAS INHIBITED CONVECTIVE
INITIATION ACROSS OUR AREA EARLY THIS AFTERNOON. THE FEW CELLS THAT
HAVE MANAGED TO DEVELOP IN THE NORTHWESTERN PART OF THE FORECAST AREA
HAVE REMAINED RELATIVELY WEAK. THE CONVECTIVE COMPLEX NOW CROSSING IL
INTO INDIANA SHOULD MAINTAIN ITSELF AS IT MOVES ACROSS THE SEVERE
THUNDERSTORM WATCH TO OUR WEST. BASED ON CURRENT MOVEMENT THIS
COMPLEX WILL REACH THE NORTHWEST PART OF OUR FORECAST AREA AROUND 7
PM. SHORT RANGE GUIDANCE HAS BEEN POINTING TOWARDS FAIRLY WIDESPREAD
THUNDERSTORMS ACROSS OUR AREA TONIGHT.

UP TO TWO INCHES OF RAIN FELL IN A FEW SPOTS ACROSS THE NORTHERN PART
OF THE FORECAST AREA OVER THE PAST 24 HOURS. WHERE HEAVIEST RAIN FELL
LAST NIGHT 1 HOUR FLASH FLOOD GUIDANCE IS AS LOW AS 1 INCH...WITH 3
HOUR GUIDANCE AS LOW AS 1.3 INCHES. BASED ON THIS AND QPF HAVE ISSUED
A FLASH FLOOD WATCH FOR THE NORTHEAST TWO THIRDS OF THE FORECAST AREA
FOR TONIGHT. THIS HAS BEEN COORDINATED WITH WFO CHARLESTON AND ALL OF
NE KY IS IN THE WATCH.

UNSETTLED WEATHER WILL CONTINUE INTO SATURDAY AS THE FRONT CURRENTLY
TO OUR NORTH SAGS SOUTH. ADDITIONAL SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE ON SATURDAY. WILL TAPER OFF PRECIPITATION CHANCES SATURDAY
NIGHT. TEMPERATURES AND DEWPOINTS WILL REMAIN MORE LIKE SUMMER TIME
VALUES INTO SATURDAY.

.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 326 AM EDT SAT MAY 5 2012

THE MODELS ARE IN UNUSUALLY GOOD AGREEMENT THROUGH WEDNESDAY. AFTER
WEDNESDAY...THE GFS IS A LITTLE FASTER WITH THE UPPER TROUGH MOVING
TO THE EAST. THE PATTERN CONTINUES TO BE UNSETTLED FROM SUNDAY NIGHT
THROUGH WEDNESDAY WITH A FRONT STAYING NEAR THE AREA. EASTERN
KENTUCKY WILL ALSO STAY MOSTLY IN THE WARM MOIST SECTOR WHICH WILL
BE CONDUCIVE FOR THUNDERSTORMS TO DEVELOP IN THE LATE AFTERNOON AND
EVENING. A COLD FRONT MOVING THROUGH THE AREA ON WEDNESDAY WILL
FINALLY USHER IN SOME COOLER AND DRIER AIR AND GIVE THE COAL FIELDS
A BREAK FROM THE UNUSUALLY HOT AND HUMID WEATHER. WITH THE MODELS IN
SUCH GOOD AGREEMENT...KEPT THE TEMPERATURES CLOSE TO THE MODEL
BLEND.


&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 135 AM EDT SAT MAY 5 2012

LINE OF SHRA AND TSTMS MOVING SSE THRU CNTRL AND ERN KY AT ISSUANCE.
GENERALLY VFR CONDITIONS PERSIST AROUND THE ACTIVITY UPSTREAM THOUGH
MVFR CIGS HAVE BEEN NOTED RIGHT AROUND THE HEAVIER SHRA/TSTMS WITH
VSBYS DROPPING TO AROUND 1 SM OR LESS IN AND AROUND THE HEAVIER
DOWNPOURS...AND HAVE INCLUDED A TEMPO GROUP AT ALL SITES WITHIN THE
FIRST 3 HRS OF THE PERIOD TO ADDRESS THIS. LOW END VFR CIGS IN SHRA
LOOK TO LINGER THRU THE MORNING AND POSSIBLY INTO THE AFTERNOON AS
WELL. CANNOT RULE OUT ADDITIONAL CONVECTION LATER IN THE MORNING
WHICH MAY REDUCE CONDITIONS AGAIN...HOWEVER UNCERTAINTY AROUND THIS
WILL PRECLUDE MENTIONING IN THE TAFS. HIGH PRESSURE BEGINS BUILDING
OVER THE OHIO VALLEY AFTER 06/00Z AND SHOULD BRING CLEARING
SKIES...WHICH WILL ALSO BRING A THREAT FOR FOG AROUND THE VALLEYS
TOWARDS THE END OF THE PERIOD. HAVE TRENDED THE TAFS IN THIS
DIRECTION BUT WILL LET THE SUBSEQUENT TAFS FINE TUNE THE TIMING AND
IMPACTS.


&&

.JKL WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 6 AM EDT EARLY THIS MORNING FOR KYZ044-
050>052-058>060-104-106>115-118>120.

&&

$$

UPDATE...MB/JP
SHORT TERM...SBH
LONG TERM....JJ
AVIATION...MB







AREA FORECAST DISCUSSION

NWS JACKSON KY

 206 AM EDT SAT MAY 5 2012

.UPDATE...
ISSUED AT 205 AM EDT SAT MAY 5 2012

LINE OF SHOWERS AND TSTMS HAS FINALLY ARRIVED AND IS STILL SHOWING
SOME SIGNS OF HEALTHY CONVECTION...PARTICULARLY ALONG THE WRN HALF OF
THE LINE...WHICH IS UNFORTUNATELY HEADING STRAIGHT FOR OUR COUNTIES
OUTSIDE OF THE CURRENT FFA. RECENT OBS UPSTREAM SUGGEST PRECIP RATES
AROUND 1 TO 1.5 IN/HR...WHICH IS CLOSE TO OUR 1 HR FFG AND WITH
PRECIP EXPECTED OVER THE NEXT FEW HRS AT LEAST...SEVERAL LOCALS HAVE
A GOOD POTENTIAL OF REACHING 3 HR...IF NOT 1 HR FFG VALUES.
ALSO...CONVECTION ALONG THE WRN FLANK OF THE LINE IS CURRENTLY SHOWING
SOME SEVERE POTENTIAL WITH HAIL REPORTS IN THE LAST HOUR OF PENNY TO
NICKLE SIZE HAIL. NO DOUBT...A BUSY NIGHT AHEAD AND WILL CONTINUE TO
MONITOR HYDRO CLOSELY OVER THE NEXT FEW HOURS. UPDATED ZONES WILL BE
ISSUED SHORTLY.

UPDATE ISSUED AT 1049 PM EDT FRI MAY 4 2012

THE CWA HAS BEEN RATHER VOID OF CONVECTION OVER THE PAST COUPLE OF
HOURS. THE CURRENT CONVECTION ACROSS THE OH VALLEY REGION IS CLOSE TO
IF NOT NORTH OF THE OH RIVER. EXTRAPOLATION AND RECENT RUC AND NAM
RUNS AS WELL AS 21Z SREF GENERALLY DROP THIS CONVECTION SOUTH INTO
THE AREA OVERNIGHT. THE GUIDANCE MAY BE A BIT TO FAR SW WITH ITS
TRACK INTO THE CWA LATER ON TONIGHT. IF NOT...THEN THE HEAVIEST RAIN
MAY FALL OUTSIDE OF THE FFA. CONFIDENCE IN THE EXACT CONVECTIVE
EVOLUTION IS NOT THAT HIGH FOR THE OVERNIGHT AS INSTABILITY IS RATHER
MEAGER AS MUCH OF CENTRAL KY HAS BEEN WORKED OVER OR HAS HAD AN
OUTFLOW PASS.

UPDATE ISSUED AT 740 PM EDT FRI MAY 4 2012

MODELS OTHER THAN THE MOST RECENT RUN SEEM TO BE HAVING TROUBLE WITH
THE CONVECTION CURRENTLY ONGOING ACROSS THE OH VALLEY REGION. THE
FORECAST FOR THE REMAINDER OF THE NIGHT IS HIGHLY DEPENDENT ON THE
CONVECTIVE EVOLUTION CLOSER TO THE BOUNDARY TO OUR NORTH AND
NORTHWEST AND IF THIS CONVECTION CAN HOLD TOGETHER ACROSS THE AREAS
THAT HAVE BEEN RECENTLY WORKED OVER. EARLIER STRONGER CONVECTION
THAT WAS OVER CENTRAL KY HAS FIZZLED AND CONVECTION OVER OH AND FAR
NE KY SEEMS DESTINED TO HEAD TO OUR EAST IN THE IMMEDIATE FUTURE.
HOWEVER...OUTFLOWS FROM THIS CONVECTION OR FURTHER DEVELOPMENT TO OUR
NW SHOULD REACH THE CWA SOMETIME OVERNIGHT...BUT THIS IS A LOW
CONFIDENCE FORECAST AT THIS TIME. IF/WHEN CONVECTION AFFECTS THE CWA
THERE WOULD BE SOME POTENTIAL FOR IT TO TRAIN ACROSS SOME OF THE
AREAS THAT HAVE BEEN WET IN THE LAST 24 HOURS. OVERALL...IT APPEARS
THAT WITH THE LOSS OF DAYTIME HEATING THE THREAT FOR SEVERE
CONVECTION IS DIMINISHING...UNLESS AN MCS DEVELOPS A STRONG COLD POOL
AND MOVES INTO THE AREA. WE WILL CONTINUE TO MONITOR CONVECTIVE
DEVELOPMENT AND EVALUATE THE NEED FOR THE FLASH FLOOD WATCH A BIT
LATER THIS EVENING.

UPDATE ISSUED AT 508 PM EDT FRI MAY 4 2012

SKY AND POPS WERE UPDATED TO BETTER REFLECT TIMING OF THE CONVECTION
APPROACHING FROM THE WEST NOW NEAR THE I 65 CORRIDOR/KSDF VICINITY
AND MORE ISOLATED CONVECTION OVER THE BLUEGRASS REGION. RECENT
ANALYSIS INDICATES HIGHER INSTABILITY ML CAPE NEAR 2000 J/KG AND LI
-6C OR LOWER ACROSS THE NORTHERN CWA. DEWPOINTS ARE ALSO HIGHER IN
THIS REGION COMPARED TO THE SW. HOWEVER...LAPSE RATES IN THE LOW AND
MID LEVELS ARE MORE MARGINAL WITH SOME MID LEVEL CAPPING CURRENTLY
OVER THE CWA. HOWEVER...THIS SHOULD ERODE PER MODEL GUIDANCE AS THE
CONVECTION AND ASSOCIATED MID LEVEL WAVE TO OUR NW APPROACHES. AT THIS
POINT...IT STILL APPEARS THAT THE BEST CHANCE FOR THUNDERSTORMS WITH
HEAVY RAIN WILL BE ACROSS THE NORTHERN CWA WHERE CURRENT FFA IS IN
PLACE. EXTRAPOLATION AND INSTABILITY AND SHEAR PARAMETERS POINT TO
THE POSSIBILITY OF DAMAGING WINDS OR MARGINALLY SEVERE HAIL POSSIBLE
WITH ANY CONVECTION THIS EVENING ACROSS THE NORTHERN TWO THIRDS OF
THE CWA BETWEEN ABOUT 22Z AND 3Z.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 300 PM EDT FRI MAY 4 2012

EXTENSIVE CLOUDINESS AND A MID LEVEL CAP HAS INHIBITED CONVECTIVE
INITIATION ACROSS OUR AREA EARLY THIS AFTERNOON. THE FEW CELLS THAT
HAVE MANAGED TO DEVELOP IN THE NORTHWESTERN PART OF THE FORECAST AREA
HAVE REMAINED RELATIVELY WEAK. THE CONVECTIVE COMPLEX NOW CROSSING IL
INTO INDIANA SHOULD MAINTAIN ITSELF AS IT MOVES ACROSS THE SEVERE
THUNDERSTORM WATCH TO OUR WEST. BASED ON CURRENT MOVEMENT THIS
COMPLEX WILL REACH THE NORTHWEST PART OF OUR FORECAST AREA AROUND 7
PM. SHORT RANGE GUIDANCE HAS BEEN POINTING TOWARDS FAIRLY WIDESPREAD
THUNDERSTORMS ACROSS OUR AREA TONIGHT.

UP TO TWO INCHES OF RAIN FELL IN A FEW SPOTS ACROSS THE NORTHERN PART
OF THE FORECAST AREA OVER THE PAST 24 HOURS. WHERE HEAVIEST RAIN FELL
LAST NIGHT 1 HOUR FLASH FLOOD GUIDANCE IS AS LOW AS 1 INCH...WITH 3
HOUR GUIDANCE AS LOW AS 1.3 INCHES. BASED ON THIS AND QPF HAVE ISSUED
A FLASH FLOOD WATCH FOR THE NORTHEAST TWO THIRDS OF THE FORECAST AREA
FOR TONIGHT. THIS HAS BEEN COORDINATED WITH WFO CHARLESTON AND ALL OF
NE KY IS IN THE WATCH.

UNSETTLED WEATHER WILL CONTINUE INTO SATURDAY AS THE FRONT CURRENTLY
TO OUR NORTH SAGS SOUTH. ADDITIONAL SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE ON SATURDAY. WILL TAPER OFF PRECIPITATION CHANCES SATURDAY
NIGHT. TEMPERATURES AND DEWPOINTS WILL REMAIN MORE LIKE SUMMER TIME
VALUES INTO SATURDAY.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 300 PM EDT FRI MAY 4 2012

THE MODELS ARE IN GOOD AGREEMENT WITH THE LONG WAVE PATTERN THROUGH
THE PERIOD...WITH THE FLOW AMPLIFYING AND BECOMING MORE SPLIT WITH
TIME. THE MAIN UPPER LEVEL FEATURE OF INTEREST WILL BE A NORTHERN
STREAM TROUGH THAT WILL GRADUALLY SHIFT EAST WITH TIME AND
EVENTUALLY CUTOFF AND RIDE THE US/CANADIAN BORDER THROUGH THE END OF
THE NEXT WORK WEEK. THIS WILL BE BRINGING MORE UNSETTLED WEATHER TO
THE AREA FROM MONDAY THROUGH WEDNESDAY. OF COURSE...THE MODELS
HANDLE THE DETAILS WITH THE EVOLUTION OF THIS TROUGH QUITE A BIT
DIFFERENTLY. THE LAST 00Z ECMWF RUN HAS BECOME TOO AMPLIFIED AND
SLOW COMPARED TO THE REST OF THE GUIDANCE. AS SUCH...HAVE DISCOUNTED
THE OPERATIONAL RUN...AND ALLOWED BLENDING FROM ITS ENSEMBLE MEAN
WHICH SEEMS TO JIVE BETTER WITH THE REST OF THE CONSENSUS SOLUTION.

WARM AND HUMID CONDITIONS WITH ISOLATED SHOWERS AND THUNDERSTORMS
POSSIBLE ARE EXPECTED ON SUNDAY. AS WE HEAD INTO MONDAY...THE
TROUGH AND ASSOCIATED SURFACE COLD FRONT WILL BE MOVING IN FROM THE
WEST. POPS WILL BE ON THE INCREASE...WITH MONDAY NIGHT INTO EARLY
TUESDAY MORNING STILL LOOKING LIKE THE BEST CHANCE...AND HAVE STUCK
WITH THE GIVEN HIGH LIKELY. ON TUESDAY...THE FRONT WILL BE SHIFTING
EAST...WITH LIKELY POPS HANGING ON FOR MOST THROUGH AT LEAST THE
FIRST PART OF THE DAY...BEFORE DIMINISHING IN THE EVENING. THE
TROUGH AXIS WILL LINGER THROUGH WEDNESDAY...ALLOWING FOR SOME
ADDITIONAL SCATTERED SHOWER ACTIVITY. BY THURSDAY AND FRIDAY...THE
TROUGH AXIS WILL HAVE EXITED EAST...WITH RIDGING BUILDING
IN...BRINGING DRIER AND COOLER WEATHER TO CONCLUDE THE REST OF THE
PERIOD.

FOR TEMPERATURES...ABOVE NORMAL READINGS AND HUMID CONDITIONS WILL
COOL OFF TO NEAR NORMAL VALUES WITH LESS HUMIDITY THROUGH THE PERIOD.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 135 AM EDT SAT MAY 5 2012

LINE OF SHRA AND TSTMS MOVING SSE THRU CNTRL AND ERN KY AT ISSUANCE.
GENERALLY VFR CONDITIONS PERSIST AROUND THE ACTIVITY UPSTREAM THOUGH
MVFR CIGS HAVE BEEN NOTED RIGHT AROUND THE HEAVIER SHRA/TSTMS WITH
VSBYS DROPPING TO AROUND 1 SM OR LESS IN AND AROUND THE HEAVIER
DOWNPOURS...AND HAVE INCLUDED A TEMPO GROUP AT ALL SITES WITHIN THE
FIRST 3 HRS OF THE PERIOD TO ADDRESS THIS. LOW END VFR CIGS IN SHRA
LOOK TO LINGER THRU THE MORNING AND POSSIBLY INTO THE AFTERNOON AS
WELL. CANNOT RULE OUT ADDITIONAL CONVECTION LATER IN THE MORNING
WHICH MAY REDUCE CONDITIONS AGAIN...HOWEVER UNCERTAINTY AROUND THIS
WILL PRECLUDE MENTIONING IN THE TAFS. HIGH PRESSURE BEGINS BUILDING
OVER THE OHIO VALLEY AFTER 06/00Z AND SHOULD BRING CLEARING
SKIES...WHICH WILL ALSO BRING A THREAT FOR FOG AROUND THE VALLEYS
TOWARDS THE END OF THE PERIOD. HAVE TRENDED THE TAFS IN THIS
DIRECTION BUT WILL LET THE SUBSEQUENT TAFS FINE TUNE THE TIMING AND
IMPACTS.


&&

.JKL WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 6 AM EDT EARLY THIS MORNING FOR KYZ044-
050>052-058>060-104-106>115-118>120.

&&

$$

UPDATE...MB/JP
SHORT TERM...SBH
LONG TERM....GEOGERIAN
AVIATION...MB







AREA FORECAST DISCUSSION

NWS JACKSON KY

 135 AM EDT SAT MAY 5 2012

.UPDATE...
ISSUED AT 1049 PM EDT FRI MAY 4 2012

THE CWA HAS BEEN RATHER VOID OF CONVECTION OVER THE PAST COUPLE OF
HOURS. THE CURRENT CONVECTION ACROSS THE OH VALLEY REGION IS CLOSE TO
IF NOT NORTH OF THE OH RIVER. EXTRAPOLATION AND RECENT RUC AND NAM
RUNS AS WELL AS 21Z SREF GENERALLY DROP THIS CONVECTION SOUTH INTO
THE AREA OVERNIGHT. THE GUIDANCE MAY BE A BIT TO FAR SW WITH ITS
TRACK INTO THE CWA LATER ON TONIGHT. IF NOT...THEN THE HEAVIEST RAIN
MAY FALL OUTSIDE OF THE FFA. CONFIDENCE IN THE EXACT CONVECTIVE
EVOLUTION IS NOT THAT HIGH FOR THE OVERNIGHT AS INSTABILITY IS RATHER
MEAGER AS MUCH OF CENTRAL KY HAS BEEN WORKED OVER OR HAS HAD AN
OUTFLOW PASS.

UPDATE ISSUED AT 740 PM EDT FRI MAY 4 2012

MODELS OTHER THAN THE MOST RECENT RUN SEEM TO BE HAVING TROUBLE WITH
THE CONVECTION CURRENTLY ONGOING ACROSS THE OH VALLEY REGION. THE
FORECAST FOR THE REMAINDER OF THE NIGHT IS HIGHLY DEPENDENT ON THE
CONVECTIVE EVOLUTION CLOSER TO THE BOUNDARY TO OUR NORTH AND
NORTHWEST AND IF THIS CONVECTION CAN HOLD TOGETHER ACROSS THE AREAS
THAT HAVE BEEN RECENTLY WORKED OVER. EARLIER STRONGER CONVECTION
THAT WAS OVER CENTRAL KY HAS FIZZLED AND CONVECTION OVER OH AND FAR
NE KY SEEMS DESTINED TO HEAD TO OUR EAST IN THE IMMEDIATE FUTURE.
HOWEVER...OUTFLOWS FROM THIS CONVECTION OR FURTHER DEVELOPMENT TO OUR
NW SHOULD REACH THE CWA SOMETIME OVERNIGHT...BUT THIS IS A LOW
CONFIDENCE FORECAST AT THIS TIME. IF/WHEN CONVECTION AFFECTS THE CWA
THERE WOULD BE SOME POTENTIAL FOR IT TO TRAIN ACROSS SOME OF THE
AREAS THAT HAVE BEEN WET IN THE LAST 24 HOURS. OVERALL...IT APPEARS
THAT WITH THE LOSS OF DAYTIME HEATING THE THREAT FOR SEVERE
CONVECTION IS DIMINISHING...UNLESS AN MCS DEVELOPS A STRONG COLD POOL
AND MOVES INTO THE AREA. WE WILL CONTINUE TO MONITOR CONVECTIVE
DEVELOPMENT AND EVALUATE THE NEED FOR THE FLASH FLOOD WATCH A BIT
LATER THIS EVENING.

UPDATE ISSUED AT 508 PM EDT FRI MAY 4 2012

SKY AND POPS WERE UPDATED TO BETTER REFLECT TIMING OF THE CONVECTION
APPROACHING FROM THE WEST NOW NEAR THE I 65 CORRIDOR/KSDF VICINITY
AND MORE ISOLATED CONVECTION OVER THE BLUEGRASS REGION. RECENT
ANALYSIS INDICATES HIGHER INSTABILITY ML CAPE NEAR 2000 J/KG AND LI
-6C OR LOWER ACROSS THE NORTHERN CWA. DEWPOINTS ARE ALSO HIGHER IN
THIS REGION COMPARED TO THE SW. HOWEVER...LAPSE RATES IN THE LOW AND
MID LEVELS ARE MORE MARGINAL WITH SOME MID LEVEL CAPPING CURRENTLY
OVER THE CWA. HOWEVER...THIS SHOULD ERODE PER MODEL GUIDANCE AS THE
CONVECTION AND ASSOCIATED MID LEVEL WAVE TO OUR NW APPROACHES. AT THIS
POINT...IT STILL APPEARS THAT THE BEST CHANCE FOR THUNDERSTORMS WITH
HEAVY RAIN WILL BE ACROSS THE NORTHERN CWA WHERE CURRENT FFA IS IN
PLACE. EXTRAPOLATION AND INSTABILITY AND SHEAR PARAMETERS POINT TO
THE POSSIBILITY OF DAMAGING WINDS OR MARGINALLY SEVERE HAIL POSSIBLE
WITH ANY CONVECTION THIS EVENING ACROSS THE NORTHERN TWO THIRDS OF
THE CWA BETWEEN ABOUT 22Z AND 3Z.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 300 PM EDT FRI MAY 4 2012

EXTENSIVE CLOUDINESS AND A MID LEVEL CAP HAS INHIBITED CONVECTIVE
INITIATION ACROSS OUR AREA EARLY THIS AFTERNOON. THE FEW CELLS THAT
HAVE MANAGED TO DEVELOP IN THE NORTHWESTERN PART OF THE FORECAST AREA
HAVE REMAINED RELATIVELY WEAK. THE CONVECTIVE COMPLEX NOW CROSSING IL
INTO INDIANA SHOULD MAINTAIN ITSELF AS IT MOVES ACROSS THE SEVERE
THUNDERSTORM WATCH TO OUR WEST. BASED ON CURRENT MOVEMENT THIS
COMPLEX WILL REACH THE NORTHWEST PART OF OUR FORECAST AREA AROUND 7
PM. SHORT RANGE GUIDANCE HAS BEEN POINTING TOWARDS FAIRLY WIDESPREAD
THUNDERSTORMS ACROSS OUR AREA TONIGHT.

UP TO TWO INCHES OF RAIN FELL IN A FEW SPOTS ACROSS THE NORTHERN PART
OF THE FORECAST AREA OVER THE PAST 24 HOURS. WHERE HEAVIEST RAIN FELL
LAST NIGHT 1 HOUR FLASH FLOOD GUIDANCE IS AS LOW AS 1 INCH...WITH 3
HOUR GUIDANCE AS LOW AS 1.3 INCHES. BASED ON THIS AND QPF HAVE ISSUED
A FLASH FLOOD WATCH FOR THE NORTHEAST TWO THIRDS OF THE FORECAST AREA
FOR TONIGHT. THIS HAS BEEN COORDINATED WITH WFO CHARLESTON AND ALL OF
NE KY IS IN THE WATCH.

UNSETTLED WEATHER WILL CONTINUE INTO SATURDAY AS THE FRONT CURRENTLY
TO OUR NORTH SAGS SOUTH. ADDITIONAL SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE ON SATURDAY. WILL TAPER OFF PRECIPITATION CHANCES SATURDAY
NIGHT. TEMPERATURES AND DEWPOINTS WILL REMAIN MORE LIKE SUMMER TIME
VALUES INTO SATURDAY.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 300 PM EDT FRI MAY 4 2012

THE MODELS ARE IN GOOD AGREEMENT WITH THE LONG WAVE PATTERN THROUGH
THE PERIOD...WITH THE FLOW AMPLIFYING AND BECOMING MORE SPLIT WITH
TIME. THE MAIN UPPER LEVEL FEATURE OF INTEREST WILL BE A NORTHERN
STREAM TROUGH THAT WILL GRADUALLY SHIFT EAST WITH TIME AND
EVENTUALLY CUTOFF AND RIDE THE US/CANADIAN BORDER THROUGH THE END OF
THE NEXT WORK WEEK. THIS WILL BE BRINGING MORE UNSETTLED WEATHER TO
THE AREA FROM MONDAY THROUGH WEDNESDAY. OF COURSE...THE MODELS
HANDLE THE DETAILS WITH THE EVOLUTION OF THIS TROUGH QUITE A BIT
DIFFERENTLY. THE LAST 00Z ECMWF RUN HAS BECOME TOO AMPLIFIED AND
SLOW COMPARED TO THE REST OF THE GUIDANCE. AS SUCH...HAVE DISCOUNTED
THE OPERATIONAL RUN...AND ALLOWED BLENDING FROM ITS ENSEMBLE MEAN
WHICH SEEMS TO JIVE BETTER WITH THE REST OF THE CONSENSUS SOLUTION.

WARM AND HUMID CONDITIONS WITH ISOLATED SHOWERS AND THUNDERSTORMS
POSSIBLE ARE EXPECTED ON SUNDAY. AS WE HEAD INTO MONDAY...THE
TROUGH AND ASSOCIATED SURFACE COLD FRONT WILL BE MOVING IN FROM THE
WEST. POPS WILL BE ON THE INCREASE...WITH MONDAY NIGHT INTO EARLY
TUESDAY MORNING STILL LOOKING LIKE THE BEST CHANCE...AND HAVE STUCK
WITH THE GIVEN HIGH LIKELY. ON TUESDAY...THE FRONT WILL BE SHIFTING
EAST...WITH LIKELY POPS HANGING ON FOR MOST THROUGH AT LEAST THE
FIRST PART OF THE DAY...BEFORE DIMINISHING IN THE EVENING. THE
TROUGH AXIS WILL LINGER THROUGH WEDNESDAY...ALLOWING FOR SOME
ADDITIONAL SCATTERED SHOWER ACTIVITY. BY THURSDAY AND FRIDAY...THE
TROUGH AXIS WILL HAVE EXITED EAST...WITH RIDGING BUILDING
IN...BRINGING DRIER AND COOLER WEATHER TO CONCLUDE THE REST OF THE
PERIOD.

FOR TEMPERATURES...ABOVE NORMAL READINGS AND HUMID CONDITIONS WILL
COOL OFF TO NEAR NORMAL VALUES WITH LESS HUMIDITY THROUGH THE PERIOD.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 135 AM EDT SAT MAY 5 2012

LINE OF SHRA AND TSTMS MOVING SSE THRU CNTRL AND ERN KY AT ISSUANCE.
GENERALLY VFR CONDITIONS PERSIST AROUND THE ACTIVITY UPSTREAM THOUGH
MVFR CIGS HAVE BEEN NOTED RIGHT AROUND THE HEAVIER SHRA/TSTMS WITH
VSBYS DROPPING TO AROUND 1 SM OR LESS IN AND AROUND THE HEAVIER
DOWNPOURS...AND HAVE INCLUDED A TEMPO GROUP AT ALL SITES WITHIN THE
FIRST 3 HRS OF THE PERIOD TO ADDRESS THIS. LOW END VFR CIGS IN SHRA
LOOK TO LINGER THRU THE MORNING AND POSSIBLY INTO THE AFTERNOON AS
WELL. CANNOT RULE OUT ADDITIONAL CONVECTION LATER IN THE MORNING
WHICH MAY REDUCE CONDITIONS AGAIN...HOWEVER UNCERTAINTY AROUND THIS
WILL PRECLUDE MENTIONING IN THE TAFS. HIGH PRESSURE BEGINS BUILDING
OVER THE OHIO VALLEY AFTER 06/00Z AND SHOULD BRING CLEARING
SKIES...WHICH WILL ALSO BRING A THREAT FOR FOG AROUND THE VALLEYS
TOWARDS THE END OF THE PERIOD. HAVE TRENDED THE TAFS IN THIS
DIRECTION BUT WILL LET THE SUBSEQUENT TAFS FINE TUNE THE TIMING AND
IMPACTS.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 6 AM EDT EARLY THIS MORNING FOR KYZ044-
050>052-058>060-104-106>115-118>120.

&&

$$

UPDATE...JP
SHORT TERM...SBH
LONG TERM....GEOGERIAN
AVIATION...MB







AREA FORECAST DISCUSSION

NWS PITTSBURGH PA

 129 AM EDT SAT MAY 5 2012

.SYNOPSIS...
A SOUTHWARD MOVING COLD FRONT CAN STILL BRING SOME THUNDERSTORMS
OVERNIGHT, ALONG WITH PATCHY FOG. CANADIAN HIGH PRESSURE WILL FOLLOW
TO PROVIDE DRY, SEASONABLE CONDITIONS FOR SATURDAY AND SUNDAY.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
OUTFLOW DRIVEN CONVECTION CONTINUES TO DIE A VERY SLOW DEATH
ACROSS THE FAR SOUTHERN TIER OF THE CWA. THE BEST DEVELOPMENT IS
CLEARLY ACROSS NORTHERN KENTUCKY INTO CENTRAL WEST
VIRGINIA...WHERE A FAIRLY COHERENT SQUALL LINE HAS DEVELOPED AND
IS TRACKING TO THE SOUTH. HOWEVER...FARTHER TO THE NORTH AND EAST
IN OUR NECK OF THE WOODS...SOME DRIER AIR IN THE 700-500 MB LAYER
HAS WORKED IN AT LEAST TEMPORARILY. WITH THIS DRIER AIR
ALOFT...RAINFALL CHANCES SHOULD DIMINISH THE FARTHER NORTH YOU GO
INTO THE CWA OVERNIGHT...YIELDING LIKELY MAINLY DRY CONDITIONS
FROM I-70 NORTHWARD THE REST OF THE NIGHT. FARTHER UPSTREAM...THE
PATTERN AGAIN GETS VERY MESSY WITH A DISSIPATING MCS PRESENT OVER
WISCONSIN AND A PLETHORA OF CONVECTIVE BLOW UPS ALONG THE FRONT
THROUGH THE OHIO VALLEY DOMINATING THE SCENE. THESE FEATURES WILL
LIKELY PLAY INTO THE FORECAST FOR SATURDAY...HOWEVER FOR
TONIGHT...THINGS SHOULD DEFINITELY BE WINDING DOWN WITH FOG LIKELY
TO DEVELOP GIVEN NARROW DEWPOINT DEPRESSIONS ALREADY PRESENT OVER
MUCH OF THE CWA THAT SAW RAINFALL TODAY. FRIES

&&

.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/...
RECENT SREF MODEL OUTPUT SHOWS CANADIAN HIGH PRESSURE WILL
MAINTAIN DRY CONDITIONS WITH NO MORE THAN SCATTERED CLOUDS MOST OF
THE TIME THROUGH DAYTIME SUNDAY.

OPTED FOR SLOWER GFS SOLUTION SUNDAY NIGHT AND MONDAY, WITH
NORTHWARD RETURN OF A WARM FRONTAL BOUNDARY AND MOISTURE AHEAD OF
A FAIRLY STRONG SURFACE LOW AND COLD FRONT FOR MONDAY. THIS IS
MORE IN LINE WITH 12Z ECMWF AND A BLEND OF GFS/ECMWF USED.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
12Z GFS SHOWS A CLOSED UPPER LOW AND ASSOCIATED SURFACE LOW TRACKING
NORTH OF THE GREAT LAKES EARLY IN THE WEEK AND REACHING SOUTHERN
QUEBEC LATE WEDNESDAY. OLD 00Z ECMWF TRACK DIGS THE UPPER LOW MUCH
FURTHER SOUTHWARD INTO THE APPALACHIANS BY THURSDAY. LEANED TOWARD
HPC PROGS WHICH ARE CLOSER TO GFS SOLUTION.

FORECAST LIKELY POPS FOR SHOWERS AND THUNDER MONDAY NIGHT INTO
TUESDAY WITH FRONTAL PASSAGE. TAPERED POPS TO SCATTERED COVERAGE
TUESDAY NIGHT INTO THURSDAY AS SYSTEM MAKES SLOW EASTWARD PROGRESS.
DRY CONDITIONS ARE FORECAST BY FRIDAY AS SURFACE HIGH BUILDS IN
FROM THE WEST.

&&

.AVIATION /05Z SATURDAY THROUGH WEDNESDAY/...
BLEND OF RECENT RADAR DATA AND HRRR MODEL OUTPUT SHOWS PREFRONTAL BANDS
OF MVFR SHOWERS AND SCATTERED IFR THUNDERSTORMS, WITH HEAVY RAIN, WILL
MOVE SOUTHEASTWARD THROUGH THE UPPER OHIO VALLEY THROUGH ABOUT
08Z.

AREAS OF POST-FRONTAL POST-RAIN IFR FOG AND STRATUS CAN DEVELOP
LATE TONIGHT AND LINGER UNTIL ABOUT 13Z.

HIGH PRESSURE SUBSIDENCE AND DRYING, COUPLED WITH DAYTIME
VERTICAL MIXING, WILL PROVIDE IMPROVING CONDITIONS TO VFR CUMULUS
CEILINGS BY SATURDAY AFTERNOON.

SURFACE WINDS WILL BECOME NORTHWEST 6-10 KTS LATE TONIGHT AND
SATURDAY. HIGHER GUSTS ARE POSSIBLE WITH THUNDERSTORMS THROUGH
08Z.

.OUTLOOK...SATURDAY NIGHT THROUGH WEDNESDAY...
HIGH PRESSURE WILL PROVIDE VFR CONDITIONS SATURDAY NIGHT THROUGH
EARLY MONDAY. RESTRICTIONS WILL BE POSSIBLE MONDAY THROUGH
WEDNESDAY DUE TO SHOWERS AND POSSIBLE THUNDERSTORMS ASSOCIATED
WITH THE EASTBOUND PASSAGE OF A LOW PRESSURE SYSTEM.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

$$







AREA FORECAST DISCUSSION

NWS DULUTH MN

 333 AM CDT SAT MAY 5 2012

.SHORT TERM...[NOW - SUNDAY]...

CLOUDY AND COOLER THAN NORMAL WEATHER IS EXPECTED THROUGH SUNDAY
WITH CHANCES FOR PCPN...ESPECIALLY TONIGHT AND SUNDAY MORNING WHEN
LOW PRESSURE IN THE PLAINS MOVES EASTWARD INTO THE UPPER MIDWEST.

TODAY...HIGH PRESSURE WILL CONTINUE TO DOMINATE MANITOBA AND
ONTARIO...WHILE PRESSURE ORGANIZES IN THE CENTRAL PLAINS...AND A
MID/UPPER LEVEL TROUGH LIFTS THROUGH IDAHO AND MONTANA. RAIN
SHOWERS ASSOCIATED WITH MID LEVEL WARM AIR ADVECTION COULD LINGER
THROUGH THIS MORNING. LOWERED POPS ACROSS THE WESTERN FA SINCE IT
APPEARS MOST OF THE SHOWERS WILL BE LINGERING ACROSS THE EASTERN
FA. EASTERLY WINDS WILL CONTINUE TODAY...WITH THE STRONGEST WINDS
BETWEEN 10 AND 15 MPH NEAR THE TWIN PORTS AND ALONG THE LAKE
SUPERIOR SHORELINE DUE TO THE EXPECTED GUSTY WINDS OVER THE LAKE.
THE EASTERLY WINDS AND CLOUDY SKIES TODAY WILL RESULT IN COOLER
THAN NORMAL TEMPERATURES...ESPECIALLY NEAR THE TWIN PORTS.
INHERITED A FORECASTED FOR FOG AROUND LAKE SUPERIOR FOR THIS
MORNING...AND DECIDED TO KEEP THAT DUE TO THE EASTERLY WINDS OFF
THE LAKE AND THE HRRR SUGGESTING SOME FOG. THE MODELS ARE IN
REASONABLE AGREEMENT THAT THE LOW PRESSURE IN THE PLAINS WILL
ORGANIZE AND BEGIN TO MOVE EASTWARD THIS AFTERNOON AND BRING
SHOWERS TO THE SOUTHERN FA LATER THIS AFTERNOON.
THEREFORE...INCREASED POPS A BIT.

TONIGHT...THE MID/UPPER LEVEL TROUGH IN MONTANA WILL MOVE INTO
SOUTHERN SASKATCHEWAN AND DEVELOP A DISTINCT MID/UPPER LEVEL LOW.
AN ASSOCIATED SURFACE LOW WILL DEVELOP IN SOUTHERN
SASKATCHEWAN...WHILE A OCCLUDED FRONT MOVES THROUGH THE DAKOTAS
TOWARDS WESTERN MINNESOTA. THIS WILL RESULT IN A SURGE OF MOISTURE
OVER THE NORTHLAND WITH PRECIPITABLE WATER VALUES CLIMBING TO
AROUND 1.25 INCHES. THE MODELS ARE IN GOOD AGREEMENT WITH BRINGING
SIGNIFICANT RAINFALL TO THE NORTHLAND...SO INCREASED POPS. A GOOD
PORTION OF THE FA IS FORECASTED TO GET AROUND A QUARTER TO NEARLY
THREE QUARTERS OF A INCH OF RAINFALL WITH THE SOUTHWESTERN FA AT
THE HIGHEST END OF THE RANGE. NOT THRILLED ABOUT THE PROSPECTS OF
THUNDER...BUT SINCE THE MODELS SUGGEST SOME LIMITED MOST UNSTABLE
CAPE AND SLIGHTLY NEGATIVE LIFTED INDICES...FORECASTED ISOLATED
THUNDER ACROSS THE SOUTHERN FA.

SUNDAY...THE MID/UPPER LEVEL LOW WILL DRIFT TOWARDS SOUTHERN
MANITOBA...AND THE ASSOCIATED OCCLUDED FRONT WILL CONTINUE TO
APPROACH THE NORTHLAND. RAIN SHOWERS WILL PROBABLY CONTINUE ACROSS
THE FA...AT LEAST DURING THE MORNING. ANOTHER QUARTER TO THREE
QUARTERS OF AN INCH OF RAIN IS FORECASTED FOR MUCH OF THE
FA...WITH NORTHWESTERN WISCONSIN LIKELY GETTING THE HIGHEST
AMOUNTS. FORECASTED ISOLATED THUNDER ACROSS THE SOUTHERN FA DUE TO
THE MODELS SUGGESTING THE POSSIBILITY OF LIMITED INSTABILITY. THE
CLOUDY AND WET CONDITIONS WILL RESULT IN COOLER THAN NORMAL
TEMPERATURES.


.LONG TERM...[SUNDAY NIGHT - FRIDAY]...

A CLOSED UPPER LOW WILL MEANDER ALONG THE CANADIAN BORDER FROM
SUNDAY NIGHT THROUGH MONDAY NIGHT. BY TUESDAY, THE LOW OPENS UP
INTO A LONG WAVE TROF AS IT DROPS THROUGH THE WESTERN GREAT
LAKES EXITING BY 12Z WEDNESDAY. THE RESULT IS A MENTION OF POPS
THROUGH TUESDAY NIGHT. UPPER LEVEL SFC RIDGING FOLLOWS BEHIND
WEDNESDAY INTO THURSDAY. THE UPPER RIDGING PERSISTS THURSDAY NIGHT
EVEN THOUGH THE SFC RIDGE DRIFTS OFF TO THE SE. THIS ALLOWS A WAA
REGIME TO ESTABLISH BRINGING THE CHANCE OF SHOWERS AND
THUNDERSTORMS INTO THE FA THURSDAY NIGHT. MODELS DISAGREE WITH THE
TIMING OF PCPN AND HAVE USED A MODEL BLEND. A COLD FRONT BEGINS TO
MARCH THROUGH THE FA LATE THURSDAY NIGHT AND FRIDAY WITH MORE
SHOWERS POSSIBLE.

&&

.AVIATION...06Z TAF ISSUANCE...

SHOWERS HAVE INCREASED OVER THE PAST COUPLE HOURS OVER THE
NORTHLAND...AND LOWER CEILINGS WERE DEVELOPING OVER CENTRAL
MINNESOTA. THESE MVFR CEILINGS WERE MOVING QUICKLY NORTH...AND
SHOULD REACH KBRD AROUND OR SHORTLY AFTER 06Z...AND THE REST OF
THE TAF SITES BETWEEN 07Z-09Z. CEILINGS SHOULD LOWER TO IFR IN
MANY AREAS LATE TONIGHT INTO EARLY SATURDAY MORNING...THEN REMAIN
AT IFR/MVFR THROUGH THE REST OF THE PERIOD.

&&

.POINT TEMPS/POPS...
DLH  49  39  47  40 /  30  70  70  50
INL  56  41  54  42 /  30  50  50  40
BRD  61  47  60  43 /  30  80  60  30
HYR  59  45  60  45 /  40  70  70  60
ASX  50  41  52  43 /  40  60  70  60

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 AM CDT SUNDAY FOR LSZ121-142>148.

&&

$$

SHORT TERM...GROCHOCINSKI
LONG TERM....GSF
AVIATION...GSF







AREA FORECAST DISCUSSION

NWS KANSAS CITY/PLEASANT HILL MO

 1201 AM CDT Sat May 5 2012


...UPDATED AVIATION DISCUSSION...


.DISCUSSION...

Main concerns continue to be thunderstorm chances with a multitude of
outflow boundaries to be concerned about.

This Evening and Tonight:

The strongest outflow boundary and the one that seems to have the
best chance of initiating convection is still residing from near
Paola to south of Clinton, MO. There has been some deeper cloud
development in the vicinity of the boundary and given the extreme
instability, MUCAPE approaching 5,000 J/kg, if something could
develop it would likely become severe. But limited deep layer shear
would inhibit much organization so more multicell clusters would be
the most likely convective mode. Forecast soundings offer a mixed
scenario. The NAM maintains a fairly strong cap and inhibits
convection. The RUC weakens the cap to the point that mixed layer
parcel would be uninhibited and we`d be off to the races. Something
in between is probably the best scenario in which case a little
better forcing would be needed to break the cap. That said the
presence of the boundary within the extreme instability warrants at
least a small mention of thunderstorms. Forecast soundings in the
southern portions of the forecast area also show some mid level dry
air. All that said, should any storm get going they could easily
become severe with damaging winds and large hail possible. Also,
with ample amounts of moisture available any storm could drop
copious amounts of rainfall over a localized area.

During the overnight hours, storms may fire again in far northern MO
or southern IA and NE and move into northern MO. This area is not as
unstable as it is still recovering from morning convection but
3-4,000 J/kg could still be realized by late this afternoon. Shear
looks weak in this area so if any storms can get going and/or move
into northern MO they would likely be disorganized. There is still
ample moisture in this area and some areas received heavy rain so
any storm could easily produce additional flooding problems.

Saturday:

Hot and humid conditions will persist with heat indices in the mid
90s. This is very unseasonal and could pose problems for those who
are most sensitive to heat. Otherwise, it looks like the area should
be capped for most of the day inhibiting convective chances until
closer to sunset. By the evening and overnight hours we may see some
storms move into or develop in northern MO. Instability should be
around 3,000 J/kg but again shear looks marginal at best for storm
organization. So a more disorganized storm mode would be expected
with hail and damaging winds possible should storms impact the area.

Sunday:

Extreme instability is expected to build back into the forecast area
by Sunday afternoon and evening with potential 4-5,000 J/kg MUCAPE to
work with. Models differ a little with the timing of the frontal
boundary with the NAM bringing the boundary into NW MO late Sunday
morning. The GFS is little slower, holding it up until the evening
hours. Shear continues to looks rather weak in the warm sector of
the system which would limit storm organization. But with the
extreme instability and front to act as a trigger thunderstorms are
expected to develop during the afternoon hours and could easily
become severe. It looks like the biggest hazards with this system
will be large hail and damaging winds as well locally heavy rainfall
given the copious amounts of moisture available.

CDB

Medium Range (Monday through Friday)...

Medium range models are in very good agreement on the overall
pattern aloft which is marked by a dry airmass with seasonal
temperatures. Except for the possibility of some lingering post
frontal showers over the eastern CWA Monday morning as high pressure
builds in from the Rockies.

The first portion of this forecast period will be dominated by an
upper trough which will deepen as it digs southeast from south
central Canada through the Great Lakes and Upper MS Valley. The
ECMWF and GEM are in closer agreement on the depth of the system/
timing and thus get a slight nod over the more progressive GFS. This
allows a bit more cold air advection to work its way southward out
of southern Canada but temperatures through mid week will still be
near seasonal averages. Could see some light instability showers
sneak across the IA/MO border Tuesday afternoon but have low
confidence this far out.

By the end of the work week expect to see warm air advection move
back in as the surface high departs and an upper ridge builds into
the Northern Plains. GFS/ECMWF similarly address the issue of a closed
upper low over either northern Mexico or the far southwestern U.S.
opening up and being lifted northeast by the developing
southwesterly mid/upper level flow. Both models lift this feature
into the Central Plains by Friday and interact with an approaching
cold front to generate convection. Despite both models being on the
same page with this feature have limited confidence in them as they
both tend to have issues in handling closed upper lows this far out.
So, best option is to use a blend of models and await the next
couple of model runs.


MJ

&&

.AVIATION...
For 06z TAFs, short-term MOS guidance continues to bring in
MVFR/IFR ceilings towards morning, so as with previous TAF issuances
will keep with this trend however push timing back a bit. Low
confidence in taking conditions down to IFR conditions, so at this
time will just stick with MVFR. However with abundant low level
moisture and nocturnally decoupled winds it is not out of the realm
of possibility that ceilings could get that low. Otherwise convection
should stay north of the TAF sites through this forecast period.

MJM

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&

$$

WFO EAX







AREA FORECAST DISCUSSION

NWS NORTH PLATTE NE

 359 AM CDT SAT MAY 5 2012

.SYNOPSIS...
LAST NIGHT CONVECTION HAS PUSHED NEARLY STATIONARY SURFACE
BOUNDARY SOUTHWARD...CLOSE TO THE NEB/KS BORDER...MEANWHILE A
SURFACE LOW IS POSITIONED OVER NW KS. SECONDARY SURFACE LOW OVER N
CENTRAL MT WITH A COLD FRONT STRETCH TO THE SOUTHWEST. UPPER LEVEL
RIDGE OVER THE SOUTHERN PLAINS...WITH A TROUGH DIGGING OVER THE
NORTHWEST.

&&

.DISCUSSION...
MORNING PATCHY FOG LIKELY WITH DEW POINTS IN THE 50S...ESPECIALLY
IN THE RIVER VALLEY. LOCALLY COULD SEE VISBY LESS THAN 1
MILE...HOWEVER NOT EXPECTED WIDESPREAD ENOUGH FOR ANY TYPE OF
HEADLINE. MORE OF A CONCERN WILL BE AFTERNOON TEMPERATURES THEN
THE SEVERE WEATHER OUTBREAK. SOUTHERN BOUNDARY WILL LIFT NORTH AS
A WARM FRONT TODAY WITH TEMPS RETURNING BACK INTO THE 80S SOUTH
OF THE FRONT...70S TO THE NORTH. FRONTAL BOUNDARY WILL AGAIN BE
PRIMED FOR A REPEAT OF SEVERE THUNDERSTORMS...WITH STEEP LAPSE
RATES WITH CAPE VALUES 3000 TO 4000 J/KG OVER THE EASTERN HALF OF
THE CWA. PRIMARY THREAT WILL BE VERY LARGE HAIL...HOWEVER SOME
BACKED WINDS ALONG THE BOUNDARY IN CONJUNCTION WITH THE GOOD
INSTABILITY COULD RESULT IN A FEW TORNADOES. AGREE WITH SPC
PLACEMENT OF 10 PERCENT TOR OUTLOOK. THEN THE COLD FRONT TO CROSS
THE AREA WITH ADDITIONAL LIFT. MODELS STILL STRUGGLING WITH THE
TIMING OF THE FRONT...HOWEVER EXPECT PASSAGE OVERNIGHT...WHEN THE
FRONT DOES NOT HAVE TO PUSH 80+ DEGREE HEAT BUBBLE. THE FRONT IS
LIKELY TO PRODUCE AT LEAST A BROKEN LINE OF STORMS...BUT WILL
NEED TO MONITOR OUTFLOW BOUNDARIES.

NOTICEABLY COOLER AIR BEHIND THE FRONT IN PLACE FOR SUNDAY...AS
HIGHS STRUGGLE INTO THE 60S. COULD SEE SOME LINGERING
SHOWERS...MAYBE SOME THUNDER IN THE EAST...OTHERWISE MOST AREAS
SHOULD SEE A DRY DAY. LATE IN THE DAY SHOULD SEE SOME SHOWERS
DEVELOP OVER THE HIGHER TERRAIN OF THE FRONT RANGE WITH MOIST
UPSLOPE FLOW. MID LEVEL FLOW IS TO THE NORTHEAST AND COULD DRIFT
INTO THE FAR SW ZONES OVERNIGHT. TYPICALLY THIS ACTIVITY WILL DIE
AS IT PUSHES TOWARDS THE CWA...SO WHEN WITH THE DRIER NAM
SOLUTION.

SUNDAY NIGHT AS THE SURFACE HIGH PUSHES TOWARDS THE AREA...WILL
HAVE TO MONITOR LOW TEMPERATURES. CURRENT THOUGHT IS THE CENTER
OF THE HIGH WILL REMAIN TO THE NW AND WILL SEE A FEW HIGH CLOUDS
FROM UPSLOPE SHOWERS TO THE SW...THIS WILL COMBINE TO HOLD
COLDEST LOWS NEAR 40. HOWEVER WILL CONTINUE TO MONITOR FOR
POSSIBLY FROSTY CONDITIONS.

THE WORK WEEK WILL BE DOMINATED BY NORTHWEST FLOW. TROUGH DIGS
OVER THE GREAT LAKES AND WILL RESULT IN SEASONAL
TEMPERATURES...AROUND 60S...AND A DRY PERIOD. STORM SYSTEMS TRACK
TO THE NORTH WITH LIMITED MOISTURE TO WORK WITH. EXPECT TO SEE
SOME PASSING CLOUDS...BUT NO PRECIP. SLIGHT WARMUP INTO THE LOW
TO MID 70S AHEAD OF THE NEXT SYSTEM FOR WEDNESDAY AND THURSDAY.
MODELS TRACK THE SYSTEM ACROSS THE AREA THURSDAY NIGHT...WHICH
SHOULD BE THE NEXT CHANCE FOR THUNDERSTORMS.

&&

.AVIATION...
STRATUS CONTINUING TO REMAIN PUSHED UP AGAINST THE HIGHER TERRAIN
OF THE PANHANDLE IN THE WAKE OF THE OUTFLOW BOUNDARY THAT MOVED
THROUGH THE AREA OVERNIGHT. STABLE AIR IN THE WAKE OF THE OUTFLOW
BOUNDARY SERVED TO KEEP SKIES CLEAR EAST OF THE BOUNDARY...THOUGH
SUSPECT SOME OF THAT STABILITY IS FADING AS STRATUS/AND IN SOME
CASES FOG/ TRYING TO MAKE A RETURN BACK EASTWARD. CURRENT THINKING
IS THAT VSBY WILL BECOME REDUCED TO IFR ESPECIALLY IN THE PLATTE
RIVER VALLEY TWD SUNRISE. HRRR SUGGESTS STRATUS WILL EVENTUALLY
WIN OUT ACROSS THE SANDHILLS AND PORTIONS OF SOUTHWEST NEBRASKA BY
SUNRISE ALSO...THOUGH RAP MODEL KEEPS MOST IFR CIGS FURTHER NORTH.
FORECAST WILL BE TRENDED TWD A MORE PESSIMISTIC FORECAST IN THE
NORTH BASED ON PREVIOUS FEW MORNINGS EVENTUAL PROGRESSION. SHOULD
SEE IMPROVEMENT IN IFR FOG CONDITIONS AT KLBF BY LATE MORNING
THOUGH KVTN WILL LIKELY BE ON THE FRINGE OF STRATUS THROUGH EARLY
AFTERNOON.

ATTENTION TURNS TO CONVECTION POTENTIAL THIS AFTERNOON AND
TONIGHT. SIGNIFICANT DIFFERENCES IN SHORT RANGE MODELS WITH
RESPECT TO TIMING OF WIND SHIFT/FRONTAL PASSAGE BY EVENING WITH
NAM BEING THE FASTEST AS IT HAS BEEN FOR SEVERAL RUNS. CONVECTIVE
POTENTIAL WILL BE HIGHEST ACROSS NORTH CENTRAL NEB BY LATE
MORNING INTO AFTERNOON. FURTHER TO THE SOUTH...DRYLINE LOCATION
WILL BE CRITICAL IN DETERMINING CONVECTIVE TRENDS. AS COLD FRONT
MOVES ACROSS THE AREA TONIGHT STRATUS WILL EXPAND BEHIND IT SO IFR
CONDITIONS IN ITS WAKE WILL BE EXPECTED.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SYNOPSIS/DISCUSSION...MASEK
AVIATION...JWS






AREA FORECAST DISCUSSION

NWS NORTH PLATTE NE

 1233 AM CDT SAT MAY 5 2012

.AVIATION...
MVFR/IFR IS EXPECTED IN MANY AREAS THROUGH 16Z. VFR IS EXPECTED MOST
AREAS THEREAFTER.

ISOLATED SEVERE STORMS SHOULD DISSIPATE BETWEEN 06Z AND 08Z TONIGHT.
NEW STORM DEVELOPMENT IS EXPECTED SATURDAY AFTERNOON FROM AROUND 20Z
ONWARD. BEST FOCUS APPEARS TO BE ALONG A STATIONARY FRONT WHICH IS
EXPECTED TO BE LOCATED ACROSS NRN NEB SATURDAY AFTERNOON.

THE RUC IS AGAIN FCSTING STRATUS AND VERY LOW CIGS TONIGHT ACROSS
THE ENTIRE FCST AREA BUT THE MODEL APPEARS TO BE TOO FAST.
ALSO...IT IS UNCERTAIN AS TO HOW LOW THE CIGS WILL GO. MVFR IS
LIKELY IN MANY AREAS...IFR IS POSSIBLE IN SOME AREAS AND AND THE
POTENTIAL FOR LIFR APPEARS TO BE SMALL AS STABLE OUTFLOW HAS MOVED
IN THIS EVENING IN THE WAKE OF THE SEVERE STORMS ACROSS NERN NEB.

BURNOFF SHOULD BE BETWEEN 16Z AND 18Z SATURDAY. VFR IS EXPECTED
THEREAFTER EXCEPT FOR NORTHERN NEBRASKA WHERE SEVERE STORMS WILL
DEVELOP.

IN THE WAKE OF THE SEVERE WEATHER SATURDAY AFTERNOON AND EARLY
EVENING...A STRONG COLD FRONT AND MVFR CIGS WILL BEGIN MOVING SOUTH
THROUGH THE FCST AREA. THIS MAY BEGIN OCCURRING AROUND 03Z SATURDAY
EVENING.

&&

.PREV DISCUSSION... /ISSUED 325 PM CDT FRI MAY 4 2012/

SYNOPSIS...

FOR THE MOST PART...THE H5 PATTERN IS SIMILAR TO YESTERDAYS AT THIS
TIME. A BROAD TROUGH OF LOW PRESSURE EXTENDED ACROSS THE ALASKA
PANHANDLE SSEWD TO THE NRN CA COAST. LOW AMPLITUDE RIDGING WAS
PRESENT ACROSS CENTRAL CANADA...WHILE THE WRN HALF OF THE CONUS WAS
UNDER THE INFLUENCE OF WEST SOUTHWESTERLY FLOW WITH SEVERAL WEAK
DISTURBANCES NOTED ACROSS THE SWRN CONUS. AT THE SURFACE...LOW
PRESSURE WAS NOTED OVER NRN COLORADO. A DRY LINE WAS NOTED FROM WEST
OF OGALLALA TO THE EASTERN OK PANHANDLE. A WARM FRONT EXTENDED
ACROSS SWRN AND SRN NEBRASKA WITH AN OUTFLOW BOUNDARY NOTED ACROSS
NRN NEBRASKA. TEMPERATURES AS OF 2 PM CDT RANGED FROM 67 AT KVTN AND
KANW...TO 85 AT KLBF.

DISCUSSION...

NEAR TERM...TONIGHT THROUGH MONDAY...MAIN FORECASTING CHALLENGES ARE
PRECIPITATION CHANCES AND SEVERE POTENTIAL FOR TONIGHT THROUGH
SUNDAY. THE FORECAST FOCUS SHIFTS TO TEMPERATURES MONDAY...IN
PARTICULAR...MONDAY MORNING WITH THE THREAT FOR LOWS POSSIBLY IN THE
30S.

FOR TONIGHT...THUNDERSTORMS THIS EVENING...FOLLOWED BY FOG POTENTIAL
ARE THE MAIN FORECASTING CONCERNS OVER THE NEXT 12 HRS.

THUNDERSTORMS...APART FROM WHAT IS ONGOING IN THE NERN ZONES...ARE
EXPECTED TO INITIATE ACROSS PORTIONS OF WEST CENTRAL NEBRASKA OVER
THE NEXT 1 TO 3 HRS AS A DRYLINE BULGE WORKS INTO THE WESTERN SAND
HILLS. ANY STORMS WHICH DO DEVELOP HAVE THE POTENTIAL TO BE SEVERE.
VERY STEEP MID LEVEL LAPSE RATES AND BULK SHEAR OF 45 TO 55 KTS WILL
BE CONDUCIVE FOR VERY LARGE HAIL...ESPECIALLY ALONG AND NORTH OF
HIGHWAY 2 AND 91 FROM HYANNIS TO ERICSON. CONVECTION IS EXPECTED TO
SHIFT EAST OF THE AREA BY 06Z TONIGHT. ATTM...THE THREAT FOR
REDEVELOPMENT OVERNIGHT APPEARS MINIMAL GIVEN THE ABSENCE OF A LOW
LEVEL JET OVERNIGHT.

FOG IS EXPECTED TO DEVELOP OVERNIGHT AS A WARM FRONTAL BOUNDARY IS
FORCED SOUTH INTO SRN NEBRASKA CONVECTION ACROSS NRN NEBRASKA. ERLY
UPSLOPE WINDS WILL TRANSPORT BOUNDARY LAYER MOISTURE INTO WRN AND
NORTH CENTRAL NEBRASKA OVERNIGHT FROM ERN NEBRASKA ALONG AND NORTH
OF THE WARM FRONT. WITH COOLING TEMPERATURES OVERNIGHT AND LIGHT
WINDS...A STRONG SETUP FOR FOG EXISTS AND HAVE PLACED IT IN THE
ENTIRE FORECAST FROM 09Z THROUGH 15Z SATURDAY.

ON SATURDAY MORNING...A FRONTAL BOUNDARY WILL BE ANCHORED ACROSS SRN
NEBRASKA. WITH SURFACE HEATING AND DEEPENING LOW PRESSURE OVER WRN
KS...THIS FEATURE WILL TRACK NORTH AS A WARM FRONT ON SATURDAY.
ATTM...THE MODELS BEGIN SATURDAY WITH THIS FEATURE SOUTH OF
INTERSTATE 80. A WORD OF CAUTION HERE. IF CONVECTION TONIGHT IS
STRONGER THAN WHAT THE MODELS DEPICT...THIS FRONT WOULD BE ACROSS
NRN KS...WHICH WOULD INCREASE THE SVR THREAT FURTHER SOUTH. AS IT
STANDS RIGHT NOW...THE FRONTAL BOUNDARY WILL LIFT INTO CENTRAL AND
EASTERN SANDHILLS BY SATURDAY AFTERNOON. THIS WOULD FACILITATE THE
GREATEST SVR THREAT ACROSS THE CENTRAL AND NORTHERN FORECAST
AREA...OR ALONG AND NORTH OF INTERSTATE 80. LIKE TODAY...THE
GREATEST SEVERE THREAT WILL BE FROM LARGE DAMAGING HAIL GIVEN THE
VERY STEEP MID LEVEL LAPSE RATES...3000-4000 CAPES...AND EFFECTIVE
BULK SHEAR OF 45 TO 55 KTS. COVERAGE WILL INCREASE SATURDAY EVENING
AS A POWERFUL COLD FRONT TRACKS ACROSS WESTERN AND NORTH CENTRAL
NEBRASKA THROUGH SUNDAY MORNING. ATTM...THE BEST CHANCES FOR
MEASURABLE PRECIPITATION WILL BE ACROSS NRN NEBRASKA WHERE JET
DYNAMICS ARE MOST FAVORABLE. FURTHER SOUTH...PRECIPITATION WILL BE
CONFINED TO THE FROPA WHICH WILL BE BRIEF IN COMPARISON TO WHAT IS
EXPECTED OVER NRN NEBRASKA. ONE FINAL NOTE ON WINDS ALONG AND BEHIND
THE FROPA. FOR THE FIRST 72 HRS OF THE FORECAST...WE UTILIZED THE
GFS SOLN AS THE NAM FRONTAL TIMING APPEARED WAY TOO FAST. THE NAM
PUSHED THE FRONTAL BOUNDARY THROUGH THE ENTIRE FORECAST AREA BY
SATURDAY EVENING. THIS APPEARED WAY TOO FAST AS THE FRONT WOULD BE
PUSHING INTO UPPER 80S AND LWR 90S TEMPERATURES EXPECTED ACROSS
CENTRAL AND SWRN NEBRASKA SAT AFTN. THE GFS WAS MUCH
SLOWER...PUSHING THE FRONT THROUGH THE CWA BY SUNDAY MORNING WHICH
SEEMED MUCH MORE PLAUSIBLE.

SHOWERS WILL LINGER SUNDAY MORNING IN EASTERN AREAS AS THE FRONT
CLEARS THE FORECAST AREA. MUCH COOLER TEMPERATURES AND DRIER AIR
WILL PUSH INTO WRN AND NORTH CENTRAL NEBRASKA. HIGHS SUNDAY WILL BE
IN THE 60S WITH DRY CONDS EXPECTED SUNDAY AND SUNDAY NIGHT.

EARLY MONDAY...TEMPERATURE TRENDS WILL NEED TO BE MONITORED CLOSELY
AS THE MET GUIDANCE HAS WIDESPREAD 30S ACROSS THE FORECAST AREA.
THIS SEEMS PLAUSIBLE WITH COOL HIGH PRESSURE BUILDING INTO THE
CENTRAL AND NRN ROCKIES AND THE DEVELOPMENT OF LIGHT WESTERLY WINDS
THROUGH MONDAY MORNING. THERE ARE STILL SOME SIGNIFICANT DIFFERENCES
BETWEEN THE NAM AND GFS WITH RESPECT TO WIND SPEEDS...SURFACE DEW
POINTS...AND ULTIMATELY LOW TEMPS. LOWS WERE TRENDED DOWNWARD SOME
FOR MONDAY MORNING...BUT NOT AS FAR AS THE MET GUIDANCE WOULD
SUGGEST.

LONG TERM...MONDAY THROUGH FRIDAY...A BENIGN WEATHER PATTERN WILL
SET UP NEXT WEEK AS A CLOSED LOW TRACKS FROM THE GREAT LAKES INTO
ERN CANADA. THIS WILL PLACE THE FORECAST AREA IN DRY NWRLY
FLOW...TRANSITIONING TO RIDGING ACROSS THE CENTRAL CONUS THROUGH THE
END OF THE WEEK. THE NEXT MINIMAL PRECIPITATION CHANCE WILL ARRIVE
ON THURSDAY NIGHT INTO FRIDAY AS THE RIDGE BREAKS DOWN AND SWRLY
FLOW TRANSITIONS EAST ACROSS THE CENTRAL PLAINS.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&

$$

SHORT TERM/EXTENDED...MASEK
AVIATION...JWS/COLE






AREA FORECAST DISCUSSION

NWS SAN ANGELO TX

 1110 PM CDT FRI MAY 4 2012


.DISCUSSION...

SEE AVIATION DISCUSSION BELOW.

&&

.AVIATION...
A MID AND UPPER LEVEL TROUGH OF LOW PRESSURE IS MOVING EAST OF THE
AREA TONIGHT AND WILL BE REPLACED BY A WEAK RIDGE OF HIGH PRESSURE
THAT MOVES IN FROM THE WEST BY MORNING. A LINE OF SHOWERS THAT
MOVED THROUGH THE AREA MOSTLY NORTH OF SAN ANGELO AND EAST OF
SWEETWATER HAS WEAKENED AND IS NOW EAST OF THE FORECAST AREA. THE
LOWER LEVEL ATMOSPHERE IS STABILIZING AS SURFACE TEMPERATURES DROP
OVERNIGHT...THUS TERMINATING CHANCES FOR RAINFALL AT LEAST THROUGH
TOMORROW EARLY AFTERNOON. EXPECT MOSTLY VFR CONDITIONS ACROSS THE
AREA WITH AN INFLUX OF HIGH CLOUDS AT AND ABOVE TWENTY FIVE
THOUSAND FEET TOMORROW. THE EXCEPTION IS THE FORMATION OF SOME LOW
CLOUDS IN THE SOUTHERN AND SOUTHEASTERN PORTIONS OF THE FORECAST
AREA...INCLUDING SONORA AND JUNCTION...WHERE BRIEF PERIODS OF MVFR
OR POSSIBLY IFR CONDITIONS MAY OCCUR AND LINGER FROM JUST BEFORE
DAWN TO SEVERAL HOURS AFTER SUNRISE. SOUTHERLY WINDS OF 10 KT IN
MORNING HOURS WILL INCREASE BY AFTERNOON TO AROUND 15 KT AS
STRONGER WINDS ALOFT MIX TO THE SURFACE DURING DAYTIME HEATING.
WIND DIRECTIONS WILL NOT CHANGE MUCH AS A SURFACE LOW PRESSURE
AREA NEAR CENTRAL NORTHERN OKLAHOMA REMAINS QUASI STATIONARY THE
NEXT 24 HOURS.

&&

.PREV DISCUSSION... /ISSUED 456 PM CDT FRI MAY 4 2012/

DISCUSSION...

SEE AVIATION DISCUSSION BELOW

AVIATION...
A SHORT WAVE TROUGH CENTERED IN CENTRAL OKLAHOMA WITH AN AXIS
EXTENDING SOUTH SOUTHWEST THROUGH CROCKETT COUNTY IS MOVING EAST
SLOWLY. A LINE OF SHOWERS AND THUNDERSTORMS APPROXIMATELY FIFTY TO
SIXTY MILES WIDE IS CURRENTLY NORTH OF BLACKWELL TX EXTENDS
NORTHEAST TO NEAR ALBANY AND FORT GRIFFIN TX AND ABILENE... IS
ASSOCIATED WITH A WEAK DRY LINE. SOME STORMS ARE SEVERE OR WILL
BECOME SEVERE WITH GUSTY WINDS...HEAVY RAIN AND POSSIBLE HAIL.
ADDITIONAL SHOWERS ARE EXPECTED TO DEVELOP ALONG THIS LINE FARTHER
SOUTH THIS EVENING AS THE ENTIRE LINE ADVANCES EAST THROUGH THE
AREA THE NEXT 6 HOURS. NEAR THIS DEVELOPING LINE OF SHOWERS AND
THUNDERSTORMS EXPECT IFR CONDITIONS...LOCALLY HEAVY RAIN IN
THUNDERSTORMS...AND LOCALLY GUSTY SURFACE WINDS THAT MAY CAUSE
LOCAL AND BRIEF WINDY CONDITIONS AND CROSS WIND LANDING AND
TAKEOFF CONDITIONS THE NEXT 3 TO 6 HOURS. ELSEWHERE AWAY FROM THIS
SHOWER LINE MOSTLY VFR CONDITIONS WILL PREVAIL.MOSTLY VRF
CONDITIONS ARE EXPECTED TO PREVAIL ACROSS MOST OF THE AREA BY LATE
NIGHT AND INTO EARLY SATURDAY MORNING. VERY LOCALIZED PATCHY
GROUND FOG IS POSSIBLE BY EARLY MORNING IN THE VICINITY OF EVENING
RAIN AREAS.

PREV DISCUSSION... /ISSUED 354 PM CDT FRI MAY 4 2012/

SHORT TERM..
LATEST RUC SHOWING INITIATION OF CONVECTIVE ACTIVITY ASSOCIATED WITH
AN UPPER SHORT WAVE JUST WEST OF CROCKETT COUNTRY CONCOMITANT WITH
THE POSITION OF THE DRYLINE...WHERE LATEST RADAR LOOP IS ALSO
SHOWING SOME DEVELOPMENT. RUC ALSO SHOWING A DAMPENING OF THIS
FEATURE OVER THE NEXT SEVERAL HOURS. MORE PROMISING FOR LATER THIS
AFTERNOON INTO EARLY EVENING IS A DEEPENING UPPER SHORTWAVE IN THE
VICINITY  OF A TIGHTENING DRYLINE OVER THE EASTERN BIG COUNTRY SOUTH
INTO THE HEARTLAND... WHERE THE BEST CHANCE OF CONVECTION WOULD
RESIDE. DRYLINE WILL RETREAT THROUGH THE LATE EVENING HOURS WITH
RAINFALL ENDING OVER THE CWA AFTER MIDNIGHT.

LOOKING FOR A WARMER DAY TOMORROW WITH 100 PLUS TEMPS OVER THE BIG
COUNTRY AND THE WESTERN CONCHO VALLEY. UPPER RIDGING OVER THE
FORECAST AREA TOMORROW WILL BE UNDERCUT BY A SHORTWAVE MOVING OVER
THE SOUTHERN CWA BY LATE TOMORROW AFTERNOON...WITH THE BEST CHANCE
OF CONVECTIVE ACTIVITY...PER THE LATEST NAM...OVER OUR SOUTHEASTERN
COUNTIES.

LONG TERM...
LOW CONFIDENCE FORECAST FOR MUCH OF THE EXTENDED PERIOD. DRYLINE
WILL RETREAT WESTWARD SATURDAY EVENING WITH A FEW STORMS POSSIBLE
DURING THE EVENING HOURS. ONE LAST DAY OF TEMPERATURES IN THE 90S
ON SUNDAY...AS COOLER TEMPERATURES ARE ON THE WAY FOR NEXT WEEK
WITH HIGHS MAINLY IN THE 80S MONDAY THROUGH FRIDAY. CONSIDERABLE
MODEL DIFFERENCES EXIST WITH THE SOUTHWARD PROGRESSION OF THE COLD
FRONT SUNDAY NIGHT INTO MONDAY. THE NAM IS THE FASTEST MODEL AND
BRINGS THE FRONT INTO THE NORTHERN BIG COUNTRY LATE SUNDAY AFTERNOON
WHILE THE GFS IS ABOUT 12 HOURS SLOWER. DECIDED TO SPLIT THE
DIFFERENCE BETWEEN THE TWO BUT LEAN A BIT MORE IN FAVOR WITH THE
NAM AND BRING THE FRONT ACROSS THE AREA DURING THE OVERNIGHT
HOURS. KEPT SLIGHT POPS GOING SUNDAY NIGHT AND AGAIN ON MONDAY
WITH THE PASSAGE OF THE FRONT.

THE FRONT IS EXPECTED TO STALL JUST SOUTH OF THE AREA THROUGH MID
WEEK BEFORE WASHING OUT. MEDIUM RANGE MODELS CONTINUE TO SHOW A
CLOSED UPPER LOW DEVELOPING OVER THE DESERT SOUTHWEST/BAHA REGION
EARLY NEXT WEEK...THEN TRACKING EAST TOWARDS WEST TEXAS BY MID
WEEK. GFS REMAINS VERY WET WITH THIS SCENARIO BUT CONFIDENCE
CONTINUES TO BE LOW CONCERNING PRECIPITATION CHANCES NEXT WEEK.
THE FORECAST WILL CONTINUE TO ADVERTISE SLIGHT PRECIPITATION CHANCES
FOR MUCH OF NEXT WEEK...PENDING HIGHER CONFIDENCE IN THE MODELS.

&&

.PRELIMINARY POINT TEMPS/POPS...
ABILENE  72 100  71  93  64 /  20  10  10  10  20
SAN ANGELO  70 100  70  94  64 /  20  10  20  10  20
JUNCTION  71  97  70  93  64 /  20  10  20  10  20

&&

.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

99/99/99






AREA FORECAST DISCUSSION

NWS SPOKANE WA

 302 AM PDT Sat May 5 2012

.SYNOPSIS...
Today will be another cooler than average day over the Inland
Northwest. A few showers will linger over the Idaho Panhandle
through this afternoon. High pressure will build over the region
on Sunday bringing a warming trend and a prolonged period of dry
weather. Monday and Tuesday will be warmer than average. A weak
cold front will move through the region on Wednesday bringing
breezy and cooler conditions. A return to near average
temperatures is expected for Wednesday through the end of the
week.

&&

.DISCUSSION...

Today through Sunday night: Satellite imagery shows the upper low
over our area with the comma head in the clouds located near
Castlegar. HRRR model shows this well on the forecast reflectivity
fields. The last few runs of the HRRR have been consistent in
bringing this comma head southward across northeast Washington and
the northern Panhandle today. Some of this shower activity could
spread as far west as Spokane to Lewiston. All of this activity
will move out of the area tonight as the upper-level trough moves
east.

Tonight`s low temperatures don`t look quite as cold as previously
thought. Even so, there will still be some valleys with freezing
temperatures. This is mainly due to some mid-level clouds moving
through the area in the northwest flow. This is primarily north
and east of a line from Omak to Pullman. Besides the affect on
temperatures, these clouds could also obscure the super moon
(perigee and full moon) tonight.

For Sunday a ridge of high pressure begins to move into the area from
the Pacific. The resulting weather looks dry and sunny with seasonable
temperatures. RJ

Monday and Tuesday: Warm and dry weather will start the week as a
high amplitude 500mb ridge translates across the Inland Northwest
Monday into Tuesday. There has been little change in the GFS and
ECMWF solutions over the last day or two. Model soundings show
little moisture through the column Monday and light surface winds.
Afternoon temperatures in the upper 60s and lower 70s combined
with sunny skies will feel quite warm on Monday...after the
recent chilly weather we have experienced. Tuesday will be the
warmest day of the week ahead of an approaching cold front.
Southerly surface winds ahead of the front will draw mild air into
eastern Washington and northern Idaho. 850mb temperatures between
13C-14C should yield high temperatures in the 70s over most of the
Spokane forecast area. Moses Lake, Wenatchee, Omak, Lewiston and
other elevations below 1500 feet may flirt with 80 degrees Tuesday
afternoon.

Wednesday through Saturday: The passage of a cold front Tuesday
night and Wednesday will bring temperatures back to average. The
most notable weather changes associated with the cold front will be
the breezy winds Wednesday afternoon/evening and the cooler
temperatures. The surface low associated with this cold front
will track well north of the Spokane area (through central B.C.).
The ECMWF, GFS and Canadian models prog very little deep layer
moisture along and behind the cold front. It is hard to get very
excited about precipitation Wednesday or Thursday given the scant
moisture profiles forecast by the models. Chances for showers have
been retained in the mountains, but the low elevations of central
and eastern Washington will likely remain dry. If Spokane does
remain dry Wednesday and Thursday, it should remain precipitation-
free through the weekend. In fact, this will likely be the longest
stretch without precipitation this spring so far. Spokane has not
had a stretch of more than 5 days without precipitation since
early February. /GKoch

&&

.AVIATION...
06Z TAFS: A slow-moving Pacific low will keep some light shower
activity across extreme NE WA and north Idaho overnight. Gusty
winds will also weaken tonight for most of the area. Colder air
coming off the Cascade crest will be funneled down the gap
valleys, allowing winds to remain breezy in the KEAT area
overnight. High pressure will build in for the weekend with light
winds and clearing skies. /EK




&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        53  35  60  41  68  43 /  30   0   0   0   0   0
Coeur d`Alene  51  34  60  36  68  39 /  30  10   0   0   0   0
Pullman        50  31  58  35  68  42 /  20   0   0   0   0   0
Lewiston       56  37  63  39  75  46 /  20   0   0   0   0   0
Colville       61  34  69  35  72  42 /  20  10   0   0   0   0
Sandpoint      52  31  59  33  68  36 /  70  20  10  10   0   0
Kellogg        47  32  56  35  68  37 /  40  10  10  10   0   0
Moses Lake     63  34  66  39  74  45 /   0   0   0   0   0   0
Wenatchee      62  40  68  45  73  48 /   0   0   0   0   0   0
Omak           63  32  68  38  73  46 /  10   0   0   0   0   0

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&

$$











AREA FORECAST DISCUSSION

NWS LA CROSSE WI

 255 AM CDT SAT MAY 5 2012

.SHORT TERM...TODAY THROUGH MONDAY NIGHT
255 AM CDT SAT MAY 5 2012

FORECAST CONTINUES TO FOCUS ON THE PCPN CHANCES FOR THE NEXT FEW
DAYS.

REMNANTS OF THE MCS HAS EXITED INTO EASTERN WI EARLY THIS
MORNING...WHILE A PIECE OF UPPER LEVEL ENERGY WORKS INTO NORTHEAST
WI. THE SHORTWAVE IS FUELING SCATTERED SHOWERS OVER
NORTHERN/NORTHEAST WI THIS MORNING. LATEST HRRR AND RADAR TRENDS
WOULD KEEP THIS JUST NORTH AND NORTHEAST.

LOTS OF SMALL...EMBEDDED PIECES OF UPPER LEVEL ENERGY PUSHING INTO A
BROAD UPPER LEVEL RIDGE CURRENTLY ACROSS THE CENTER OF
U.S...EVIDENCED IN THE LATEST WATERVAPOR SATELLITE IMAGERY. THE GFS
AND NAM SUGGEST THAT A SHORTWAVE TROUGH OR TWO COULD TOP THE RIDGE
TODAY...MOVING ACROSS NORTHERN PARTS OF THE REGION. NORTH-SOUTH
X-SECTIONS INDICATE SOME DRY MID LEVEL AIR THAT THIS SHORT WAVE
WOULD HAVE TO CONTEND WITH...WITH LITTLE LOW LEVEL THERMODYNAMIC
SUPPORT OR INSTABILTY TO TAP INTO. THE NAM12 SUGGEST SOME PCPN
POSSIBLE AS IT MOVES ACROSS MN...BUT RUNS THE DRIER AIR IN WI. DON/T
ANTICIPATE ANY PCPN LOCALLY WITH THIS FEATURE.

CURRENTLY JUST TO THE WEST...88-D IMAGERY DEPICTS SCATTERED
CONVECTION DEVELOPING IN THE VICINITY OF THE 850 MB WARM
FRONT...ACROSS SOUTHERN MN. NAM12/RAP/HRRR SUGGEST THAT THIS
BOUNDARY WILL CONTINUE TO ACT AS A SHOWER/STORM
PRODUCER...INTERACTING WITH SOME LOW LEVEL MOISTURE TRANSPORT. SMALL
CHANCES FOR PARTS OF SOUTHEAST MN/NORTHEAST IA...BUT DON/T THINK IT
WILL VENTURE EAST OF THERE...OUTSIDE THE PUSH OF THE LOW LEVEL
MOISTURE.

FARTHER SOUTH...THE SFC WARM FRONT STILL WAVERS ACROSS PARTS OF IA
INTO ILL...ALTHOUGH POSITIONING IS DIFFICULT TO DISCERN WITH
MULTIPLE OUTFLOW BOUNDARIES FROM THE EVENING/CURRENT CONVECTION.
MUCAPES EXPECTED TO REACH 3000 J/KG OR MORE LATER THIS AFTERNOON
OVER CENTRAL IA WITH 30-40 KTS OF 0-6 KM SHEAR. NOT A LOT OF
FRONTOGENETIC FORCING IN THE VICINITY OF THE BOUNDARY THOUGH...AND
NO UPPER AIR SUPPORT. FARTHER NORTH INTO NORTHEAST IA/SOUTHWEST
WI...BUFKIT SOUNDINGS HINT AT A LOW LEVEL INVERSION HANGING FOR MUCH
OF TODAY...WITH ANY CAPE ABOVE THAT RATHER SKINNY...AND NOT
FAVORABLE FOR STRONG/SEVERE THUNDERSTORM DEVELOPMENT.

LATE TONIGHT...SUNDAY/SUNDAY NIGHT WILL BRING BETTER...WIDESPREAD
RAIN CHANCES AS A SHORTWAVE TROUGH SPINS ACROSS THE REGION AND AN
INVERTED TROUGH STRETCHES NORTH FROM A SFC LOW OVER THE SOUTHERN
PLAINS. A GOOD AMOUNT OF 925-850 MB WARM AIR ADVECTION FROM 06-21Z
WITH ISENTROPIC UPGLIDE ON THE 295-310 K SFCS. LOW LEVEL MOISTURE
TRANSPORT WILL SURGE AHEAD OF THE BOUNDARY...WITH THE 850 MB JET
FOCUSED INTO NORTHERN MN/WI OVERNIGHT TONIGHT. THIS SUGGESTS THAT
THE MAIN RAIN SHIELD COULD BE ACROSS THESE AREAS LATE
TONIGHT/SUN MORNING. DEVELOPMENT SHOULD SHIFT SOUTH ALONG THE FRONT
ON SUNDAY AS INSTABILTY INCREASES. THE BETTER WIND SHEAR SEEMS TO BE
DISPLACED POST THE FRONT THOUGH...WHICH WILL BE A LIMITING FACTOR
INTO STORM ORGANIZATION/SEVERE POTENTIAL SUNDAY. IF IT WOULD
DEVELOP...IT SHOULD STAY SOUTH OF THE FORECAST AREA. OVERALL...IT
WILL BE A WET PERIOD.

THAT SAID...LATE SAT NIGHT COULD PROVIDE A SEVERE RISK. A
THUNDERSTORM COMPLEX IS EXPECTED TO DEVELOP THIS EVENING IN THE
SD/NEB/SW MN AREA AS THE LOW LEVEL JET IMPINGES ON THE SFC TROUGH.
AMPLE INSTABILITY AND SHEAR SUPPORTS STORM ORGANIZATION/SEVERE WX IN
THIS REGION. THE MCS WOULD TRAVEL EAST...AND COULD MOVE INTO
PORTIONS OF SOUTHEAST MN/NORTHEAST IA OVERNIGHT. 30-40 KTS OF 0-6 KM
SHEAR STILL DEPICTED BY THE GFS AND NAM...BUT INSTABILTY WILL
QUICKLY BE WANING. CONDITIONS WILL HAVE TO BE MONITORED CLOSELY.

AS FOR RAIN AMOUNTS...THERE COULD BE PERIODS OF HEAVIER RAINFALL ON
SUNDAY/SUNDAY NIGHT WITH PWS STILL IN EXCESS OF 200 PERCENT AND WARM
CLOUD DEPTH NEAR 3.5 KM. TRENDS ARE TO KEEP THE PCPN MOVING
THOUGH...WITH NO WEST-EAST BOUNDARIES TO ORIENT ON...AND THUS
TRAINING STORMS. STILL...IF THE RAINFALL RATES WOULD BE HIGH
ENOUGH...THERE COULD BE A FLASH FLOOD RISK...QUICK RESPONSE ON SOME
RIVERS. 3 HOUR FFG IS STILL BELOW 2 INCHES FOR A GOOD PORTION OF THE
AREA.


.LONG TERM...TUESDAY THROUGH FRIDAY
255 AM CDT SAT MAY 5 2012

GOOD AGREEMENT BETWEEN THE GFS AND ECMWF WITH SLIDING AN UPPER LEVEL
TROUGH ACROSS THE GREAT LAKES TUE-WED. BITS OF ENERGY
ALOFT...COUPLED WITH AN INVERTED TROUGH AND LOW LEVEL COLD AIR
ADVECTION COULD LEAD TO SCT SHOWERS TUE-WED...MOSTLY OF THE
AFTERNOON/EVENING VARIETY. HIGH PRESSURE THEN BUILDS IN FOR WED
NIGHT-THU...WITH THE PROMISE FOR A DRIER/QUIETER PERIOD. THIS LOOKS
SHORT-LIVED THOUGH AS THE GFS AND EC WOULD DRIVE ANOTHER
TROUGH/FRONT ACROSS THE UPPER MISSISSIPPI RIVER VALLEY ON FRI/FRI
NIGHT. SHOWERS/THUNDERSTORMS WOULD BE LIKELY ALONG THE FRONT

&&

.AVIATION...THROUGH 06Z SUNDAY
1140 PM CDT FRI MAY 4 2012

MAIN FOCUS AT THE TAF SITES IS WITH THE LOW LEVEL CLOUD DECK THAT
WILL LIKELY BE IN PLACE THROUGH MUCH OF THE NEXT 24 HOURS. THE
WAKE OF THE EARLIER STORMS BROUGHT SOME GUSTY WINDS WITH IT FOR A
FEW HOURS BEFORE DIMINISHING WITH THE MEAN FLOW RETURNING BACK TO
BEING EASTERLY AT ABOUT 10KT. WITH ABUNDANT LOW LEVEL MOISTURE
REMAINING IN PLACE ALONG WITH EASTERLY LOW LEVEL FLOW...EXPECT
THAT THESE MVFR TO IFR CEILINGS WILL PERSIST THROUGH MUCH OF
SATURDAY. SOME STORMS WILL BE POSSIBLE SATURDAY
AFTERNOON/EVENING...BUT IT LOOKS LIKE THE BETTER CHANCES WILL MOVE
IN OVERNIGHT.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
255 AM CDT SAT MAY 5 2012

WI...NONE.
MN...NONE.
IA...NONE.

&&

$$

SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION.....HALBACH










AREA FORECAST DISCUSSION

NWS CHEYENNE WY

 1126 PM MDT FRI MAY 4 2012

.AVIATION...06Z TAFS. WIDESPREAD IFR AND MVFR IN FOG AND LOW CLOUDS
THROUGH MID MORNING EAST OF A DOUGLAS TO KIMBALL LINE ALONG WITH
ISOLATED SHOWERS AND THUNDERSTORMS...VFR ELSEWHERE. AFTER 18Z...EAST
OF A DOUGLAS TO SIDNEY LINE...SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS PRODUCING LOCALIZED MVFR AND TURBULENCE...VFR
ELSEWHERE. STRONG COLD FRONT MOVES NORTH TO SOUTH ACROSS TAF SITES
BETWEEN 18Z AND 00Z WITH WINDS BECOMING GUSTY FROM THE NORTH.

&&

.PREVIOUS DISCUSSION.../ISSUED AT 919 PM MDT FRI MAY 4 2012/...

.UPDATE...
MOIST LOW LEVEL AIR MAKING ITS WAY WESTWARD THIS EVENING. DEW
POINTS NOW IN THE LOW TO MID 50S AND RISING ACROSS NORTHERN
PORTIONS OF THE WESTERN NEBRASKA PANHANDLE. MOIST LOW LEVEL
EASTERLY UPSLOPE FLOW WILL LIKELY PRODUCE FOG ACROSS MOST OF THE
PANHANDLE TONIGHT...REACHING INTO PORTIONS OF SOUTHEAST WYOMING.
FOG MAY BECOME DENSE BY LATE TONIGHT INTO SATURDAY MORNING BEFORE
DISSIPATING.

FOG IS NOT THE ONLY CONCERN TONIGHT. BASED ON LATEST MODEL
RUNS...THERE IS THE POTENTIAL FOR THE DEVELOPMENT OF ELEVATED
THUNDERSTORMS IN FAR EASTERN PORTIONS OF THE FORECAST AREA. STORM
PREDICTION CENTER HAS PUSHED THE SLIGHT RISK FOR SEVERE FARTHER
WEST...AND NOW INCLUDES CHADRON. BASED OFF THE LATEST NAM...THE
SEVERE POTENTIAL MAY BE EVEN FARTHER WEST...POSSIBLY BACK NEAR THE
WYOMING BORDER. MAIN THREAT WOULD BE LARGE HAIL. EFFECTIVE BULK
SHEAR OF 50 KTS OR GREATER COMBINED WITH ELEVATED CAPE 1500-2000
JOULES/KG WILL BE SUPPORTIVE OF LARGE HAIL. STRONG THETAE
ADVECTION SHOULD BE ENOUGH TO POP STORMS OVER THE NORTHERN
PORTIONS OF THE NEBRASKA PANHANDLE MAINLY AFTER
MIDNIGHT...ASSUMING THE 00Z NAM SOLUTION HAS A GOOD HANDLE ON
SYNOPTIC CONDTIONS. THE 23Z HRRR IS LESS BULLISH ON CONVECTION
OVER THE FORECAST AREA AND KEEPS THE STORMS A BIT FARTHER NORTH
INTO WESTERN SOUTH DAKOTA.

NEW FORECAST WILL BE FOLLOW SHORTLY.

&&

.PREV DISCUSSION... /ISSUED 535 PM MDT FRI MAY 4 2012/

AVIATION...00Z TAFS. SCATTERED TO BROKEN LOW AND MID CLOUDS
THIS EVENING. 05Z THROUGH 17Z ACROSS WESTERN NEBRASKA...AREAS
OF IFR AND MVFR CEILINGS AND VISIBILITIES IN LOW CLOUDS AND FOG...
VFR ELSEWHERE. AFTER 18Z...EAST OF A DOUGLAS TO SIDNEY LINE...
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS PRODUCING LOCALIZED
MVFR AND TURBULENCE...VFR ELSEWHERE.  RUBIN

PREV DISCUSSION... /ISSUED 336 PM MDT FRI MAY 4 2012/

SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT...VISIBLE SATELLITE
IMAGERY FROM TODAY SHOWS DEEPER CONVECTION DEVELOPING OFF THE
NORTHERN LARAMIE RANGE WITH SOME SHALLOW CONVECTION ELSEWHERE ACROSS
WYOMING AND NEBRASKA. EXPECT THIS TO BECOME MORE WIDESPREAD THROUGH
THE LATE AFTERNOON...WITH A FEW SHOWERS AND WEAK THUNDERSTORMS STILL
PROGGED IN THAT AREA OF DEEPER CONVECTION COMING OFF THE NORTHERN
LARAMIE RANGE. SIMILAR TO LAST NIGHT...EXPECTING A RETURN OF LOW
CLOUDS TO NORTHERN AND EASTERN PORTIONS OF THE FORECAST AREA
TONIGHT. THE APPROACHING UPPER LEVEL TROUGH WILL INDUCE LEESIDE
TROUGHING WITH SFC WINDS BECOMING NORTHEAST TO EAST ACROSS THE LOWER
ELEVATIONS OF THE EASTERN PLAINS IN RESPONSE. THIS WILL ADVECT
DEWPOINTS FROM THE UPPER 40S TO 50S IN THIS AREA...WHICH WILL
ROUGHLY BE EAST OF A LINE STRETCHING FROM DOUGLAS TO SIDNEY. THESE
EASTERLY WINDS WILL STRENGTHEN SLIGHTLY THIS EVENING AS THE UPPER
WAVE APPROACHES...AND WILL ADD AN ADDITIONAL UPSLOPE COMPONENT ALONG
THE PINE RIDGE FOR SIOUX...DAWES...AND BOX BUTTE COUNTIES TO SEE A
DEEPER SATURATED LAYER IN THE LOW LEVELS. NAM BUFKIT SOUNDINGS SHOW
THIS LAYER TO BE A GOOD 50 TO 100 MB THICK NEAR ALLIANCE AND CHADRON
SO THERE EXISTS A GOOD POTENTIAL FOR DRIZZLE TO OCCUR HERE. OUTSIDE
OF THE NORTHERN PANHANDLE...THINK THAT THE LLVL GRADIENT AND
RESULTANT EASTERLY WINDS WILL BE STRONG ENOUGH TO ADVECT LOW CLOUDS
AND FOG ACROSS MUCH OF THE PANHANDLE AND INTO THE LOWER ELEVATIONS OF
SOUTHEAST WYOMING BUT MOISTURE MAY BE TOO SHALLOW TO PRODUCE DRIZZLE
HERE. THE SATURATED LAYER ALSO DOES NOT LOOK DEEP ENOUGH TO MAKE IT
UP THE CHEYENNE RIDGE SO LEFT THAT AREA AND VCTY OUT OF ANY FOG.
OTHERWISE...WENT AHEAD AND ADDED IN FOG AND DRIZZLE TO
AFOREMENTIONED AREAS FOR TONIGHT. LOW CLOUDS AND FOG SHOULD LAST
THROUGH THE NIGHT AND WILL BURN OFF WITH SUNRISE. THE NORTHERN
PANHANDLE IN THE DEEPER UPSLOPE FLOW MAY LAST A LITTLE LONGER
THROUGH 18Z.

UPPER LEVEL ENERGY WITH SOME MODEST 500 TO 700MB MOISTURE WILL
COMBINE WITH INCREASING LLVL CONVERGENCE AS CYCLOGENESIS OCCURS
OVER EASTERN COLORADO TO BRING A CHANCE FOR SHOWERS AND A FEW
THUNDERSTORMS ACROSS THE EASTERN PLAINS TOMORROW. THE EXCEPTION WILL
BE THE CHEYENNE RIDGE ONCE AGAIN WHERE WESTERLY DOWNSLOPE WINDS
INDUCED BY THE DEVELOPING SURFACE LOW WILL MINIMIZE ANY POTENTIAL
FOR PRECIP HERE. FURTHER WEST...LACK OF GOOD MID LAYER MOISTURE WITH
DRY LOW LEVELS WILL ALSO REDUCE ANY CHANCE FOR ANY PRECIP.
INCREASING WINDS ACROSS THIS AREA WILL MORE INCREASE THE FIRE
WEATHER THREAT...ESPECIALLY IN THE SOUTHERN LARAMIE RANGE AND VCTY
BUT STEADY GREENUP OF FUELS AND MARGINAL WINDS/HUMIDITIES WILL DETER
FROM ISSUING ANY HIGHLIGHTS. COLD FRONT WILL THEN MOVE FROM NORTH TO
SOUTH TOMORROW EVENING AND EARLY OVERNIGHT PERIOD BRINGING GUSTY
NORTHWEST WINDS AND COOLER TEMPS TO THE AREA FOR SATURDAY NIGHT AND
SUNDAY. LOOKS LIKE MODELS ARE TRENDING DOWNWARD WITH WIND SPEEDS IN
THE LLVLS SO WILL MAINTAIN JUST BREEZY CONDITIONS ACROSS THE
PANHANDLE. DO EXPECT A FEW SHOWERS WITH MAYBE A CLAP OF THUNDER TO
ACCOMPANY THE FRONT IN THE FAR EAST WHERE BETTER MOISTURE IS
AVAILABLE SATURDAY AFTERNOON AND EVENING. HIGH PRESSURE BUILDING IN
FROM THE NORTH WILL TURN WINDS TO THE NORTHEAST ALONG THE FRONT
RANGE WITH A BETTER CHANCE FOR LOW CLOUDS TO DEVELOP ALONG THE
SOUTHERN LARAMIE RANGE EARLY SUNDAY MORNING...WITH CHANCES FOR
MAINLY RAIN SHOWERS IN THE LATE AFTERNOON AND EVENING. TEMPS LOOK TO
DROP A GOOD 10 TO 20 DEGREES BEHIND THE FRONT FOR SUNDAY.

LONG TERM...MONDAY THROUGH FRIDAY...
THE NORTHERN STREAM PORTION OF THE SPLIT SYSTEM WILL BE OVER
SOUTHERN MANITOBA ON MONDAY. 12Z ECMWF DATA PROGS A DEEPER SYSTEM
COMPARED TO THE GFS WHICH WOULD RESULT IN CYCLONIC NORTHWEST FLOW
PERSISTING THRU MONDAY. ADDITIONALLY...THE 12Z ECMWF ROTATES A
SHORTWAVE THRU THIS NORTHWEST FLOW. AS A RESULT...WOULD EXPECT AT A
MINIMUM RESIDUAL CLOUD-COVER ON MONDAY WITH PERHAPS SOME LIGHT
SHOWER ACTIVITY IN AND AROUND THE SOUTHERN LARAMIE RANGE. ANY LIGHT
SHOWERS WILL DECREASE THROUGH THE DAY ON MONDAY AS THE SYSTEM
DEPARTS. MONDAYS TEMPERATURES WILL STILL BE COOL WITH H7
TEMPERATURES OF AROUND -2 OR -3C. THIS WILL RESULT IN HIGHS THAT
WILL ONLY CLIMB INTO THE 50S TO NR 60. FOR TUESDAY AND
WEDNESDAY...HEIGHTS WILL BUILD OVER THE NORTHERN ROCKIES AND
NORTHERN PLAINS AS MID/UPPER-LEVEL RIDGING BUILDS IN. SO...DRY AND
WARMING CONDITIONS CAN BE EXPECT BOTH DAYS WITH AFTERNOON HIGHS THAT
WILL CLIMB BACK INTO THE 70S BY WEDNESDAY. FOR THURSDAY...THE UPPER
RIDGE WILL PUSH EAST INTO THE PLAINS ALLOWING MID/UPPER-LEVEL FLOW
TO BACK TO THE SOUTHWEST AHEAD OF ANOTHER SHORTWAVE THAT WILL RACE
ACROSS SOUTHERN CANADA. THIS SHORTWAVE WILL DRAG A COLD FRONT
THROUGH THE CWA LATE THURSDAY BRINGING A CHANCE OF SHOWERS AND
THUNDERSTORMS THAT WILL LINGER INTO FRIDAY. TEMPERATURES WILL BE
COOLER ON FRIDAY AS WELL...WITH HIGHS THAT WILL ONCE AGAIN ONLY
REACH THE 60S.

AVIATION...18Z TAF ISSUANCE...
VFR CONDITIONS WILL PREVAIL AT AREA TERMINALS THROUGH THE
AFTERNOON...WITH JUST SOME AFTERNOON CLOUDS DEVELOPING OVER THE
LARAMIE RANGE AND ACROSS EAST CENTRAL WYOMING. CONDITIONS WILL
DETERIORATE AFT 03Z FOR WESTERN NEBRASKA AIRPORTS IN FOG AND AREAS
OF DRIZZLE AS A FRONT BACKS IN. IFR AND PERHAPS EVEN LIFR
CONDITIONS CAN BE EXPECTED LATE TONIGHT/EARLY SATURDAY FOR WESTERN
NEBRASKA AIRFIELDS. OTHERWISE VFR CONDITIONS CAN BE EXPECTED TO
HOLD THROUGH THE PERIOD FOR SOUTHEAST WYOMING TAF SITES.

FIRE WEATHER...WARM AND BREEZY SOUTHWEST WINDS WILL CONTINUE
THROUGH LATE THIS AFTERNOON ALONG AND WEST OF THE LARAMIE RANGE.
HUMIDITIES WILL REMAIN IN THE LOW TO MID TEENS WITH WIND
SPEEDS QUITE VARIABLE BUT GENERAL GUSTING 20 TO 35 MPH. THE
LOCATIONS WITH CONDITIONS AT OR NEAR CRITICAL STATUS ARE UNDER
GREENUP SO WILL NOT ISSUE ANY SHORT TERM HIGHLIGHTS FOR THIS
AFTERNOON. SIMILAR CONDITIONS ARE EXPECTED TOMORROW SO WILL
HEADLINE THE FORECAST ONCE AGAIN FOR INCREASED FIRE WEATHER THREAT
FOR SATURDAY AFTERNOON IN THE VICINITY OF THE LARAMIE RANGE AND
ALSO IN FAR SOUTHWEST CARBON COUNTY. A COLD FRONT WILL MOVE NORTH TO
SOUTH ACROSS THE DISTRICT LATE SATURDAY AFTERNOON AND EVENING WITH
GUSTY NORTHWEST WINDS BEHIND THE FRONT EXPECTED ACROSS THE EASTERN
PLAINS...ALONG WITH COOLING TEMPS AND A CHANCE FOR SHOWERS AND A FEW
TSTORMS.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.

&&

$$

UPDATE...LIEBL
SHORT TERM/FIRE WEATHER...RJM
LONG TERM/AVIATION...HAHN










AREA FORECAST DISCUSSION

NWS DENVER CO

 944 AM MDT SAT MAY 5 2012

.UPDATE...FCST LOOKS ON TRACK SO FAR THIS MORNING. STRATUS/FOG
CONTINUES FM EARLIER THIS MORNING CONTINUES TO DISSIPATE ACROSS
THE NORTHEAST PLAINS. HRRR SCOURS THIS OUT BY 17Z...AND THE TREND
IN THE STLT SEEMS TO SUPPORT THIS. NO CHANGES TO THE ONGOING RED
FLAG WARNING.


&&

.AVIATION...LINGERING STRATUS NORTH OF DENVER SHOULD DISSIPATE
THROUGH THE REST OF THIS MORNING. WL NOT MAKE ANY SIGNIFICANT
CHANGES TO THE TAFS IN THE UPCOMING 18Z ISSUANCE.


&&

.PREV DISCUSSION... /ISSUED 417 AM MDT SAT MAY 5 2012/

SHORT TERM...IN GENERAL...ONE MORE SUNNY AND WARM DAY IN STORE
FOR NORTHEAST COLORADO TODAY AS MODERATE SOUTHWEST FLOW ALOFT
CONTINUES. WE WILL LIKELY SEE A LITTLE MORE CIRRUS CLOUD COVER
TODAY THAN WE SAW YESTERDAY WHICH COULD BE JUST ENOUGH TO CUT A
FEW DEGREES OFF THE AFTERNOON TEMPERATURES THAT WE SAW YESTERDAY.
CURRENT DEW POINTS FROM STATIONS IN THE MOUNTAINS SHOW HOW DRY THE
AIRMASS WILL BE TODAY. A RED FLAG WARNING WILL BE IN EFFECT FOR
THE UPPER COLORADO/FRASER RIVER VALLEY AND NORTH PARK TODAY DUE TO
THE LOW HUMIDITIES AND ANTICIPATED BREEZY CONDITIONS THIS
AFTERNOON. THE OTHER DETAIL TO THIS MORNINGS FORECAST IS AND AREA
OF STRATUS AND FOG IN LOGAN...SEDGWICK AND PHILLIPS COUNTIES.
METARS OUT THERE SHOW 1-3 MILE VISIBILITIES IN FOG...BUT ALSO
RECEIVED A REPORT OF 1/8 MILE VISIBILITY AROUND JULESBURG. POCKETS
OF DENSE FOG WILL CONTINUE FOR THE NEXT SEVERAL HOURS...BUT IT
DOESN/T SEEM TO BE WIDESPREAD ENOUGH TO WARRANT A DENSE FOG
ADVISORY.

CHANGES WILL MOVE INTO THE FORECAST AREA TONIGHT AS A COLD FRONT
MOVES OUT OF WYOMING. GUSTY WINDS WILL BE THE MAIN IMPACT...
ALTHOUGH THERE WILL ALSO BE A CHANCE FOR A ROUND OF EVENING
CONVECTION. MODEL SOUNDINGS SHOW RAPID STABILIZATION AT THE LOWEST
LEVELS...BUT CAN NOT RULE OUT SOME ELEVATED CONVECTION BEHIND THE
COLD FRONT AND ASSOCIATED WITH THE ENTRANCE REGION OF THE UPPER
JET THAT IS FORECAST TO BE OVER SOUTHEASTERN WYOMING. COOLER
MORNING LOWS WILL ALSO SUNDAY MORNING IN THE POST-FRONTAL AIRMASS.

LONG TERM...A WEAK UPPER LEVEL TROUGH WILL MOVE ACROSS THE AREA
FM SUN AFTN INTO MON AS SFC HIGH PRESSURE BUILDS INTO NRN CO WITH
SOME UPSLOPE. FOR SUN THERE WILL BE A SLIGHT CHC OF SHOWERS MAINLY
OVER THE PLAINS IN THE MORNING. BY AFTN THE BEST CHC OF PCPN WILL
BE OVER THE HIGHER TERRAIN AS SOME WK MID LVL QG ASCENT DEVELOPS.
OVERALL INSTABILITY IS NOT THAT GREAT SO WILL KEEP PCPN MOSTLY AS
SHOWERS. HIGHS ON SUN WILL BE MUCH COOLER WITH READINGS MAINLY IN
THE LOWER 60S ACROSS NERN CO.

BY SUN NIGHT AS WK UPPER LEVEL TROUGH BEGINS TO AFFECT AREA
COMBINATION OF WK QG ASCENT...UPPER LEVEL JET AND SOME UPSLOPE
FLOW SHOULD LEAD TO A BETTER CHC OF PCPN OVER THE HIGHER TERRAIN
AND EVENTUALLY ALONG THE FRONT RANGE. SNOW LEVELS WILL LOWER TO
AROUND 9000 FEET SO MAY SEE SOME ACCUMULATIONS IN TH MTNS. ON MON
THE GFS...ECMWF AND GEM CONTINUE TO SHOW SOME PCPN OVER MUCH OF
NRN CO AS THE WK UPPER LEVEL TROUGH SLOWLY MOVES ACROSS IN
COMBINATION WITH WK UPSLOPE FLOW. THUS WILL KEEP CHC POPS IN MOST
AREAS. HIGHS ON MON MAY NOT GET OUT OF THE 50S OVER MUCH OF NERN
CO DUE TO CLOUD COVER AND PCPN.

FOR MON NIGHT INTO TUE THE UPPER LEVEL TROUGH WILL GRADUALLY
SHIFT SE WITH PCPN CHANCES DECREASING FM NORTH TO SOUTH AND ENDING
BY TUE MORNING. HIGHS WILL BE MAINLY IN THE LOWER TO MID 60S
ACROSS NERN CO. BY WED AN UPPER LEVEL WILL BE OVER THE AREA AS A
WEAK UPPER LEVEL LOW MOVES SLOWLY ACROSS SRN AZ/SRN NM. THERE MAY
BE ENOUGH INSTABILITY AND LEFT OVER MOISTURE FOR A SLIGHT CHC OF
CONVECTION OVER THE HIGHER TERRAIN AND POSSIBLY ALONG THE FRONT
RANGE. HIGHS ON WED WILL RISE BACK INTO THE LOWER TO MID 70S
ACROSS NERN CO.

BY THU BOTH THE GFS AND ECMWF SHOW AN UPPER LEVEL TROUGH MOVING
ACROSS THE NRN ROCKIES WITH RATHER WEKA MID LVL FLOW ACROSS NRN
CO. THERE STILL MAY BE ENOUGH MOISTURE FOR SOME WDLY SCT
AFTN CONVECTION ONCE AGAIN OVER THE HIGHER TERRAIN AND POSSIBLY
ALONG THE FRONT RANGE. HIGHS WILL BE IN THE 75 TO 80 RANGE OVER
NERN CO. FOR FRI BOTH THE ECMWF AND GFS SHOW A CDFNT MOVING ACROSS
NRN CO BRINGING COOLER TEMPS ALONG WITH AT LEAST A SLIGHT CHC OF
SHOWERS AS A WEAK DISTURBANCE MAY AFFECT THE AREA.

AVIATION...VFR CONDITIONS TODAY WITH NORTHWEST TO NORTHERLY WINDS
THROUGH THE AFTERNOON. FRONTAL PASSAGE EXPECTED AFTER 02Z TONIGHT
WITH GUSTY NORTH WINDS AND A CHANCE OF CIGS 5000-6000 FEET AGL
ASSOCIATED WITH RAIN SHOWERS OR THUNDERSTORMS.

HYDROLOGY...NO HYDROLOGIC IMPACTS TODAY OR TONIGHT.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 6 PM MDT THIS EVENING FOR COZ211-213.

&&

$$

SHORT TERM...COOPER
LONG TERM....RPK
AVIATION...COOPER






AREA FORECAST DISCUSSION

NWS NEW YORK NY

 1147 AM EDT SAT MAY 5 2012

.SYNOPSIS...
A COLD FRONT WILL SLIDE TO OUR SOUTH AND EAST THIS
MORNING...FOLLOWED BY HIGH PRESSURE BUILDING DOWN FROM SOUTH
CENTRAL CANADA INTO SUNDAY NIGHT...THEN SLIDING OFFSHORE MONDAY. A
COMPLEX AND SLOW MOVING STORM SYSTEM IMPACTS THE TRI-STATE FROM
MONDAY NIGHT INTO THURSDAY NIGHT. HIGH PRESSURE BUILDS IN FROM THE
WEST ON FRIDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED GRIDS BASED ON LATEST TRENDS IN OBSERVATIONS AND GUIDANCE.
PATCHY FOG FORECAST THROUGH THE REST OF THE MORNING OVER LAND
AREAS AND AREAS OF FOG OVER THE OCEAN. INCREASED CLOUDS AND
LOWERED MAX TEMPS BY 2 TO 3 DEGREES WITH RESULTING 65-70 DEGREES
FOR WESTERN AREAS AND UPPER 50S TO LOWER 60S FOR EASTERN COASTAL
LOCATIONS. FOG DISSIPATES EARLY THIS AFTERNOON. FROM EXPECTED
SLIGHT LOWERING OF 500MB HEIGHTS...LINGERING FRONTAL
BOUNDARY...AND SOME INCREASE IN INSTABILITY WITH SOME WARMING
TODAY...COULD SEE MORE SHOWERS DEVELOP. THIS IS SHOWN BY 09Z RUN
OF HRRR IN ITS REFLECTIVITY FIELDS. SHOWERS WERE KEPT MOSTLY IN
ISOLATED COVERAGE. OUTSIDE OF SHOWERS...SPRINKLES ARE EXPECTED
FROM TIME TO TIME.

A COLD FRONT STRETCHING FROM NORTHERN MAINE INTO EASTERN NEW
JERSEY WILL PUSH TO OUR SOUTH AND EAST THIS MORNING. HAVE SLIGHT
CHANCE POPS WITH ITS PASSAGE...AS RADAR SHOWS A FEW RETURNS OVER
THE TRI-STATE...BUT EXPECT MOST AREAS TO REMAIN DRY. MODELS ARE
SPLIT OVER HOW FAR S THIS BOUNDARY PUSHES...SO HAVE LEFT IN SLIGHT
CHANCE POPS OVER SOUTHERN ZONES. SUSPECT THAT THESE ULTIMATELY
WILL BE PROVEN TO BE NOT NEEDED...AS THE FARTHER S SOLUTION IS
ARGUED FOR BY THE NAM...WHICH USUALLY FARES RATHER WELL WITH
SHALLOW COOL AIRMASSES SUCH AS THIS ONE.

OTHERWISE NW FLOW ALOFT...ALONG WITH LOW LEVEL MOISTURE TRAPPED
UNDER A LOW LEVEL INVERSION THAT GRADUALLY LIFTS TO AROUND 800 HPA
BY LATE AFTERNOON WILL BE THE MAIN WEATHER PLAYERS TODAY. THE
QUESTION IS...WILL THE DOWNSLOPE FROM THE NW FLOW BY SUFFICIENT TO
ERODE THE GRADUALLY LIFTING CLOUD DECK OVER THE REGION. FOR NOW IT
APPEARS THAT THIS COULD HAPPEN OVER AREAS MAINLY TO THE NW OF NYC.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
NW FLOW ALOFT CONTINUES FROM TONIGHT INTO SUNDAY NIGHT AS A DEEP
LAYERED RIDGE SLOWLY APPROACHES FROM THE WEST...WITH THIS RIDGE
BUILDING OVER THE AREA ON MONDAY. FOR NOW HAVE GONE WITH A DRY
FORECAST IN THIS TIME FRAME...HOWEVER A SHORTWAVE TROUGH FORECAST
TO PASS TO OUR NE ON SUNDAY COULD ULTIMATELY END UP BRINGING A FEW
SHOWERS BUT FOR NOW...IT APPEARS THE BEST FORCING WITH THIS SYSTEM
WILL STAY TO OUR NORTH AND EAST.

THE LOW LEVEL INVERSION AT AROUND 800 HPA IS FORECAST TO PERSIST
THROUGH SUNDAY...SO STILL WOULD EXPECT TO SEE SOME CLOUDS UNDER IT
TONIGHT AND SUNDAY. SUBSIDENCE FROM THE APPROACHING RIDGE SHOULD
BE SUFFICIENT TO YIELD MAINLY MOSTLY CLEAR SKY CONDITIONS SUNDAY
NIGHT. HIGH AND MID CLOUDS THEN SLOWLY BUILD IN FROM SW TO NE
MONDAY AS MOISTURE FROM A STORM SYSTEM TRACKING INTO THE GREAT
LAKES BY LATE MONDAY MOVES IN AS THE MID TO UPPER LEVEL RIDGE AXIS
SLIDES TO OUR EAST.

FOR TEMPERATURES IN THE SHORT TERM...USED A BLEND OF BIAS
CORRECTED MAV GUIDANCE WITH MET GUIDANCE AND NAM 2-METER
TEMPERATURES FOR LOWS TONIGHT...WITH VALUES A FEW DEGREES ABOVE
NORMAL EXPECTED. FOR SUNDAY...EXPECT HIGHS TO BE NEAR NORMAL
CONSISTENT WITH A BLEND OF MAV/MET GUIDANCE WITH NAM 2-METER
TEMPERATURES AND MIXING DOWN FROM 850 HPA. HIGHS COULD END UP A
FEW DEGREES WARMER IF CLOUD COVER ERODES MORE THAN EXPECTED UNDER
THE INVERSION IN THE AFTERNOON. FOR LOWS SUNDAY NIGHT...USED THE
SAME BLEND AS FOR TONIGHT...WITH VALUES A FEW DEGREES ABOVE NORMAL
FORECAST. FOR MONDAY EXPECT HIGHS TO BE SLIGHTLY ABOVE
NORMAL...CONSISTENT WITH A BLEND OF MAV/MET GUIDANCE WITH NAM
2-METER TEMPERATURES AND A MIX DOWN FROM 850 HPA ACROSS THE
INTERIOR AND 925 HPA FOR COASTAL LOCATIONS.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THERE STILL CONTINUE TO BE MODEL DISCREPANCIES IN THE HANDLING OF
THE SYSTEM THAT WILL IMPACT THE TRI-STATE THROUGH THE MIDDLE OF
THE WEEK. THE GFS APPEARS TO BE AT ODDS WITH SLOWER ECMWF/CMC-
GLOBAL MODELS AND THE GEFS MEAN...SO USED A BLEND OF THESE LATTER
MODELS FOR THE EXTENDED FORECAST.

BRING CHANCE POPS INTO THE WESTERN 1/3 OF THE CWA...SLIGHT CHANCE
POPS INTO THE CENTRAL 1/3 OF THE CWA AND KEEP THE EASTERN 1/3 DRY
MONDAY NIGHT...CONSISTENT WITH THE IDEA OF A SLOWER DEPARTURE OF
THE UPPER RIDGE TO OUR EAST. INCREASE POPS TO CHANCE THROUGHOUT
TUESDAY WITH MORNING RAIN TRANSITIONING TO SHOWERS AS IT APPEARS
THE SURFACE WARM FRONT ASSOCIATED WITH LOW PRESSURE OVER THE
EASTERN GREAT LAKES SHOULD LIFT TO OUR N...PLACING US IN THE WARM
SECTOR BY AFTERNOON. WITH ALL GUIDANCE SUGGESTING PRECIPITATION
TUESDAY NIGHT...WENT WITH SHOWERS LIKELY.

THE FORECAST BECOMES A BIT MORE PROBLEMATIC WEDNESDAY AND
WEDNESDAY NIGHT AS THERE IS QUITE A BIT OF SPREAD OVER WHERE A
SECONDARY LOW ULTIMATELY DEVELOPS. FOR NOW WENT WITH THE IDEA OF
THE COASTAL LOW DEVELOPING NEAR CAPE COD WEDNESDAY NIGHT...BUT
CANNOT RULE OUT THE ECMWF DEVELOPING THE LOW TO OUR SW ON
WEDNESDAY. AS A RESULT WENT WITH A CHANCE OF SHOWERS IN THIS TIME
FRAME...AND WENT WITH A WARMER TEMPERATURE SOLUTION THAN THE ECMWF
WOULD SUGGEST.

THE SURFACE LOW SHOULD SLOWLY TREK TO OUR NE THURSDAY AND THURSDAY
NIGHT AS THE 700-500 HPA TROUGH AXIS CROSSES THE REGION. WENT WITH
CHANCE POPS THURSDAY AND SLIGHT CHANCE POPS THURSDAY NIGHT AS A RESULT.

WENT DRY ON FRIDAY WITH A DRYING NW FLOW SETTING UP ALOFT AND HIGH
PRESSURE BUILDING IN AT THE SURFACE.

USED A BLEND OF MEX/MEX ENSEMBLE MEAN GUIDANCE WITH HPC GUIDANCE
FOR TEMPERATURES IN THE LONG TERM...WITH LOWS GENERALLY RUNNING
SLIGHTLY ABOVE NORMAL AND HIGHS SLIGHTLY BELOW NORMAL. THE
EXCEPTION IS HIGHS ON WEDNESDAY...WHICH ARE CURRENTLY FORECAST TO
RUN SLIGHTLY ABOVE NORMAL...HOWEVER...AS NOTED ABOVE...IF THE
ECMWF ENDS UP BEING CORRECT...THEN THESE VALUES COULD END UP BELOW
NORMAL AS WELL.

&&

.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
MVFR/IFR THIS MORNING BEFORE SLOWLY IMPROVING BY THIS AFTERNOON.
TIMING UNCERTAINTY OF 1-2 HOURS ON TRANSITION BETWEEN CATEGORIES
WITH AMENDMENTS POSSIBLE. MID TO LATE AFTERNOON...MOSTLY MVFR TO VFR
FOR MORE NORTHERN TERMINALS. LOW CONFIDENCE IN THE VFR.

FROM UPSTREAM TERMINAL TRENDS...16-17Z SEEMS TO BE THE TIME OF IFR
TO MVFR IMPROVEMENT FOR CITY TERMINALS. AGAIN...THIS COULD VARY BY
ABOUT AN HOUR.

POSSIBLE STRATUS FORMATION/MVFR AGAIN TONIGHT ESP AFTER 03Z.
CONFIDENCE LOW AT THIS TIME AT EXACTLY HOW LOW THE CIGS WILL BE SO
HAVE SIDED WITH A MORE CONSERVATIVE SIDE. GUIDANCE ALSO WANTS FOG
INCLUDED...BUT SUCH LOW CONFIDENCE IN THE FORMATION AT THIS TIME
TO INCLUDE WITH THE THINKING STRATUS WILL BE THE MAIN ISSUE
OVERNIGHT.

WINDS REMAIN LESS THAN 10 KTS FOR THE PERIOD...SHIFTING FROM A
NELY TO ELY FLOW.

OUTLOOK FOR 12Z SUN THROUGH WED...
.SUN-MON...VFR.
.TUE-WED...SUB VFR POSSIBLE IN RAIN.

&&

.MARINE...
UPDATED GRIDS BASED ON LATEST TRENDS IN OBSERVATIONS AND GUIDANCE.
FORECAST APPEARS ON TRACK.

WITH HIGH PRESSURE BUILDING IN...AND A WEAK PRESSURE GRADIENT
PERSISTING...EXPECTING SUB SCA CONDITIONS FOR THE WEEKEND.
RELATIVELY LIGHT NORTHEASTERLY TO EASTERLY FLOW...WITH WINDS
REMAINING LESS THAN 10 KTS...WITH OCCASIONAL GUSTS UP TO 15 KTS.
WINDS SHIFT TO A SOUTHERLY FLOW BY THE END OF THE WEEKEND AS THE
HIGH CENTER NEARS THE REGION. SEAS GENERALLY 2 FT OR LESS ON THE
OCEAN WATERS...AND LESS THAN 1 FT ELSEWHERE.

LOW PRESSURE WILL NEAR THE WATERS MID WEEK...INCREASING THE WINDS
THE SEAS. SHOULD SEE THE SEAS BEGIN TO REACH AROUND 5 FT IN THE
OCEAN WATERS BY TUESDAY...WHILE WIND GUSTS WILL APPROACH 25 KTS LATE
TUES. SCA CONDITIONS EXPECTED THROUGH MID WEEK...WITH SEAS AND WINDS
DIMINISHING BY THE END OF THE WEEK AS HIGH PRESSURE BUILDS IN ONCE
AGAIN.

&&

.HYDROLOGY...
MAINLY DRY CONDITIONS ARE EXPECTED THROUGH MONDAY. THERE IS THE
POTENTIAL FOR SIGNIFICANT RAINFALL ACROSS THE TRI-STATE FROM
MONDAY NIGHT INTO THURSDAY.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES TONIGHT ARE FORECASTED TO BE WITHIN ONE-HALF
FOOT OF MINOR COASTAL FLOOD BENCHMARKS. THIS...COMBINED WITH A
PERSISTENT WIND FLOW...MAY LEAD TO ISOLATED AREAS TONIGHT JUST
REACHING THE MINOR FLOOD BENCHMARK. HOWEVER...DUE TO THE LACK OF
COVERAGE...HAVE ISSUED A COASTAL FLOOD STATEMENT FOR PORTIONS OF
WESTERN LONG ISLAND SOUND...NEW YORK HARBOR...AND PORTIONS OF
SOUTHWESTERN LI.

THE BETTER CHANCE FOR MINOR FLOODING WILL OCCUR TOMORROW
NIGHT...WHEN THE HIGH TIDES ARE FORECASTED TO BE THE HIGHEST. HIGH
TIDES ARE EXPECTED TO REACH WITHIN A COUPLE INCHES OF MINOR FLOOD
LEVELS IN PORTIONS ALONG THE WESTERN LI SOUND.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...MALOIT
NEAR TERM...MALOIT/JM
SHORT TERM...MALOIT
LONG TERM...MALOIT
AVIATION...JM/SEARS
MARINE...SEARS
HYDROLOGY...MALOIT
TIDES/COASTAL FLOODING...







AREA FORECAST DISCUSSION

NWS NEW YORK NY

 1102 AM EDT SAT MAY 5 2012

.SYNOPSIS...
A COLD FRONT WILL SLIDE TO OUR SOUTH AND EAST THIS
MORNING...FOLLOWED BY HIGH PRESSURE BUILDING DOWN FROM SOUTH
CENTRAL CANADA INTO SUNDAY NIGHT...THEN SLIDING OFFSHORE MONDAY. A
COMPLEX AND SLOW MOVING STORM SYSTEM IMPACTS THE TRI-STATE FROM
MONDAY NIGHT INTO THURSDAY NIGHT. HIGH PRESSURE BUILDS IN FROM THE
WEST ON FRIDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED GRIDS BASED ON LATEST TRENDS IN OBSERVATIONS AND GUIDANCE.
PATCHY FOG FORECAST THROUGH THE REST OF THE MORNING OVER LAND
AREAS AND AREAS OF FOG OVER THE OCEAN. INCREASED CLOUDS AND
LOWERED MAX TEMPS BY 2 TO 3 DEGREES WITH RESULTING 65-70 DEGREES
FOR WESTERN AREAS AND UPPER 50S TO LOWER 60S FOR EASTERN COASTAL
LOCATIONS. FOG DISSIPATES EARLY THIS AFTERNOON. FROM EXPECTED
SLIGHT LOWERING OF 500MB HEIGHTS...LINGERING FRONTAL
BOUNDARY...AND SOME INCREASE IN INSTABILITY WITH SOME WARMING
TODAY...COULD SEE MORE SHOWERS DEVELOP. THIS IS SHOWN BY 09Z RUN
OF HRRR IN ITS REFLECTIVITY FIELDS. SHOWERS WERE KEPT MOSTLY IN
ISOLATED COVERAGE.

A COLD FRONT STRETCHING FROM NORTHERN MAINE INTO EASTERN NEW
JERSEY WILL PUSH TO OUR SOUTH AND EAST THIS MORNING. HAVE SLIGHT
CHANCE POPS WITH ITS PASSAGE...AS RADAR SHOWS A FEW RETURNS OVER
THE TRI-STATE...BUT EXPECT MOST AREAS TO REMAIN DRY. MODELS ARE
SPLIT OVER HOW FAR S THIS BOUNDARY PUSHES...SO HAVE LEFT IN SLIGHT
CHANCE POPS OVER SOUTHERN ZONES. SUSPECT THAT THESE ULTIMATELY
WILL BE PROVEN TO BE NOT NEEDED...AS THE FARTHER S SOLUTION IS
ARGUED FOR BY THE NAM...WHICH USUALLY FARES RATHER WELL WITH
SHALLOW COOL AIRMASSES SUCH AS THIS ONE.

OTHERWISE NW FLOW ALOFT...ALONG WITH LOW LEVEL MOISTURE TRAPPED
UNDER A LOW LEVEL INVERSION THAT GRADUALLY LIFTS TO AROUND 800 HPA
BY LATE AFTERNOON WILL BE THE MAIN WEATHER PLAYERS TODAY. THE
QUESTION IS...WILL THE DOWNSLOPE FROM THE NW FLOW BY SUFFICIENT TO
ERODE THE GRADUALLY LIFTING CLOUD DECK OVER THE REGION. FOR NOW IT
APPEARS THAT THIS COULD HAPPEN OVER AREAS MAINLY TO THE NW OF NYC.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
NW FLOW ALOFT CONTINUES FROM TONIGHT INTO SUNDAY NIGHT AS A DEEP
LAYERED RIDGE SLOWLY APPROACHES FROM THE WEST...WITH THIS RIDGE
BUILDING OVER THE AREA ON MONDAY. FOR NOW HAVE GONE WITH A DRY
FORECAST IN THIS TIME FRAME...HOWEVER A SHORTWAVE TROUGH FORECAST
TO PASS TO OUR NE ON SUNDAY COULD ULTIMATELY END UP BRINGING A FEW
SHOWERS BUT FOR NOW...IT APPEARS THE BEST FORCING WITH THIS SYSTEM
WILL STAY TO OUR NORTH AND EAST.

THE LOW LEVEL INVERSION AT AROUND 800 HPA IS FORECAST TO PERSIST
THROUGH SUNDAY...SO STILL WOULD EXPECT TO SEE SOME CLOUDS UNDER IT
TONIGHT AND SUNDAY. SUBSIDENCE FROM THE APPROACHING RIDGE SHOULD
BE SUFFICIENT TO YIELD MAINLY MOSTLY CLEAR SKY CONDITIONS SUNDAY
NIGHT. HIGH AND MID CLOUDS THEN SLOWLY BUILD IN FROM SW TO NE
MONDAY AS MOISTURE FROM A STORM SYSTEM TRACKING INTO THE GREAT
LAKES BY LATE MONDAY MOVES IN AS THE MID TO UPPER LEVEL RIDGE AXIS
SLIDES TO OUR EAST.

FOR TEMPERATURES IN THE SHORT TERM...USED A BLEND OF BIAS
CORRECTED MAV GUIDANCE WITH MET GUIDANCE AND NAM 2-METER
TEMPERATURES FOR LOWS TONIGHT...WITH VALUES A FEW DEGREES ABOVE
NORMAL EXPECTED. FOR SUNDAY...EXPECT HIGHS TO BE NEAR NORMAL
CONSISTENT WITH A BLEND OF MAV/MET GUIDANCE WITH NAM 2-METER
TEMPERATURES AND MIXING DOWN FROM 850 HPA. HIGHS COULD END UP A
FEW DEGREES WARMER IF CLOUD COVER ERODES MORE THAN EXPECTED UNDER
THE INVERSION IN THE AFTERNOON. FOR LOWS SUNDAY NIGHT...USED THE
SAME BLEND AS FOR TONIGHT...WITH VALUES A FEW DEGREES ABOVE NORMAL
FORECAST. FOR MONDAY EXPECT HIGHS TO BE SLIGHTLY ABOVE
NORMAL...CONSISTENT WITH A BLEND OF MAV/MET GUIDANCE WITH NAM
2-METER TEMPERATURES AND A MIX DOWN FROM 850 HPA ACROSS THE
INTERIOR AND 925 HPA FOR COASTAL LOCATIONS.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THERE STILL CONTINUE TO BE MODEL DISCREPANCIES IN THE HANDLING OF
THE SYSTEM THAT WILL IMPACT THE TRI-STATE THROUGH THE MIDDLE OF
THE WEEK. THE GFS APPEARS TO BE AT ODDS WITH SLOWER ECMWF/CMC-
GLOBAL MODELS AND THE GEFS MEAN...SO USED A BLEND OF THESE LATTER
MODELS FOR THE EXTENDED FORECAST.

BRING CHANCE POPS INTO THE WESTERN 1/3 OF THE CWA...SLIGHT CHANCE
POPS INTO THE CENTRAL 1/3 OF THE CWA AND KEEP THE EASTERN 1/3 DRY
MONDAY NIGHT...CONSISTENT WITH THE IDEA OF A SLOWER DEPARTURE OF
THE UPPER RIDGE TO OUR EAST. INCREASE POPS TO CHANCE THROUGHOUT
TUESDAY WITH MORNING RAIN TRANSITIONING TO SHOWERS AS IT APPEARS
THE SURFACE WARM FRONT ASSOCIATED WITH LOW PRESSURE OVER THE
EASTERN GREAT LAKES SHOULD LIFT TO OUR N...PLACING US IN THE WARM
SECTOR BY AFTERNOON. WITH ALL GUIDANCE SUGGESTING PRECIPITATION
TUESDAY NIGHT...WENT WITH SHOWERS LIKELY.

THE FORECAST BECOMES A BIT MORE PROBLEMATIC WEDNESDAY AND
WEDNESDAY NIGHT AS THERE IS QUITE A BIT OF SPREAD OVER WHERE A
SECONDARY LOW ULTIMATELY DEVELOPS. FOR NOW WENT WITH THE IDEA OF
THE COASTAL LOW DEVELOPING NEAR CAPE COD WEDNESDAY NIGHT...BUT
CANNOT RULE OUT THE ECMWF DEVELOPING THE LOW TO OUR SW ON
WEDNESDAY. AS A RESULT WENT WITH A CHANCE OF SHOWERS IN THIS TIME
FRAME...AND WENT WITH A WARMER TEMPERATURE SOLUTION THAN THE ECMWF
WOULD SUGGEST.

THE SURFACE LOW SHOULD SLOWLY TREK TO OUR NE THURSDAY AND THURSDAY
NIGHT AS THE 700-500 HPA TROUGH AXIS CROSSES THE REGION. WENT WITH
CHANCE POPS THURSDAY AND SLIGHT CHANCE POPS THURSDAY NIGHT AS A RESULT.

WENT DRY ON FRIDAY WITH A DRYING NW FLOW SETTING UP ALOFT AND HIGH
PRESSURE BUILDING IN AT THE SURFACE.

USED A BLEND OF MEX/MEX ENSEMBLE MEAN GUIDANCE WITH HPC GUIDANCE
FOR TEMPERATURES IN THE LONG TERM...WITH LOWS GENERALLY RUNNING
SLIGHTLY ABOVE NORMAL AND HIGHS SLIGHTLY BELOW NORMAL. THE
EXCEPTION IS HIGHS ON WEDNESDAY...WHICH ARE CURRENTLY FORECAST TO
RUN SLIGHTLY ABOVE NORMAL...HOWEVER...AS NOTED ABOVE...IF THE
ECMWF ENDS UP BEING CORRECT...THEN THESE VALUES COULD END UP BELOW
NORMAL AS WELL.

&&

.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
FOG AND LOW CIGS THIS MORNING SHOULD BEGIN INCREASING AS A COLD
FRONT PUSHES THROUGH. AREAS OF FOG WILL LINGER THROUGH AROUND 16Z
THIS MORNING BEFORE INCREASING TO VFR. SHOULD SEE VIS BETWEEN 2
AND 4SM IMPROVING TO P6SM.

EXPECTING BKN TO OVC SKIES ACROSS THE REGION TODAY INTO TONIGHT...WITH
MAINLY MVFR WITH POSSIBLE BRIEF PERIOD OF VFR BY LATE AFTERNOON.
POSSIBLE STRATUS FORMATION/MVFR AGAIN TONIGHT ESP AFTER 03Z.
CONFIDENCE LOW AT THIS TIME AT EXACTLY HOW LOW THE CIGS WILL BE SO
HAVE SIDED WITH A MORE CONSERVATIVE SIDE. GUIDANCE ALSO WANTS FOG
INCLUDED...BUT SUCH LOW CONFIDENCE IN THE FORMATION AT THIS TIME
TO INCLUDE WITH THE THINKING STRATUS WILL BE THE MAIN ISSUE
OVERNIGHT.

WINDS REMAIN LESS THAN 10 KTS FOR THE PERIOD...SHIFTING FROM A
NELY TO ELY FLOW.

OUTLOOK FOR 12Z SUN THROUGH WED...
.SUN-MON...VFR.
.TUE-WED...SUB VFR POSSIBLE IN RAIN.

&&

.MARINE...
UPDATED GRIDS BASED ON LATEST TRENDS IN OBSERVATIONS AND GUIDANCE.
FORECAST APPEARS ON TRACK.

WITH HIGH PRESSURE BUILDING IN...AND A WEAK PRESSURE GRADIENT
PERSISTING...EXPECTING SUB SCA CONDITIONS FOR THE WEEKEND.
RELATIVELY LIGHT NORTHEASTERLY TO EASTERLY FLOW...WITH WINDS
REMAINING LESS THAN 10 KTS...WITH OCCASIONAL GUSTS UP TO 15 KTS.
WINDS SHIFT TO A SOUTHERLY FLOW BY THE END OF THE WEEKEND AS THE
HIGH CENTER NEARS THE REGION. SEAS GENERALLY 2 FT OR LESS ON THE
OCEAN WATERS...AND LESS THAN 1 FT ELSEWHERE.

LOW PRESSURE WILL NEAR THE WATERS MID WEEK...INCREASING THE WINDS
THE SEAS. SHOULD SEE THE SEAS BEGIN TO REACH AROUND 5 FT IN THE
OCEAN WATERS BY TUESDAY...WHILE WIND GUSTS WILL APPROACH 25 KTS LATE
TUES. SCA CONDITIONS EXPECTED THROUGH MID WEEK...WITH SEAS AND WINDS
DIMINISHING BY THE END OF THE WEEK AS HIGH PRESSURE BUILDS IN ONCE
AGAIN.

&&

.HYDROLOGY...
MAINLY DRY CONDITIONS ARE EXPECTED THROUGH MONDAY. THERE IS THE
POTENTIAL FOR SIGNIFICANT RAINFALL ACROSS THE TRI-STATE FROM
MONDAY NIGHT INTO THURSDAY.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES TONIGHT ARE FORECASTED TO BE WITHIN ONE-HALF
FOOT OF MINOR COASTAL FLOOD BENCHMARKS. THIS...COMBINED WITH A
PERSISTENT WIND FLOW...MAY LEAD TO ISOLATED AREAS TONIGHT JUST
REACHING THE MINOR FLOOD BENCHMARK. HOWEVER...DUE TO THE LACK OF
COVERAGE...HAVE ISSUED A COASTAL FLOOD STATEMENT FOR PORTIONS OF
WESTERN LONG ISLAND SOUND...NEW YORK HARBOR...AND PORTIONS OF
SOUTHWESTERN LI.

THE BETTER CHANCE FOR MINOR FLOODING WILL OCCUR TOMORROW
NIGHT...WHEN THE HIGH TIDES ARE FORECASTED TO BE THE HIGHEST. HIGH
TIDES ARE EXPECTED TO REACH WITHIN A COUPLE INCHES OF MINOR FLOOD
LEVELS IN PORTIONS ALONG THE WESTERN LI SOUND.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...MALOIT
NEAR TERM...MALOIT/JM
SHORT TERM...MALOIT
LONG TERM...MALOIT
AVIATION...SEARS
MARINE...SEARS
HYDROLOGY...MALOIT
TIDES/COASTAL FLOODING...








AREA FORECAST DISCUSSION

NWS LINCOLN IL

 1044 AM CDT SAT MAY 5 2012

.DISCUSSION...
ISSUED 1044 AM CDT SAT MAY 5 2012

FRONTAL BOUNDARY HAS DROPPED SOUTHWARD AND BECOME STATIONARY FROM
NORTHERN MISSOURI INTO SOUTH-CENTRAL ILLINOIS THIS MORNING.
SURFACE DEWPOINTS TO THE NORTH OF THE FRONT HAVE DROPPED INTO
THE LOWER 60S ACROSS MUCH OF THE KILX CWA...WHILE UPPER 60S/LOWER
70S DEWPOINTS POOL NEAR THE BOUNDARY. 12 NAM MAINTAINS A DRY
FORECAST THROUGHOUT THE DAY...HOWEVER THE LATEST HRRR SUGGESTS
WIDELY SCATTERED STORMS FIRING FROM NEAR QUINCY E/SE TO
LAWRENCEVILLE THIS AFTERNOON. GIVEN PRESENCE OF WEAK FORCING
MECHANISM...THINK SLIGHT CHANCE POPS ACROSS THE S/SE CWA LOOK
GOOD. 15Z TEMPS ARE MAINLY IN THE LOWER TO MIDDLE 70S...BUT ARE
HOLDING IN THE LOWER 60S NORTH OF PEORIA AND BLOOMINGTON WHERE
EARLY MORNING FOG HAS LIFTED INTO A LOW OVERCAST. THINK CLOUDS
WILL GRADUALLY DISSIPATE ACROSS THE NORTH...WITH PARTLY SUNNY
SKIES EXPECTED ACROSS THE BOARD THIS AFTERNOON. DUE TO THE COOL
START AND A CONTINUED E/NE BREEZE TO THE NORTH OF THE FRONT...HAVE
LOWERED HIGH TEMPS BY A COUPLE OF DEGREES. READINGS WILL REMAIN IN
THE UPPER 70S ACROSS THE FAR NORTH AROUND HENRY AND LACON...BUT
WILL STILL REACH THE MIDDLE 80S ACROSS THE S/SE CWA. ZONE UPDATE
HAS ALREADY BEEN ISSUED.

BARNES
&&

.AVIATION...
ISSUED 658 AM CDT SAT MAY 5 2012...FOR THE 12Z TAFS

VLIFR FOG WILL AFFECT BMI FOR A COUPLE OF HOURS TO START OFF THIS
TAF PERIOD. PIA AND CMI WILL SEE IFR FOG DURING THAT TIME...WITH
MVFR FOG FOR SPI/DEC. THE FOG AND STRATUS SHOULD BURN OFF
RELATIVELY QUICKLY WITH HEATING AND MIXING THIS MORNING.

THE WARM FRONT WILL REMAIN CLOSE BY TO THE SOUTH. STORMS WILL
REMAIN PRIMARILY SOUTH OF THE TERMINAL SITES...BUT SPI MAY BE
CLOSE TO A FEW STORMS TODAY. WE DID NOT INCLUDE VCTS AT ALL...DUE
TO ENOUGH UNCERTAINTY AS TO WHEN ANY STORMS WOULD GET CLOSE TO
SPI.

WINDS WILL REMAIN PRIMARILY FROM THE EAST AS ALL TAF SITES WILL
REMAIN NORTH OF THE WARM FRONT OVER THE NEXT 24 HOURS. SUSTAINED WIND
SPEEDS SHOULD NOT CLIMB MUCH ABOVE 12-13KT TODAY.

SHIMON
&&

.PREV DISCUSSION...
ISSUED 257 AM CDT SAT MAY 5 2012

FRONTAL BOUNDARY ROUGHLY ALONG A LINE FROM BURLINGTON TO TERRE
HAUTE EARLY THIS MORNING. HAVE HAD WAVES OF THUNDERSTORMS
DEVELOPING ALONG THE SOUTHERN EDGES OF THE FORECAST AREA THE LAST
FEW HOURS...PRODUCING SOME PERIODIC HAIL. TEMPERATURES NORTH OF
THE FRONT HAVE FALLEN INTO THE 50S FROM ABOUT PEORIA TO DANVILLE
NORTHWARD...ACCOMPANIED BY A LARGE AREA OF LOW STRATUS CLOUDS WHICH
COVER ABOUT THE NORTHEAST THIRD OF THE STATE.

THE ACTIVE WEATHER PATTERN WILL CONTINUE FOR A COUPLE MORE DAYS.
THE MAIN FORECAST FOCUS IS WITH POTENTIAL FOR SEVERE WEATHER
SUNDAY AFTERNOON AND NIGHT...AND TIMING OF THE ENDING FOR THE RAIN
ON MONDAY.

SHORT TERM...TODAY THROUGH MONDAY...

WILL MONITOR CURRENT CONVECTION UP UNTIL THE LAST MINUTE...BUT IT
CURRENTLY APPEARS THIS SHOULD LARGELY BE OUT OF THE FORECAST AREA
BY ISSUANCE TIME. AS IS TYPICAL IN SUCH PATTERNS...POTENTIAL FOR
ANY CONVECTIVE REDEVELOPMENT TODAY WILL DEPEND ON THE SETUP OF ANY
RESIDUAL BOUNDARIES FROM THE OVERNIGHT STORMS. HIGH-RESOLUTION
MODELS APPEAR TO FOCUS THE BEST CHANCES JUST TO OUR SOUTH THIS
AFTERNOON. WILL INCLUDE SOME SLIGHT CHANCES OF RAIN SOUTHEAST OF A
RUSHVILLE TO MATTOON LINE THIS AFTERNOON AND EVENING.

THE FRONTAL BOUNDARY IS EXPECTED TO RETREAT NORTHWARD OVERNIGHT...
AS A WAVE OF LOW PRESSURE DEVELOPS OVER SOUTHWEST MINNESOTA. MOST
OF THE EVENING MODELS ARE SIMILAR IN THE EVOLUTION...ALTHOUGH THE
NAM IS MUCH MORE PROGRESSIVE AND HAS THE TRAILING COLD FRONT
THROUGH THE AREA BY SUNDAY EVENING. THINK THIS IS A BIT TOO FAST
AND WILL LEAN TOWARD THE SLOWER SOLUTIONS OF THE OTHER MODELS...
WHICH DO NOT FULLY BRING THE FRONT THROUGH UNTIL MONDAY AFTERNOON.
MAIN CONCERN IS SUNDAY AFTERNOON AND EVENING...AS MUCAPES RISE TO
OVER 3500 J/KG BY AFTERNOON. LATEST DAY2 OUTLOOK FROM SPC HAS A
SLIGHT RISK OF SEVERE WEATHER BUT WITH ENHANCED POTENTIAL FOR
LARGE HAIL. AREAS ALONG AND WEST OF I-55 MOST LIKELY TO SEE ANY
DEVELOPMENT DURING THE AFTERNOON...WITH THE THREAT SHIFTING EAST
DURING THE EVENING. MAIN SEVERE THREAT BY MONDAY MORNING SHOULD
MAINLY BE TO OUR SOUTHEAST...BUT MAY STILL SEE SOME ISOLATED
STRONG/SEVERE STORMS ACROSS THE EASTERN CWA EARLY. ANY LINGERING
RAIN SHOULD DIMINISH EARLY MONDAY EVENING.

HAVE NOT MADE MUCH CHANGE TO THE TEMPERATURE FORECAST FOR THIS
WEEKEND...WITH HIGHS WELL INTO THE 80S OVER THE AREA.

LONG TERM...TUESDAY THROUGH FRIDAY...

SMALL UPPER LOW WHICH WILL DEVELOP OVER MONTANA THIS WEEKEND IS
PROGGED TO MOVE TO THE MINNESOTA/ONTARIO BORDER BY TUESDAY
MORNING...BEFORE OPENING UP INTO A WAVE. WILL LIKELY SEE SOME
WRAPAROUND SHOWERS OVER PORTIONS OF THE UPPER MIDWEST TUESDAY AND
WEDNESDAY. CURRENT INDICATIONS KEEP THE BULK OF THESE TO OUR
NORTH AND NORTHEAST...BUT HAVE INCLUDED SOME SLIGHT CHANCES ACROSS
THE NORTHEAST THIRD OF THE CWA LATE TUESDAY NIGHT AND WEDNESDAY.
HIGH PRESSURE SETTLING INTO THE MIDWEST WILL PROVIDE FAIR WEATHER
THE REMAINDER OF THE WORK WEEK. AFTER A RELATIVELY COOL PERIOD
WEDNESDAY AND THURSDAY...TEMPERATURES WILL BEGIN TO REBOUND BY THE
END OF THE WEEK.

GEELHART

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$









AREA FORECAST DISCUSSION

NWS INDIANAPOLIS IN

 1028 AM EDT SAT MAY 5 2012

.UPDATE...

THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 253 AM EDT SAT MAY 5 2012

A FRONTAL BOUNDARY WILL LINGER NEAR THE OHIO RIVER TODAY AND
SUNDAY AS A RIDGE OF HIGH PRESSURE BUILDS ALOFT. THIS WILL RESULT IN
MOSTLY DRY WEATHER TODAY THROUGH SUNDAY.

AN AREA OF LOW PRESSURE WILL APPROACH CENTRAL INDIANA ON
SUNDAY NIGHT AND MONDAY AND THIS WILL PUSH THE FRONTAL BOUNDARY
BACK NORTH ACROSS CENTRAL INDIANA. SHOWERS AND THUNDERSTORMS ARE
EXPECTED TO ACCOMPANY THE FRONT AS IT PUSHES NORTH AND AS THE LOW
PRESSURE SYSTEM PASSES ON MONDAY.

A FEW SHOWERS WILL BE POSSIBLE ON TUESDAY NIGHT AND WEDNESDAY AS
AN AREA OF BROAD LOW PRESSURE PUSHES THROUGH THE GREAT LAKES...BUT
THE END OF THE WORK WEEK LOOKS COOL AND DRY AS HIGH PRESSURE
BUILDS ACROSS THE CENTRAL PLAINS.

&&

.NEAR TERM /TODAY/...
ISSUED AT 1000 AM EDT SAT MAY 5 2012

HAD TO INCREASE CLOUD COVER ACROSS OUR NORTHERN THIRD OF COUNTIES
BASED ON SATELLITE AND OBSERVATIONS. NAM12 AND RUC SOUNDINGS SUGGEST
THE INVERSION WILL BREAK AROUND NOON OR SHORTLY AFTER. THEN...EXPECT
SCATTERED TO BROKEN DIURNAL CU PER THE CU RULE. DUE TO THE
CLOUDS...HAD TO LOWER THE TEMPERATURES THROUGH MID DAY ACROSS
ESPECIALLY THE NORTH BUT TO A LESSER DEGREE THE SOUTH BASED ON
OBSERVATIONAL TRENDS. STILL THINK MAX TEMPERATURES ARE
ATTAINABLE...HOWEVER WITH AT LEAST SOME AFTERNOON SUN.

PREVIOUS DISCUSSION FOLLOWS...

MAIN FORECAST CHALLENGE TODAY WILL BE TEMPS.

SURFACE ANALYSIS EARLY THIS MORNING SHOWS A FRONTAL BOUNDARY
STRETCHING ACROSS SOUTHERN ILLINOIS TO SOUTHWEST INDIANA AND
NORTHERN KENTUCKY. SHRA AND TSRA WERE LINGERING ALONG THE
FRONT...BUT WERE STILL DRIVING SOUTHEAST. COOLER HIGH PRESSURE WAS
FOUND ACROSS THE GREAT LAKES...PROVIDING COOL NORTHEAST WINDS TO
CENTRAL INDIANA.

FORECAST SOUNDINGS TODAY INDICATE A WEAK CAP IN PLACE AS THE GFS
AND NAM BOTH SUGGEST RIDGING BUILDING ACROSS THE
AREA...FURTHERMORE THE SURFACE HIGH TO THE NORTH WILL CONTINUE TO
PROVIDE DRY EAST TO NORTHEAST FLOW. CU RULE SUGGESTS SCT-BKN
CU...THUS PTCLDY WILL WORK FINE ACROSS THE AREA. GIVEN THE
EXPECTED 850MB TEMPS...A BLEND OF MAVMOS AND METMOS LOOKS ON THE
MARK FOR HIGHS.

&&

.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
ISSUED AT 253 AM EDT SAT MAY 5 2012

MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE POPS ON SUNDAY
NIGHT. GFS/NAM AND ECMWF ARE IN PRETTY GOOD AGREEMENT UNTIL SUNDAY
NIGHT...AS AT THAT TIME THE NAM IS QUICKER WITH THE ADVANCING
SYSTEM. FOR NOW WILL LEAN CLOSER TO THE GFS/ECMWF SOLUTION GIVEN
THE RIDGING ALOFT AND THE EASTERLY FLOW THAT IS EXPECTED TO
PERSIST PRIOR TO THE ARRIVAL OF THE FRONT AND LOW.

LITTLE CHANGE FROM TODAY IS EXPECTED FOR TONIGHT AND SUNDAY AS THE
FRONTAL BOUNDARY IS EXPECTED TO CONTINUE TO LINGER NEAR THE OHIO
RIVER AS RIDGING BUILDS ALOFT...AND HIGH PRESSURE SLOWLY MOVING
THROUGH THE GREAT LAKES CONTINUES TO PROVIDE A COOLER EASTERLY
FLOW. FURTHERMORE FORECAST SOUNDINGS CONTINUE TO INDICATE A
RELATIVELY DRY COLUMN...THUS PTCLDY SHOULD CONTINUE TO WORK WELL.
GIVEN THE EXPECTED 850MB TEMPS...A BLEND OF THE MAVMOS AND METMOS
WILL WORK FOR TONIGHTS LOW AND SUNDAY HIGHS.

ON SUNDAY NIGHT THE NAM WISHES TO BRING THE WARM FRONT FARTHER
NORTH...WHILE THE GFS AND ECMWF KEEP IT FARTHER SOUTH. GIVEN THE
STRENGTH OF THE HIGH IN PLACE...THE TREND OF THE SLOWER GFS AND
ECMWF IS PREFERRED. FURTHER SUPPORTING THIS IS FORECAST SOUNDINGS
THAT FAIL TO SHOW DEEP MOISTURE OR STRONG FORCING UNTIL MONDAY.
THIS WILL TREND TOWARD INCREASING CLOUDS ON SUNDAY NIGHT ALONG
WITH THE LESS WET MAVMOS POPS...FOCUSED LATE IN THE PERIOD. GIVEN
THE EXPECTED CLOUD COVER WILL TREND SUNDAY NIGHT LOWS WARMER THAN
MAVMOS.

GFS AND ECMWF PUSH A SHORT WAVE OUT OF THE MISSISSIPPI VALLEY ON
MONDAY...PUSHING STRONG DYNAMICS ACROSS INDIANA. THIS SHOULD ALSO
HELP TO PULL THE LINGERING FRONTAL BOUNDARY NEAR THE OHIO RIVER
BACK NORTH AS A WARM FRONT...ADDING TO THE AVAILABLE FORCING. TIME
HEIGHT SECTIONS INDICATE DEEP MOISTURE IS AVAILABLE AS FORECAST
SOUNDINGS REMAIN SATURATED. THUS GIVEN THE FORCING AND MOISTURE
WILL TREND POPS HIGHER THAN MAVMOS AND TREND HIGH TEMPERATURES
COOLER...GIVEN THE EXPECTED CLOUDS...RAIN AND TSRA.

SHORT WAVE DEPARTS ON MONDAY NIGHT...AND AS FORCING IS LOST PRECIP
IS EXPECTED TO END AS DEEP MOISTURE IS LOST. COLD AIR ADVECTION IS
EXPECTED TO BEGIN BY 12Z TUESDAY AS A COLD FRONT IS PUSHED ACROSS
THE STATE IN THE WAKE OF THE LOW. WILL NEED TO CARRY SOME POPS
FOR EARLY MONDAY NIGHT AS TIMING OF THE DEPARTURE OF THE SYSTEM
WILL STILL BE RATHER VARIABLE AT THIS TIME AND MAY EASILY GET
ADJUSTED BACK OR FORTH A FEW HOURS IN LATTER FORECAST RUNS. WILL
TREND LOWS COOLER THAN MEXMOS

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 253 AM EDT SAT MAY 5 2012

MAIN FEATURES OF NOTE FOR THE LONG TERM ARE A COLD FRONT WHICH WILL
BE JUST OUT OF THE AREA EARLY TUESDAY MORNING...FOLLOWED QUICKLY BY
AN UPPER TROUGH WEDNESDAY. HIGH PRESSURE BUILDS IN QUICKLY WEDNESDAY
EVENING...WHICH WILL ALLOW A DRY FORECAST FOR THE REMAINDER OF THE
PERIOD.

LITTLE TO QUIBBLE ABOUT ON THESE FEATURES AS MODELS ARE IN DECENT
AGREEMENT WITH ONLY TYPICAL MINOR TIMING AND STRENGTH DIFFERENCES AT
THOSE TIME SCALES. ALLBLEND CAPTURES THESE FEATURES WELL AND NO
MAJOR DEVIATIONS REQUIRED.

ANY PRECIP FALLING TUESDAY NIGHT AND WEDNESDAY WITH THE UPPER TROUGH
AXIS WILL BE SHOWERY IN NATURE...AND THUNDERSTORMS SHOULD NOT BE AN
ISSUE.

DEPENDING ON THE AMOUNT OF CLOUD COVER...MAX TEMPS FROM
INITIALIZATION MAY BE A BIT TOO WARM WEDNESDAY AND THURSDAY...BUT
THIS WOULD BE BY ONLY A FEW DEGREES. SOME AREAS MAY STRUGGLE TO GET
OUT OF THE 50S AROUND MID WEEK.

&&

.AVIATION /DISCUSSION FOR THE 051500Z KIND TAF UPDATE/...
ISSUED AT 1028 AM EDT SAT MAY 5 2012

IFR DECK AROUND 007 AGL HOVERING ABOUT 5-10SM NORTHWEST OF THE KIND
TERMINAL. SATELLITE SHOWS THIS DECK IS BEGINNING TO ERODE FROM THE
SOUTH...SO IT DOESN/T APPEAR THESE CEILINGS WILL DIRECTLY IMPACT
KIND.

LOW LEVEL LAPSE RATES REMAIN RATHER STEEP THROUGH THE MIDDAY
HOURS...BUT SHORT TERM MODEL DATA SLACKEN THESE OFF LATER IN THE
AFTERNOON. MAY SEE SOME BRIEF PERIODS OF CEILINGS 020-040 AT KIND
THROUGH THE EARLY AFTERNOON...BUT DON/T THINK CEILINGS WILL BE
PROLONGED OR WIDESPREAD ENOUGH TO PUT IN THE FORECAST. PREVIOUS
DISCUSSION FOLLOWS.

WITH A VERY MOIST AIRMASS IN PLACE...MVFR FOG IS OCCURRING AT ALL
SITES THIS MORNING...WITH IFR CEILINGS ACCOMPANYING AT LAF.
FLUCTUATING CONDITIONS CAN BE EXPECTED THROUGH THE FIRST 1-3 HOURS
OF THE TAF...WITH A GRADUAL IMPROVEMENT TREND. CANNOT RULE OUT BRIEF
FORAYS INTO IFR VISIBILITIES AT ANY SITE. FREQUENT AMENDMENTS MAY BE
NEEDED THIS MORNING. EXPECT CONDITIONS TO IMPROVE THIS MORNING TO
BROKEN VFR CUMULUS.

LATE IN THE TAF PERIOD...EXPECTING MVFR FOG TO DEVELOP. MOIST
AIRMASS WILL REMAIN IN PLACE AS A SURFACE HIGH BUILDS INTO THE
AREA...AND EAST WINDS ARE SLIGHTLY PREFERRED CLIMATOLOGICALLY FOR
MVFR RESTRICTIONS.

WINDS WILL GENERALLY BE EASTERLY LESS THAN 10KT THROUGH THE PERIOD.

&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SYNOPSIS...PUMA
NEAR TERM...PUMA/MK
SHORT TERM...PUMA
LONG TERM....NIELD
AVIATION...NIELD/JAS






AREA FORECAST DISCUSSION

NWS INDIANAPOLIS IN

 1000 AM EDT SAT MAY 5 2012

.UPDATE...

THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 253 AM EDT SAT MAY 5 2012

A FRONTAL BOUNDARY WILL LINGER NEAR THE OHIO RIVER TODAY AND
SUNDAY AS A RIDGE OF HIGH PRESSURE BUILDS ALOFT. THIS WILL RESULT IN
MOSTLY DRY WEATHER TODAY THROUGH SUNDAY.

AN AREA OF LOW PRESSURE WILL APPROACH CENTRAL INDIANA ON
SUNDAY NIGHT AND MONDAY AND THIS WILL PUSH THE FRONTAL BOUNDARY
BACK NORTH ACROSS CENTRAL INDIANA. SHOWERS AND THUNDERSTORMS ARE
EXPECTED TO ACCOMPANY THE FRONT AS IT PUSHES NORTH AND AS THE LOW
PRESSURE SYSTEM PASSES ON MONDAY.

A FEW SHOWERS WILL BE POSSIBLE ON TUESDAY NIGHT AND WEDNESDAY AS
AN AREA OF BROAD LOW PRESSURE PUSHES THROUGH THE GREAT LAKES...BUT
THE END OF THE WORK WEEK LOOKS COOL AND DRY AS HIGH PRESSURE
BUILDS ACROSS THE CENTRAL PLAINS.

&&

.NEAR TERM /TODAY/...
ISSUED AT 1000 AM EDT SAT MAY 5 2012

HAD TO INCREASE CLOUD COVER ACROSS OUR NORTHERN THIRD OF COUNTIES
BASED ON SATELLITE AND OBSERVATIONS. NAM12 AND RUC SOUNDINGS SUGGEST
THE INVERSION WILL BREAK AROUND NOON OR SHORTLY AFTER. THEN...EXPECT
SCATTERED TO BROKEN DIURNAL CU PER THE CU RULE. DUE TO THE
CLOUDS...HAD TO LOWER THE TEMPERATURES THROUGH MID DAY ACROSS
ESPECIALLY THE NORTH BUT TO A LESSER DEGREE THE SOUTH BASED ON
OBSERVATIONAL TRENDS. STILL THINK MAX TEMPERATURES ARE
ATTAINABLE...HOWEVER WITH AT LEAST SOME AFTERNOON SUN.

PREVIOUS DISCUSSION FOLLOWS...

MAIN FORECAST CHALLENGE TODAY WILL BE TEMPS.

SURFACE ANALYSIS EARLY THIS MORNING SHOWS A FRONTAL BOUNDARY
STRETCHING ACROSS SOUTHERN ILLINOIS TO SOUTHWEST INDIANA AND
NORTHERN KENTUCKY. SHRA AND TSRA WERE LINGERING ALONG THE
FRONT...BUT WERE STILL DRIVING SOUTHEAST. COOLER HIGH PRESSURE WAS
FOUND ACROSS THE GREAT LAKES...PROVIDING COOL NORTHEAST WINDS TO
CENTRAL INDIANA.

FORECAST SOUNDINGS TODAY INDICATE A WEAK CAP IN PLACE AS THE GFS
AND NAM BOTH SUGGEST RIDGING BUILDING ACROSS THE
AREA...FURTHERMORE THE SURFACE HIGH TO THE NORTH WILL CONTINUE TO
PROVIDE DRY EAST TO NORTHEAST FLOW. CU RULE SUGGESTS SCT-BKN
CU...THUS PTCLDY WILL WORK FINE ACROSS THE AREA. GIVEN THE
EXPECTED 850MB TEMPS...A BLEND OF MAVMOS AND METMOS LOOKS ON THE
MARK FOR HIGHS.

&&

.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
ISSUED AT 253 AM EDT SAT MAY 5 2012

MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE POPS ON SUNDAY
NIGHT. GFS/NAM AND ECMWF ARE IN PRETTY GOOD AGREEMENT UNTIL SUNDAY
NIGHT...AS AT THAT TIME THE NAM IS QUICKER WITH THE ADVANCING
SYSTEM. FOR NOW WILL LEAN CLOSER TO THE GFS/ECMWF SOLUTION GIVEN
THE RIDGING ALOFT AND THE EASTERLY FLOW THAT IS EXPECTED TO
PERSIST PRIOR TO THE ARRIVAL OF THE FRONT AND LOW.

LITTLE CHANGE FROM TODAY IS EXPECTED FOR TONIGHT AND SUNDAY AS THE
FRONTAL BOUNDARY IS EXPECTED TO CONTINUE TO LINGER NEAR THE OHIO
RIVER AS RIDGING BUILDS ALOFT...AND HIGH PRESSURE SLOWLY MOVING
THROUGH THE GREAT LAKES CONTINUES TO PROVIDE A COOLER EASTERLY
FLOW. FURTHERMORE FORECAST SOUNDINGS CONTINUE TO INDICATE A
RELATIVELY DRY COLUMN...THUS PTCLDY SHOULD CONTINUE TO WORK WELL.
GIVEN THE EXPECTED 850MB TEMPS...A BLEND OF THE MAVMOS AND METMOS
WILL WORK FOR TONIGHTS LOW AND SUNDAY HIGHS.

ON SUNDAY NIGHT THE NAM WISHES TO BRING THE WARM FRONT FARTHER
NORTH...WHILE THE GFS AND ECMWF KEEP IT FARTHER SOUTH. GIVEN THE
STRENGTH OF THE HIGH IN PLACE...THE TREND OF THE SLOWER GFS AND
ECMWF IS PREFERRED. FURTHER SUPPORTING THIS IS FORECAST SOUNDINGS
THAT FAIL TO SHOW DEEP MOISTURE OR STRONG FORCING UNTIL MONDAY.
THIS WILL TREND TOWARD INCREASING CLOUDS ON SUNDAY NIGHT ALONG
WITH THE LESS WET MAVMOS POPS...FOCUSED LATE IN THE PERIOD. GIVEN
THE EXPECTED CLOUD COVER WILL TREND SUNDAY NIGHT LOWS WARMER THAN
MAVMOS.

GFS AND ECMWF PUSH A SHORT WAVE OUT OF THE MISSISSIPPI VALLEY ON
MONDAY...PUSHING STRONG DYNAMICS ACROSS INDIANA. THIS SHOULD ALSO
HELP TO PULL THE LINGERING FRONTAL BOUNDARY NEAR THE OHIO RIVER
BACK NORTH AS A WARM FRONT...ADDING TO THE AVAILABLE FORCING. TIME
HEIGHT SECTIONS INDICATE DEEP MOISTURE IS AVAILABLE AS FORECAST
SOUNDINGS REMAIN SATURATED. THUS GIVEN THE FORCING AND MOISTURE
WILL TREND POPS HIGHER THAN MAVMOS AND TREND HIGH TEMPERATURES
COOLER...GIVEN THE EXPECTED CLOUDS...RAIN AND TSRA.

SHORT WAVE DEPARTS ON MONDAY NIGHT...AND AS FORCING IS LOST PRECIP
IS EXPECTED TO END AS DEEP MOISTURE IS LOST. COLD AIR ADVECTION IS
EXPECTED TO BEGIN BY 12Z TUESDAY AS A COLD FRONT IS PUSHED ACROSS
THE STATE IN THE WAKE OF THE LOW. WILL NEED TO CARRY SOME POPS
FOR EARLY MONDAY NIGHT AS TIMING OF THE DEPARTURE OF THE SYSTEM
WILL STILL BE RATHER VARIABLE AT THIS TIME AND MAY EASILY GET
ADJUSTED BACK OR FORTH A FEW HOURS IN LATTER FORECAST RUNS. WILL
TREND LOWS COOLER THAN MEXMOS

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 253 AM EDT SAT MAY 5 2012

MAIN FEATURES OF NOTE FOR THE LONG TERM ARE A COLD FRONT WHICH WILL
BE JUST OUT OF THE AREA EARLY TUESDAY MORNING...FOLLOWED QUICKLY BY
AN UPPER TROUGH WEDNESDAY. HIGH PRESSURE BUILDS IN QUICKLY WEDNESDAY
EVENING...WHICH WILL ALLOW A DRY FORECAST FOR THE REMAINDER OF THE
PERIOD.

LITTLE TO QUIBBLE ABOUT ON THESE FEATURES AS MODELS ARE IN DECENT
AGREEMENT WITH ONLY TYPICAL MINOR TIMING AND STRENGTH DIFFERENCES AT
THOSE TIME SCALES. ALLBLEND CAPTURES THESE FEATURES WELL AND NO
MAJOR DEVIATIONS REQUIRED.

ANY PRECIP FALLING TUESDAY NIGHT AND WEDNESDAY WITH THE UPPER TROUGH
AXIS WILL BE SHOWERY IN NATURE...AND THUNDERSTORMS SHOULD NOT BE AN
ISSUE.

DEPENDING ON THE AMOUNT OF CLOUD COVER...MAX TEMPS FROM
INITIALIZATION MAY BE A BIT TOO WARM WEDNESDAY AND THURSDAY...BUT
THIS WOULD BE BY ONLY A FEW DEGREES. SOME AREAS MAY STRUGGLE TO GET
OUT OF THE 50S AROUND MID WEEK.

&&

.AVIATION /DISCUSSION FOR THE 05/12Z TAFS/...
ISSUED AT 707 AM EDT SAT MAY 5 2012

WITH A VERY MOIST AIRMASS IN PLACE...MVFR FOG IS OCCURRING AT ALL
SITES THIS MORNING...WITH IFR CEILINGS ACCOMPANYING AT LAF.
FLUCTUATING CONDITIONS CAN BE EXPECTED THROUGH THE FIRST 1-3 HOURS
OF THE TAF...WITH A GRADUAL IMPROVEMENT TREND. CANNOT RULE OUT BRIEF
FORAYS INTO IFR VISIBILITIES AT ANY SITE. FREQUENT AMENDMENTS MAY BE
NEEDED THIS MORNING. EXPECT CONDITIONS TO IMPROVE THIS MORNING TO
BROKEN VFR CUMULUS.

LATE IN THE TAF PERIOD...EXPECTING MVFR FOG TO DEVELOP. MOIST
AIRMASS WILL REMAIN IN PLACE AS A SURFACE HIGH BUILDS INTO THE
AREA...AND EAST WINDS ARE SLIGHTLY PREFERRED CLIMATOLOGICALLY FOR
MVFR RESTRICTIONS.

WINDS WILL GENERALLY BE EASTERLY LESS THAN 10KT THROUGH THE PERIOD.

&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SYNOPSIS...PUMA
NEAR TERM...PUMA/MK
SHORT TERM...PUMA
LONG TERM....NIELD
AVIATION...NIELD









AREA FORECAST DISCUSSION

NWS DODGE CITY KS

 600 AM CDT SAT MAY 5 2012

...UPDATE TO AVIATION FOR 12Z TAFS...

.SYNOPSIS...
ISSUED AT 127 AM CDT SAT MAY 5 2012

AT 00Z SATURDAY A -26 TO -28C 500MB TROUGH WAS LOCATED FROM
NORTHERN CALIFORNIA TO SOUTHERN BRITISH COLUMBIA. A 250MB +110
KNOT JET STREAK EXTEND FROM THE BASED OF THIS TROUGH NORTHEASTWARD
INTO THE NORTHERN ROCKIES WITH THE RIGHT EXIT REGION OF THIS UPPER
JET POSITIONED NEAR THE FOUR CORNERS REGION. IN THE CENTRAL UNITED
STATES A WEST TO EAST 850MB BAROCLINIC ZONE/SURFACE STATIONARY
FRONT STRETCHED FROM SOUTHEAST WYOMING ACROSS NEBRASKA AND AN AREA
OF LOW PRESSURE AT THE SURFACE EXTENDED SOUTH OF THIS FRONT ACROSS
EASTERN COLORADO. A WARM +10 TO +12C 700MB TEMPERATURES WAS
LOCATED ACROSS EASTERN COLORADO AND WESTERN KANSAS. AT THE SURFACE
TO 850MB LEVEL THE BETTER MOISTURE RETURN FROM THE SOUTH/SOUTHEAST
WINDS WERE LOCATED ACROSS FROM CENTRAL OKLAHOMA, ACROSS CENTRAL
KANSAS AND INTO SOUTHWEST NEBRASKA.

&&

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 127 AM CDT SAT MAY 5 2012

EARLY THIS MORNING AND TODAY...SURFACE PRESSURES WILL CONTINUE TO
FALL ALONG THE LEE OF THE ROCKIES IN RESPONSE TO THE WEST COAST
UPPER LEVEL TROUGH MOVING EASTWARDS TOWARDS THE NORTHERN AND
CENTRAL ROCKIES. SOUTHEASTERLY FLOW NEAR THE SURFACE WILL DRAW
MORE HUMID AIR BACK ACROSS PORTIONS OF NORTH CENTRAL KANSAS BUT AT
THIS TIME BASED ON VARIOUS BUFR SOUNDINGS AND HRRR ANY STATUS OR
FOG THAT MAY DEVELOP EARLY THIS MORNING IS NOT EXPECTED TO BE
WIDESPREAD OR DENSE. BY LATE MORNING A LEE TROUGH/DRYLINE WILL
MOVE EAST ACROSS WESTERN KANSAS ALLOWING DRIER AIR TO RETURN.
THESE LOW DEW POINT BEHIND THIS BOUNDARY COMBINED WITH AFTERNOON
TEMPERATURES TOPPING OUT IN THE MID-UPPER 90S, BASED ON 850-700MB
MIX DOWN TEMPERATURES, WILL ALLOW AFTERNOON RELATIVE HUMIDITIES TO
FALL BACK TO NEAR 10 PERCENT IN A FEW LOCATIONS. WINDS HOWEVER ARE
EXPECTED TO AVERAGE AT LESS THAN 20 MPH AND THE FUEL STATUS PAGE
DOES INDICATE MOST LOCATIONS DO NOT HAVE THE FUELS NEEDED TO
SUPPORT RED FLAG WARNING CONDITIONS. AS A RESULT WILL NOT BE
ISSUING ANY TYPE OF FIRE WEATHER PRODUCTS AT THIS TIME.

TONIGHT...AN UPPER LEVEL JET WILL CROSS THE ROCKIES AND MOVE OUT
INTO THE NORTHERN PLAINS. AS IT DOES THE STATIONARY FRONT ACROSS
NEBRASKA WILL BEGIN TO MOVE SOUTH INTO NORTHWEST KANSAS. BASED ON
THE LOCATION OF THE RIGHT ENTRANCE REGION OF THE UPPER LEVEL JET,
NORTHERN EDGE OF THE WARM 700MB WARM LAYER, AND WHERE THE MOIST
UPSLOPE FLOW WILL BE PRESENT SATURDAY EVENING THE BETTER CHANCES
FOR CONVECTION EARLY TONIGHT WILL STAY WELL NORTH OF INTERSTATE 70
IN NORTHEAST COLORADO AND NORTHWEST KANSAS. THIS AREA OF
CONVECTION WILL MOVE EAST/SOUTHEAST OVERNIGHT AS THE SURFACE COLD
FRONT BEGINS TO WORK ITS WAY INTO WESTERN KANSAS. AT THIS TIME
BASED THE LOCATION OF THE BETTER MOISTURE AND LOW LEVEL FORCING
ALONG WITH THE BETTER MID LEVEL INSTABILITY THE PRECIPITATION
CHANCES STILL APPEARS TO BE IN/NEAR OUR NORTH CENTRAL KANSAS AND
MAINLY AFTER 09Z. AS A RESULT WILL CONTINUE TO LEAN TOWARD LEAVING
THE FORECAST DRY BUT DID INSERT SOME 10-14% CHANCES INTO THE HAYS
AREA. AS FOR TEMPERATURES THE PREVIOUS FORECAST STILL APPEARS TO
HAVE A DECENT HANDLE ON KEEPING LOWS MAINLY IN THE 60S ALONG AND
AHEAD OF THE COLD FRONT WHICH WILL BE LOCATED NEAR SOUTH CENTRAL
KANSAS AT 12Z.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 403 AM CDT SAT MAY 5 2012

SUNDAY:

A STRONG COLD FRONT WILL HAVE CLEARED MUCH OF THE REGION BY SUNDAY MORNING,
EXCEPT AROUND MEDICINE LODGE. THIS FRONT IS BEING USHERED IN BY A 500
HPA SHORTWAVE TROUGH WELL TO THE NORTH. THE RIGHT ENTRANCE REGION OF
A 250 HPA JET WILL SKIRT ACROSS NEBRASKA DURING THE DAY AND AS A RESULT,
I HAVE HIGHEST POPS ACROSS CENTRAL KANSAS DUE TO RESULTANT INCREASING
UPPER LEVEL DYNAMICS/DIVERGENCE ALOFT. THE COLD FRONT WILL HAVE SCOURED
OUT MUCH OF THE BOUNDARY LAYER MOISTURE EXCEPT ACROSS SOUTH CENTRAL
KANSAS. FORECAST SOUNDINGS DO NOT SHOW MUCH IN THE WAY OF CAPE EXCEPT
SOUTHEAST OF A LARNED TO COLDWATER LINE. SO HAVE PUT ISOLATED THUNDERSTORMS,
BUT THE EVENT LOOKS MORE LIKE A SHOWER EVENT IF ANYTHING. THE STRONGER
DYNAMICS WILL BE WELL TO THE NORTHEAST SO AM NOT EXPECTING A HIGH QPF
EVENT. TEMPERATURES WILL COOL DOWN TO WHERE THEY SHOULD BE FOR THIS
TIME OF YEAR (NEAR NORMAL) WITH NEAR 70 DEG F TOWARDS TOWARDS SCOTT
CITY AND WARMER LOWER 80S DEG F SOUTH OF THE FRONT TOWARDS MEDICINE
LODGE. 850 HPA WINDS ARE FORECAST TO BE AROUND 35 TO 40 KT SO SUNDAY
WILL BE WINDY WITH REFRESHING NORTHERLY WINDS 2O TO 30 MPH. A WELCOME
CHANGE FROM THE MID 90S DEG F THE DAY BEFORE.

MONDAY:

HIGH PRESSURE WILL BUILD ACROSS THE CENTRAL PLAINS MONDAY AND A MUCH
DRIER AIRMASS WILL SPREAD ACROSS WESTERN KANSAS. OVERNIGHT LOWS WILL
BE MORE SEASONABLE WITH 40S AND 50S DEG F FORECAST ACROSS MUCH OF THE
REGION. THERE WILL BE A BROAD UPPER LEVEL SHORTWAVE TROUGH ACROSS THE
ROCKIES AND 700 AND 850 HPA TRAJECTORIES WILL BE UPSLOPE ACROSS FAR
WESTERN KANSAS AND INTO COLORADO. AS A RESULT, HAVE SLIGHT POPS IN ACROSS
THE WESTERN HALF AND INTO PORTIONS OF THE SOUTHERN HALF OF THE REGION
DUE TO UPSLOPE CONDITIONS. COOL HIGH PRESSURE WILL PROVIDE TEMPERATURES
IN THE 60S DEG F TOWARDS I 70 AND MID 70S DEG F TOWARDS THE OKLAHOMA
BORDER.

TUESDAY THROUGH THURSDAY:

TEMPERATURES WILL MODERATE THROUGH THE MIDDLE PORTION OF NEXT WEEK AS
THE COOL HIGH PRESSURE CENTER SLIDES OFF TO THE EAST AND WEAK LEE SURFACE
TROUGHING DEVELOPS ACROSS THE HIGH PLAINS. THIS PORTION OF THE FORECAST
PERIOD WILL BE DRY AS A 500 HPA RIDGE AXIS EJECTS OUT FROM THE ROCKIES
AND EVENTUALLY ACROSS THE PLAINS BY THURSDAY AFTERNOON. THE MODELS SHOW
A 500 HPA LOW ACROSS SOUTHWEST TEXAS BUT SW KANSAS LOOKS LIKE TO BE
IN THE COL POINT...MEANING BASICALLY NO IMPACT IN TERMS OF SENSIBLE
WEATHER.

FRIDAY:

THEN NEXT CHANCE FOR PRECIPITATION APPEARS TO BE ON FRIDAY. UNFORTUNATELY
THE AFOREMENTIONED LOW WILL IMPEDE DECENT GULF OF MEXICO MOISTURE FROM
RETURNING NORTHWARD WITH ONLY 50 DEG F DEWPOINTS ADVECTING IN FROM THE
SOUTHERN PLAINS AND MOSTLY LIKELY JUST ACROSS SOUTH CENTRAL KANSAS.
MEANWHILE, AN UPPER LEVEL SHORTWAVE TROUGH SKIRTING ACROSS THE NORTHERN
PLAINS WILL USHER IN A COLD FRONT DURING THE DAY. THE MODELS (EVEN THE
ECMWF WHICH IS A LITTLE MORE CONSERVATIVE ON MOISTURE RETURN) INDICATES
SOME CAPE FORMING SO THERE COULD BE A FEW THUNDERSTORMS AROUND. THE
GFS, AS USUAL, IS TOO AGGRESSIVE WITH WARM AIR/MOISTURE ADVECTION AND
WAS DISREGARDED.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 600 AM CDT SAT MAY 5 2012

MVFR CIGS ARE POSSIBLE THIS MORNING AT KHYS IN ASSOCIATION WITH FOG.
OTHERWISE, VFR CIGS WILL PREVAIL. S WINDS WILL BE BREEZY AT 13-15 KT
WITH GUSTS TO 22-25 KT BETWEEN 17Z AND 00Z. A STRONG COLD FRONT IS EXPECTED
TOMORROW MORNING JUST OUTSIDE THE TAF PD.

&&

.PRELIMINARY POINT TEMPS/POPS...
DDC  95  61  71  52 /   0  10  20  10
GCK  96  58  68  50 /   0  10  20  20
EHA  95  58  72  48 /   0   0  10  20
LBL  97  59  72  50 /   0   0  10  20
HYS  93  63  70  51 /   0  20  30  10
P28  94  68  82  58 /   0  10  20  10

&&

.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...SUGDEN
AVIATION...SUGDEN







AREA FORECAST DISCUSSION...UPDATED

NWS DULUTH MN

 1050 AM CDT SAT MAY 5 2012

.UPDATE...
MOST OF THE RAIN HAS MOVED OUT OF THE AREA LATE THIS MORNING...SO
DECIDED TO REDUCED POPS...BEFORE THE NEXT ROUND OF SHOWERS MOVES
IN LATE THIS AFTERNOON AND THROUGH THE EVENING AND OVERNIGHT
HOURS TONIGHT. NO MAJOR CHANGES TO THE FORECAST AT THIS TIME. WILL
LOOK AT INCREASING THE WORDING FOR PERIODS OF HEAVY RAIN ACROSS
THE SOUTH TONIGHT AS MOST MODELS INDICATING A TIME OF 1-1.5 INCHES
OF PRECIP FROM AFTER MIDNIGHT THROUGH SUNDAY MORNING ACROSS THE
SRN HALF OF THE FORECAST AREA.

&&

.PREV DISCUSSION... /ISSUED 632 AM CDT SAT MAY 5 2012/

AVIATION...12Z TAFS.
A MIX OF VFR/MVFR CIGS INITIALLY WILL GIVE WAY TO MVFR FOR THE
REMAINDER OF THE TAF PERIOD. AFTER SOME MORNING SHOWERS NEAR THE
CANADIAN BORDER...ADDITIONAL SHOWER ACTIVITY SHOULD HOLD OFF UNTIL
AFTER 06Z WHEN SHOWERS AND THUNDERSTORMS WILL SPREAD ACROSS THE
TAF SITES. IFR/LIFR CIGS/VSBYS ARE POSSIBLE IN THE VCNTY OF
STRONGER STORMS.

PREV DISCUSSION... /ISSUED 620 AM CDT SAT MAY 5 2012/

UPDATE...

THE FOG THAT WAS FORECASTED TO DEVELOP THIS MORNING NEAR LAKE
SUPERIOR HAS NOT DEVELOPED. SINCE THE WINDS NEAR LAKE SUPERIOR ARE
AROUND 10 TO 20 MPH...WHICH IS RATHER STRONG FOR FOG
FORMATION...DEW POINT DEPRESSIONS ARE ABOUT 5 TO 10 DEGREES...AND
THERE IS NO CLEAR INDICATION OF THE FOG FORMING...DECIDED TO
REMOVE THE PATCHY FOG FROM THE MORNING FORECAST. ALSO...BASED ON
THE LATEST RADAR TRENDS...IT APPEARS MOST OF THE LINGERING SHOWERS
HAVE EITHER MOVED OUT OF THE FA OR DISSIPATED. MOST OF THE
REMAINING SHOWERS ARE IN THE NORTH CENTRAL FA...SO UPDATED THE
MORNING POPS AND WEATHER FORECAST TO REFLECT THIS.

PREV DISCUSSION... /ISSUED 333 AM CDT SAT MAY 5 2012/

SHORT TERM...[NOW - SUNDAY]...

CLOUDY AND COOLER THAN NORMAL WEATHER IS EXPECTED THROUGH SUNDAY
WITH CHANCES FOR PCPN...ESPECIALLY TONIGHT AND SUNDAY MORNING WHEN
LOW PRESSURE IN THE PLAINS MOVES EASTWARD INTO THE UPPER MIDWEST.

TODAY...HIGH PRESSURE WILL CONTINUE TO DOMINATE MANITOBA AND
ONTARIO...WHILE PRESSURE ORGANIZES IN THE CENTRAL PLAINS...AND A
MID/UPPER LEVEL TROUGH LIFTS THROUGH IDAHO AND MONTANA. RAIN
SHOWERS ASSOCIATED WITH MID LEVEL WARM AIR ADVECTION COULD LINGER
THROUGH THIS MORNING. LOWERED POPS ACROSS THE WESTERN FA SINCE IT
APPEARS MOST OF THE SHOWERS WILL BE LINGERING ACROSS THE EASTERN
FA. EASTERLY WINDS WILL CONTINUE TODAY...WITH THE STRONGEST WINDS
BETWEEN 10 AND 15 MPH NEAR THE TWIN PORTS AND ALONG THE LAKE
SUPERIOR SHORELINE DUE TO THE EXPECTED GUSTY WINDS OVER THE LAKE.
THE EASTERLY WINDS AND CLOUDY SKIES TODAY WILL RESULT IN COOLER
THAN NORMAL TEMPERATURES...ESPECIALLY NEAR THE TWIN PORTS.
INHERITED A FORECASTED FOR FOG AROUND LAKE SUPERIOR FOR THIS
MORNING...AND DECIDED TO KEEP THAT DUE TO THE EASTERLY WINDS OFF
THE LAKE AND THE HRRR SUGGESTING SOME FOG. THE MODELS ARE IN
REASONABLE AGREEMENT THAT THE LOW PRESSURE IN THE PLAINS WILL
ORGANIZE AND BEGIN TO MOVE EASTWARD THIS AFTERNOON AND BRING
SHOWERS TO THE SOUTHERN FA LATER THIS AFTERNOON.
THEREFORE...INCREASED POPS A BIT.

TONIGHT...THE MID/UPPER LEVEL TROUGH IN MONTANA WILL MOVE INTO
SOUTHERN SASKATCHEWAN AND DEVELOP A DISTINCT MID/UPPER LEVEL LOW.
AN ASSOCIATED SURFACE LOW WILL DEVELOP IN SOUTHERN
SASKATCHEWAN...WHILE A OCCLUDED FRONT MOVES THROUGH THE DAKOTAS
TOWARDS WESTERN MINNESOTA. THIS WILL RESULT IN A SURGE OF MOISTURE
OVER THE NORTHLAND WITH PRECIPITABLE WATER VALUES CLIMBING TO
AROUND 1.25 INCHES. THE MODELS ARE IN GOOD AGREEMENT WITH BRINGING
SIGNIFICANT RAINFALL TO THE NORTHLAND...SO INCREASED POPS. A GOOD
PORTION OF THE FA IS FORECASTED TO GET AROUND A QUARTER TO NEARLY
THREE QUARTERS OF A INCH OF RAINFALL WITH THE SOUTHWESTERN FA AT
THE HIGHEST END OF THE RANGE. NOT THRILLED ABOUT THE PROSPECTS OF
THUNDER...BUT SINCE THE MODELS SUGGEST SOME LIMITED MOST UNSTABLE
CAPE AND SLIGHTLY NEGATIVE LIFTED INDICES...FORECASTED ISOLATED
THUNDER ACROSS THE SOUTHERN FA.

SUNDAY...THE MID/UPPER LEVEL LOW WILL DRIFT TOWARDS SOUTHERN
MANITOBA...AND THE ASSOCIATED OCCLUDED FRONT WILL CONTINUE TO
APPROACH THE NORTHLAND. RAIN SHOWERS WILL PROBABLY CONTINUE ACROSS
THE FA...AT LEAST DURING THE MORNING. ANOTHER QUARTER TO THREE
QUARTERS OF AN INCH OF RAIN IS FORECASTED FOR MUCH OF THE
FA...WITH NORTHWESTERN WISCONSIN LIKELY GETTING THE HIGHEST
AMOUNTS. FORECASTED ISOLATED THUNDER ACROSS THE SOUTHERN FA DUE TO
THE MODELS SUGGESTING THE POSSIBILITY OF LIMITED INSTABILITY. THE
CLOUDY AND WET CONDITIONS WILL RESULT IN COOLER THAN NORMAL
TEMPERATURES.

LONG TERM...[SUNDAY NIGHT - FRIDAY]...

A CLOSED UPPER LOW WILL MEANDER ALONG THE CANADIAN BORDER FROM
SUNDAY NIGHT THROUGH MONDAY NIGHT. BY TUESDAY, THE LOW OPENS UP
INTO A LONG WAVE TROF AS IT DROPS THROUGH THE WESTERN GREAT
LAKES EXITING BY 12Z WEDNESDAY. THE RESULT IS A MENTION OF POPS
THROUGH TUESDAY NIGHT. UPPER LEVEL SFC RIDGING FOLLOWS BEHIND
WEDNESDAY INTO THURSDAY. THE UPPER RIDGING PERSISTS THURSDAY NIGHT
EVEN THOUGH THE SFC RIDGE DRIFTS OFF TO THE SE. THIS ALLOWS A WAA
REGIME TO ESTABLISH BRINGING THE CHANCE OF SHOWERS AND
THUNDERSTORMS INTO THE FA THURSDAY NIGHT. MODELS DISAGREE WITH THE
TIMING OF PCPN AND HAVE USED A MODEL BLEND. A COLD FRONT BEGINS TO
MARCH THROUGH THE FA LATE THURSDAY NIGHT AND FRIDAY WITH MORE
SHOWERS POSSIBLE.

AVIATION...06Z TAF ISSUANCE...

SHOWERS HAVE INCREASED OVER THE PAST COUPLE HOURS OVER THE
NORTHLAND...AND LOWER CEILINGS WERE DEVELOPING OVER CENTRAL
MINNESOTA. THESE MVFR CEILINGS WERE MOVING QUICKLY NORTH...AND
SHOULD REACH KBRD AROUND OR SHORTLY AFTER 06Z...AND THE REST OF
THE TAF SITES BETWEEN 07Z-09Z. CEILINGS SHOULD LOWER TO IFR IN
MANY AREAS LATE TONIGHT INTO EARLY SATURDAY MORNING...THEN REMAIN
AT IFR/MVFR THROUGH THE REST OF THE PERIOD.

&&

.POINT TEMPS/POPS...
DLH  48  39  44  40 /  20  80  80  50
INL  55  40  53  42 /  20  60  50  40
BRD  58  47  56  43 /  30  80  60  30
HYR  58  45  58  45 /  10  70  80  60
ASX  56  40  52  43 /  10  60  80  60

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 AM CDT SUNDAY FOR LSZ121-142>148.

&&

$$

SHORT TERM...TENTINGER






AREA FORECAST DISCUSSION

NWS DULUTH MN

 632 AM CDT SAT MAY 5 2012

.AVIATION...12Z TAFS.
A MIX OF VFR/MVFR CIGS INITIALLY WILL GIVE WAY TO MVFR FOR THE
REMAINDER OF THE TAF PERIOD. AFTER SOME MORNING SHOWERS NEAR THE
CANADIAN BORDER...ADDITIONAL SHOWER ACTIVITY SHOULD HOLD OFF UNTIL
AFTER 06Z WHEN SHOWERS AND THUNDERSTORMS WILL SPREAD ACROSS THE
TAF SITES. IFR/LIFR CIGS/VSBYS ARE POSSIBLE IN THE VCNTY OF
STRONGER STORMS.

&&

.PREV DISCUSSION... /ISSUED 620 AM CDT SAT MAY 5 2012/

UPDATE...

THE FOG THAT WAS FORECASTED TO DEVELOP THIS MORNING NEAR LAKE
SUPERIOR HAS NOT DEVELOPED. SINCE THE WINDS NEAR LAKE SUPERIOR ARE
AROUND 10 TO 20 MPH...WHICH IS RATHER STRONG FOR FOG
FORMATION...DEW POINT DEPRESSIONS ARE ABOUT 5 TO 10 DEGREES...AND
THERE IS NO CLEAR INDICATION OF THE FOG FORMING...DECIDED TO
REMOVE THE PATCHY FOG FROM THE MORNING FORECAST. ALSO...BASED ON
THE LATEST RADAR TRENDS...IT APPEARS MOST OF THE LINGERING SHOWERS
HAVE EITHER MOVED OUT OF THE FA OR DISSIPATED. MOST OF THE
REMAINING SHOWERS ARE IN THE NORTH CENTRAL FA...SO UPDATED THE
MORNING POPS AND WEATHER FORECAST TO REFLECT THIS.

PREV DISCUSSION... /ISSUED 333 AM CDT SAT MAY 5 2012/

SHORT TERM...[NOW - SUNDAY]...

CLOUDY AND COOLER THAN NORMAL WEATHER IS EXPECTED THROUGH SUNDAY
WITH CHANCES FOR PCPN...ESPECIALLY TONIGHT AND SUNDAY MORNING WHEN
LOW PRESSURE IN THE PLAINS MOVES EASTWARD INTO THE UPPER MIDWEST.

TODAY...HIGH PRESSURE WILL CONTINUE TO DOMINATE MANITOBA AND
ONTARIO...WHILE PRESSURE ORGANIZES IN THE CENTRAL PLAINS...AND A
MID/UPPER LEVEL TROUGH LIFTS THROUGH IDAHO AND MONTANA. RAIN
SHOWERS ASSOCIATED WITH MID LEVEL WARM AIR ADVECTION COULD LINGER
THROUGH THIS MORNING. LOWERED POPS ACROSS THE WESTERN FA SINCE IT
APPEARS MOST OF THE SHOWERS WILL BE LINGERING ACROSS THE EASTERN
FA. EASTERLY WINDS WILL CONTINUE TODAY...WITH THE STRONGEST WINDS
BETWEEN 10 AND 15 MPH NEAR THE TWIN PORTS AND ALONG THE LAKE
SUPERIOR SHORELINE DUE TO THE EXPECTED GUSTY WINDS OVER THE LAKE.
THE EASTERLY WINDS AND CLOUDY SKIES TODAY WILL RESULT IN COOLER
THAN NORMAL TEMPERATURES...ESPECIALLY NEAR THE TWIN PORTS.
INHERITED A FORECASTED FOR FOG AROUND LAKE SUPERIOR FOR THIS
MORNING...AND DECIDED TO KEEP THAT DUE TO THE EASTERLY WINDS OFF
THE LAKE AND THE HRRR SUGGESTING SOME FOG. THE MODELS ARE IN
REASONABLE AGREEMENT THAT THE LOW PRESSURE IN THE PLAINS WILL
ORGANIZE AND BEGIN TO MOVE EASTWARD THIS AFTERNOON AND BRING
SHOWERS TO THE SOUTHERN FA LATER THIS AFTERNOON.
THEREFORE...INCREASED POPS A BIT.

TONIGHT...THE MID/UPPER LEVEL TROUGH IN MONTANA WILL MOVE INTO
SOUTHERN SASKATCHEWAN AND DEVELOP A DISTINCT MID/UPPER LEVEL LOW.
AN ASSOCIATED SURFACE LOW WILL DEVELOP IN SOUTHERN
SASKATCHEWAN...WHILE A OCCLUDED FRONT MOVES THROUGH THE DAKOTAS
TOWARDS WESTERN MINNESOTA. THIS WILL RESULT IN A SURGE OF MOISTURE
OVER THE NORTHLAND WITH PRECIPITABLE WATER VALUES CLIMBING TO
AROUND 1.25 INCHES. THE MODELS ARE IN GOOD AGREEMENT WITH BRINGING
SIGNIFICANT RAINFALL TO THE NORTHLAND...SO INCREASED POPS. A GOOD
PORTION OF THE FA IS FORECASTED TO GET AROUND A QUARTER TO NEARLY
THREE QUARTERS OF A INCH OF RAINFALL WITH THE SOUTHWESTERN FA AT
THE HIGHEST END OF THE RANGE. NOT THRILLED ABOUT THE PROSPECTS OF
THUNDER...BUT SINCE THE MODELS SUGGEST SOME LIMITED MOST UNSTABLE
CAPE AND SLIGHTLY NEGATIVE LIFTED INDICES...FORECASTED ISOLATED
THUNDER ACROSS THE SOUTHERN FA.

SUNDAY...THE MID/UPPER LEVEL LOW WILL DRIFT TOWARDS SOUTHERN
MANITOBA...AND THE ASSOCIATED OCCLUDED FRONT WILL CONTINUE TO
APPROACH THE NORTHLAND. RAIN SHOWERS WILL PROBABLY CONTINUE ACROSS
THE FA...AT LEAST DURING THE MORNING. ANOTHER QUARTER TO THREE
QUARTERS OF AN INCH OF RAIN IS FORECASTED FOR MUCH OF THE
FA...WITH NORTHWESTERN WISCONSIN LIKELY GETTING THE HIGHEST
AMOUNTS. FORECASTED ISOLATED THUNDER ACROSS THE SOUTHERN FA DUE TO
THE MODELS SUGGESTING THE POSSIBILITY OF LIMITED INSTABILITY. THE
CLOUDY AND WET CONDITIONS WILL RESULT IN COOLER THAN NORMAL
TEMPERATURES.

LONG TERM...[SUNDAY NIGHT - FRIDAY]...

A CLOSED UPPER LOW WILL MEANDER ALONG THE CANADIAN BORDER FROM
SUNDAY NIGHT THROUGH MONDAY NIGHT. BY TUESDAY, THE LOW OPENS UP
INTO A LONG WAVE TROF AS IT DROPS THROUGH THE WESTERN GREAT
LAKES EXITING BY 12Z WEDNESDAY. THE RESULT IS A MENTION OF POPS
THROUGH TUESDAY NIGHT. UPPER LEVEL SFC RIDGING FOLLOWS BEHIND
WEDNESDAY INTO THURSDAY. THE UPPER RIDGING PERSISTS THURSDAY NIGHT
EVEN THOUGH THE SFC RIDGE DRIFTS OFF TO THE SE. THIS ALLOWS A WAA
REGIME TO ESTABLISH BRINGING THE CHANCE OF SHOWERS AND
THUNDERSTORMS INTO THE FA THURSDAY NIGHT. MODELS DISAGREE WITH THE
TIMING OF PCPN AND HAVE USED A MODEL BLEND. A COLD FRONT BEGINS TO
MARCH THROUGH THE FA LATE THURSDAY NIGHT AND FRIDAY WITH MORE
SHOWERS POSSIBLE.

AVIATION...06Z TAF ISSUANCE...

SHOWERS HAVE INCREASED OVER THE PAST COUPLE HOURS OVER THE
NORTHLAND...AND LOWER CEILINGS WERE DEVELOPING OVER CENTRAL
MINNESOTA. THESE MVFR CEILINGS WERE MOVING QUICKLY NORTH...AND
SHOULD REACH KBRD AROUND OR SHORTLY AFTER 06Z...AND THE REST OF
THE TAF SITES BETWEEN 07Z-09Z. CEILINGS SHOULD LOWER TO IFR IN
MANY AREAS LATE TONIGHT INTO EARLY SATURDAY MORNING...THEN REMAIN
AT IFR/MVFR THROUGH THE REST OF THE PERIOD.

&&

.POINT TEMPS/POPS...
DLH  49  39  47  40 /  20  70  70  50
INL  56  41  54  42 /  30  50  50  40
BRD  61  47  60  43 /  30  80  60  30
HYR  59  45  60  45 /  20  70  70  60
ASX  50  41  52  43 /  20  60  70  60

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 AM CDT SUNDAY FOR LSZ121-142>148.

&&

$$

AVIATION...GSF






AREA FORECAST DISCUSSION...UPDATED

NWS DULUTH MN

 620 AM CDT SAT MAY 5 2012

.UPDATE...

THE FOG THAT WAS FORECASTED TO DEVELOP THIS MORNING NEAR LAKE
SUPERIOR HAS NOT DEVELOPED. SINCE THE WINDS NEAR LAKE SUPEIOR ARE
AROUND 10 TO 20 MPH...WHICH IS RATHER STRONG FOR FOG
FORMATION...DEW POINT DEPRESSIONS ARE ABOUT 5 TO 10 DEGREES...AND
THERE IS NO CLEAR INIDCATION OF THE FOG FORMING...DECIDED TO
REMOVE THE PATCHY FOG FROM THE MORNING FORECAST. ALSO...BASED ON
THE LATEST RADAR TRENDS...IT APPEARS MOST OF THE LINGERING SHOWERS
HAVE EITHER MOVED OUT OF THE FA OR DISSIPATED. MOST OF THE
REMAINING SHOWERS ARE IN THE NORTH CENTRAL FA...SO UPDATED THE
MORNING POPS AND WEATHER FORECAST TO REFLECT THIS.

&&

.PREV DISCUSSION... /ISSUED 333 AM CDT SAT MAY 5 2012/

SHORT TERM...[NOW - SUNDAY]...

CLOUDY AND COOLER THAN NORMAL WEATHER IS EXPECTED THROUGH SUNDAY
WITH CHANCES FOR PCPN...ESPECIALLY TONIGHT AND SUNDAY MORNING WHEN
LOW PRESSURE IN THE PLAINS MOVES EASTWARD INTO THE UPPER MIDWEST.

TODAY...HIGH PRESSURE WILL CONTINUE TO DOMINATE MANITOBA AND
ONTARIO...WHILE PRESSURE ORGANIZES IN THE CENTRAL PLAINS...AND A
MID/UPPER LEVEL TROUGH LIFTS THROUGH IDAHO AND MONTANA. RAIN
SHOWERS ASSOCIATED WITH MID LEVEL WARM AIR ADVECTION COULD LINGER
THROUGH THIS MORNING. LOWERED POPS ACROSS THE WESTERN FA SINCE IT
APPEARS MOST OF THE SHOWERS WILL BE LINGERING ACROSS THE EASTERN
FA. EASTERLY WINDS WILL CONTINUE TODAY...WITH THE STRONGEST WINDS
BETWEEN 10 AND 15 MPH NEAR THE TWIN PORTS AND ALONG THE LAKE
SUPERIOR SHORELINE DUE TO THE EXPECTED GUSTY WINDS OVER THE LAKE.
THE EASTERLY WINDS AND CLOUDY SKIES TODAY WILL RESULT IN COOLER
THAN NORMAL TEMPERATURES...ESPECIALLY NEAR THE TWIN PORTS.
INHERITED A FORECASTED FOR FOG AROUND LAKE SUPERIOR FOR THIS
MORNING...AND DECIDED TO KEEP THAT DUE TO THE EASTERLY WINDS OFF
THE LAKE AND THE HRRR SUGGESTING SOME FOG. THE MODELS ARE IN
REASONABLE AGREEMENT THAT THE LOW PRESSURE IN THE PLAINS WILL
ORGANIZE AND BEGIN TO MOVE EASTWARD THIS AFTERNOON AND BRING
SHOWERS TO THE SOUTHERN FA LATER THIS AFTERNOON.
THEREFORE...INCREASED POPS A BIT.

TONIGHT...THE MID/UPPER LEVEL TROUGH IN MONTANA WILL MOVE INTO
SOUTHERN SASKATCHEWAN AND DEVELOP A DISTINCT MID/UPPER LEVEL LOW.
AN ASSOCIATED SURFACE LOW WILL DEVELOP IN SOUTHERN
SASKATCHEWAN...WHILE A OCCLUDED FRONT MOVES THROUGH THE DAKOTAS
TOWARDS WESTERN MINNESOTA. THIS WILL RESULT IN A SURGE OF MOISTURE
OVER THE NORTHLAND WITH PRECIPITABLE WATER VALUES CLIMBING TO
AROUND 1.25 INCHES. THE MODELS ARE IN GOOD AGREEMENT WITH BRINGING
SIGNIFICANT RAINFALL TO THE NORTHLAND...SO INCREASED POPS. A GOOD
PORTION OF THE FA IS FORECASTED TO GET AROUND A QUARTER TO NEARLY
THREE QUARTERS OF A INCH OF RAINFALL WITH THE SOUTHWESTERN FA AT
THE HIGHEST END OF THE RANGE. NOT THRILLED ABOUT THE PROSPECTS OF
THUNDER...BUT SINCE THE MODELS SUGGEST SOME LIMITED MOST UNSTABLE
CAPE AND SLIGHTLY NEGATIVE LIFTED INDICES...FORECASTED ISOLATED
THUNDER ACROSS THE SOUTHERN FA.

SUNDAY...THE MID/UPPER LEVEL LOW WILL DRIFT TOWARDS SOUTHERN
MANITOBA...AND THE ASSOCIATED OCCLUDED FRONT WILL CONTINUE TO
APPROACH THE NORTHLAND. RAIN SHOWERS WILL PROBABLY CONTINUE ACROSS
THE FA...AT LEAST DURING THE MORNING. ANOTHER QUARTER TO THREE
QUARTERS OF AN INCH OF RAIN IS FORECASTED FOR MUCH OF THE
FA...WITH NORTHWESTERN WISCONSIN LIKELY GETTING THE HIGHEST
AMOUNTS. FORECASTED ISOLATED THUNDER ACROSS THE SOUTHERN FA DUE TO
THE MODELS SUGGESTING THE POSSIBILITY OF LIMITED INSTABILITY. THE
CLOUDY AND WET CONDITIONS WILL RESULT IN COOLER THAN NORMAL
TEMPERATURES.

LONG TERM...[SUNDAY NIGHT - FRIDAY]...

A CLOSED UPPER LOW WILL MEANDER ALONG THE CANADIAN BORDER FROM
SUNDAY NIGHT THROUGH MONDAY NIGHT. BY TUESDAY, THE LOW OPENS UP
INTO A LONG WAVE TROF AS IT DROPS THROUGH THE WESTERN GREAT
LAKES EXITING BY 12Z WEDNESDAY. THE RESULT IS A MENTION OF POPS
THROUGH TUESDAY NIGHT. UPPER LEVEL SFC RIDGING FOLLOWS BEHIND
WEDNESDAY INTO THURSDAY. THE UPPER RIDGING PERSISTS THURSDAY NIGHT
EVEN THOUGH THE SFC RIDGE DRIFTS OFF TO THE SE. THIS ALLOWS A WAA
REGIME TO ESTABLISH BRINGING THE CHANCE OF SHOWERS AND
THUNDERSTORMS INTO THE FA THURSDAY NIGHT. MODELS DISAGREE WITH THE
TIMING OF PCPN AND HAVE USED A MODEL BLEND. A COLD FRONT BEGINS TO
MARCH THROUGH THE FA LATE THURSDAY NIGHT AND FRIDAY WITH MORE
SHOWERS POSSIBLE.

AVIATION...06Z TAF ISSUANCE...

SHOWERS HAVE INCREASED OVER THE PAST COUPLE HOURS OVER THE
NORTHLAND...AND LOWER CEILINGS WERE DEVELOPING OVER CENTRAL
MINNESOTA. THESE MVFR CEILINGS WERE MOVING QUICKLY NORTH...AND
SHOULD REACH KBRD AROUND OR SHORTLY AFTER 06Z...AND THE REST OF
THE TAF SITES BETWEEN 07Z-09Z. CEILINGS SHOULD LOWER TO IFR IN
MANY AREAS LATE TONIGHT INTO EARLY SATURDAY MORNING...THEN REMAIN
AT IFR/MVFR THROUGH THE REST OF THE PERIOD.

&&

.POINT TEMPS/POPS...
DLH  49  39  47  40 /  20  70  70  50
INL  56  41  54  42 /  30  50  50  40
BRD  61  47  60  43 /  30  80  60  30
HYR  59  45  60  45 /  20  70  70  60
ASX  50  41  52  43 /  20  60  70  60

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 AM CDT SUNDAY FOR LSZ121-142>148.

&&

$$

SHORT TERM...GROCHOCINSKI
LONG TERM....GSF







AREA FORECAST DISCUSSION

NWS LINCOLN IL

 1258 PM CDT SAT MAY 5 2012

.DISCUSSION...
ISSUED 1044 AM CDT SAT MAY 5 2012

FRONTAL BOUNDARY HAS DROPPED SOUTHWARD AND BECOME STATIONARY FROM
NORTHERN MISSOURI INTO SOUTH-CENTRAL ILLINOIS THIS MORNING.
SURFACE DEWPOINTS TO THE NORTH OF THE FRONT HAVE DROPPED INTO
THE LOWER 60S ACROSS MUCH OF THE KILX CWA...WHILE UPPER 60S/LOWER
70S DEWPOINTS POOL NEAR THE BOUNDARY. 12 NAM MAINTAINS A DRY
FORECAST THROUGHOUT THE DAY...HOWEVER THE LATEST HRRR SUGGESTS
WIDELY SCATTERED STORMS FIRING FROM NEAR QUINCY E/SE TO
LAWRENCEVILLE THIS AFTERNOON. GIVEN PRESENCE OF WEAK FORCING
MECHANISM...THINK SLIGHT CHANCE POPS ACROSS THE S/SE CWA LOOK
GOOD. 15Z TEMPS ARE MAINLY IN THE LOWER TO MIDDLE 70S...BUT ARE
HOLDING IN THE LOWER 60S NORTH OF PEORIA AND BLOOMINGTON WHERE
EARLY MORNING FOG HAS LIFTED INTO A LOW OVERCAST. THINK CLOUDS
WILL GRADUALLY DISSIPATE ACROSS THE NORTH...WITH PARTLY SUNNY
SKIES EXPECTED ACROSS THE BOARD THIS AFTERNOON. DUE TO THE COOL
START AND A CONTINUED E/NE BREEZE TO THE NORTH OF THE FRONT...HAVE
LOWERED HIGH TEMPS BY A COUPLE OF DEGREES. READINGS WILL REMAIN IN
THE UPPER 70S ACROSS THE FAR NORTH AROUND HENRY AND LACON...BUT
WILL STILL REACH THE MIDDLE 80S ACROSS THE S/SE CWA. ZONE UPDATE
HAS ALREADY BEEN ISSUED.



&&

.AVIATION...
ISSUED 1258 PM CDT SAT MAY 5 2012

VFR CONDITIONS WILL PREVAIL THROUGH THE ENTIRE 18Z TAF PERIOD.
LIGHT EASTERLY WINDS THIS AFTERNOON WILL GRADUALLY BECOME
SOUTHEASTERLY TONIGHT INTO SUNDAY. DUE TO A VERY MOIST LOW-LEVEL
AIRMASS AND RELATIVELY LIGHT WINDS...PATCHY FOG WILL DEVELOP
AT THE TERMINALS OVERNIGHT. WILL LOWER VISBYS TO AROUND 3SM AFTER
09Z ACCORDINGLY. ANY FOG WILL RAPIDLY DISSIPATE SUNDAY
MORNING...FOLLOWED BY MOSTLY CLEAR CONDITIONS.

BARNES
&&

.PREV DISCUSSION...
ISSUED 257 AM CDT SAT MAY 5 2012

FRONTAL BOUNDARY ROUGHLY ALONG A LINE FROM BURLINGTON TO TERRE
HAUTE EARLY THIS MORNING. HAVE HAD WAVES OF THUNDERSTORMS
DEVELOPING ALONG THE SOUTHERN EDGES OF THE FORECAST AREA THE LAST
FEW HOURS...PRODUCING SOME PERIODIC HAIL. TEMPERATURES NORTH OF
THE FRONT HAVE FALLEN INTO THE 50S FROM ABOUT PEORIA TO DANVILLE
NORTHWARD...ACCOMPANIED BY A LARGE AREA OF LOW STRATUS CLOUDS WHICH
COVER ABOUT THE NORTHEAST THIRD OF THE STATE.

THE ACTIVE WEATHER PATTERN WILL CONTINUE FOR A COUPLE MORE DAYS.
THE MAIN FORECAST FOCUS IS WITH POTENTIAL FOR SEVERE WEATHER
SUNDAY AFTERNOON AND NIGHT...AND TIMING OF THE ENDING FOR THE RAIN
ON MONDAY.

SHORT TERM...TODAY THROUGH MONDAY...

WILL MONITOR CURRENT CONVECTION UP UNTIL THE LAST MINUTE...BUT IT
CURRENTLY APPEARS THIS SHOULD LARGELY BE OUT OF THE FORECAST AREA
BY ISSUANCE TIME. AS IS TYPICAL IN SUCH PATTERNS...POTENTIAL FOR
ANY CONVECTIVE REDEVELOPMENT TODAY WILL DEPEND ON THE SETUP OF ANY
RESIDUAL BOUNDARIES FROM THE OVERNIGHT STORMS. HIGH-RESOLUTION
MODELS APPEAR TO FOCUS THE BEST CHANCES JUST TO OUR SOUTH THIS
AFTERNOON. WILL INCLUDE SOME SLIGHT CHANCES OF RAIN SOUTHEAST OF A
RUSHVILLE TO MATTOON LINE THIS AFTERNOON AND EVENING.

THE FRONTAL BOUNDARY IS EXPECTED TO RETREAT NORTHWARD OVERNIGHT...
AS A WAVE OF LOW PRESSURE DEVELOPS OVER SOUTHWEST MINNESOTA. MOST
OF THE EVENING MODELS ARE SIMILAR IN THE EVOLUTION...ALTHOUGH THE
NAM IS MUCH MORE PROGRESSIVE AND HAS THE TRAILING COLD FRONT
THROUGH THE AREA BY SUNDAY EVENING. THINK THIS IS A BIT TOO FAST
AND WILL LEAN TOWARD THE SLOWER SOLUTIONS OF THE OTHER MODELS...
WHICH DO NOT FULLY BRING THE FRONT THROUGH UNTIL MONDAY AFTERNOON.
MAIN CONCERN IS SUNDAY AFTERNOON AND EVENING...AS MUCAPES RISE TO
OVER 3500 J/KG BY AFTERNOON. LATEST DAY2 OUTLOOK FROM SPC HAS A
SLIGHT RISK OF SEVERE WEATHER BUT WITH ENHANCED POTENTIAL FOR
LARGE HAIL. AREAS ALONG AND WEST OF I-55 MOST LIKELY TO SEE ANY
DEVELOPMENT DURING THE AFTERNOON...WITH THE THREAT SHIFTING EAST
DURING THE EVENING. MAIN SEVERE THREAT BY MONDAY MORNING SHOULD
MAINLY BE TO OUR SOUTHEAST...BUT MAY STILL SEE SOME ISOLATED
STRONG/SEVERE STORMS ACROSS THE EASTERN CWA EARLY. ANY LINGERING
RAIN SHOULD DIMINISH EARLY MONDAY EVENING.

HAVE NOT MADE MUCH CHANGE TO THE TEMPERATURE FORECAST FOR THIS
WEEKEND...WITH HIGHS WELL INTO THE 80S OVER THE AREA.

LONG TERM...TUESDAY THROUGH FRIDAY...

SMALL UPPER LOW WHICH WILL DEVELOP OVER MONTANA THIS WEEKEND IS
PROGGED TO MOVE TO THE MINNESOTA/ONTARIO BORDER BY TUESDAY
MORNING...BEFORE OPENING UP INTO A WAVE. WILL LIKELY SEE SOME
WRAPAROUND SHOWERS OVER PORTIONS OF THE UPPER MIDWEST TUESDAY AND
WEDNESDAY. CURRENT INDICATIONS KEEP THE BULK OF THESE TO OUR
NORTH AND NORTHEAST...BUT HAVE INCLUDED SOME SLIGHT CHANCES ACROSS
THE NORTHEAST THIRD OF THE CWA LATE TUESDAY NIGHT AND WEDNESDAY.
HIGH PRESSURE SETTLING INTO THE MIDWEST WILL PROVIDE FAIR WEATHER
THE REMAINDER OF THE WORK WEEK. AFTER A RELATIVELY COOL PERIOD
WEDNESDAY AND THURSDAY...TEMPERATURES WILL BEGIN TO REBOUND BY THE
END OF THE WEEK.

GEELHART


&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$








AREA FORECAST DISCUSSION

NWS INDIANAPOLIS IN

 1230 PM EDT SAT MAY 5 2012

.UPDATE...

THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 253 AM EDT SAT MAY 5 2012

A FRONTAL BOUNDARY WILL LINGER NEAR THE OHIO RIVER TODAY AND
SUNDAY AS A RIDGE OF HIGH PRESSURE BUILDS ALOFT. THIS WILL RESULT IN
MOSTLY DRY WEATHER TODAY THROUGH SUNDAY.

AN AREA OF LOW PRESSURE WILL APPROACH CENTRAL INDIANA ON
SUNDAY NIGHT AND MONDAY AND THIS WILL PUSH THE FRONTAL BOUNDARY
BACK NORTH ACROSS CENTRAL INDIANA. SHOWERS AND THUNDERSTORMS ARE
EXPECTED TO ACCOMPANY THE FRONT AS IT PUSHES NORTH AND AS THE LOW
PRESSURE SYSTEM PASSES ON MONDAY.

A FEW SHOWERS WILL BE POSSIBLE ON TUESDAY NIGHT AND WEDNESDAY AS
AN AREA OF BROAD LOW PRESSURE PUSHES THROUGH THE GREAT LAKES...BUT
THE END OF THE WORK WEEK LOOKS COOL AND DRY AS HIGH PRESSURE
BUILDS ACROSS THE CENTRAL PLAINS.

&&

.NEAR TERM /TODAY/...
ISSUED AT 1000 AM EDT SAT MAY 5 2012

HAD TO INCREASE CLOUD COVER ACROSS OUR NORTHERN THIRD OF COUNTIES
BASED ON SATELLITE AND OBSERVATIONS. NAM12 AND RUC SOUNDINGS SUGGEST
THE INVERSION WILL BREAK AROUND NOON OR SHORTLY AFTER. THEN...EXPECT
SCATTERED TO BROKEN DIURNAL CU PER THE CU RULE. DUE TO THE
CLOUDS...HAD TO LOWER THE TEMPERATURES THROUGH MID DAY ACROSS
ESPECIALLY THE NORTH BUT TO A LESSER DEGREE THE SOUTH BASED ON
OBSERVATIONAL TRENDS. STILL THINK MAX TEMPERATURES ARE
ATTAINABLE...HOWEVER WITH AT LEAST SOME AFTERNOON SUN.

PREVIOUS DISCUSSION FOLLOWS...

MAIN FORECAST CHALLENGE TODAY WILL BE TEMPS.

SURFACE ANALYSIS EARLY THIS MORNING SHOWS A FRONTAL BOUNDARY
STRETCHING ACROSS SOUTHERN ILLINOIS TO SOUTHWEST INDIANA AND
NORTHERN KENTUCKY. SHRA AND TSRA WERE LINGERING ALONG THE
FRONT...BUT WERE STILL DRIVING SOUTHEAST. COOLER HIGH PRESSURE WAS
FOUND ACROSS THE GREAT LAKES...PROVIDING COOL NORTHEAST WINDS TO
CENTRAL INDIANA.

FORECAST SOUNDINGS TODAY INDICATE A WEAK CAP IN PLACE AS THE GFS
AND NAM BOTH SUGGEST RIDGING BUILDING ACROSS THE
AREA...FURTHERMORE THE SURFACE HIGH TO THE NORTH WILL CONTINUE TO
PROVIDE DRY EAST TO NORTHEAST FLOW. CU RULE SUGGESTS SCT-BKN
CU...THUS PTCLDY WILL WORK FINE ACROSS THE AREA. GIVEN THE
EXPECTED 850MB TEMPS...A BLEND OF MAVMOS AND METMOS LOOKS ON THE
MARK FOR HIGHS.

&&

.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
ISSUED AT 253 AM EDT SAT MAY 5 2012

MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE POPS ON SUNDAY
NIGHT. GFS/NAM AND ECMWF ARE IN PRETTY GOOD AGREEMENT UNTIL SUNDAY
NIGHT...AS AT THAT TIME THE NAM IS QUICKER WITH THE ADVANCING
SYSTEM. FOR NOW WILL LEAN CLOSER TO THE GFS/ECMWF SOLUTION GIVEN
THE RIDGING ALOFT AND THE EASTERLY FLOW THAT IS EXPECTED TO
PERSIST PRIOR TO THE ARRIVAL OF THE FRONT AND LOW.

LITTLE CHANGE FROM TODAY IS EXPECTED FOR TONIGHT AND SUNDAY AS THE
FRONTAL BOUNDARY IS EXPECTED TO CONTINUE TO LINGER NEAR THE OHIO
RIVER AS RIDGING BUILDS ALOFT...AND HIGH PRESSURE SLOWLY MOVING
THROUGH THE GREAT LAKES CONTINUES TO PROVIDE A COOLER EASTERLY
FLOW. FURTHERMORE FORECAST SOUNDINGS CONTINUE TO INDICATE A
RELATIVELY DRY COLUMN...THUS PTCLDY SHOULD CONTINUE TO WORK WELL.
GIVEN THE EXPECTED 850MB TEMPS...A BLEND OF THE MAVMOS AND METMOS
WILL WORK FOR TONIGHTS LOW AND SUNDAY HIGHS.

ON SUNDAY NIGHT THE NAM WISHES TO BRING THE WARM FRONT FARTHER
NORTH...WHILE THE GFS AND ECMWF KEEP IT FARTHER SOUTH. GIVEN THE
STRENGTH OF THE HIGH IN PLACE...THE TREND OF THE SLOWER GFS AND
ECMWF IS PREFERRED. FURTHER SUPPORTING THIS IS FORECAST SOUNDINGS
THAT FAIL TO SHOW DEEP MOISTURE OR STRONG FORCING UNTIL MONDAY.
THIS WILL TREND TOWARD INCREASING CLOUDS ON SUNDAY NIGHT ALONG
WITH THE LESS WET MAVMOS POPS...FOCUSED LATE IN THE PERIOD. GIVEN
THE EXPECTED CLOUD COVER WILL TREND SUNDAY NIGHT LOWS WARMER THAN
MAVMOS.

GFS AND ECMWF PUSH A SHORT WAVE OUT OF THE MISSISSIPPI VALLEY ON
MONDAY...PUSHING STRONG DYNAMICS ACROSS INDIANA. THIS SHOULD ALSO
HELP TO PULL THE LINGERING FRONTAL BOUNDARY NEAR THE OHIO RIVER
BACK NORTH AS A WARM FRONT...ADDING TO THE AVAILABLE FORCING. TIME
HEIGHT SECTIONS INDICATE DEEP MOISTURE IS AVAILABLE AS FORECAST
SOUNDINGS REMAIN SATURATED. THUS GIVEN THE FORCING AND MOISTURE
WILL TREND POPS HIGHER THAN MAVMOS AND TREND HIGH TEMPERATURES
COOLER...GIVEN THE EXPECTED CLOUDS...RAIN AND TSRA.

SHORT WAVE DEPARTS ON MONDAY NIGHT...AND AS FORCING IS LOST PRECIP
IS EXPECTED TO END AS DEEP MOISTURE IS LOST. COLD AIR ADVECTION IS
EXPECTED TO BEGIN BY 12Z TUESDAY AS A COLD FRONT IS PUSHED ACROSS
THE STATE IN THE WAKE OF THE LOW. WILL NEED TO CARRY SOME POPS
FOR EARLY MONDAY NIGHT AS TIMING OF THE DEPARTURE OF THE SYSTEM
WILL STILL BE RATHER VARIABLE AT THIS TIME AND MAY EASILY GET
ADJUSTED BACK OR FORTH A FEW HOURS IN LATTER FORECAST RUNS. WILL
TREND LOWS COOLER THAN MEXMOS

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 253 AM EDT SAT MAY 5 2012

MAIN FEATURES OF NOTE FOR THE LONG TERM ARE A COLD FRONT WHICH WILL
BE JUST OUT OF THE AREA EARLY TUESDAY MORNING...FOLLOWED QUICKLY BY
AN UPPER TROUGH WEDNESDAY. HIGH PRESSURE BUILDS IN QUICKLY WEDNESDAY
EVENING...WHICH WILL ALLOW A DRY FORECAST FOR THE REMAINDER OF THE
PERIOD.

LITTLE TO QUIBBLE ABOUT ON THESE FEATURES AS MODELS ARE IN DECENT
AGREEMENT WITH ONLY TYPICAL MINOR TIMING AND STRENGTH DIFFERENCES AT
THOSE TIME SCALES. ALLBLEND CAPTURES THESE FEATURES WELL AND NO
MAJOR DEVIATIONS REQUIRED.

ANY PRECIP FALLING TUESDAY NIGHT AND WEDNESDAY WITH THE UPPER TROUGH
AXIS WILL BE SHOWERY IN NATURE...AND THUNDERSTORMS SHOULD NOT BE AN
ISSUE.

DEPENDING ON THE AMOUNT OF CLOUD COVER...MAX TEMPS FROM
INITIALIZATION MAY BE A BIT TOO WARM WEDNESDAY AND THURSDAY...BUT
THIS WOULD BE BY ONLY A FEW DEGREES. SOME AREAS MAY STRUGGLE TO GET
OUT OF THE 50S AROUND MID WEEK.

&&

.AVIATION /DISCUSSION FOR THE 051800Z TAFS/...
ISSUED AT 1230 PM EDT SAT MAY 5 2012

IFR DECK EXTENDING FROM NORTH OF KIND INTO THE KLAF AREA HAS BEEN
ERODING FROM SOUTH. SHOULD CLEAR THE KLAF TERMINAL BY ISSUANCE TIME.

LOW LEVEL LAPSE RATES REMAIN RATHER STEEP THROUGH THE MIDDAY
HOURS...BUT SHORT TERM MODEL DATA SLACKEN THESE OFF LATER IN THE
AFTERNOON. AS A RESULT...MAY SEE SOME PERIODS OF MVFR CEILINGS
020-025 EARLY THIS AFTERNOON ON THE SOUTHERN END OF THE RETREATING
IFR DECK IN THE KIND/KLAF AREAS.

OTHERWISE...DIFFUSE FRONTAL SYSTEM APPEARS TO BE LOCATED OVER
SOUTHWEST INDIANA IN THE VICINITY OF KHUF/KBMG. MODERATE AMOUNTS OF
INSTABILITY EXIST ALONG/SOUTH OF THIS FRONT...ALTHOUGH THE HIGHEST
INSTABILITY HAS BEEN SHOVED WELL TO THE SOUTHWEST ALONG AN OUTFLOW
BOUNDARY. MAY SEE SOME WIDELY SCATTERED CONVECTION DEVELOP NEAR THE
FRONT THIS AFTERNOON...BUT ANYTHING THAT DEVELOPS SHOULD STAY TO THE
SOUTHWEST OF KHUF/KBMG.

NO WIND OR VISIBILITY ISSUES EXPECTED THROUGH THIS EVENING.

&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SYNOPSIS...PUMA
NEAR TERM...PUMA/MK
SHORT TERM...PUMA
LONG TERM....NIELD
AVIATION...JAS









AREA FORECAST DISCUSSION

NWS DODGE CITY KS

 1221 PM CDT SAT MAY 5 2012

...UPDATED AVIATION SECTION...

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 127 AM CDT SAT MAY 5 2012

EARLY THIS MORNING AND TODAY...SURFACE PRESSURES WILL CONTINUE TO
FALL ALONG THE LEE OF THE ROCKIES IN RESPONSE TO THE WEST COAST
UPPER LEVEL TROUGH MOVING EASTWARDS TOWARDS THE NORTHERN AND
CENTRAL ROCKIES. SOUTHEASTERLY FLOW NEAR THE SURFACE WILL DRAW
MORE HUMID AIR BACK ACROSS PORTIONS OF NORTH CENTRAL KANSAS BUT AT
THIS TIME BASED ON VARIOUS BUFR SOUNDINGS AND HRRR ANY STATUS OR
FOG THAT MAY DEVELOP EARLY THIS MORNING IS NOT EXPECTED TO BE
WIDESPREAD OR DENSE. BY LATE MORNING A LEE TROUGH/DRYLINE WILL
MOVE EAST ACROSS WESTERN KANSAS ALLOWING DRIER AIR TO RETURN.
THESE LOW DEW POINT BEHIND THIS BOUNDARY COMBINED WITH AFTERNOON
TEMPERATURES TOPPING OUT IN THE MID-UPPER 90S, BASED ON 850-700MB
MIX DOWN TEMPERATURES, WILL ALLOW AFTERNOON RELATIVE HUMIDITIES TO
FALL BACK TO NEAR 10 PERCENT IN A FEW LOCATIONS. WINDS HOWEVER ARE
EXPECTED TO AVERAGE AT LESS THAN 20 MPH AND THE FUEL STATUS PAGE
DOES INDICATE MOST LOCATIONS DO NOT HAVE THE FUELS NEEDED TO
SUPPORT RED FLAG WARNING CONDITIONS. AS A RESULT WILL NOT BE
ISSUING ANY TYPE OF FIRE WEATHER PRODUCTS AT THIS TIME.

TONIGHT...AN UPPER LEVEL JET WILL CROSS THE ROCKIES AND MOVE OUT
INTO THE NORTHERN PLAINS. AS IT DOES THE STATIONARY FRONT ACROSS
NEBRASKA WILL BEGIN TO MOVE SOUTH INTO NORTHWEST KANSAS. BASED ON
THE LOCATION OF THE RIGHT ENTRANCE REGION OF THE UPPER LEVEL JET,
NORTHERN EDGE OF THE WARM 700MB WARM LAYER, AND WHERE THE MOIST
UPSLOPE FLOW WILL BE PRESENT SATURDAY EVENING THE BETTER CHANCES
FOR CONVECTION EARLY TONIGHT WILL STAY WELL NORTH OF INTERSTATE 70
IN NORTHEAST COLORADO AND NORTHWEST KANSAS. THIS AREA OF
CONVECTION WILL MOVE EAST/SOUTHEAST OVERNIGHT AS THE SURFACE COLD
FRONT BEGINS TO WORK ITS WAY INTO WESTERN KANSAS. AT THIS TIME
BASED THE LOCATION OF THE BETTER MOISTURE AND LOW LEVEL FORCING
ALONG WITH THE BETTER MID LEVEL INSTABILITY THE PRECIPITATION
CHANCES STILL APPEARS TO BE IN/NEAR OUR NORTH CENTRAL KANSAS AND
MAINLY AFTER 09Z. AS A RESULT WILL CONTINUE TO LEAN TOWARD LEAVING
THE FORECAST DRY BUT DID INSERT SOME 10-14% CHANCES INTO THE HAYS
AREA. AS FOR TEMPERATURES THE PREVIOUS FORECAST STILL APPEARS TO
HAVE A DECENT HANDLE ON KEEPING LOWS MAINLY IN THE 60S ALONG AND
AHEAD OF THE COLD FRONT WHICH WILL BE LOCATED NEAR SOUTH CENTRAL
KANSAS AT 12Z.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 403 AM CDT SAT MAY 5 2012

SUNDAY:

A STRONG COLD FRONT WILL HAVE CLEARED MUCH OF THE REGION BY SUNDAY MORNING,
EXCEPT AROUND MEDICINE LODGE. THIS FRONT IS BEING USHERED IN BY A 500
HPA SHORTWAVE TROUGH WELL TO THE NORTH. THE RIGHT ENTRANCE REGION OF
A 250 HPA JET WILL SKIRT ACROSS NEBRASKA DURING THE DAY AND AS A RESULT,
I HAVE HIGHEST POPS ACROSS CENTRAL KANSAS DUE TO RESULTANT INCREASING
UPPER LEVEL DYNAMICS/DIVERGENCE ALOFT. THE COLD FRONT WILL HAVE SCOURED
OUT MUCH OF THE BOUNDARY LAYER MOISTURE EXCEPT ACROSS SOUTH CENTRAL
KANSAS. FORECAST SOUNDINGS DO NOT SHOW MUCH IN THE WAY OF CAPE EXCEPT
SOUTHEAST OF A LARNED TO COLDWATER LINE. SO HAVE PUT ISOLATED THUNDERSTORMS,
BUT THE EVENT LOOKS MORE LIKE A SHOWER EVENT IF ANYTHING. THE STRONGER
DYNAMICS WILL BE WELL TO THE NORTHEAST SO AM NOT EXPECTING A HIGH QPF
EVENT. TEMPERATURES WILL COOL DOWN TO WHERE THEY SHOULD BE FOR THIS
TIME OF YEAR (NEAR NORMAL) WITH NEAR 70 DEG F TOWARDS TOWARDS SCOTT
CITY AND WARMER LOWER 80S DEG F SOUTH OF THE FRONT TOWARDS MEDICINE
LODGE. 850 HPA WINDS ARE FORECAST TO BE AROUND 35 TO 40 KT SO SUNDAY
WILL BE WINDY WITH REFRESHING NORTHERLY WINDS 2O TO 30 MPH. A WELCOME
CHANGE FROM THE MID 90S DEG F THE DAY BEFORE.

MONDAY:

HIGH PRESSURE WILL BUILD ACROSS THE CENTRAL PLAINS MONDAY AND A MUCH
DRIER AIRMASS WILL SPREAD ACROSS WESTERN KANSAS. OVERNIGHT LOWS WILL
BE MORE SEASONABLE WITH 40S AND 50S DEG F FORECAST ACROSS MUCH OF THE
REGION. THERE WILL BE A BROAD UPPER LEVEL SHORTWAVE TROUGH ACROSS THE
ROCKIES AND 700 AND 850 HPA TRAJECTORIES WILL BE UPSLOPE ACROSS FAR
WESTERN KANSAS AND INTO COLORADO. AS A RESULT, HAVE SLIGHT POPS IN ACROSS
THE WESTERN HALF AND INTO PORTIONS OF THE SOUTHERN HALF OF THE REGION
DUE TO UPSLOPE CONDITIONS. COOL HIGH PRESSURE WILL PROVIDE TEMPERATURES
IN THE 60S DEG F TOWARDS I 70 AND MID 70S DEG F TOWARDS THE OKLAHOMA
BORDER.

TUESDAY THROUGH THURSDAY:

TEMPERATURES WILL MODERATE THROUGH THE MIDDLE PORTION OF NEXT WEEK AS
THE COOL HIGH PRESSURE CENTER SLIDES OFF TO THE EAST AND WEAK LEE SURFACE
TROUGHING DEVELOPS ACROSS THE HIGH PLAINS. THIS PORTION OF THE FORECAST
PERIOD WILL BE DRY AS A 500 HPA RIDGE AXIS EJECTS OUT FROM THE ROCKIES
AND EVENTUALLY ACROSS THE PLAINS BY THURSDAY AFTERNOON. THE MODELS SHOW
A 500 HPA LOW ACROSS SOUTHWEST TEXAS BUT SW KANSAS LOOKS LIKE TO BE
IN THE COL POINT...MEANING BASICALLY NO IMPACT IN TERMS OF SENSIBLE
WEATHER.

FRIDAY:

THEN NEXT CHANCE FOR PRECIPITATION APPEARS TO BE ON FRIDAY. UNFORTUNATELY
THE AFOREMENTIONED LOW WILL IMPEDE DECENT GULF OF MEXICO MOISTURE FROM
RETURNING NORTHWARD WITH ONLY 50 DEG F DEWPOINTS ADVECTING IN FROM THE
SOUTHERN PLAINS AND MOSTLY LIKELY JUST ACROSS SOUTH CENTRAL KANSAS.
MEANWHILE, AN UPPER LEVEL SHORTWAVE TROUGH SKIRTING ACROSS THE NORTHERN
PLAINS WILL USHER IN A COLD FRONT DURING THE DAY. THE MODELS (EVEN THE
ECMWF WHICH IS A LITTLE MORE CONSERVATIVE ON MOISTURE RETURN) INDICATES
SOME CAPE FORMING SO THERE COULD BE A FEW THUNDERSTORMS AROUND. THE
GFS, AS USUAL, IS TOO AGGRESSIVE WITH WARM AIR/MOISTURE ADVECTION AND
WAS DISREGARDED.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1220 PM CDT SAT MAY 5 2012

VFR CONDITIONS WILL PREVAIL TODAY AS A SURFACE TROUGH CONTINUES TO
BE POSITIONED ACROSS EASTERN COLORADO. WINDS WILL GENERALLY BE
FROM THE SOUTH TO SOUTHEAST AROUND 12 KNOTS WITH GUSTS OVER 20
KNOTS THIS AFTERNOON. A COLD FRONT WILL MOVE THROUGH THE AREA
AROUND SUNRISE TOMORROW SHIFTING WINDS TO THE NORTHEAST AT 15 TO
20 KNOTS WITH SOME GUSTS AROUND 30 KNOTS. CLOUDS WILL ALSO BE ON
THE INCREASE TOWARDS SUNRISE BUT SHOULD REMAIN VFR.

&&

.PRELIMINARY POINT TEMPS/POPS...
DDC  95  61  71  52 /   0  10  20  10
GCK  96  58  68  50 /   0  10  20  20
EHA  95  58  72  48 /   0   0  10  20
LBL  97  59  72  50 /   0   0  10  20
HYS  93  63  70  51 /   0  20  30  10
P28  94  68  82  58 /   0  10  20  10

&&

.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...BURGERT
LONG TERM...SUGDEN
AVIATION...HOVORKA 42







AREA FORECAST DISCUSSION

NWS LOUISVILLE KY

 523 PM EDT SAT MAY 05 2012

.Forecast Update...
Issued at 520 pm EDT May 5 2012

Updated the afternoon forecast to included scattered thunderstorms
that have developed along a weak convergence boundary across
Jefferson County, Indiana and Trimble County. Localized convergence
and weak instability will allow this thin line of broken
thunderstorms to drift southwards across Trimble, Henry and into
eastern Shelby Counties through 7 pm this evening. Other storms may
drift southwards into our southern Indiana Counties. With weak
forcing, these storms are based almost solely on surface instability
and will diminish rapidly towards or just after sunset.



.Short Term (Tonight through Sunday Night)...
Issued at 330 PM EDT May 5 2012

Late this afternoon we sit between two upper level shortwaves with a
sfc boundary located from a low pressure over the central Plains to
central Illinois then southeast through central Kentucky.  Generally
we sit in an area of subsidence or only weak instability between the
waves. This morning`s MCS really stabilized our region today and
it`s had a hard time recovering.  Plus, low clouds have remained
prominent from Louisville to Lexington and points northeast. No
strong trigger exists to set off convection this afternoon and
evening.  Therefore will remove POPs.  However, clouds will remain
over our eastern forecast area through the evening hours.

Although low clouds are expected to decay over our northeast area
somewhat overnight, some short range models indicate that they could
build back in from the east after midnight.  So that will be a
forecast challenge overnight.  Also, patchy fog looks possible given
the light winds and moist boundary layer in place.  Any cloud cover
would hinder fog formation somewhat, but still think that conditions
are supportive of at least patchy fog at this point.  Will need to
further investigate fog visibilities later this evening.  Expect
overnight lows in the low to mid 60s.

Sunday upper level ridging will move over the area providing a dry
sunny day with highs in the 80s.

Late Sunday night, convection will approach our western areas ahead
of an approaching cold front.  Based on the latest model guidance,
did delay the arrival of POPs until after midnight.  With this later
arrival and more time for rad cooling, lowered min temps a bit into
the mid to upper 60s.

.Long Term (Monday through Saturday)...
Issued at 250 PM EDT May 5 2012

Monday - Tuesday:
Strong upper low will dive out of Canada into the Great Lakes, and
push a healthy cold front through the Ohio Valley. Have gone with
likely POPs Monday into Monday evening due to a good moisture feed
ahead of the front. Exact timing is still in question, but moderate
instability and decent shear will support multicell storms and a
damaging wind threat.

Front should be through around daybreak on Tuesday, but may be slow
to clear the area. Have held on to chance POPs south of the Ohio
River, with slight chance or less in Indiana to account for
lingering shower activity. Temps on Tuesday afternoon will be
noticeably cooler than recent days, but actually very close to
normal.

Wednesday - Saturday:

Mean upper trof over the Great Lakes will be the predominant feature
for the latter half of the week, with NW flow aloft from the upper
Midwest to the Ohio Valley. Surface high pressure will bring a
Pacific air mass, which means dry weather and seasonable
temperatures. Closest proximity to the surface ridge is Wednesday
night and Thursday night, and will see very favorable radiational
cooling conditions. Most locations will bottom out around 50, but
some of the typical cold spots could dip to 40 or even a little
cooler.

Forecast confidence drops off again by Saturday as the GFS progs a
closed low over the southern Plains, and tries to spread moisture
northeast into the Ohio Valley. At this point will opt for no more
than a slight chance POP, but later shifts can refine the timing on
that. Temps near normal by day and several degrees above normal by
night due to increasing cloud cover.

&&

.Aviation (18Z TAF Issuance)...
Updated at 145 PM EDT May 5 2012

MVFR CIGS look to be problematic this afternoon.  I pretty thick
shield of BKN014-BKN027 exists over the LEX/SDF terminals.
According to the latest HRRR CIG data and soundings, looks like this
MVFR deck should stay over the area for most of the area and then
gradually decay toward late afternoon or this evening.  BWG will
also see on and off MVFR CIGS but it will not be near as predominant
as at SDF/LEX so will handle BWG MVFR CIGS with a tempo group. Also
of note this afternoon are very small convection chances...too small
to mention at SDF/LEX terminals but will include a VCSH at BWG.

Then tonight the challenge will be fog development and any low CIGS
building back into SDF/LEX.  Have relied on a combination of models
to determine the most likely scenario.  For fog, looks like winds
will be light with plentiful low level moisture which will support
at least MVFR fog possibly IFR.  However, a decent deck of upper
level clouds is expected to move into the area which could limit fog
development.  Also at SDF/LEX, some of the short range models hint
that the low clouds will build back into the TAF sites after 7-8Z
especially at LEX.  Therefore will go ahead and include an
MVFR CIG in the LEX TAF.  Will go with MVFR fog at all sites with a
note that lower VSBYS may be possible.

Conditions should improve to VFR tomorrow by mid to late morning.

&&

.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$


Update...........JSD
Short Term.......AS
Long Term........RS
Aviation.........AS






AREA FORECAST DISCUSSION

NWS LOUISVILLE KY

 332 PM EDT SAT MAY 05 2012

.Short Term (Tonight through Sunday Night)...
Issued at 330 PM EDT May 5 2012

Late this afternoon we sit between two upper level shortwaves with a
sfc boundary located from a low pressure over the central Plains to
central Illinois then southeast through central Kentucky.  Generally
we sit in an area of subsidence or only weak instability between the
waves. This morning`s MCS really stabilized our region today and
it`s had a hard time recovering.  Plus, low clouds have remained
prominent from Louisville to Lexington and points northeast. No
strong trigger exists to set off convection this afternoon and
evening.  Therefore will remove POPs.  However, clouds will remain
over our eastern forecast area through the evening hours.

Although low clouds are expected to decay over our northeast area
somewhat overnight, some short range models indicate that they could
build back in from the east after midnight.  So that will be a
forecast challenge overnight.  Also, patchy fog looks possible given
the light winds and moist boundary layer in place.  Any cloud cover
would hinder fog formation somewhat, but still think that conditions
are supportive of at least patchy fog at this point.  Will need to
further investigate fog visibilities later this evening.  Expect
overnight lows in the low to mid 60s.

Sunday upper level ridging will move over the area providing a dry
sunny day with highs in the 80s.

Late Sunday night, convection will approach our western areas ahead
of an approaching cold front.  Based on the latest model guidance,
did delay the arrival of POPs until after midnight.  With this later
arrival and more time for rad cooling, lowered min temps a bit into
the mid to upper 60s.

.Long Term (Monday through Saturday)...
Issued at 250 PM EDT May 5 2012

Monday - Tuesday:
Strong upper low will dive out of Canada into the Great Lakes, and
push a healthy cold front through the Ohio Valley. Have gone with
likely POPs Monday into Monday evening due to a good moisture feed
ahead of the front. Exact timing is still in question, but moderate
instability and decent shear will support multicell storms and a
damaging wind threat.

Front should be through around daybreak on Tuesday, but may be slow
to clear the area. Have held on to chance POPs south of the Ohio
River, with slight chance or less in Indiana to account for
lingering shower activity. Temps on Tuesday afternoon will be
noticeably cooler than recent days, but actually very close to
normal.

Wednesday - Saturday:

Mean upper trof over the Great Lakes will be the predominant feature
for the latter half of the week, with NW flow aloft from the upper
Midwest to the Ohio Valley. Surface high pressure will bring a
Pacific air mass, which means dry weather and seasonable
temperatures. Closest proximity to the surface ridge is Wednesday
night and Thursday night, and will see very favorable radiational
cooling conditions. Most locations will bottom out around 50, but
some of the typical cold spots could dip to 40 or even a little
cooler.

Forecast confidence drops off again by Saturday as the GFS progs a
closed low over the southern Plains, and tries to spread moisture
northeast into the Ohio Valley. At this point will opt for no more
than a slight chance POP, but later shifts can refine the timing on
that. Temps near normal by day and several degrees above normal by
night due to increasing cloud cover.

&&

.Aviation (18Z TAF Issuance)...
Updated at 145 PM EDT May 5 2012

MVFR CIGS look to be problematic this afternoon.  I pretty thick
shield of BKN014-BKN027 exists over the LEX/SDF terminals.
According to the latest HRRR CIG data and soundings, looks like this
MVFR deck should stay over the area for most of the area and then
gradually decay toward late afternoon or this evening.  BWG will
also see on and off MVFR CIGS but it will not be near as predominant
as at SDF/LEX so will handle BWG MVFR CIGS with a tempo group. Also
of note this afternoon are very small convection chances...too small
to mention at SDF/LEX terminals but will include a VCSH at BWG.

Then tonight the challenge will be fog development and any low CIGS
building back into SDF/LEX.  Have relied on a combination of models
to determine the most likely scenario.  For fog, looks like winds
will be light with plentiful low level moisture which will support
at least MVFR fog possibly IFR.  However, a decent deck of upper
level clouds is expected to move into the area which could limit fog
development.  Also at SDF/LEX, some of the short range models hint
that the low clouds will build back into the TAF sites after 7-8Z
especially at LEX.  Therefore will go ahead and include an
MVFR CIG in the LEX TAF.  Will go with MVFR fog at all sites with a
note that lower VSBYS may be possible.

Conditions should improve to VFR tomorrow by mid to late morning.

&&

.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$


Short Term.......AMS
Long Term........RAS
Aviation.........AMS






AREA FORECAST DISCUSSION

NWS LOUISVILLE KY

 147 PM EDT SAT MAY 05 2012

.Forecast Update...
Issued at 1245 PM EDT May 5 2012

Decreased POPs by about 10% for this update as well as lowered high
temperatures for this afternoon.  Low level clouds have built in to
our northeast forecast area including Louisville and Lexington, so
this should really limit convective potential today in that region
in addition to that sfc front starting to sag south.  The latest 12Z
NAM guidance indicates the front will make really good progress
southwest and has virtually no precip for this afternoon for our
region.  However, have sided toward the 9Z SREF guidance which has a
slightly slower progression of the front southwest this afternoon
and does blow up some weak convection southwest of a line from
Huntingburg to Louisville to Lexington.  Therefore will
concentrate scattered POPs in that southern sector of our forecast
area.

Also decreased high temps for today especially for the Bluegrass
region which is still in the upper 60s as of 1630Z.  Therefore went
with an east-west gradient of upper 70s to around 80 in the east to
mid 80s over the west.  The west should definitely see a longer
period of near full sunshine today.

Update issued at 904 AM EDT May 5 2012

Decreased POPs for this morning, as early morning MCS has weakened
and moved mostly south of the area.  We should continue to see light
rain over south central Kentucky decrease in coverage over the next
few hours.  For the late morning hours and early afternoon, we
should only see about 20-30% POPs.  By mid to late afternoon, if we
can get some breaks in the clouds and some sfc heating, we may see
some scattered showers and t-storms this afternoon and evening. The
Bowling Green area has the best chance to see afternoon convection.
Wind shear is really weak so if any storms can get going they would
only be pulse type storms at best with mostly heavy rain and cloud
to ground lightning the main threats.  Gusty winds around 30-40 mph
or small hail cannot be ruled out in the strongest storms but are
unlikely.

Update issued at 705 AM EDT May 5 2012

Updated the forecast to cancel the last 2 counties of WW 245.  Looks
like steady light to moderate rains with embedded thunder will
continue to move south over the area this morning.  However, rain
chances should decrease and clouds erode bit from the north this
afternoon.

Update issued at 604 AM EDT May 5 2012

Issued a quick update to cancel most of WW 245. Have left Logan and
Simpson counties in for now. The stronger storms in these two
counties should diminish over the next hour or so.

Update issued at 354 AM EDT May 5 2012

Issuing a quick update to include WW 245 for portions of southern
Kentucky. Updates out shortly.

.Short Term (Today through Sunday)...
Issued at 320 AM EDT May 5 2012

Convection has been training across a large portion of southern IN
and central KY for much of the evening and overnight hours. Storms
continue along a northwest to southeast boundary from Evansville IN
to about Somerset KY at this time. The latest suite of guidance
depicts these heavy rain producing storms will slowly slide south
and east through the morning hours. This convection has been in
response to an upper-level shortwave tracking through the Ohio
Valley and a 30-35 knot low level jet.

As this convection slides south and east, the northern forecast area
will remain covered with debris clouds for a good portion of the
morning. There will be slow clearing from the north through the
afternoon. Given the current conditions, it will be difficult to
spark new storms this afternoon, but an isolated thunderstorm cannot
be ruled out with remnant outflow boundaries being scattered across
the forecast area and some clearing by this afternoon. Plus, a
stationary surface frontal boundary is projected to be stretched
across the Ohio River late this afternoon and early evening. So,
there is a small chance, but I certainly would not cancel any
outdoor plans you may have. Temperatures this afternoon will be
tricky given mainly the uncertainties in cloud cover. However, if
conditions pan out, we should reach the low and mid 80s. With all
the low level moisture, it will feel muggy.

The frontal boundary will remain quasi-stationary across the
forecast area Saturday night and most of the day Sunday. This will
become a source of weak surface convergence and will combine with
heating Sunday afternoon to generate mainly isolated thunderstorms.
Temperatures will reach the low and mid 80s once again.

.Long Term (Sunday Night through Friday)...
Issued at 250 AM EDT May 5 2012

Spent more time watching radar for the near term than with this
forecast, so take it with a grain of salt. Used a model blend with
the previous forecast. At the start of the period will have a
weakening ridge over the region with a front moving into the
Mississippi river valley. This front looks to move through the
region Monday night, bringing good rain chances mainly during the
day Monday and lingering into early Tuesday. Troughing will move
into the Great Lakes region for midweek, bringing a cool and dry
down. Cannot rule out some stray lake effect light rain during the
day Wednesday, which will help to keep us cool.

That trough will get replaced by ridging moving in from the west by
Friday. Moisture return will be slow for the end of the week, so
think the rest of the period will be dry.

Temperatures will start off in the low 80s Monday, ahead of that
front, then cool to the lower 70s as the front kicks through
Tuesday.  Wednesday and Thursday may end up cooler than the around
70s I have in there, depending on cloud cover Wednesday. Thursday
looks to be the coldest morning, with high pressure in the vicinity.
For now have lows 45-50, but if that high gets right over us for the
night, we could see some 30s in the coldest spots. Then Friday
should rebound into the 70s.

&&

.Aviation (18Z TAF Issuance)...
Updated at 145 PM EDT May 5 2012

MVFR CIGS look to be problematic this afternoon.  I pretty thick
shield of BKN014-BKN027 exists over the LEX/SDF terminals.
According to the latest HRRR CIG data and soundings, looks like this
MVFR deck should stay over the area for most of the area and then
gradually decay toward late afternoon or this evening.  BWG will
also see on and off MVFR CIGS but it will not be near as predominant
as at SDF/LEX so will handle BWG MVFR CIGS with a tempo group. Also
of note this afternoon are very small convection chances...too small
to mention at SDF/LEX terminals but will include a VCSH at BWG.

Then tonight the challenge will be fog development and any low CIGS
building back into SDF/LEX.  Have relied on a combination of models
to determine the most likely scenario.  For fog, looks like winds
will be light with plentiful low level moisture which will support
at least MVFR fog possibly IFR.  However, a decent deck of upper
level clouds is expected to move into the area which could limit fog
development.  Also at SDF/LEX, some of the short range models hint
that the low clouds will build back into the TAF sites after 7-8Z
especially at LEX.  Therefore will go ahead and include an
MVFR CIG in the LEX TAF.  Will go with MVFR fog at all sites with a
note that lower VSBYS may be possible.

Conditions should improve to VFR tomorrow by mid to late morning.

&&

.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$


Update...........AMS/MJP
Short Term.......MJP
Long Term........RJS
Aviation.........AMS






AREA FORECAST DISCUSSION

NWS DULUTH MN

 1259 PM CDT SAT MAY 5 2012

.AVIATION.../18Z TAF ISSUANCE/
WIDESPREAD MVFR AND OCCASIONAL IFR CIGS/VSBYS ARE IN STORE FOR THE
DURATION OF THE TAF CYCLE. AS THE AFTERNOON AND NIGHT WEARS
ON...PRECIPITATION WILL BECOME WIDESPREAD WITH NUMEROUS
THUNDERSTORMS EXPECTED IN THE SOUTHERN PORTION OF THE CWA. MOST OF
THE THUNDERSTORMS ARE EXPECTED TO STAY SOUTH OF THE BORDER REGION.
THE MOST WIDESPREAD RAINFALL SHOULD MOVE IN DURING THE NIGHT AND
END ON SUNDAY MORNING.

&&

.PREV DISCUSSION... /ISSUED 1050 AM CDT SAT MAY 5 2012/

UPDATE...
MOST OF THE RAIN HAS MOVED OUT OF THE AREA LATE THIS MORNING...SO
DECIDED TO REDUCED POPS...BEFORE THE NEXT ROUND OF SHOWERS MOVES
IN LATE THIS AFTERNOON AND THROUGH THE EVENING AND OVERNIGHT
HOURS TONIGHT. NO MAJOR CHANGES TO THE FORECAST AT THIS TIME. WILL
LOOK AT INCREASING THE WORDING FOR PERIODS OF HEAVY RAIN ACROSS
THE SOUTH TONIGHT AS MOST MODELS INDICATING A TIME OF 1-1.5 INCHES
OF PRECIP FROM AFTER MIDNIGHT THROUGH SUNDAY MORNING ACROSS THE
SRN HALF OF THE FORECAST AREA.

PREV DISCUSSION... /ISSUED 632 AM CDT SAT MAY 5 2012/

AVIATION...12Z TAFS.
A MIX OF VFR/MVFR CIGS INITIALLY WILL GIVE WAY TO MVFR FOR THE
REMAINDER OF THE TAF PERIOD. AFTER SOME MORNING SHOWERS NEAR THE
CANADIAN BORDER...ADDITIONAL SHOWER ACTIVITY SHOULD HOLD OFF UNTIL
AFTER 06Z WHEN SHOWERS AND THUNDERSTORMS WILL SPREAD ACROSS THE
TAF SITES. IFR/LIFR CIGS/VSBYS ARE POSSIBLE IN THE VCNTY OF
STRONGER STORMS.

PREV DISCUSSION... /ISSUED 620 AM CDT SAT MAY 5 2012/

UPDATE...

THE FOG THAT WAS FORECASTED TO DEVELOP THIS MORNING NEAR LAKE
SUPERIOR HAS NOT DEVELOPED. SINCE THE WINDS NEAR LAKE SUPERIOR ARE
AROUND 10 TO 20 MPH...WHICH IS RATHER STRONG FOR FOG
FORMATION...DEW POINT DEPRESSIONS ARE ABOUT 5 TO 10 DEGREES...AND
THERE IS NO CLEAR INDICATION OF THE FOG FORMING...DECIDED TO
REMOVE THE PATCHY FOG FROM THE MORNING FORECAST. ALSO...BASED ON
THE LATEST RADAR TRENDS...IT APPEARS MOST OF THE LINGERING SHOWERS
HAVE EITHER MOVED OUT OF THE FA OR DISSIPATED. MOST OF THE
REMAINING SHOWERS ARE IN THE NORTH CENTRAL FA...SO UPDATED THE
MORNING POPS AND WEATHER FORECAST TO REFLECT THIS.

PREV DISCUSSION... /ISSUED 333 AM CDT SAT MAY 5 2012/

SHORT TERM...[NOW - SUNDAY]...

CLOUDY AND COOLER THAN NORMAL WEATHER IS EXPECTED THROUGH SUNDAY
WITH CHANCES FOR PCPN...ESPECIALLY TONIGHT AND SUNDAY MORNING WHEN
LOW PRESSURE IN THE PLAINS MOVES EASTWARD INTO THE UPPER MIDWEST.

TODAY...HIGH PRESSURE WILL CONTINUE TO DOMINATE MANITOBA AND
ONTARIO...WHILE PRESSURE ORGANIZES IN THE CENTRAL PLAINS...AND A
MID/UPPER LEVEL TROUGH LIFTS THROUGH IDAHO AND MONTANA. RAIN
SHOWERS ASSOCIATED WITH MID LEVEL WARM AIR ADVECTION COULD LINGER
THROUGH THIS MORNING. LOWERED POPS ACROSS THE WESTERN FA SINCE IT
APPEARS MOST OF THE SHOWERS WILL BE LINGERING ACROSS THE EASTERN
FA. EASTERLY WINDS WILL CONTINUE TODAY...WITH THE STRONGEST WINDS
BETWEEN 10 AND 15 MPH NEAR THE TWIN PORTS AND ALONG THE LAKE
SUPERIOR SHORELINE DUE TO THE EXPECTED GUSTY WINDS OVER THE LAKE.
THE EASTERLY WINDS AND CLOUDY SKIES TODAY WILL RESULT IN COOLER
THAN NORMAL TEMPERATURES...ESPECIALLY NEAR THE TWIN PORTS.
INHERITED A FORECASTED FOR FOG AROUND LAKE SUPERIOR FOR THIS
MORNING...AND DECIDED TO KEEP THAT DUE TO THE EASTERLY WINDS OFF
THE LAKE AND THE HRRR SUGGESTING SOME FOG. THE MODELS ARE IN
REASONABLE AGREEMENT THAT THE LOW PRESSURE IN THE PLAINS WILL
ORGANIZE AND BEGIN TO MOVE EASTWARD THIS AFTERNOON AND BRING
SHOWERS TO THE SOUTHERN FA LATER THIS AFTERNOON.
THEREFORE...INCREASED POPS A BIT.

TONIGHT...THE MID/UPPER LEVEL TROUGH IN MONTANA WILL MOVE INTO
SOUTHERN SASKATCHEWAN AND DEVELOP A DISTINCT MID/UPPER LEVEL LOW.
AN ASSOCIATED SURFACE LOW WILL DEVELOP IN SOUTHERN
SASKATCHEWAN...WHILE A OCCLUDED FRONT MOVES THROUGH THE DAKOTAS
TOWARDS WESTERN MINNESOTA. THIS WILL RESULT IN A SURGE OF MOISTURE
OVER THE NORTHLAND WITH PRECIPITABLE WATER VALUES CLIMBING TO
AROUND 1.25 INCHES. THE MODELS ARE IN GOOD AGREEMENT WITH BRINGING
SIGNIFICANT RAINFALL TO THE NORTHLAND...SO INCREASED POPS. A GOOD
PORTION OF THE FA IS FORECASTED TO GET AROUND A QUARTER TO NEARLY
THREE QUARTERS OF A INCH OF RAINFALL WITH THE SOUTHWESTERN FA AT
THE HIGHEST END OF THE RANGE. NOT THRILLED ABOUT THE PROSPECTS OF
THUNDER...BUT SINCE THE MODELS SUGGEST SOME LIMITED MOST UNSTABLE
CAPE AND SLIGHTLY NEGATIVE LIFTED INDICES...FORECASTED ISOLATED
THUNDER ACROSS THE SOUTHERN FA.

SUNDAY...THE MID/UPPER LEVEL LOW WILL DRIFT TOWARDS SOUTHERN
MANITOBA...AND THE ASSOCIATED OCCLUDED FRONT WILL CONTINUE TO
APPROACH THE NORTHLAND. RAIN SHOWERS WILL PROBABLY CONTINUE ACROSS
THE FA...AT LEAST DURING THE MORNING. ANOTHER QUARTER TO THREE
QUARTERS OF AN INCH OF RAIN IS FORECASTED FOR MUCH OF THE
FA...WITH NORTHWESTERN WISCONSIN LIKELY GETTING THE HIGHEST
AMOUNTS. FORECASTED ISOLATED THUNDER ACROSS THE SOUTHERN FA DUE TO
THE MODELS SUGGESTING THE POSSIBILITY OF LIMITED INSTABILITY. THE
CLOUDY AND WET CONDITIONS WILL RESULT IN COOLER THAN NORMAL
TEMPERATURES.

LONG TERM...[SUNDAY NIGHT - FRIDAY]...

A CLOSED UPPER LOW WILL MEANDER ALONG THE CANADIAN BORDER FROM
SUNDAY NIGHT THROUGH MONDAY NIGHT. BY TUESDAY, THE LOW OPENS UP
INTO A LONG WAVE TROF AS IT DROPS THROUGH THE WESTERN GREAT
LAKES EXITING BY 12Z WEDNESDAY. THE RESULT IS A MENTION OF POPS
THROUGH TUESDAY NIGHT. UPPER LEVEL SFC RIDGING FOLLOWS BEHIND
WEDNESDAY INTO THURSDAY. THE UPPER RIDGING PERSISTS THURSDAY NIGHT
EVEN THOUGH THE SFC RIDGE DRIFTS OFF TO THE SE. THIS ALLOWS A WAA
REGIME TO ESTABLISH BRINGING THE CHANCE OF SHOWERS AND
THUNDERSTORMS INTO THE FA THURSDAY NIGHT. MODELS DISAGREE WITH THE
TIMING OF PCPN AND HAVE USED A MODEL BLEND. A COLD FRONT BEGINS TO
MARCH THROUGH THE FA LATE THURSDAY NIGHT AND FRIDAY WITH MORE
SHOWERS POSSIBLE.

AVIATION...06Z TAF ISSUANCE...

SHOWERS HAVE INCREASED OVER THE PAST COUPLE HOURS OVER THE
NORTHLAND...AND LOWER CEILINGS WERE DEVELOPING OVER CENTRAL
MINNESOTA. THESE MVFR CEILINGS WERE MOVING QUICKLY NORTH...AND
SHOULD REACH KBRD AROUND OR SHORTLY AFTER 06Z...AND THE REST OF
THE TAF SITES BETWEEN 07Z-09Z. CEILINGS SHOULD LOWER TO IFR IN
MANY AREAS LATE TONIGHT INTO EARLY SATURDAY MORNING...THEN REMAIN
AT IFR/MVFR THROUGH THE REST OF THE PERIOD.

&&

.POINT TEMPS/POPS...
DLH  48  39  44  40 /  20  80  80  50
INL  55  40  53  42 /  20  60  50  40
BRD  58  47  56  43 /  30  80  60  30
HYR  58  45  58  45 /  10  70  80  60
ASX  56  40  52  43 /  10  60  80  60

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 AM CDT SUNDAY FOR LSZ121-142>148.

&&

$$

SHORT TERM...TENTINGER
LONG TERM....DAP
AVIATION...DAP






AREA FORECAST DISCUSSION

NWS WILMINGTON NC

 631 PM EDT SAT MAY 5 2012

.SYNOPSIS...
A COLD FRONT DROPPING SOUTH ACROSS THE AREA COULD BRING STRONG TO
SEVERE THUNDERSTORMS THIS EVENING. A FEW SHOWERS WILL LINGER INTO
SUNDAY...WITH COOLER DAYTIME TEMPERATURES BOTH SUNDAY AND MONDAY AS
HIGH PRESSURE BUILDS FROM THE NORTH. WARMING WILL FOLLOW INTO MID
WEEK...AS HIGH PRESSURE MOVES OFFSHORE AND A COLD FRONT APPROACHES
FROM THE WEST.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 PM SATURDAY...THE LATEST HRRR AND NAM RUNS SHOW FAIRLY
WIDESPREAD CONVECTION DEVELOPING WITHIN THE NEXT 60-90 MINUTES
ACROSS NORTHERN SOUTH CAROLINA...CONSOLIDATING INTO A SQUALL LINE
WITH THE ACTIVITY OVER EAST-CENTRAL NORTH CAROLINA...AND MOVING
SOUTHEAST AND OFF THE COAST THIS EVENING. WHILE THERE IS OBVIOUSLY
SUFFICIENT AREAL COVERAGE OF CONVECTION IN THE RALEIGH/SANFORD
VICINITY TO GENERATE A SIGNIFICANT SURFACE COLD POOL AND STRONG
LEADING-EDGE WINDS...OUR FORECAST FOR 50-60 PERCENT COVERAGE OF
STORMS ACROSS NORTHEAST SOUTH CAROLINA IS HEAVILY CONTINGENT ON MUCH
MORE STORM ORGANIZATION DEVELOPING SOUTH OF FAYETTEVILLE THAN IS
CURRENTLY OBSERVED ON RADAR. SURFACE-BASED CAPE IN THE 1500-2000
J/KG RANGE...LIFTED INDICIES TO -5...AND 0-6 KM BULK SHEAR VALUES
AROUND 30 KT ARE SUPPORTIVE OF STORM ORGANIZATION THIS EVENING.
COMPARED TO THE PREVIOUS FORECAST WE HAVE ONLY MADE SMALL DOWNWARD
EDITS TO PREDICTED COVERAGE OF STORMS IN SOUTH CAROLINA. THE BEST
POTENTIAL OF CONVECTION IN OUR FORECAST AREA REMAINS ACROSS
SOUTHEASTERN NORTH CAROLINA NORTH OF CAPE FEAR WHERE THE
RALEIGH/SANFORD SQUALL LINE MAY DRAG THROUGH IN THE NEXT FEW HOURS.
DAMAGING WINDS ARE THE PRIMARY EXPECTED SEVERE WEATHER MODE...
ALTHOUGH SOME MARGINALLY SEVERE HAIL CANNOT BE RULED OUT.

THE SYNOPTIC SETTING HAS AN EAST-WEST COLD FRONT SAGGING SOUTHWARD
ACROSS CENTRAL NORTH CAROLINA EARLY THIS EVENING...WITH HIGH
PRESSURE ACROSS FLORIDA AND THE NORTHERN BAHAMAS RETREATING TO THE
SOUTH. THE PASSAGE OF A PACKET OF STRONG MID-LEVEL WINDS THIS
EVENING WILL HELP ENHANCE STORM ORGANIZATION FROM NOW UNTIL 10-11 PM
OR SO...AT WHICH POINT THE BULK OF THE SIGNIFICANT CONVECTION SHOULD
BE PUSHING EAST AND OFFSHORE. NW AND N WINDS WILL OVERSPREAD THE
AREA AFTER MIDNIGHT BEHIND THE FRONT...BUT WITH LITTLE REAL COLD
ADVECTION UNTIL SUNDAY. NO CHANGES HAVE BEEN MADE TO LOW
TEMPERATURES...WITH MID TO UPPER 60S EXPECTED FOR MOST AREAS.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 230 PM SATURDAY...DAYBREAK SUNDAY INCREASING NE WINDS WILL
BE OVERSPREADING THE REGION...AS A SURFACE LOW DEPARTING OFFSHORE
OF CAPE FEAR INTERACTS WITH HIGH PRESSURE BUILDING FROM THE NORTH.
HAVE MAINTAINED A SLIGHT CHANCE OF SHOWERS SUNDAY SINCE POST-FRONT
MOISTURE WILL REMAIN ADEQUATE AND A FEW IMPULSES ALOFT DROP SOUTH
OVER THE AREA IN THE EARLY AND MID AFTERNOON. IT DOES APPEAR THAT
DRYING WILL WIN OUT OVER NC BY MID AFTERNOON AND OVER OUR SOUTHERN
ZONES BY THE EARLY EVENING.

DAYTIME TEMPERATURES WILL BE 10-15 COOLER ACROSS THE FORECAST AREA
BOTH SUNDAY AND MONDAY COMPARED TO TODAY DUE TO CLOUDS AND AIR OF
COOLER ORIGIN BEHIND THE FRONT. BECAUSE OF SUSTAINED WINDS
OVERNIGHT OUR MINIMUMS WILL REMAIN SOMEWHAT ELEVATED BOTH MON/TUE
MORNING WITH READINGS AROUND 60 DEG...MILDEST COASTAL ZONES AND
COOLEST OVER THE INTERIOR WHERE LESS WIND INFLUENCE WILL BE SEEN.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 230 PM SATURDAY...HIGH PRESSURE OFFSHORE TUESDAY CREATES WARM
SOUTHERLY RETURN FLOW ACROSS THE CAROLINAS. WITH GUIDANCE NOW
SHOWING A SLOWER FROPA...TUESDAY WILL END UP BEING MOSTLY SUNNY WITH
TEMPS AT OR SLIGHTLY ABOVE 80. CANNOT RULE OUT AN ISOLATED TSTM IN
THE AFTN...BUT DRY AIR IN THE MID LEVELS WILL PRECLUDE MUCH IN THE
WAY OF COVERAGE. CONTINUED WARM SOUTHERLY FLOW AND INCREASING CLOUD
COVER WILL KEEP MINS TUESDAY NIGHT ONLY IN THE MID 60S.

WEDNESDAY STILL LOOKS TO BE AN ACTIVE DAY WITH POTENTIALLY
WIDESPREAD CONVECTION ALONG AND AHEAD OF A POTENT COLD FRONT. RETURN
FLOW PUSHES PWATS UP TO 1.75 INCHES AND ALLOWS FOR ADVECTION OF THE
THETA-E RIDGE INTO THE EASTERN CAROLINAS. WHILE THIS HAPPENS...S/W
TROUGH SPAWNS A SURFACE LOW ACROSS THE OHIO VALLEY WHICH DRAGS A
COLD FRONT THROUGH THIS AREA WEDNESDAY AFTN. ATTM IT APPEARS THIS
COULD COINCIDE WITH PEAK HEATING...AND INSTABILITY PARAMETERS AS
WELL AS UPPER SUPPORT LOOK DECENT...SO CONFIDENCE IS INCREASING IN
TSTM DEVELOPMENT DURING THE AFTN. HOWEVER...SOUNDINGS NO LONGER SHOW
FULL AND DEEP SATURATION WHICH COULD SERVE AS A LIMITING FACTOR TO
RAINFALL...UNFORTUNATELY. NOTE AS WELL THAT THE GFS CONTINUES TO
SHOW AN AREA OF CONVECTION NEAR FLORIDA EARLY WED WHICH TRIES TO
WORK UP THE COAST. THIS COULD ENHANCE RAINFALL ALONG THE COAST...BUT
IN THIS SETUP FREQUENTLY ACTS TO SQUELCH RAINFALL SINCE IT CUTS OFF
THE DEEP MOIST FLOW. WE WILL HAVE TO WAIT AND SEE...BUT FOR NOW WILL
CARRY HIGH CHC POP FOR WEDNESDAY...WITH HIGHEST POP ACROSS THE
NORTH. STILL BELIEVE MEX NUMBERS ARE TOO HIGH WEDNESDAY...BUT HIGHS
A DEGREE OR TWO ABOVE 80 SEEM REASONABLE.

COOL HIGH PRESSURE BUILDS IN BEHIND THE FRONT EARLY THURSDAY...AND
THE END OF THE WEEK THROUGH SATURDAY WILL SEE TEMPS RETURN TO JUST
BELOW CLIMO WITH AMPLE SUNSHINE. EXPECT MAX TEMPS IN THE UPPER 70S
TO AROUND 80...WITH MINS AT NIGHT IN THE MID AND UPPER 50S.


&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 18Z...A MCS OUTFLOW WILL MOVE TO THE COASTAL TERMINALS BY
MID-AFTERNOON AND KICK OFF ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS ALONG A SEA BREEZE PINNED NEAR THE COAST...BEFORE
MOVING OFFSHORE LATE THIS AFTERNOON. AS A RESULT...WILL INCLUDE
VCTS AT THE COASTAL TERMINALS AND AMEND AS NECESSARY.

EXPECT OTHER THUNDERSTORMS ALONG A COLD FRONT TO DROP SOUTHWARD.
BY LATE THIS AFTERNOON THIS ACTIVITY SHOULD AFFECT THE LBT
TERMINAL... THEN SPREAD TO THE REMAINING TERMINALS DURING THE
EVENING. TEMPO MVFR/IFR POSSIBLE WITH THE THUNDERSTORMS AS WELL AS
WIND GUSTS TO 20-25 KNOTS. EXPECT THE STRONGEST ACTIVITY TO END BY
LATE EVENING. AS THE FRONT MOVES SOUTHWARD THERE WILL LIKELY STILL
BE ISOLATED TO SCATTERED SHOWERS DUE TO A LAGGING 850/700MB TROFS.
MOIST LOW-LEVELS AND WEAK CAA SHOULD SET THE STAGE FOR POST-
FRONTAL SCATTERED TO BROKEN IFR CEILINGS TO DEVELOP AND SPREAD
SOUTH. THESE CEILINGS SHOULD LIFT TO MVFR BY MID-LATE MORNING.
WINDS BY SUNDAY MORNING WILL BE NORTH TO NORTHEAST AT 10-15 KNOTS.

EXTENDED OUTLOOK...LOW CONFIDENCE EARLY MORNING FOG/IFR MONDAY AND
TUESDAY. CHANCE SHOWERS AND THUNDERSTORMS TUESDAY NIGHT INTO
WEDNESDAY. VFR THURSDAY.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 PM SATURDAY...HIGH PRESSURE CENTERED FROM FLORIDA ACROSS
THE NORTHERN BAHAMAS WILL BECOME SUPPRESSED TO THE SOUTH AS A COLD
FRONT SLIDES SOUTH ALONG THE CAROLINA COAST TONIGHT. OF IMMEDIATE
CONCERN WITH THIS FRONT IS THE POTENTIAL FOR STRONG TO SEVERE
THUNDERSTORMS TO DEVELOP IN THE NEXT 1-2 HOURS. LATEST SHORT-TERM
MODEL GUIDANCE SHOWS A BROKEN SQUALL LINE POSSIBLY DEVELOPING ACROSS
THE EASTERN CAROLINAS AND PUSHING OUT ACROSS THE WATERS BEFORE
MIDNIGHT. STRONG WINDS ALONG THE LEADING EDGE OF THE SQUALL LINE ARE
THE PRIMARY THREAT AND COULD RESULT IN SPECIAL MARINE WARNINGS LATER
THIS EVENING.

OTHERWISE...SYNOPTIC SOUTHWEST WINDS 10-15 KT HAVE INCREASED TO
15-18 KT NEAR THE BEACHES WITH THE SEABREEZE. THESE SYNOPTIC WINDS
WILL SHIFT TO THE W AND NW AFTER MIDNIGHT AS THE COLD FRONT SINKS
INTO THE AREA...THEN TO THE N SUNDAY MORNING. SEAS AVERAGE 3 FT WITH
SOME 2-FOOTERS NEAR THE SC COAST.

SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 230 PM SATURDAY...PRIMARY THREAT WILL BE TSTMS OFFSHORE
EARLY ON SUNDAY AND THE POTENTIAL FOR LOCALLY STRONG WINDS AND
CLOUD TO WATER LIGHTNING STRIKES ASSOCIATED WITH A SURFACE LOW
OFFSHORE. INCREASING NE WINDS WILL REQUIRE A CAUTIONARY HEADLINE
IN THE CWF MAINLY FOR SUNDAY AFTN...POSSIBLY INTO EVENING AS HIGH
PRESSURE BUILDS FROM THE NORTH. THE TREND IN WINDS IS TO WEAKEN
AND VEER MONDAY AND TUESDAY...BECOMING SSE MONDAY NIGHT AND SSW
BY TUESDAY AS HIGH PRESSURE MOVES OFFSHORE...AND A WEAK COLD FRONT
APPROACHES FROM THE NORTH. S-SE WAVE ENERGY WILL BECOME ENE SUNDAY
IN A BUMPY 3-5 FEET OVER THE 0-20NM WATERS...HIGHEST SEAS NORTH OF
FRYING PAN SHOALS AND WELL OFFSHORE. THE GULF STREAM WILL BE A BIT
HAZARDOUS SUNDAY AS NE WINDS CLASH WITH THE ROBUST CURRENTS.

LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 230 PM SATURDAY...HIGH PRESSURE OFFSHORE DRIFTS FURTHER FROM
THE COAST THROUGH WEDNESDAY AHEAD OF AN ADVANCING COLD FRONT. THIS
CREATES A TIGHTENING PRESSURE GRADIENT...AND WINDS VEERING SLOWLY
FROM SE TUESDAY...TO SW WEDNESDAY...AT 10-15 KTS. SEVERAL DIFFERENT
WAVES WILL BE EVIDENT WITHIN THE SPECTRUM DURING THIS TIME...A SE
SWELL OF 2FT/10 SEC...AND A SE WIND WAVE...BECOMING SW WEDNESDAY.
FORTUNATELY...THESE WILL ALL BE AT RATHER LOW AMPLITUDES...SO TOTAL
SEAS WILL BE ONLY IN THE 2-4 FT RANGE. LATE WED NIGHT COLD FRONT
OCCURS ACROSS THE WATERS TURNING WINDS TO THE NORTH...THEN NE BY
THURSDAY EVE. THERE WILL BE A PERIOD OF ENHANCED NORTH WINDS BEHIND
THE FRONT...UP TO 15-20 KTS...BEFORE EASING LATE TO 5-10 KTS.
ALTHOUGH WAVE HEIGHTS WILL REMAIN AROUND 2-4 FT THROUGH
THURSDAY...WAVE STEEPNESS WILL INCREASE BEHIND FROPA FOR SEVERAL
HOURS AS N/NE WIND WAVES BECOME PREDOMINANT WITHIN THE WAVE
SPECTRUM.

&&

.TIDES/COASTAL FLOODING...
AS OF 230 PM SATURDAY...A FULL MOON TONIGHT WILL BRING UNUSUALLY
HIGH WATER LEVELS FOR THE NEXT FEW DAYS DURING THE EVENING HIGH
TIDE...THE HIGHEST OF THE TWO HIGH TIDES. TONIGHT...MINOR FLOODING
SHOULD BE CONFINED TO PORTIONS OF THE CAPE FEAR RIVER IN DOWNTOWN
WILMINGTON WHERE WATER LEVELS ARE EXPECTED TO REACH JUST OVER 5.5
FT DURING THE EVE. THIS WILL BE ENOUGH TO ISSUE A COASTAL FLOOD
ADVISORY FOR A PORTION OF NEW HANOVER COUNTY. NORTHEAST WINDS MAY
DRIVE TIDES EVEN HIGHER SUN NIGHT...AND ACROSS A BROADER AREA TO
INCLUDE THE BEACHES. HIGH TIDE THIS EVENING IS AROUND 8 PM AT THE
COAST AND 10 PM ALONG THE CAPE FEAR IN DOWNTOWN WILMINGTON. HIGH
TIDE SUNDAY NIGHT IS AROUND 830 PM ALONG THE BEACHES. THERE IS
ABOUT A TWO HOUR LAG TIME IN DOWNTOWN WILMINGTON.

.ILM WATCHES/WARNINGS/ADVISORIES...

SC...NONE.
NC...COASTAL FLOOD ADVISORY FROM 8 PM THIS EVENING TO MIDNIGHT
     EDT TONIGHT FOR NCZ107.

MARINE...NONE.

&&

$$

SYNOPSIS...8
NEAR TERM...TRA
SHORT TERM...COLBY
LONG TERM...JDW
AVIATION...MRR
TIDES/COASTAL FLOODING...RJD






AREA FORECAST DISCUSSION

NWS SAN ANGELO TX

 517 PM CDT SAT MAY 5 2012


.DISCUSSION...
SEE AVIATION DISCUSSION BELOW

&&

.AVIATION...
A LINE OF CUMULUS CLOUDS AND ISOLATED SHOWERS IS BEGINNING TO
DEVELOP ALONG A WEAK DRY LINE AXIS FROM JUST EAST OF SONORA TX TO
NORTHWESTERN BROWN COUNTY WITH A SECOND LINE OF CLOUDS EXTENDING
FROM JUST NORTHEAST OF JUNCTION TX TO THE VICINITY OF BRADY TX.
SOME COULD BECOME SEVERE LATER THIS EVENING...A SEVERE THUNDERSTORM WATCH
UNTIL 10 PM CDT HAS BEEN ISSUED FOR COUNTIES NEAR AND EAST OF THIS
LINE...INCLUDING CONCHO...COLEMAN...BROWN...MCCULLOCH...SAN
SABA...MENARD...MASON AND KIMBLE COUNTIES TX. ALONG THIS LINE OF
CUMULUS AND DEVELOPING SHOWERS LOCALLY MVFR AND IFR CONDITIONS ARE
POSSIBLE ALONG WITH GUSTY WINDS NEAR THUNDERSTORMS...SOME
HAIL...LOCALLY HEAVY RAIN AND DANGEROUS LIGHTNING. THESE LOCALLY
LIMITING CONDITIONS ARE LIKELY TO SUBSIDE AFTER MIDNIGHT.

HOWEVER LOCALLY MVFR AND POSSIBLY LOCALLY IFR CONDITIONS ARE
EXPECTED TO DEVELOP ACROSS THE SOUTHEASTERN COUNTIES ESPECIALLY
WHERE RAIN HAS FALLEN BEFORE DAWN AND LINGERING THROUGH EARLY
MORNING HOURS DUE TO DEVELOPMENT OF LOW CLOUDS WITH CAUSING
CEILINGS NEAR OR BELOW 1500 FEET...MOSTLY LIKELY IN KIMBLE...
MASON AND SUTTON COUNTIES TX.

ANOTHER SMALLER AND WEAKER LINE OF DEVELOPING CUMULUS
IS SEEN OVER EAST CENTRAL THROCKMORTON COUNTY...MOVING EAST
SLOWLY. A VAIL OF BROKEN TO TEMPORARILY OVERCAST HIGH CLOUDS IS
STREAMING TOWARD THE NORTHEAST OVER MOST OF THE FORECAST AREA.
MOSTLY VFR CONDITIONS SHOULD PREVAIL NORTH AND WEST OF A LINE FROM
SONORA TX TO SAN ANGELO TX THROUGH ABILENE TX.

&&

.PREV DISCUSSION... /ISSUED 400 PM CDT SAT MAY 5 2012/

SHORT TERM...
DRYLINE HAS MOVED EAST INTO OUR WESTERN COUNTIES EARLY THIS
AFTERNOON AND SHOULD CONTINUE TO MOVE QUICKLY EAST AND OVER OUR
EASTERN COUNTIES BY LATE THIS AFTERNOON. LATEST NAM AND RUC ARE
SHOWING AN UPPER SHORTWAVE EMBEDDED IN THE SOUTHWEST FLOW ALOFT
MOVING OVER OUR EASTERN COUNTIES...AND THE DRYLINE...BY EARLY THIS
EVENING. GIVEN STRONG AFTERNOON HEARING...SHOULD SEE CONVECTIVE
INITIATION ALONG THE DRYLINE LATER THIS AFTERNOON CONTINUING THROUGH
THE EVENING HOURS. WILL GO WITH A 20 PERCENT CHANCE OF STORMS OVER
THE EASTERN HALF OF THE CWA THROUGH THE EVENING. ANY STORMS THAT
DEVELOP SHOULD ABATE QUICKLY AFTER SUNSET...WILL KEEP A DRY FORECAST
THROUGH THE REMAINDER OF THE NIGHT AND INTO TOMORROW AFTERNOON.
AFTER WARM MORNING LOWS IN THE 70S TOMORROW MORNING...WILL NOT BE
QUITE AS HOT TOMORROW AFTERNOON WITH HIGHS GENERALLY IN THE UPPER
90S ACROSS THE AREA.

FIRE WEATHER...
ELEVATED FIRE WEATHER CONDITIONS WILL CONTINUE THIS AFTERNOON WEST OF
A LINE FROM THROCKMORTON TO SAN ANGELO. FIRE WEATHER CONDITIONS
SHOULD EASE SUNDAY WITH ELEVATED CONCERNS CONFINED TO THE WESTERN
CONCHO VALLEY AND WESTERN NORTHERN EDWARDS PLATEAU. MINIMAL FIRE
WEATHER CONDITIONS ARE EXPECTED BEGINNING MONDAY AND CONTINUING
THROUGH THE REMAINDER OF THE WEEK.

LONG TERM...
BIG CHANGES IN STORE FOR WEST CENTRAL TEXAS NEXT WEEK WITH MUCH
COOLER TEMEPERATURES EXPECTED ALONG WITH INCREASING RAIN CHANCES.

A POTENT SHORT WAVE MOVING ACROSS THE NORTHERN ROCKIES WILL SEND
A COLD FRONT SOUTH ACROSS THE AREA SUNDAY NIGHT AND EARLY MONDAY.
THE NAM STALLS THE FRONT JUST SOUTH OF THE I-10 CORRIDOR ON MONDAY
WHILE THE GFS STALLS IT OVER THE CONCHO VALLEY AND HEARTLAND. THINK
THE NAM IS MORE REALISTIC GIVEN ITS BETTER RESOLUTION SO I HAVE THE
FRONT STALLING JUST SOUTH OF THE I-10 CORRDIOR BY MONDAY AFTERNOON.
THE FRONT WILL BRING COOLER TEMPERATURES ON MONDAY WITH AFTERNOON
HIGHS RANGING FROM NEAR 80 ACROSS THE BIG COUNTRY...TO THE LOW TO
MID 80S ELSEWHERE. RAIN CHANCES WILL INCREASE ALONG AND NORTH OF
THE FRONT LATE MONDAY AFTERNOON AND ESPECIALLY MONDAY NIGHT AS LOW
LEVEL WARM AIR ADVECTION INCREASES ATOP THE FRONT AND SYNOPTIC
SCALE LIFT INCREASES AS LEFT EXIT REGION OF THE SUBTROPICAL JET
OVERSPREADS THE AREA.

ON TUESDAY...MODELS SHOW A STRONG SURFACE RIDGE BUILDING SOUTH
ACROSS THE PLAINS WHICH WILL DRIVE THE COLD FRONT WELL SOUTH OF
THE AREA AND BRING BELOW NORMAL TEMPERATURES TO WEST CENTRAL TEXAS
THROUGH THE END OF THE WEEK. A POTENT CLOSED UPPER LOW IS STILL
PROGGED TO MOVE EAST FROM THE BAHA REGION BY MID WEEK AND MOVE
ACROSS WEST TEXAS BY WEEKS END. WHILE THE EXACT EVOLUTION OF THIS
SYSTEM IS STILL IN QUESTION...CINFIDENCE IS INCREASING THAT BENEFICIAL
RAINFALL...POSSIBLY HEAVY....WILL AFFECT WEST CENTRAL TEXAS THIS
COMING WEEK. CURRENT HIGHS ARE FORECAST TO BE IN THE 70S TUESDAY
THROUGH FRIDAY AND THESE NUMBERS MAY BE TOO WARM...ESPECIALLY ON
THURSDAY AS THE UPPER LOW MOVES ACROSS THE AREA. STAY TUNED!

&&

.PRELIMINARY POINT TEMPS/POPS...
ABILENE  72  97  64  81  62 /  20  10  10  20  30
SAN ANGELO  70 100  66  84  64 /  20  10  10  20  40
JUNCTION  71  95  68  87  64 /  20  10  20  20  30

&&

.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

99/99/99







AREA FORECAST DISCUSSION

NWS SAN ANGELO TX

 400 PM CDT SAT MAY 5 2012

.SHORT TERM...
DRYLINE HAS MOVED EAST INTO OUR WESTERN COUNTIES EARLY THIS
AFTERNOON AND SHOULD CONTINUE TO MOVE QUICKLY EAST AND OVER OUR
EASTERN COUNTIES BY LATE THIS AFTERNOON. LATEST NAM AND RUC ARE
SHOWING AN UPPER SHORTWAVE EMBEDDED IN THE SOUTHWEST FLOW ALOFT
MOVING OVER OUR EASTERN COUNTIES...AND THE DRYLINE...BY EARLY THIS
EVENING. GIVEN STRONG AFTERNOON HEARING...SHOULD SEE CONVECTIVE
INITIATION ALONG THE DRYLINE LATER THIS AFTERNOON CONTINUING THROUGH
THE EVENING HOURS. WILL GO WITH A 20 PERCENT CHANCE OF STORMS OVER
THE EASTERN HALF OF THE CWA THROUGH THE EVENING. ANY STORMS THAT
DEVELOP SHOULD ABATE QUICKLY AFTER SUNSET...WILL KEEP A DRY FORECAST
THROUGH THE REMAINDER OF THE NIGHT AND INTO TOMORROW AFTERNOON.
AFTER WARM MORNING LOWS IN THE 70S TOMORROW MORNING...WILL NOT BE
QUITE AS HOT TOMORROW AFTERNOON WITH HIGHS GENERALLY IN THE UPPER
90S ACROSS THE AREA.

FIRE WEATHER...
ELEVATED FIRE WEATHER CONDITIONS WILL CONTINUE THIS AFTERNOON WEST OF
A LINE FROM THROCKMORTON TO SAN ANGELO. FIRE WEATHER CONDITIONS
SHOULD EASE SUNDAY WITH ELEVATED CONCERNS CONFINED TO THE WESTERN
CONCHO VALLEY AND WESTERN NORTHERN EDWARDS PLATEAU. MINIMAL FIRE
WEATHER CONDITIONS ARE EXPECTED BEGINNING MONDAY AND CONTINUING
THROUGH THE REMAINDER OF THE WEEK.

&&

.LONG TERM...
BIG CHANGES IN STORE FOR WEST CENTRAL TEXAS NEXT WEEK WITH MUCH
COOLER TEMEPERATURES EXPECTED ALONG WITH INCREASING RAIN CHANCES.

A POTENT SHORT WAVE MOVING ACROSS THE NORTHERN ROCKIES WILL SEND
A COLD FRONT SOUTH ACROSS THE AREA SUNDAY NIGHT AND EARLY MONDAY.
THE NAM STALLS THE FRONT JUST SOUTH OF THE I-10 CORRIDOR ON MONDAY
WHILE THE GFS STALLS IT OVER THE CONCHO VALLEY AND HEARTLAND. THINK
THE NAM IS MORE REALISTIC GIVEN ITS BETTER RESOLUTION SO I HAVE THE
FRONT STALLING JUST SOUTH OF THE I-10 CORRDIOR BY MONDAY AFTERNOON.
THE FRONT WILL BRING COOLER TEMPERATURES ON MONDAY WITH AFTERNOON
HIGHS RANGING FROM NEAR 80 ACROSS THE BIG COUNTRY...TO THE LOW TO
MID 80S ELSEWHERE. RAIN CHANCES WILL INCREASE ALONG AND NORTH OF
THE FRONT LATE MONDAY AFTERNOON AND ESPECIALLY MONDAY NIGHT AS LOW
LEVEL WARM AIR ADVECTION INCREASES ATOP THE FRONT AND SYNOPTIC
SCALE LIFT INCREASES AS LEFT EXIT REGION OF THE SUBTROPICAL JET
OVERSPREADS THE AREA.

ON TUESDAY...MODELS SHOW A STRONG SURFACE RIDGE BUILDING SOUTH
ACROSS THE PLAINS WHICH WILL DRIVE THE COLD FRONT WELL SOUTH OF
THE AREA AND BRING BELOW NORMAL TEMPERATURES TO WEST CENTRAL TEXAS
THROUGH THE END OF THE WEEK. A POTENT CLOSED UPPER LOW IS STILL
PROGGED TO MOVE EAST FROM THE BAHA REGION BY MID WEEK AND MOVE
ACROSS WEST TEXAS BY WEEKS END. WHILE THE EXACT EVOLUTION OF THIS
SYSTEM IS STILL IN QUESTION...CINFIDENCE IS INCREASING THAT BENEFICIAL
RAINFALL...POSSIBLY HEAVY....WILL AFFECT WEST CENTRAL TEXAS THIS
COMING WEEK. CURRENT HIGHS ARE FORECAST TO BE IN THE 70S TUESDAY
THROUGH FRIDAY AND THESE NUMBERS MAY BE TOO WARM...ESPECIALLY ON
THURSDAY AS THE UPPER LOW MOVES ACROSS THE AREA. STAY TUNED!

&&

.PRELIMINARY POINT TEMPS/POPS...
ABILENE  72  97  64  81  62 /  20  10  10  20  30
SAN ANGELO  70 100  66  84  64 /  20  10  10  20  40
JUNCTION  71  95  68  87  64 /  20  10  20  20  30

&&

.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

15/24