Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 05/07/12
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
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 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 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 NORTHERN INDIANA
1203 AM EDT MON MAY 7 2012
.UPDATE...
ZONES/GRIDS UPDATED TO REFLECT CURRENT RADAR TRENDS AND TRENDS OF
LATEST HRRR MODELS.
CONVECTION HAS BEEN RAPIDLY DEVELOPING OVER THE PAST FEW HOURS
ACROSS PORTIONS OF SOUTHERN LAKE MI INTO N ILLINOIS IN AREA OF
MODERATE INSTABILITY AND NUMEROUS OUTFLOW BOUNDARIES. A FEW
SHOWERS AND STORMS HAVE DEVELOPED ACROSS LAPORTE AND BERRIEN
COUNTIES AND ARE TRYING TO MOVE EAST. HOWEVER...LARGE SFC DEWPT
GRADIENT NOTED WITH MUCH OF THE NE PARTS OF THE CWA SEEING DEWPTS
IN THE 30S AND 40S VS READINGS IN THE UPEPR 50S TO LOWER 60S ALONG
THE WESTERN TIER OF COUNTIES. HRRR PICKED UP ON THIS FEATURE AND
HOLDS WITH THESE LOWER SFC DEWPTS THROUGH THE NIGHT. HOWEVER...LL
MSTR ADVECTION CONTINUES TO INCREASE WHICH ALLOWS FOR AT LEAST AN
SLOW UPSWING IN SHOWER TRENDS. HAVE ADJUSTED GRIDS TO REFLECT
SLOWER ARRIVAL OF HIGHER POPS FROM WEST TO EAST THROUGH THE
REMAINDER OF THE NIGHT. THREW IN MENTION OF HEAVY RAIN GIVEN
INCREASING PWATS AND SLOW FLOW TO ALLOW FOR BACKBUILDING AND SLOW
FORWARD PROPAGATION.
&&
.PREV DISCUSSION... /ISSUED 825 PM EDT SUN MAY 6 2012/
AVIATION...
DRY EASTERLY FLOW AT THE SURFACE SHOULD KEEP BOTH TERMINALS VFR
THOUGH THE EVENING AND FIRST PART OF THE OVERNIGHT AS A DECAYING
MCS MOVES ACROSS NORTHERN INDIANA. ADDITIONAL DEVELOPMENT IS
EXPECTED ACROSS NORTHERN ILLINOIS TONIGHT AND WILL TREK ACROSS THE
AREA DURING THE EARLY MORNING HOURS. CONVECTIVE ELEMENT REMAINS
UNCERTAIN...AND WILL CONTINUE TO BE MONITORED. WINDS WILL SHIFT TO
NORTHWEST TOMORROW BEHIND A COLD FRONT...BUT WILL REMAIN LIGHT.
PREV DISCUSSION... /ISSUED 354 PM EDT SUN MAY 6 2012/
SHORT TERM... / LATE THIS AFTERNOON THROUGH MONDAY NIGHT /
MAIN CONCERN THIS PERIOD REMAINS CHANCES FOR CONVECTION.
SYNOPTICALLY...A CLOSED UPPER LOW OVER SOUTHERN SASKATCHEWAN WILL
TRACK EWD TOWARD THE NORTH DAKOTA/MANITOBA BORDER...WITH A TRAILING
POSITIVELY TILTED H5 TROUGH DROPPING INTO THE NORTH-CENTRAL CONUS.
AT THE SFC AS OF 19Z THERE WAS A QUASI STATIONARY FRONT DRAPED SW OF
THE FA FROM CENTRAL IL WEST TO A WEAK SFC REFLECTION NEAR KANSAS
CITY. AN OCCLUDED FRONT EXTENDED NORTH FROM HERE INTO THE UPPER
MIDWEST. THESE FRONTAL BOUNDARIES AND SFC REFLECTION WILL LIKELY
CONVERGE OVER THE LOCAL AREA TOMORROW. THIS WILL BRING INCREASING
CHANCES FOR SHOWERS AND STORMS TO THE AREA TONIGHT INTO TOMORROW.
LATE THIS AFTN INTO EARLY THIS EVENING...MCV ACROSS WISCONSIN WILL
WORK INTO CENTRAL AND NORTHERN PORTIONS OF MICHIGAN. SHOWERS
ASSOCIATED WITH THIS FEATURE HAVE WEAKENED ACROSS OUR FAR NW THIS
AFTN AS THEY ENCOUNTERED MUCH MORE STABLE AIR. RAISED POPS IN THE
FAR NW TO ACCOUNT FOR THESE WEAKENING SHOWERS WITH ONLY LIGHT
AMOUNTS EXPECTED OVER THE NEXT SEVERAL HOURS. FARTHER WEST ACROSS
NRN IL AND NRN MO SCT CONVECTION HAS FIRED ALONG A RATHER
IMPRESSIVE INSTABILITY GRADIENT. LATEST HI-RES GUIDANCE SUGGESTS
THAT COVERAGE WILL CONTINUE TO INCREASE INTO A MORE ORGANIZED
CONVECTIVE SYSTEM...MAINLY IMPACTING AREAS WEST INTO
CENTRAL/NORTHERN IL INTO THE EARLY EVENING HOURS. HOWEVER...COULD
SEE A FEW ELEVATED CELLS WORK INTO OUR WESTERN ZONES EARLY THIS
EVENING. OPTED TO CONTINUE WITH 30-60 POPS ACROSS MAINLY WESTERN
ZONES AFTER 00Z TO ACCOUNT FOR THIS...WITH A SLIGHT RISK FOR LARGE
HAIL AS MORE UNSTABLE AIR ADVECTS NEWD IN A WARM ADVECTION REGIME.
TONIGHT INTO MONDAY...LOW TO MID LEVEL THETA-E ADVECTION
EXPECTED AHEAD OF THE SFC LOW AND SFC INSTABILITY GRADIENT WILL
SUPPORT INCREASING CHANCES FOR SHOWERS/STORMS. COULD SEE SOME
LOCALLY HEAVY RAINFALL GIVEN EXPECTED SLOW MOVEMENT AND PWATS
INCREASING TO NEAR 1.6 INCHES. NO CHANGES TO INHERITED LIKELY POPS
INTO MONDAY AFTERNOON AS A MODEL CONSENSUS TRACKS THE AFOREMENTIONED
WEAK SFC LOW AND SOME SEMBLANCE OF A CONVECTIVELY ENHANCED/INDUCED
MID LEVEL PERTURBATION INTO NORTHERN INDIANA. THIS TRACK WOULD BRING
THE WARM FRONT AND MOIST/UNSTABLE BOUNDARY LAYER AIR INTO OUR
SOUTHEASTERN ZONES...WHICH BRINGS ABOUT THE CONCERN FOR SEVERE SFC
BASED CONVECTION HERE BY MONDAY AFTN. VERY LOW CONFIDENCE HERE GIVEN
EXPECTED LEFTOVER CLOUD COVER AND SHOWERS...WITH A MORNING MCS
OUTFLOW POSSIBLY FORCING THE FRONTAL BOUNDARY/SFC WAVE FARTHER
SOUTH. ISOLATED WIND DAMAGE/LARGE HAIL WILL BE THE PRIMARY THREAT IF
THESE AREAS ARE ABLE TO RECOVER THERMODYNAMICALLY...WITH MULTICELLS
POSSIBLE IN A WEAKLY SHEARED ENVIRONMENT.
LONG TERM...TUESDAY THROUGH SUNDAY
STRONG COLD ADVECTION TO BEGIN THIS PERIOD AS COLD FRONTAL ZONE
CONTINUES TO SHIFT EASTWARD FROM THE GREAT LAKES REGION INTO THE
LOWER OHIO VALLEY. POST FRONTAL DRY AIR ADVECTION WILL ALSO RESULT
IN MOSTLY SUNNY SKIES BY TUESDAY AFTERNOON. DESPITE COLD
ADVECTION...BOUNDARY LAYER WILL BE RELATIVELY DEEP AND BETTER LOW
LEVEL MIXING SHOULD SUPPORT HIGHS FROM MID TO UPPER 60S NORTH TO THE
LOWER 70S SOUTH.
FOR TUESDAY NIGHT...BLOCKING PATTERN ACROSS EASTERN CANADA WILL
RESULT IN SOUTHEAST MIGRATION OF UPPER LEVEL TROUGH CURRENTLY
APPROACHING THE NORTHERN HIGH PLAINS. PRECEDING DRY AIR ADVECTION
WILL MAKE PRECIP POTENTIAL QUESTIONABLE WITH THIS UPPER TROUGH.
POSITIVELY TILTED NATURE OF THIS TROUGH AS IT DROPS SOUTHWARD ACROSS
THE WESTERN GREAT LAKES SHOULD CONFINE PRECIP POTENTIAL TO
IMMEDIATELY DOWNSTREAM OF TROUGH AXIS ACROSS NORTHWEST PORTIONS OF
CWA TUESDAY NIGHT...CLOSER TO ASSOCIATED WEAK LOW LEVEL CONVERGENCE
AXIS. FURTHER DOWNSTREAM ACROSS NORTHEAST INDIANA INTO NORTHWEST
OHIO LOW LEVEL MOISTURE PROFILES WILL LIKELY REMAIN MORE MEAGER AND
HAVE REMOVED POPS TUESDAY NIGHT ACROSS THE EAST. HAVE MAINTAINED
CHANCE POPS ON WEDNESDAY AS UPPER TROUGH DIGS SOUTHEAST ACROSS THE
SOUTHERN GREAT LAKES BUT PRECIP AMOUNTS SHOULD BE ON THE LIGHT SIDE.
DRY CONDITIONS FOR WEDNESDAY NIGHT/THURSDAY AS THIS UPPER TROUGH
DEPARTS TO THE EAST AS MID/UPPER LEVEL HEIGHT RISES OVERSPREAD UPPER
MIDWEST AND GREAT LAKES REGION. SLOW MODERATION IN TEMPERATURES BACK
CLOSE TO NORMAL EXPECTED TOWARD THE END OF THE WEEK AS BROAD 1020 MB
SFC ANTICYCLONE SHIFTS INTO THE MID ATLANTIC STATES. ATTENTION FOR
THE REMAINDER OF THE PERIOD WILL FOCUS ON NEXT FAST MOVING PACIFIC
WAVE EXPECTED TO TRACK ACROSS NORTHERN CONUS/SOUTH CENTRAL CANADA
THIS WEEKEND. NARROW CORRIDOR OF MOISTURE RETURN IS POSSIBLE JUST IN
ADVANCE OF THIS FRONT BUT WILL INTRODUCE ONLY LOW CHANCE SHRA
MENTION AT THIS TIME WITH STRONGEST LOW LEVEL CONVG EXPECTED TO
REMAIN TO THE NORTH. WITH STRONGER FORCING AND MORE PROGRESSIVE FLOW
LIKELY REMAINING ACROSS GREAT LAKES INTO SOUTHEAST CANADA...THIS
BOUNDARY MAY STALL OUT ACROSS THE SOUTHERN GREAT LAKES TOWARD THE
END OF THE PERIOD...AND THUS HAVE MAINTAINED LOW CHANCE POPS INTO
SUNDAY.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...STEINWEDEL
LONG TERM...MARSILI
AVIATION...BENTLEY
UPDATE...FISHER
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 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
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 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
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 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 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
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...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 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 HASTINGS NE
1050 PM CDT SUN MAY 6 2012
.UPDATE...UPDATED THE FORECAST TONIGHT TO INCREASE SKY COVER AND
LOWER DEW POINTS...AND ALSO TO HOLD ON TO THE LINGERING SHOWERS IN
THE SOUTHEAST LONGER TONIGHT.
&&
.AVIATION...06Z KGRI TAF. WIND WILL BE THE BIGGEST ISSUE FOR THIS
FORECAST. NORTH WIND WILL PICK BACK UP AGAIN FOR MONDAY BY MID-
MORNING AS LOW-LEVEL LAPSE RATES INCREASE. THERE SHOULD BE A
CONSIDERABLE AMOUNT OF MID-LEVEL CLOUDINESS HANGING AROUND FOR
MOST IF NOT ALL OF THIS FORECAST. ANY SHOWER ACTIVITY SHOULD
REMAIN SOUTHEAST OF THE TERMINAL TONIGHT.
&&
PREV DISCUSSION... /ISSUED 400 PM CDT SUN MAY 6 2012/
SHORT TERM...TONIGHT AND MONDAY. MAIN FORECAST CONCERNS WILL BE
CHANCE FOR PRECIPITATION THIS EVENING AND TEMPERATURES.
SHOWERS AND ISOLATED THUNDERSTORMS CONTINUE TO MOVE TO THE NORTHEAST
THROUGH THE FORECAST AREA THIS AFTERNOON. CLOUDS CONTINUE ACROSS
MUCH OF THE AREA AS WELL. SURFACE ANALYSIS HAS THE MAIN BOUNDARY
WELL INTO CENTRAL AND EASTERN KANSAS. LOCAL RADAR HAS SHOWN A FEW
WEAK BOUNDARIES AND THAT IS WHAT THE SHOWERS AND THUNDERSTORMS HAVE
DEVELOPED ON THIS AFTERNOON.
AN UPPER LEVEL WAVE WILL CONTINUE TO MOVE THROUGH THE FORECAST AREA
THIS EVENING AND EXPECT THERE WILL BE SOME SCATTERED SHOWERS AND
MAYBE AN ISOLATED THUNDERSTORM THIS AFTERNOON...BUT THIS EVENING
SHOULD BE SHOWERS. THE HRRR AND WRF AS WELL AS THE NAM AND GFS ALL
CONTINUE SOME SHOWERS AROUND THE AREA THROUGH THE EVENING. AS THE
UPPER LEVEL WAVE MOVES TO THE EAST THIS EVENING THE PRECIPITATION
SHOULD COME TO AN END AND SKIES SHOULD START TO CLEAR OUT AS DRIER
AIR MOVES INTO THE AREA. TEMPERATURES TONIGHT SHOULD BE MUCH COOLER
THAN LAST NIGHT.
THERE IS A WEAK SURFACE HIGH THAT NOSES INTO THE AREA ON MONDAY.
THIS SHOULD BRING CLEARING TO THE AREA. DESPITE THE SUNSHINE...THERE
WILL CONTINUE TO BE COOLER TEMPERATURES ACROSS THE AREA.
LONG TERM...MAIN CONCERNS FOR THE EXTENDED PERIODS ARE THE CHANCE
FOR SOME PATCHY FROST ACROSS THE WESTERN FRINGES OF THE FORECAST
AREA TUESDAY MORNING AS WELL AS THE CHANCE FOR SHOWERS AND
THUNDERSTORMS LATE IN THE WEEK AND INTO NEXT WEEKEND.
A RIDGE OF HIGH PRESSURE IS EXPECTED TO BUILD ACROSS THE CENTRAL
AND NORTHERN PLAINS THROUGH MID WEEK...PEAKING ON THURSDAY...WHICH
WILL LIKELY BE THE WARMEST DAY OF THE WEEK. THE UPPER RIDGE IS
EXPECTED TO BREAK DOWN LATE THURSDAY NIGHT AS NEXT UPPER TROUGH
APPROACHES THE REGION...AND THE ASSOCIATED COLD FRONT SHOULD COOL
TEMPERATURES BACK DOWN BELOW CLIMATOLOGY AND BRING A RETURN OF
SOME SHOWERS AND THUNDERSTORMS TO THE LOCAL AREA BEGINNING IN THE
NORTHWEST THURSDAY NIGHT...AND SPREADING ACROSS THE ENTIRE
FORECAST AREA FRIDAY. SOME MINOR DISCREPANCIES BETWEEN LATEST EC
AND GFS ON EXACT TIMING OF FRONTAL BOUNDARY AS IT MOVES ACROSS THE
CENTRAL PLAINS...BUT BOTH HAVE THE FRONTAL BOUNDARY STALLING ALONG
OR JUST SOUTH OF THE FORECAST AREA BY SATURDAY MORNING AS THE
UPPER LEVEL FLOW BECOMES MORE ZONAL. AS A RESULT...KEPT SOME SMALL
POPS FROM THURSDAY NIGHT ON FOR MOST AREAS...WITH A DECREASING
CHANCE OF THUNDERSTORMS BY SATURDAY NIGHT AND SUNDAY AS
INSTABILITY BEGINS TO WANE.
IN THE MEANTIME...FOCUS IS THE POTENTIAL FOR FROST ACROSS WESTERN
PORTIONS OF THE FORECAST AREA TUESDAY MORNING AS AN AREA OF
SURFACE HIGH PRESSURE NUDGES IN FROM THE WEST. AT THIS TIME OPTED
NOT TO INCLUDE MENTION OF FROST IN THE FORECAST FOR DAWSON AND
VALLEY COUNTIES...BUT WILL NEED TO CONTINUE TO MONITOR PLACEMENT
OF SURFACE HIGH TUESDAY MORNING...AS GUIDANCE IS VERY NEAR THE 36
DEGREE THRESHOLD FOR FROST OVER THIS TIME PERIOD. OTHERWISE...THE
REMAINDER OF THE FORECAST FOR THE WEEK LOOKS PLEASANT...WITH DRY
CONDITIONS AND SEASONAL TEMPERATURES PREVAILING TUESDAY THROUGH
THURSDAY...AS THE UPPER LEVEL RIDGE AMPLIFIES ALOFT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AVIATION/UPDATE...HEINLEIN
SHORT TERM...JCB
LONG TERM...ROSSI
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 RALEIGH NC
715 PM EDT SUN MAY 6 2012
.SYNOPSIS...
HIGH PRESSURE ALONG THE MID ATLANTIC COAST WILL EXTEND SOUTHWEST
INTO THE CAROLINAS THROUGH MONDAY. A COLD FRONT WILL APPROACH THE
MOUNTAINS FROM THE WEST ON TUESDAY...BRINGING UNSETTLED WEATHER TO
THE AREA AS IT PROGRESSES THROUGH THE CAROLINAS LATE WEDNESDAY INTO
WEDNESDAY NIGHT.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 305 PM SUNDAY...
THIS MORNINGS STRATUS HAS FINALLY BEGUN TO BREAK...WITH WIDESPREAD
STRATOCU ACROSS THE CWA THIS AFTERNOON BUT STILL MOSTLY CLOUDY FOR
MUCH OF THE AREA. A WEAK LOW PRESSURE OFFSHORE OF KILM CAN BE SEEN
ON VISIBLE SATELLITE IMAGERY. THIS LOW WILL DRIFT SOUTHEAST
TONIGHT...WHILE HIGH PRESSURE SURGES INTO THE AREA FROM THE MID
ATLANTIC COAST. WITH LIMITED HEATING TODAY...MLCAPE GREATER THAN 500
J/KG IS TO THE SOUTH AND WEST OF THE CWA. PW REMAINS HIGH NEAR
1.3-1.5 INCHES...AND A FEW SPOTTY LIGHT SHOWERS HAVE DEVELOP NEAR
THE NC/SC BORDER...DRIFTING SOUTH INTO SC. THE HRRR ALSO SHOWS
SHOWERS DEVELOPING OVER THE VA MOUNTAINS AND DRIFTING SOUTH TOWARD
THE NORTHWEST PIEDMONT. HOWEVER...VERY LITTLE HAS DEVELOPED SO FAR
AND ANY THAT DO FORM SHOULD REMAIN OUTSIDE OF THE CWA PRIOR TO
SUNSET.
THE MAIN FORECAST CONCERN TONIGHT WILL THE POTENTIAL FOR FOG AND
STRATUS. WINDS WILL BE LIGHT AND REMAIN EAST-NORTHEASTERLY AND AS
THE STRATOCU DECK CONTINUES TO ERODE..SKIES SHOULD BECOME AT LEAST
PARTLY CLOUDY THIS EVENING. HOWEVER...WITH ALL OF THE MOISTURE
FOCUSED IN THE LOWEST 3000 FT...THE LOW LEVEL AIRMASS SHOULD BEING
TO RE-SATURATE BY MIDNIGHT. THE SURFACE RIDGE AXIS IS FORECAST TO
LIE NORTHEAST TO SOUTHEAST ACROSS CENTRAL NC. NEITHER FORECAST
SOUNDINGS OR SREF PROBABILITIES POINT STRONGLY TOWARD STRATUS OR
FOG...BUT GIVEN THAT MANY AREAS RECEIVED ONE TO TWO INCHES OF RAIN
LAST EVENING...WE WILL INCLUDE AT LEAST PATCHY FOG FOR TONIGHT.
LOWS IN THE UPPER 50S.
THE SURFACE RIDGE AXIS WILL SHIFT SLIGHTLY EASTWARD ON MONDAY AS
UPPER RIDGING BUILDS OVER THE CAROLINAS. SOUTHEASTERLY RETURN FLOW
WILL BEGIN TO DEVELOP BY MONDAY AFTERNOON. 1000-850MB THICKNESSES
ARE PROGGED TO RANGE FROM 1400M IN THE SOUTHWEST TO AROUND 1375M IN
THE NORTHEAST. MORNING STRATUS...IF ANY...SHOULD LIFT QUICKLY AND
THERE SHOULD BE A A FULL DAY OF HEATING....AND WITH NEUTRAL AIRMASS
ADVECTION OVER THE AREA...HIGHS WILL BE IN THE MID AND UPPER 70S
BASED ON THICKNESSES VALUES. RETURN FLOW SHOWERS AND STORMS WILL BE
POSSIBLE OVER THE HIGHER TERRAIN BUT THE COMBINATION OF THE SURFACE
HIGH AND WEAK MID LEVEL FLOW SHOULD KEEP EVERYTHING WEST OF THE
YADKIN RIVER.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 255 PM SUNDAY...
FOR MONDAY NIGHT: LOW STRATUS SHOULD FILL BACK IN OVERNIGHT WITHIN
THE LOW LEVEL WARM AIR ADVECTION REGIME. AS THE NORTHERN STREAM MID
LEVEL VORTEX DROPS SOUTHWARD INTO THE UPPER MIDWEST...THE SURFACE
COLD FRONT PUSHES INTO THE MID MISS VALLEY AND OHIO VALLEY (BENEATH
A WEAK SHORTWAVE WELL OUT AHEAD OF THE MAIN TROUGH)...WITH A FAIRLY
STRONG SURFACE LOW TRACKING ALONG THE FRONT THROUGH OH/LK ERIE/LK
ONTARIO. MODELS INDICATE SHALLOW AND WEAK MOIST ISENTROPIC UPGLIDE
NEAR THE GROUND IN THE TRIAD AREA MONDAY NIGHT ALONG WITH A BRIEF
SURGE IN LOW LEVEL MOISTURE TRANSPORT...HOWEVER THE BEST LOW LEVEL
WIND FIELD WILL SLIDE TO OUR NW AND NORTH...CLOSER TO THE SURFACE
LOW...AND ANY APPRECIABLE RAIN SHOULD STAY NW OF CENTRAL NC. WILL
RETAIN A MENTION OF JUST ISOLATED SPRINKLES IN THE FAR NW CWA. LOWS
59-63 WITH CLOUDY SKIES WEST AND PARTLY TO MOSTLY CLOUDY SKIES EAST
OVERNIGHT.
FOR TUESDAY/TUESDAY NIGHT: THE SURFACE HIGH OFF THE EAST COAST
CONTINUES MOVING EASTWARD RESULTING IN A STEADY VEERING OF LOW LEVEL
WINDS OVER CENTRAL NC TO SOUTHERLY AND SWRLY...FURTHER MOISTENING
THE COLUMN VIA MOISTURE ADVECTION. THE UPPER-MIDWEST MID LEVEL LOW
OPENS UP AS IT DROPS SOUTHEAST THROUGH MI THROUGH TUESDAY NIGHT...
AND THE AFOREMENTIONED PRECEDING WEAK WAVE DISSIPATES AS IT CROSSES
THE APPALACHIANS AND NORTHEAST...RESULTING IN VERY MINIMAL HEIGHT
FALLS INTO CENTRAL NC. BUT THE IMPROVING LOW LEVEL MASS CONVERGENCE
(WITH BOTH GULF AND ATLANTIC MOISTURE SOURCES) AND POTENTIAL FOR AT
LEAST MARGINAL INSTABILITY WILL NECESSITATE LEAVING SCATTERED
SHOWERS AND A FEW STORMS IN THE FORECAST...MAINLY IN THE AFTERNOON
THROUGH MID EVENING HOURS. WITH PERIODS OF PARTIAL SUNSHINE...
ABOVE-NORMAL THICKNESSES... AND A SOUTHWESTERLY BREEZE... EXPECT
HIGHS OF 78-83. THE SURFACE FRONT SHOULD STILL BE JUST TO OUR
NORTHWEST TUESDAY NIGHT... BUT PREFRONTAL LOW AND MID LEVEL WINDS
WILL STEADILY STRENGTHEN WITH HIGH PRECIPITABLE WATER ADVECTING INTO
THE REGION. MID LEVEL HEIGHTS BEGIN TO FALL SLOWLY WITH THE TROUGH`S
APPROACH... AND FORECAST SOUNDINGS DEPICT ENOUGH LOW LEVEL WARMTH
FOR A COUPLE HUNDRED J/KG OF MLCAPE OVERNIGHT. THE RESULTING LIFT
OVER WRN NC IS SUFFICIENT TO KEEP A RISK OF SCATTERED SHOWERS/STORMS
GOING IN THE WESTERN PORTION OF THE FORECAST AREA THROUGH TUESDAY
NIGHT...WITH LESSER CHANCES IN THE EAST WHERE THE MOISTURE TRANSPORT
WILL BE A BIT LOWER WITH LITTLE INSTABILITY BENEATH LINGERING
SLIGHTLY ANTICYCLONIC LOW LEVEL FLOW. WARM AND MUGGY LOWS OF 63-67.
FOR WEDNESDAY/WEDNESDAY NIGHT: CONFIDENCE CONTINUES TO RISE THAT
WE`LL SEE A PERIOD OF WIDESPREAD SHOWERS AND STORMS. THE MID LEVEL
TROUGH CONTINUES TO DROP ESE INTO THE INTERIOR NORTHEAST AND
MIDATLANTIC STATES...LEADING TO STRENGTHENING DYNAMIC FORCING FOR
ASCENT OVER NC...A RESULT OF MID LEVEL HEIGHT FALLS AND UPPER
DIVERGENCE IN THE RIGHT ENTRANCE REGION OF A STRENGTHENING 130+ KT
JET OVER THE EASTERN GREAT LAKES. MODELS HAVE BEEN SLOWING DOWN THIS
SYSTEM IN RECENT RUNS...AND THE GFS NOW HOLDS OFF FRONTAL PASSAGE
UNTIL AFTER NIGHTFALL WEDNESDAY EVENING. GIVEN EXPECTATIONS OF
PLENTIFUL MOISTURE (PRECIPITABLE WATER NEARLY 200% OF NORMAL) AHEAD
OF THE FRONT AND AUGMENTATION OF LIFT BY PROJECTED 800-1200 J/KG OF
(SKINNY) SURFACE CAPE...WILL RAISE POPS TO HIGH LIKELY AND LOW
CATEGORICAL FOR WEDNESDAY AFTERNOON AND EVENING. EXPECT RAIN CHANCES
TO DECREASE OVERNIGHT -- BUT NOT END -- AS THE MID LEVEL TROUGH AXIS
LAGS THE SURFACE FRONT RESULTING IN A DELAY IN DRYING ALOFT. HAVE
NUDGED HIGHS DOWN A BIT TO 73-80 WITH THICK CLOUDS EXPECTED. LOWS
55-61. -GIH
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 310 PM SUNDAY...
FOR THURSDAY/THURSDAY NIGHT: WILL DELAY THE END OF RAIN CHANCES AND
CLEARING OF CLOUDS UNTIL THURSDAY MORNING BASED ON MODEL TRENDS...
ALTHOUGH DOWNSLOPE LOW LEVEL FLOW SHOULD ALLOW FOR PARTLY TO MOSTLY
SUNNY SKIES IN THE AFTERNOON. THE NEW 12Z ECMWF HAS BACKED OFF FROM
ITS 00Z RUN WHICH BROUGHT A CLOSED MID LEVEL VORTEX WELL SOUTH
ACROSS NRN/ERN VA THURSDAY NIGHT INTO FRIDAY. THE 12Z RUN MORE
CLOSELY RESEMBLES THE GFS WITH A MORE OPEN AND PROGRESSIVE TROUGH...
SO HAVE GONE THIS ROUTE WITH IMPROVING CONDITIONS BY MIDDAY
THURSDAY. LOW LEVEL THICKNESSES DROP TO 10-15 METERS BELOW NORMAL...
SUPPORTING HIGHS OF 72-77. LOWS 46-52 WITH CHILLY HIGH PRESSURE
STARTING TO BUILD IN FROM THE NW AND THICKNESSES EXPECTED TO FALL
INTO THE 1340S.
FOR FRIDAY THROUGH SUNDAY: GENERALLY COOL AND DRY WITH A MODERATING
TREND BACK TOWARD NORMAL OVER THE WEEKEND. EXPECT HIGHS OF 70-75
FRIDAY WITH MODEL THICKNESSES OVER 30 METERS BELOW NORMAL. HIGH
PRESSURE CONTINUES TO BUILD IN AS THE MID LEVEL TROUGH COVERING THE
NORTHEAST STATES LIFTS TO THE ENE. THE CLOSED LOW OVER AZ EARLY IN
THE WEEK WEAKENS AS IT SHIFTS ACROSS NRN MEXICO AND TX THROUGH
SATURDAY... THEN MOVES INTO THE INTERIOR SOUTHEAST STATES ON SUNDAY.
WHILE THE MODELS DEPICT THE SURFACE HIGH CENTER MOVING OFFSHORE WITH
LOW LEVEL FLOW BECOMING EASTERLY AND SOUTHEASTERLY... THE COLUMN
SHOULD REMAIN FAIRLY DRY WITH STABLE MID LEVELS... AND ANY MID LEVEL
DPVA APPEARS TOO LOW/WEAK FOR ANYTHING MORE THAN A SLIGHT CHANCE OF
SHOWERS AT MOST ON SUNDAY. BELOW-NORMAL HIGHS IN THE LOW 70S SHOULD
TREND BACK UP TO THE MID 70S THEN UPPER 70S TO NEAR 80 OVER THE
WEEKEND. -GIH
&&
.AVIATION /00Z MONDAY THROUGH THURSDAY/...
AS OF 715 PM SUNDAY...
24-HR TAF PERIOD:
AS OF 23Z...MVFR CEILINGS LINGERED ACROSS PORTIONS OF CENTRAL AND
EASTERN NORTH CAROLINA. ASIDE FROM ISOLATED MVFR CEILINGS... EXPECT
VFR CONDITIONS TO PREVAIL THROUGH 06Z. A SURFACE LOW PRESSURE SYSTEM
OFFSHORE THE SOUTHEAST COAST THIS EVENING WILL PROGRESS FURTHER
OFFSHORE TONIGHT...ALLOWING NORTHEASTERLY LOW-LEVEL FLOW TO VEER TO
THE EAST AFTER MIDNIGHT. AS LOW-LEVEL FLOW VEERS TO THE EAST...
ATLANTIC MOISTURE WILL ADVECT WESTWARD INTO PORTIONS OF CENTRAL NC
BETWEEN 06-12Z MONDAY MORNING...BRINGING WITH IT A POTENTIAL FOR
IFR/LIFR CEILINGS. HOWEVER...THE LATEST MODEL GUIDANCE CONTINUES TO
VARY WITH THE AMOUNT OF LOW-LEVEL MOISTURE THAT ADVECTS INTO THE
AREA...AND UNCERTAINTY REMAINS HIGH W/REGARD TO WHETHER OR NOT
IFR/LIFR CEILINGS WILL DEVELOP BETWEEN 06-12Z MONDAY MORNING. AT
THIS TIME...WILL INCLUDE A TEMPO GROUP FOR IFR CEILINGS BETWEEN
07-12Z AT THE TAF SITES (RDU/FAY/RWI) MORE LIKELY TO SEE STRATUS
DEVELOP DURING THE PRE-DAWN HOURS. ANY SUB-VFR CEILINGS THAT DEVELOP
WOULD BE EXPECTED TO QUICKLY MIX OUT IN ASSOC/W DIURNAL HEATING
AFTER SUNRISE IN THE 12-14Z TIME FRAME. OTHERWISE...VFR CONDITIONS
ARE EXPECTED TO PREVAIL...WITH SCATTERED (RWI/FAY/RDU) TO BROKEN
(INT/GSO) DIURNAL CU (BASES ~4000 FT AGL) MONDAY AFTERNOON AND THE
BEST CHANCE FOR ISOLD CONVECTION EXPECTED TO REMAIN WEST OF THE AREA
IN THE FOOTHILLS/MOUNTAINS. LIGHT AND VARIABLE OR EASTERLY WINDS
TONIGHT WILL BECOME S/SE AT 5-10 KT BY MONDAY AFTERNOON.
LOOKING AHEAD (TUESDAY-THURSDAY):
SUB-VFR CEILINGS WILL BE POSSIBLE AGAIN LATE MONDAY NIGHT/TUE
MORNING IN ASSOC/W A MOIST SOUTHERLY RETURN FLOW. EXPECT INCREASING
CHANCES FOR CONVECTION ON TUESDAY AS A COLD FRONT PROGRESSES INTO
THE EASTERN TN/OH VALLEYS...WITH THE RELATIVE BEST CHANCE AT THE
INT/GSO TAF SITES. CHANCES FOR CONVECTION WILL CONTINUE TO INCREASE
LATE TUE NIGHT AS A PRE-FRONTAL TROUGH PROGRESSES EAST INTO THE
CAROLINAS. WIDESPREAD SHOWERS AND THUNDERSTORMS (LIKELY AFFECTING
ALL TAF SITES) ARE EXPECTED DURING THE DAY WEDNESDAY AS THE COLD
FRONT PROGRESSES THROUGH CENTRAL NC...WITH VFR CONDITIONS RETURNING
IN THE WAKE OF THE FRONT THURSDAY. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...SMITH
SHORT TERM...HARTFIELD
LONG TERM...HARTFIELD
AVIATION...VINCENT
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 TULSA OK
921 PM CDT SUN MAY 6 2012
...UPDATE...
.DISCUSSION...
COLD FRONT CURRENTLY EXTENDING FROM EAST CENTRAL KANSAS SOUTHWARD
INTO SOUTHWEST OKLAHOMA HAS PROGRESSED ONLY SLOWLY EASTWARD THIS
EVENING...AND HAS RECENTLY BECOME THE FOCUS FOR EXPANDING
THUNDERSTORM COVERAGE ACROSS EASTERN KANSAS. 00Z KOUN SOUNDING
SAMPLED THE HIGHLY UNSTABLE YET CAPPED AIRMASS CURRENTLY IN PLACE.
GIVEN THE ABSENCE OF LARGE SCALE FORCING IN PLACE...THE FOCUS FOR
LIFT WILL REMAIN NEAR THE COLD FRONT. THE EVOLUTION OF CONVECTION
ALONG THE FRONT IS UNCLEAR AS SOME SHORT TERM MODEL SOLUTIONS
DEVELOP AN AGGRESSIVE COLD POOL WHICH SPREAD SOUTHEASTWARD DURING
THE EARLY MORNING HOURS. THE 00Z NAM IS IN THIS CAMP HOWEVER WE
QUESTION WHETHER IT IS RELEASING THE HIGH CAPE ENVIRONMENT TOO
EASILY...WITH LOCAL WRF RUNS MUCH LESS AGGRESSIVE IN SOUTHEASTWARD
DEVELOPMENT. THE HRRR SOLUTIONS HAVE BEEN SOMEWHAT CONSISTENT AND
OFFER A COMPROMISE WHICH SEEMS REASONABLE AT THIS POINT...AND
ALLOW CONVECTION TO SPREAD SOUTHEASTWARD OFF THE FRONT BUT
EVENTUALLY LIMIT THE SOUTHWARD ADVANCE DURING THE OVERNIGHT HOURS.
THUS THE UPDATED FORECAST WILL TRIP POPS ACROSS THE SOUTHERN HALF
OF THE FORECAST AREA AND RETAIN THE FOCUS FOR NORTHEAST OKLAHOMA
INTO FAR NORTHWEST ARKANSAS. THE STABILIZING BOUNDARY LAYER LOOKS
TO KEEP THE HIGHEST INSTABILITY FROM BEING REALIZED...HOWEVER
POOLING DEEPER MOISTURE NEAR THE FRONTAL ZONE WILL RETAIN
SUFFICIENT ELEVATED INSTABILITY TO WARRANT A SEVERE WEATHER RISK
OVERNIGHT. OVERNIGHT LOW TEMPS LOOK ON TRACK ASSUMING SOME TYPE OF
OUTFLOW COOLS LOCATIONS AHEAD OF THE FRONTAL POSITION BEFORE
SUNRISE.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 66 75 55 74 / 50 20 10 10
FSM 70 80 60 77 / 30 60 10 10
MLC 68 76 59 75 / 20 30 20 10
BVO 64 74 52 74 / 60 10 10 10
FYV 66 74 54 72 / 70 50 10 10
BYV 66 77 56 72 / 70 50 10 10
MKO 68 76 56 75 / 30 30 10 10
MIO 66 74 54 72 / 70 20 10 10
F10 66 75 56 74 / 20 30 10 10
HHW 69 81 63 78 / 20 30 30 40
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...07
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
712 PM CDT SUN MAY 6 2012
.DISCUSSION...SEE 00Z AVIATION DISCUSSION.
&&
.AVIATION...CONVECTION IS FIRING UP IN SOUTH CENTRAL TX...AND SOME
MODELS (TTU AND HRRR) BRING THIS CONVECTION INTO KVCT AREA.
CONFIDENCE IN THIS HAPPENING ARE NOT HIGH ENOUGH AT THIS TIME
(GIVEN WEAKER LOW LEVEL WINDS TONIGHT...INCREASING CIN/LOWER CAPES AND
LACK OF UPPER SUPPORT). THAT BEING SAID...EXPECTING MUCH LESS MID
AND HIGH CLOUD COVER TONIGHT...SO WILL BRING IN THE MVFR
CONDITIONS A BIT EARLIER...OVER KVCT AOA 03Z AND KCRP/KALI AOA
06Z. EXPECTING VFR AT KLRD (AND HAVE REMOVED THUNDER). HAVE ALSO
INCLUDED A BIT OF BR (ACTUALLY KEPT FROM PREVIOUS TAFS)...WITH
POSSIBLE IFR CIGS AT KALI. WILL HAVE MVFR CONDITIONS EAST OF KLRD
TIL ABOUT 17Z. AM EXPECTING LESS WIND TOMORROW AS WELL (WITH FRONT
TO THE NORTH)...BUT WINDS WILL BE A BIT GUSTY AT TIMES DURING THE
AFTERNOON SO HAVE A MENTION OF GUSTS (LESS THAN 25 KNOTS) FOR THE
AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 327 PM CDT SUN MAY 6 2012/
SHORT TERM (TONIGHT THROUGH MONDAY NIGHT)...MAIN FORECAST
CHALLENGE IN SHORT TERM PERIOD IS CONVECTIVE CHANCES TONIGHT AND
AGAIN MON NIGHT. SEVERAL BOUNDARIES WERE EMITTED LAST NIGHT FROM
MCS THAT REMAINED JUST TO OUR NORTH. ONE BOUNDARY HAS RECENTLY PUSHED
OFF THE LOWER TX COAST WHILE ANOTHER LOST ITS CHARACTERISTICS OVER
CRP CWA. SEA BREEZE IS TRYING TO PUSH INLAND BUT MAY NOT BE ABLE
TO COMPENSATE FOR SLIGHT CIN VALUES ACROSS COASTAL PLAINS...THUS
ISO CONVECTION MAY BE VERY LIMITED ACROSS THE EAST REMAINDER OF
THIS AFTERNOON. FOCUS FOR LATE AFTERNOON AND THIS EVENING TURNS TO
WESTERN ZONES WHERE CONVECTION MAY DEVELOP OR MOVE IN FROM OLD
MEX. SURFACE DRYLINE/TROUGH CURRENTLY EXTENDS FROM ACROSS EDWARDS
PLATEAU AND FARTHER SOUTH INTO MEX. CONVECTION IS ALREADY
DEVELOPING ALONG BOUNDARY AND IN HIGHER ELEVATIONS IN MEX AND SOME
OF THIS CONVECTION MAY APPROACH WESTERN ZONES THIS EVENING.
SEVERAL CONSECUTIVE RUNS OF HRRR WANT TO BRING CONVECTION THROUGH
WESTERN ZONES OVERNIGHT WHILE OTHER 4KM WRF RUNS WERE DRIER. DO NOT
WANT TO COMPLETELY DISCOUNT HRRR AS OTHER RUNS DID NOT HANDLE THIS
MORNING/S MCS AND RESULTANT MCV WELL AND THUS HAVE DECIDED TO GO
WITH LOW CHANCE POPS TONIGHT OUT WEST. ANY STORMS THAT OCCUR MAY
BECOME STRONG WITH AN ISOLATED SEVERE THREAT POSSIBLE. WILL ALSO
NEED TO WATCH FOR POTENTIAL CONVECTION ACROSS EWX CWA AS CORFIDI
VECTORS INDICATE POTENTIAL MOVEMENT INTO OUR NORTHERN ZONES. IF
CONVECTION DOES AFFECT CWA THERE IS A SLIGHT CHANCE IT MAY REACH
THE COASTAL PLAINS LATE TONIGHT BUT THOSE CHANCES ARE CURRENTLY
LOW AS CIN VALUES FARTHER EAST WILL BE INCREASING OVERNIGHT. FOR
MONDAY...MID LEVEL RIDGING SHOULD HELP KEEP S TX HOT WITH HIGHS
AROUND 100 ACROSS WESTERN ZONES AND 90S ACROSS THE EAST UNDER
PARTLY TO MOSTLY SUNNY SKIES IN THE AFTERNOON. GFS AND CMC WANT TO
DEVELOP CONVECTION TO OUR NW IN EWX CWA MON AFTERNOON WITH
CONVECTION MOVING SOUTHEAST TOWARDS OUR AREA DURING THE EVENING.
NAM AND ECMWF ARE LESS ROBUST AND KEEP MOST ACTIVITY TO OUR NORTH.
FOR NOW...GIVEN BETTER UPPER LEVEL DYNAMICS PROG TO EXIST...HAVE
GONE WITH CHANCE POPS ACROSS NW AREAS.
LONG TERM (TUESDAY THROUGH SUNDAY)...MAIN ISSUES FOR THE
EXTENDED PART OF THE FORECAST WILL BE CONVECTION THROUGHOUT THE
WEEK. PERIOD WILL START OF WILL UPPER LEVEL RIDGE MOVING EAST AND
DAMPENING AS UPPER LEVEL LOW DEEPENS OVER SOUTHERN CA/AZ. COLD
FRONT WILL BE MOVING SOUTHWARD ACROSS TEXAS DURING THE DAY ON
TUESDAY. MODELS PROG LEFT EXIT REGION OF UPPER JET TO BE
APPROACHING THE AREA AS WELL DURING THIS TIME. MOISTURE WILL BE IN
PLACE AS PWATS CLIMB TO ABOUT 1.4 TO 1.5 INCHES OVER SOUTH TEXAS.
THIS WILL LEAD TO SHOWERS AND STORMS DEVELOPING ALONG THE BOUNDARY
TUESDAY NIGHT INTO WEDNESDAY. NAM/GFS IN FAIRLY GOOD AGREEMENT ON
EVOLUTION OF THE FRONT SO WAS COMFORTABLE RAISING POPS FOR THESE
PERIOD. WILL CARRY 50 POPS OUT WEST TO 20 POPS OVER THE COASTAL
PLAINS TUESDAY NIGHT WITH 40 POPS OVER LAND ON WEDNESDAY.
CONVECTIVE ACTIVITY WILL BE HIGHLY DEPENDENT ON WHERE FRONT ENDS
UP AND HOW LONG IT LINGERS OVER THE CWA. THESE DETAILS WILL BE
FINE TUNED OVER THE NEXT SEVERAL DAYS. UPPER LOW WILL BE MOVING
OUT OF MEXICO AND WEST TEXAS TO THE EAST NORTHEAST THURSDAY INTO
FRIDAY. MOISTURE WILL STILL REMAIN OVER SOUTH TEXAS AS PWAT VALUES
CONTINUE TO BE ABOVE NORMAL FOR THIS TIME OF YEAR. SHOWER AND
THUNDERSTORM CHANCES WILL CONTINUE FOR THE SECOND HALF OF THE WORK
WEEK. HAVE ALSO RAISED POPS DURING THE THURSDAY NIGHT AND FRIDAY
TIME FRAME. OVERALL...A WET PERIOD MAY MATERIALIZE ACROSS SOUTH
TEXAS THIS UPCOMING WEEK WITH PERIODS OF LOCALLY HEAVY RAINFALL
POSSIBLE. AFTERNOON HIGH TEMPERATURES WEDNESDAY THROUGH FRIDAY
WILL BE AT OR BELOW NORMAL FOR THIS TIME OF YEAR DUE TO CLOUD
COVER AND PRECIP CHANCES. UPPER SYSTEM WILL BEGIN TO MOVE
NORTHEAST OF THE REGION ON SATURDAY...WITH RAIN CHANCES ENDING
FROM WEST TO EAST.
MARINE...SCEC CONDITIONS TO PERSIST TONIGHT THROUGH AT LEAST
MONDAY WITH LITTLE CHANGE EXPECTED TO SEA CONDITIONS. AREAS OF
HAZE FROM AGRICULTURAL FIRES IN MEXICO MAY EXIST MONDAY ACROSS THE
OPEN WATERS OF THE MIDDLE TEXAS COAST. A LATE SEASON COLD FRONT
AND STRONG UPPER LEVEL WEATHER DISTURBANCE MAY AFFECT THE AREA BY
THE MIDDLE OF THIS WEEK WITH SHOWER AND THUNDERSTORM CHANCES
INCREASING AT TIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 74 92 74 89 72 / 10 10 10 10 20
VICTORIA 70 92 72 87 70 / 10 10 10 20 20
LAREDO 75 101 75 94 72 / 30 10 20 10 40
ALICE 72 97 73 91 71 / 10 10 10 10 30
ROCKPORT 76 86 76 85 76 / 10 10 10 10 20
COTULLA 72 99 71 91 70 / 30 20 30 20 50
KINGSVILLE 74 96 75 90 73 / 10 10 10 10 20
NAVY CORPUS 75 86 76 86 75 / 10 10 10 10 20
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
GW/86...MESO/AVIATION
TE/81...SYNOPTIC/GRIDS
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
700 PM CDT SUN MAY 6 2012
.DISCUSSION...HAVE LOWERED POPS ACROSS THE WEST ZONES TO A SLIGHT
CHC. THE ENVIRONMENT IS EXPECTED TO BECOME LESS FAVORABLE FOR
CONVECTION THROUGH THE EVENING HOURS AND STORMS CURRENTLY IN MEX
ARE EXPECTED TO WEAKEN AS THEY MOVE E TOWARD THE RIO GRANDE. A FEW
MAY STILL MOVE/DVLP GIVEN THE CAPE AND DEEPER MOISTURE ACROSS THE
RIO GRANDE PLAINS...THEREFORE DID NOT WANT TO COMPLETELY REMOVE
POPS. REST OF FCST LOOKS ON TRACK.
&&
.PREV DISCUSSION... /ISSUED 327 PM CDT SUN MAY 6 2012/
SHORT TERM (TONIGHT THROUGH MONDAY NIGHT)...MAIN FORECAST
CHALLENGE IN SHORT TERM PERIOD IS CONVECTIVE CHANCES TONIGHT AND
AGAIN MON NIGHT. SEVERAL BOUNDARIES WERE EMITTED LAST NIGHT FROM
MCS THAT REMAINED JUST TO OUR NORTH. ONE BOUNDARY HAS RECENTLY PUSHED
OFF THE LOWER TX COAST WHILE ANOTHER LOST ITS CHARACTERISTICS OVER
CRP CWA. SEA BREEZE IS TRYING TO PUSH INLAND BUT MAY NOT BE ABLE
TO COMPENSATE FOR SLIGHT CIN VALUES ACROSS COASTAL PLAINS...THUS
ISO CONVECTION MAY BE VERY LIMITED ACROSS THE EAST REMAINDER OF
THIS AFTERNOON. FOCUS FOR LATE AFTERNOON AND THIS EVENING TURNS TO
WESTERN ZONES WHERE CONVECTION MAY DEVELOP OR MOVE IN FROM OLD
MEX. SURFACE DRYLINE/TROUGH CURRENTLY EXTENDS FROM ACROSS EDWARDS
PLATEAU AND FARTHER SOUTH INTO MEX. CONVECTION IS ALREADY
DEVELOPING ALONG BOUNDARY AND IN HIGHER ELEVATIONS IN MEX AND SOME
OF THIS CONVECTION MAY APPROACH WESTERN ZONES THIS EVENING.
SEVERAL CONSECUTIVE RUNS OF HRRR WANT TO BRING CONVECTION THROUGH
WESTERN ZONES OVERNIGHT WHILE OTHER 4KM WRF RUNS WERE DRIER. DO NOT
WANT TO COMPLETELY DISCOUNT HRRR AS OTHER RUNS DID NOT HANDLE THIS
MORNING/S MCS AND RESULTANT MCV WELL AND THUS HAVE DECIDED TO GO
WITH LOW CHANCE POPS TONIGHT OUT WEST. ANY STORMS THAT OCCUR MAY
BECOME STRONG WITH AN ISOLATED SEVERE THREAT POSSIBLE. WILL ALSO
NEED TO WATCH FOR POTENTIAL CONVECTION ACROSS EWX CWA AS CORFIDI
VECTORS INDICATE POTENTIAL MOVEMENT INTO OUR NORTHERN ZONES. IF
CONVECTION DOES AFFECT CWA THERE IS A SLIGHT CHANCE IT MAY REACH
THE COASTAL PLAINS LATE TONIGHT BUT THOSE CHANCES ARE CURRENTLY
LOW AS CIN VALUES FARTHER EAST WILL BE INCREASING OVERNIGHT. FOR
MONDAY...MID LEVEL RIDGING SHOULD HELP KEEP S TX HOT WITH HIGHS
AROUND 100 ACROSS WESTERN ZONES AND 90S ACROSS THE EAST UNDER
PARTLY TO MOSTLY SUNNY SKIES IN THE AFTERNOON. GFS AND CMC WANT TO
DEVELOP CONVECTION TO OUR NW IN EWX CWA MON AFTERNOON WITH
CONVECTION MOVING SOUTHEAST TOWARDS OUR AREA DURING THE EVENING.
NAM AND ECMWF ARE LESS ROBUST AND KEEP MOST ACTIVITY TO OUR NORTH.
FOR NOW...GIVEN BETTER UPPER LEVEL DYNAMICS PROG TO EXIST...HAVE
GONE WITH CHANCE POPS ACROSS NW AREAS.
LONG TERM (TUESDAY THROUGH SUNDAY)...MAIN ISSUES FOR THE
EXTENDED PART OF THE FORECAST WILL BE CONVECTION THROUGHOUT THE
WEEK. PERIOD WILL START OF WILL UPPER LEVEL RIDGE MOVING EAST AND
DAMPENING AS UPPER LEVEL LOW DEEPENS OVER SOUTHERN CA/AZ. COLD
FRONT WILL BE MOVING SOUTHWARD ACROSS TEXAS DURING THE DAY ON
TUESDAY. MODELS PROG LEFT EXIT REGION OF UPPER JET TO BE
APPROACHING THE AREA AS WELL DURING THIS TIME. MOISTURE WILL BE IN
PLACE AS PWATS CLIMB TO ABOUT 1.4 TO 1.5 INCHES OVER SOUTH TEXAS.
THIS WILL LEAD TO SHOWERS AND STORMS DEVELOPING ALONG THE BOUNDARY
TUESDAY NIGHT INTO WEDNESDAY. NAM/GFS IN FAIRLY GOOD AGREEMENT ON
EVOLUTION OF THE FRONT SO WAS COMFORTABLE RAISING POPS FOR THESE
PERIOD. WILL CARRY 50 POPS OUT WEST TO 20 POPS OVER THE COASTAL
PLAINS TUESDAY NIGHT WITH 40 POPS OVER LAND ON WEDNESDAY.
CONVECTIVE ACTIVITY WILL BE HIGHLY DEPENDENT ON WHERE FRONT ENDS
UP AND HOW LONG IT LINGERS OVER THE CWA. THESE DETAILS WILL BE
FINE TUNED OVER THE NEXT SEVERAL DAYS. UPPER LOW WILL BE MOVING
OUT OF MEXICO AND WEST TEXAS TO THE EAST NORTHEAST THURSDAY INTO
FRIDAY. MOISTURE WILL STILL REMAIN OVER SOUTH TEXAS AS PWAT VALUES
CONTINUE TO BE ABOVE NORMAL FOR THIS TIME OF YEAR. SHOWER AND
THUNDERSTORM CHANCES WILL CONTINUE FOR THE SECOND HALF OF THE WORK
WEEK. HAVE ALSO RAISED POPS DURING THE THURSDAY NIGHT AND FRIDAY
TIME FRAME. OVERALL...A WET PERIOD MAY MATERIALIZE ACROSS SOUTH
TEXAS THIS UPCOMING WEEK WITH PERIODS OF LOCALLY HEAVY RAINFALL
POSSIBLE. AFTERNOON HIGH TEMPERATURES WEDNESDAY THROUGH FRIDAY
WILL BE AT OR BELOW NORMAL FOR THIS TIME OF YEAR DUE TO CLOUD
COVER AND PRECIP CHANCES. UPPER SYSTEM WILL BEGIN TO MOVE
NORTHEAST OF THE REGION ON SATURDAY...WITH RAIN CHANCES ENDING
FROM WEST TO EAST.
MARINE...SCEC CONDITIONS TO PERSIST TONIGHT THROUGH AT LEAST
MONDAY WITH LITTLE CHANGE EXPECTED TO SEA CONDITIONS. AREAS OF
HAZE FROM AGRICULTURAL FIRES IN MEXICO MAY EXIST MONDAY ACROSS THE
OPEN WATERS OF THE MIDDLE TEXAS COAST. A LATE SEASON COLD FRONT
AND STRONG UPPER LEVEL WEATHER DISTURBANCE MAY AFFECT THE AREA BY
THE MIDDLE OF THIS WEEK WITH SHOWER AND THUNDERSTORM CHANCES
INCREASING AT TIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 74 92 74 89 72 / 10 10 10 10 20
VICTORIA 70 92 72 87 70 / 10 10 10 20 20
LAREDO 75 101 75 94 72 / 20 10 20 10 40
ALICE 72 97 73 91 71 / 10 10 10 10 30
ROCKPORT 76 86 76 85 76 / 10 10 10 10 20
COTULLA 72 99 71 91 70 / 20 20 30 20 50
KINGSVILLE 74 96 75 90 73 / 10 10 10 10 20
NAVY CORPUS 75 86 76 86 75 / 10 10 10 10 20
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
TE/81...SHORT TERM
GW/86...AVIATION
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
629 PM CDT SUN MAY 6 2012
.AVIATION...
VFR CONDITIONS EXPECTED TO CONTINUE UNTIL 07Z-08Z...AFTER WHICH
LOW STRATUS IS FORECAST TO EXPAND SOUTH FROM THE PANHANDLES AND
AFFECT KLBB AND KCDS WITH MVFR CEILINGS...AND POSSIBLY A PERIOD OF
IFR CEILINGS AT KLBB EARLY MONDAY MORNING. THE CEILINGS SHOULD
SLOWLY LIFT AT BOTH TERMINALS ABOVE MVFR BY LATE MORNING OR MIDDAY
MONDAY...WITH WX CONDITIONS THEN EXPECTED TO DETERIORATE MONDAY
NIGHT AFTER 0Z. NE SFC WINDS BETWEEN 10 TO 18 KTS WILL PREVAIL.
&&
.PREV DISCUSSION... /ISSUED 444 PM CDT SUN MAY 6 2012/
UPDATE...
QUICK UPDATE TO ADD AN ISOLATED THUNDERSTORM MENTION FOR THE NEXT
COUPLE OF HOURS ACROSS THE EXTREME SOUTHEAST ZONES...WHERE HIGH-
BASED STORMS WERE DEVELOPING. NO OTHER CHANGES MADE TO THE
FORECAST ATTM.
PREV DISCUSSION... /ISSUED 257 PM CDT SUN MAY 6 2012/
SHORT TERM...
COLD FRONT HAS SLOWED THIS AFTN AND AS OF 19Z EXTENDED ALONG A LINE
FROM SEMINOLE-POST-PADUCAH NORTHWEST OF A DRYLINE FROM NEAR LAKE ALAN
HENRY TO GUTHRIE. ENHANCED CONVERGENCE WHERE THESE TWO BOUNDARIES
MEET IS EVIDENT ON LAPS DATA...HOWEVER A LACK OF CU THUS FAR
CONFIRMS CAPPING IS STILL QUITE ROBUST. HRRR SEEMS AWFUL BULLISH IN
CONVECTING NEAR KING AND STONEWALL COUNTIES BY 20Z. TEND TO BELIEVE
IF STORMS MATERIALIZE THEY WILL BE DELAYED IN TIME AND DISPLACED
FARTHER EAST...SO POPS WERE LEFT SILENT FOR NOW.
TONIGHT...THE AXIS OF A SURFACE HIGH WILL SHARPEN SSW INTO ERN NM
ALLOWING WINDS AROUND 850MB TO VEER NELY AND BEGIN TAPPING A RICHER
FIELD OF MOISTURE PRESENTLY IN NWRN OK. LOW CLOUDS ALREADY IN THE
CENTRAL TX PANHANDLE SHOULD EXPAND SOUTH TONIGHT IN RESPONSE TO THIS
PROCESS.
MONDAY...INITIAL COOL SURFACE RIDGING IS FORECAST TO WEAKEN IN
RESPONSE TO INCREASING WARM ADVECTION AND PRESSURE FALLS FROM SRN NM
INTO THE PERMIAN BASIN. DRIVING FORCE BEHIND THIS IS TIED TO AN
APPROACHING UPPER TROUGH CURRENTLY NEAR BAJA CA AND AN ASSOCIATED
TROPOPAUSE JET STREAK DOWNSTREAM. BRUNT OF THIS FORCING WILL NOT
AFFECT OUR CWA UNTIL THE FOLLOWING PERIOD...HOWEVER SUSTAINED LIGHT
ELY UPSLOPE FLOW THROUGHOUT THE LOWEST 5K FEET COMBINED WITH AN
ELEVATED BUT SHARPENING BAROCLINIC ZONE APPEAR SUFFICIENT FOR
CONVECTION IN ERN NM BY MIDDAY. FORECAST SOUNDINGS HERE BY LATE AFTN
INDICATE SBCAPE AND ELEVATED CAPE OF 500-1000 J/KG EMBEDDED WITHIN
STRONG 0-6KM BULK SHEAR OF 50-60 KNOTS. CURRENT THINKING IS STORMS
IN NM COULD THREATEN THE WRN SOUTH PLAINS BY LATE AFTN WITH A
CONDITIONAL THREAT OF SOME BEING SEVERE. DID REMOVE POP MENTION OFF
THE CAPROCK TOMORROW AS LIFT HERE APPEARS MUCH TOO SHALLOW TO
OVERCOME A STOUT EML AROUND 750MB. WITH STRATUS EXPECTED TO LINGER
MUCH OF THE DAY...TEMPS AREA WIDE WILL FALL BELOW NORMAL FOR THE
FIRST TIME SINCE MID APRIL!
LONG TERM...
THE CLOSED LOW PROGGED TO BE PINCHED OFF FROM THE UL TROF EDGING
ACROSS THE ROCKIES WILL DIVE SOUTH OUT OF UT INTO NRN MEXICO THRU
WED EVENING. FROM THERE GUIDANCE HAS COME TO BETTER AGREEMENT WITH
THE TRACK OF THE LOW AS IT PUSHES EASTWARD INTO WTX...ALBEIT A SLOW
PROGRESSION. THIS COMBINED WITH A QUASI-STATIONARY FRONT TO THE
SOUTH...POSSIBLE AS FAR SOUTH AS THE RGV...WILL CONTRIBUTE TO
CONTINUED PRECIP CHANCES EACH DAY DURING THE WEEK.
THE FIRST AND BEST PRECIP CHANCE REMAINS ON TUE AS A SECONDARY 850
FRONT PUSHES THRU THE AREA AS THE SFC RIDGE BUILDS IN OVER THE
PANHANDLE. NAM/GFS AGREE UPON SOME 305K ISENTROPIC UPGLIDE AOA 12Z
TUE. THIS COMBINED WITH THE CONTINUED UL DIVERGENT REGION OVER THE
REGION TUE...THE BEST CHANCES FOR HEAVY PRECIP LOOKS TO REMAIN IN
THE MORNING HOURS...WITH CHANCES TRENDING DOWN FROM THERE AS THE SFC
RIDGE SETTLES IN TO THE NORTH. THIS EVENT CONTINUES TO LOOK LIKE A
DESCENT RAIN MAKER...WITH ONLY LIMIT INSTABILITY /GENERALLY UNDER
200 J/KG MUCAPE/. THEREFORE...HAVE ONCE AGAIN LOWER THUNDER TO ONLY
AN ISOLATED MENTION.
WED 00Z ON...THE BEST PRECIP CHANCES WILL BE TIED TO THE FRONT TO
THE SOUTH AND THE AFOREMENTIONED UL LOW EDGING EAST.
THEREFORE...MOST OF THE LATER HALF OF THE WEEK HAVE CONTINUED SLGT
CHANCE POPS MAINLY ACROSS THE SWRN ZONES. HOWEVER...BY THE WEEKEND
THERE REMAINS SOME SLIGHT DIFFERENCE ON SPEED AND TRACK OF THE UL
LOW OVER THE REGION AS WELL AS THE ONE OFF THE ERN CONUS.
THEREFORE...WILL CONTINUE ECMWF TREND FROM PREVIOUS THINKING.
MEADOWS
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 49 64 44 58 44 / 10 30 50 50 20
TULIA 52 66 48 60 45 / 10 20 40 40 20
PLAINVIEW 52 68 49 59 47 / 10 20 40 40 20
LEVELLAND 53 74 52 60 50 / 10 20 60 60 20
LUBBOCK 54 74 53 60 48 / 10 10 50 60 20
DENVER CITY 52 78 52 64 50 / 10 30 70 70 20
BROWNFIELD 52 76 52 60 50 / 10 20 60 70 20
CHILDRESS 59 75 54 70 50 / 10 10 30 40 20
SPUR 57 76 54 64 49 / 10 10 40 40 20
ASPERMONT 60 80 56 70 50 / 10 10 40 40 20
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
33/23
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
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...
12Z TAFS: A low pressure center will move east of the area today.
Moisture will wrap around this low bringing showers to northeast
Washington and the Idaho Panhandle. Precipitation should generally
be light and conditions will only be briefly MVFR in the core of the
showers. Drier weather will move into the area this evening. RJ
&&
.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 TALLAHASSEE FL
500 AM EDT Mon May 7 2012
.SYNOPSIS...
The weather pattern remains quite complex over the Southeast this
morning, with several mesoscale features generated by convective
activity in the past 12-24 hours. We had quite a few thunderstorms
that developed yesterday across the area. In general, the storms
formed a common convective cold pool and pushed south eventually
weakening as they approached the Gulf of Mexico. These storms
produced sporadic wind damage and a few measured gusts in the
40-50kt range. The widespread thunderstorm development led to a
convectively overturned boundary layer, and we are still seeing
the effects of this early this morning. Our local forecast area is
essentially co-located with a minimum in both MUCAPE and boundary
layer dewpoints. This presents some challenges regarding the
convective forecast today, which will be discussed below. The
storms did produce some beneficial rainfall in our AL-GA zones.
Gauge-adjusted Q2 rainfall estimates were at least 0.50" in many
areas, with a few areas receiving up to 2-3" of rain. Things were
drier across the Florida Panhandle, as storms mostly started
dissipating by the time they arrived there.
Aloft, water vapor satellite and RUC analysis revealed that broad
cyclonic flow and a large area of slightly lower mid-level heights
had developed ESE over the past 24 hours, now centered over GA/SC.
Embedded within this region were two PV anomalies / MCVs. The
first was partially responsible for triggering storms in our area
today and is now moving quickly east over NE FL. The second is
moving more slowly over southern SC. At the surface, mesoscale
areas of high pressure were situated over SE AL and SW GA with
corresponding lower surface dewpoints. Greater low-level moisture
nearby was found in SE GA and along the FL Atlantic coast, as well
as just offshore over the Gulf of Mexico. A surface high pressure
ridge continued to build down the Carolinas.
&&
.SHORT TERM [Today through Wednesday]...
The primary focus was on trends through 06z Tuesday (today and
into this evening), with only minor tweaks made to the forecast
beyond that timeframe.
TODAY: Convection-allowing models are in much better agreement
regarding the convective evolution today. The PoPs derived from
the 4km NCEP WRF runs and our local 4km WRF-ARW were incorporated
into the grids for today - yielding a maximum in the FL Big Bend
and adjacent SC GA (70-80% PoPs). One potential pitfall is the
recovery of low-level moisture this morning. The dewpoint trends
this morning will probably tell the story: if they struggle to
rise into the mid-upper 60s, particularly in the aforementioned
area of higher PoPs, then convective coverage could be far more
limited than what we saw yesterday. In general, we expect decent
recovery across the eastern half of the area. RUC analyzed 0-1km
mixing ratio this morning showed a relative minimum of 9 g/kg near
Walton County, with a maximum of 14 g/kg near the GA coast, a
substantial west-to-east gradient. Meanwhile, area VWPs across S
GA and N FL all show increasing flow in the same layer with an
easterly component. As such, the eastern border of our forecast
area should be right near the nose of a broad easterly 0-1km
moisture transport maximum by 18z, and would be a favorable
location for convective initiation.
Severe weather potential today looks to be lower than yesterday.
Model forecast soundings almost all show slightly warmer mid-level
temperatures with slightly lower surface dewpoints, which yields a
shorter and narrower CAPE profile overall. However, models that
don`t erroneously convect earlier in the morning show maximum
delta thetae values around 20-22C with MLCAPE around 1000-1500
j/kg, which could support some isolated severe downbursts. The 5%
probabilities from SPC on the initial SWODY1 seem reasonable.
Storm motions will be very slow today, generally 10 knots or less
in the absence of organized and sizable cold pools. Therefore,
localized heavy rainfall and flooding cannot be ruled out.
Finally, high temperatures yesterday were well in excess of model
guidance. Many highs in the 90s were recorded with TLH at 93 and
VLD at 97. With 850mb temperatures only about 1C cooler today, and
limited cloud coverage prior to convective initiation, it seems
likely that many areas could reach around 90 again today.
TUESDAY AND WEDNESDAY: Very few notable changes were made in these
periods. The high temperatures were nudged up slightly each day
with forecast low-level temperature profiles expected to remain
roughly the same as today. In the big picture, the forecast will
be very similar for the entire Monday-Wednesday period, with
mesoscale details ultimately determining where the most storms are
focused each day.
.LONG TERM [Wednesday Night through next Monday]...
Not too many changes were made from the prior extended forecast,
as both the ECMWF and GFS are in very good agreement with the Cold
Frontal Passage on Wednesday Night into Thursday morning. However,
the fair, cooler, and drier air building in behind it may only
last for 2 to 3 days now (rest of Thu into Sat), as the unusual
and anomalously active subtropical jet stream for this time of
year appears poised to send yet an another Upper Level Shortwave
in our direction over the latter half of the weekend into early
next week. The new 00 UTC run of ECMWF is especially active with
this system, so PoPs were adjusted upward a bit to blend in with
the GFS. If the GFS trends more towards the Euro on later runs, it
could be a very wet period with plenty of beneficial rainfall from
Sunday through Tuesday of next week, which is certainly much
needed across our drought stricken area.
&&
.AVIATION [through 06z Tuesday]...
Had to essentially re-write the entire first portion of the
Aviation Discussion for the 06Z package, as the drier air that has
advected in behind Sunday`s MCS has caused a fairly quick erosion
of the Dense Fog at DHN, and now it appears that most sites are
likely to only experience a period of MVFR conditions into the
early morning hours, if at all. However, will still need to keep a
close eye on DHN, as some locations not too far to the north like
Troy, are continuing to deteriorate. Today, we could see fairly
similar conditions as we witnessed on Sunday, with good chances
for afternoon thunderstorms accompanied some gusty winds, likely
propagating from a NE-SW fashion during the afternoon hours, but
wind gusts are not expected to be as nearly as strong with less
daytime heating and destabilization, aided by the drier air mass
that has pushed in from the north behind the prior MCS.
&&
.MARINE...
A benign weather pattern will continue over the coastal waters
with light winds and seas 1 foot or less expected through Tuesday
Night. A slight increase in winds is expected around a cold front
passage Wednesday into Thursday, but conditions should remain
below what would necessitate a cautionary headline.
&&
.FIRE WEATHER...
Plenty of low level moisture and elevated rain chances should
preclude any fire weather concerns through at least the middle of
next week, with significantly drier conditions not expected until
Thursday and Friday.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 89 66 88 66 87 / 60 30 50 40 50
Panama City 84 68 82 69 83 / 40 30 40 30 40
Dothan 87 66 86 67 85 / 50 30 50 40 40
Albany 86 66 87 65 86 / 60 40 50 40 50
Valdosta 92 65 89 65 89 / 70 50 50 40 50
Cross City 89 64 88 65 86 / 60 40 40 40 50
Apalachicola 82 68 81 69 82 / 40 20 30 30 40
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...None.
GA...None.
FL...None.
GM...None.
&&
$$
Synopsis...Lamers
Short Term...Lamers
Long Term...Gould
Aviation...Gould
Marine...Lamers
Fire Weather...Gould
AREA FORECAST DISCUSSION
NWS MIAMI FL
416 AM EDT MON MAY 7 2012
.DISCUSSION...WATER VAPOR IMAGERY SHOWS A TROUGH IN PLACE OVER
THE DEEP SOUTH. THIS FEATURE WILL MOVE SOUTHEAST OVER THE NEXT FEW
DAYS, REPLACING THE RIDGE THAT HAS BEEN IN PLACE ACROSS SOUTH FL.
MEANWHILE, MOISTURE WILL INCREASE AS WELL. IN FACT, THIS IS
HAPPENING ALREADY WITH GPS MET DATA SHOWING A SLOW RISE IN PWATS
SINCE LAST EVENING INTO THE 1.2-1.4 INCH RANGE, THOUGH MIAMI IS
STILL HOLDING AT 1.1 INCHES. AS MOISTURE INCREASES A TAD ALONG
WITH TROUGHING ACROSS THE AREA TUE-THU, THE RESULT WILL BE AN
INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS, THOUGH CERTAINLY
NOT A WASHOUT. THEY WILL BE OF THE PULSE VARIETY DURING THE HEAT
OF THE DAY WITH FOCUS OVER THE INTERIOR-EAST COAST.
FOR THIS AFTERNOON, NOT AS HIGH OF CONFIDENCE IN A FEW
THUNDERSTORMS DEVELOPING AS COMPARED TO TUE-THU. HOWEVER, THIS
COULD OCCUR FROM THE INTERIOR TOWARDS THE WESTERN BROWARD METRO
AND ACROSS PALM BEACH COUNTY...SO HAVE SLIGHT CHANCE OF TSTORMS
ACROSS THIS AREA FOR THIS AFTERNOON. LATEST HRRR SHOWS JUST LIGHT
QPF OVER INLAND PALM BEACH/INLAND BROWARD DEVELOPING BY 4 PM WITH
MOST OF THE ACTION TO OUR NORTH OVER CENTRAL AND NORTH FL.
AS THE TROUGH MOVES IN OVERNIGHT, A FEW SHOWERS OR THUNDERSTORMS
COULD DEVELOP OVER THE GULF OF MEXICO, POSSIBLY MOVING ONSHORE THE
GULF COAST, SIGNALED SLIGHTLY BY THE ECMWF. SO ADDED SLIGHT CHANCE
POPS AFTER MIDNIGHT FOR THIS AREA. HIGHER CONFIDENCE IN SHOWER AND
TSTORM ACTIVITY DEVELOPING TUE- THU, AGAIN WITH FOCUS INTERIOR AND
EAST COAST DUE TO A WESTERLY STEERING FLOW.
GFS/ECMWF SHOW A WEAKENING COLD FRONT MOVING INTO SOUTH FL LATE
THU WHILE BECOMING DIFFUSE. BOTH GFS/ECMWF SHOW ANOTHER SHORTWAVE
MOVING INTO THE NORTHERN GULF NEXT WEEKEND, BUT WITH MOST OF THE
ACTIVE WEATHER OFF TO OUR NORTHWEST. SO MAINTAINED JUST SLIGHT
CHANCE POPS IN THE EXTENDED. TEMPS THROUGH THE PERIOD WILL REMAIN
SEASONABLY WARM.
&&
.MARINE...LIGHT WINDS WILL CONTINUE WITH SEAS GENERALLY 4 FT OR
LESS THROUGH THE PERIOD, EXCEPT POSSIBLY UP TO 5 FT OFF THE
NORTHERN PALM BEACH COAST TUE NIGHT ASSOCIATED WITH A SMALL NE
SWELL.
&&
.FIRE WEATHER...A FEW INTERIOR LOCALES SAW RH`S FALL TO JUST
BELOW 35 PERCENT YESTERDAY FOR A FEW HR. THE SLIGHT INCREASE IN
MOISTURE TODAY SHOULD KEEP RH`S ABOVE CRITICAL LEVELS TODAY AND
BEYOND.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 88 71 86 71 / 20 20 30 20
FORT LAUDERDALE 86 72 86 73 / 10 10 30 20
MIAMI 88 72 86 73 / 10 10 30 20
NAPLES 85 70 84 70 / 10 10 20 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...57/GREGORIA
AVIATION/RADAR...10/CD
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
145 AM EDT MON MAY 7 2012
.AVIATION.../06Z TAFS/
STRONG LOW LEVEL THETA-E ADVECTION CAUSING MCS DEVELOPMENT OVER NW
INDIANA/NRN IL EARLY THIS MORNING. 00Z NAM12 APPEARS TO BE TOO WK
WITH LLJ AND TOO FAR NE. EXPECT TSRA WILL CONT TO IMPACT SBN MUCH
OF THE NGT AS CONVECTION SHIFTS SLOWLY ENE WITH TS LIKELY
IMPACTING FWA AFT 08Z. ANOTHER ROUND OF TS PSBL DURING THE
DAY AS CDFNT MOVES THROUGH THE AREA BUT LEFT OUT OF TAFS FOR NOW
DUE TO CONCERN THAT DESTABILIZATION WILL BE HINDERED BY MORNING
CONVECTION. MVFR CONDITIONS IN TS OVERNIGHT SHOULD BECOME
WIDESPREAD BY MORNING AS LOW LEVELS MOISTEN UP. WINDS WILL SHIFT TO
NW BEHIND THE FRONT AS IT MOVES SLOWLY EAST ACROSS THE AREA TODAY
WITH VFR CONDITIONS EXPECTED ACROSS THE AREA BY THIS EVE.
&&
.PREV DISCUSSION... /ISSUED 1203 AM EDT MON MAY 7 2012/
UPDATE...
ZONES/GRIDS UPDATED TO REFLECT CURRENT RADAR TRENDS AND TRENDS OF
LATEST HRRR MODELS.
CONVECTION HAS BEEN RAPIDLY DEVELOPING OVER THE PAST FEW HOURS
ACROSS PORTIONS OF SOUTHERN LAKE MI INTO N ILLINOIS IN AREA OF
MODERATE INSTABILITY AND NUMEROUS OUTFLOW BOUNDARIES. A FEW
SHOWERS AND STORMS HAVE DEVELOPED ACROSS LAPORTE AND BERRIEN
COUNTIES AND ARE TRYING TO MOVE EAST. HOWEVER...LARGE SFC DEWPT
GRADIENT NOTED WITH MUCH OF THE NE PARTS OF THE CWA SEEING DEWPTS
IN THE 30S AND 40S VS READINGS IN THE UPEPR 50S TO LOWER 60S ALONG
THE WESTERN TIER OF COUNTIES. HRRR PICKED UP ON THIS FEATURE AND
HOLDS WITH THESE LOWER SFC DEWPTS THROUGH THE NIGHT. HOWEVER...LL
MSTR ADVECTION CONTINUES TO INCREASE WHICH ALLOWS FOR AT LEAST AN
SLOW UPSWING IN SHOWER TRENDS. HAVE ADJUSTED GRIDS TO REFLECT
SLOWER ARRIVAL OF HIGHER POPS FROM WEST TO EAST THROUGH THE
REMAINDER OF THE NIGHT. THREW IN MENTION OF HEAVY RAIN GIVEN
INCREASING PWATS AND SLOW FLOW TO ALLOW FOR BACKBUILDING AND SLOW
FORWARD PROPAGATION.
PREV DISCUSSION... /ISSUED 354 PM EDT SUN MAY 6 2012/
SHORT TERM... / LATE THIS AFTERNOON THROUGH MONDAY NIGHT /
MAIN CONCERN THIS PERIOD REMAINS CHANCES FOR CONVECTION.
SYNOPTICALLY...A CLOSED UPPER LOW OVER SOUTHERN SASKATCHEWAN WILL
TRACK EWD TOWARD THE NORTH DAKOTA/MANITOBA BORDER...WITH A TRAILING
POSITIVELY TILTED H5 TROUGH DROPPING INTO THE NORTH-CENTRAL CONUS.
AT THE SFC AS OF 19Z THERE WAS A QUASI STATIONARY FRONT DRAPED SW OF
THE FA FROM CENTRAL IL WEST TO A WEAK SFC REFLECTION NEAR KANSAS
CITY. AN OCCLUDED FRONT EXTENDED NORTH FROM HERE INTO THE UPPER
MIDWEST. THESE FRONTAL BOUNDARIES AND SFC REFLECTION WILL LIKELY
CONVERGE OVER THE LOCAL AREA TOMORROW. THIS WILL BRING INCREASING
CHANCES FOR SHOWERS AND STORMS TO THE AREA TONIGHT INTO TOMORROW.
LATE THIS AFTN INTO EARLY THIS EVENING...MCV ACROSS WISCONSIN WILL
WORK INTO CENTRAL AND NORTHERN PORTIONS OF MICHIGAN. SHOWERS
ASSOCIATED WITH THIS FEATURE HAVE WEAKENED ACROSS OUR FAR NW THIS
AFTN AS THEY ENCOUNTERED MUCH MORE STABLE AIR. RAISED POPS IN THE
FAR NW TO ACCOUNT FOR THESE WEAKENING SHOWERS WITH ONLY LIGHT
AMOUNTS EXPECTED OVER THE NEXT SEVERAL HOURS. FARTHER WEST ACROSS
NRN IL AND NRN MO SCT CONVECTION HAS FIRED ALONG A RATHER
IMPRESSIVE INSTABILITY GRADIENT. LATEST HI-RES GUIDANCE SUGGESTS
THAT COVERAGE WILL CONTINUE TO INCREASE INTO A MORE ORGANIZED
CONVECTIVE SYSTEM...MAINLY IMPACTING AREAS WEST INTO
CENTRAL/NORTHERN IL INTO THE EARLY EVENING HOURS. HOWEVER...COULD
SEE A FEW ELEVATED CELLS WORK INTO OUR WESTERN ZONES EARLY THIS
EVENING. OPTED TO CONTINUE WITH 30-60 POPS ACROSS MAINLY WESTERN
ZONES AFTER 00Z TO ACCOUNT FOR THIS...WITH A SLIGHT RISK FOR LARGE
HAIL AS MORE UNSTABLE AIR ADVECTS NEWD IN A WARM ADVECTION REGIME.
TONIGHT INTO MONDAY...LOW TO MID LEVEL THETA-E ADVECTION
EXPECTED AHEAD OF THE SFC LOW AND SFC INSTABILITY GRADIENT WILL
SUPPORT INCREASING CHANCES FOR SHOWERS/STORMS. COULD SEE SOME
LOCALLY HEAVY RAINFALL GIVEN EXPECTED SLOW MOVEMENT AND PWATS
INCREASING TO NEAR 1.6 INCHES. NO CHANGES TO INHERITED LIKELY POPS
INTO MONDAY AFTERNOON AS A MODEL CONSENSUS TRACKS THE AFOREMENTIONED
WEAK SFC LOW AND SOME SEMBLANCE OF A CONVECTIVELY ENHANCED/INDUCED
MID LEVEL PERTURBATION INTO NORTHERN INDIANA. THIS TRACK WOULD BRING
THE WARM FRONT AND MOIST/UNSTABLE BOUNDARY LAYER AIR INTO OUR
SOUTHEASTERN ZONES...WHICH BRINGS ABOUT THE CONCERN FOR SEVERE SFC
BASED CONVECTION HERE BY MONDAY AFTN. VERY LOW CONFIDENCE HERE GIVEN
EXPECTED LEFTOVER CLOUD COVER AND SHOWERS...WITH A MORNING MCS
OUTFLOW POSSIBLY FORCING THE FRONTAL BOUNDARY/SFC WAVE FARTHER
SOUTH. ISOLATED WIND DAMAGE/LARGE HAIL WILL BE THE PRIMARY THREAT IF
THESE AREAS ARE ABLE TO RECOVER THERMODYNAMICALLY...WITH MULTICELLS
POSSIBLE IN A WEAKLY SHEARED ENVIRONMENT.
LONG TERM...TUESDAY THROUGH SUNDAY
STRONG COLD ADVECTION TO BEGIN THIS PERIOD AS COLD FRONTAL ZONE
CONTINUES TO SHIFT EASTWARD FROM THE GREAT LAKES REGION INTO THE
LOWER OHIO VALLEY. POST FRONTAL DRY AIR ADVECTION WILL ALSO RESULT
IN MOSTLY SUNNY SKIES BY TUESDAY AFTERNOON. DESPITE COLD
ADVECTION...BOUNDARY LAYER WILL BE RELATIVELY DEEP AND BETTER LOW
LEVEL MIXING SHOULD SUPPORT HIGHS FROM MID TO UPPER 60S NORTH TO THE
LOWER 70S SOUTH.
FOR TUESDAY NIGHT...BLOCKING PATTERN ACROSS EASTERN CANADA WILL
RESULT IN SOUTHEAST MIGRATION OF UPPER LEVEL TROUGH CURRENTLY
APPROACHING THE NORTHERN HIGH PLAINS. PRECEDING DRY AIR ADVECTION
WILL MAKE PRECIP POTENTIAL QUESTIONABLE WITH THIS UPPER TROUGH.
POSITIVELY TILTED NATURE OF THIS TROUGH AS IT DROPS SOUTHWARD ACROSS
THE WESTERN GREAT LAKES SHOULD CONFINE PRECIP POTENTIAL TO
IMMEDIATELY DOWNSTREAM OF TROUGH AXIS ACROSS NORTHWEST PORTIONS OF
CWA TUESDAY NIGHT...CLOSER TO ASSOCIATED WEAK LOW LEVEL CONVERGENCE
AXIS. FURTHER DOWNSTREAM ACROSS NORTHEAST INDIANA INTO NORTHWEST
OHIO LOW LEVEL MOISTURE PROFILES WILL LIKELY REMAIN MORE MEAGER AND
HAVE REMOVED POPS TUESDAY NIGHT ACROSS THE EAST. HAVE MAINTAINED
CHANCE POPS ON WEDNESDAY AS UPPER TROUGH DIGS SOUTHEAST ACROSS THE
SOUTHERN GREAT LAKES BUT PRECIP AMOUNTS SHOULD BE ON THE LIGHT SIDE.
DRY CONDITIONS FOR WEDNESDAY NIGHT/THURSDAY AS THIS UPPER TROUGH
DEPARTS TO THE EAST AS MID/UPPER LEVEL HEIGHT RISES OVERSPREAD UPPER
MIDWEST AND GREAT LAKES REGION. SLOW MODERATION IN TEMPERATURES BACK
CLOSE TO NORMAL EXPECTED TOWARD THE END OF THE WEEK AS BROAD 1020 MB
SFC ANTICYCLONE SHIFTS INTO THE MID ATLANTIC STATES. ATTENTION FOR
THE REMAINDER OF THE PERIOD WILL FOCUS ON NEXT FAST MOVING PACIFIC
WAVE EXPECTED TO TRACK ACROSS NORTHERN CONUS/SOUTH CENTRAL CANADA
THIS WEEKEND. NARROW CORRIDOR OF MOISTURE RETURN IS POSSIBLE JUST IN
ADVANCE OF THIS FRONT BUT WILL INTRODUCE ONLY LOW CHANCE SHRA
MENTION AT THIS TIME WITH STRONGEST LOW LEVEL CONVG EXPECTED TO
REMAIN TO THE NORTH. WITH STRONGER FORCING AND MORE PROGRESSIVE FLOW
LIKELY REMAINING ACROSS GREAT LAKES INTO SOUTHEAST CANADA...THIS
BOUNDARY MAY STALL OUT ACROSS THE SOUTHERN GREAT LAKES TOWARD THE
END OF THE PERIOD...AND THUS HAVE MAINTAINED LOW CHANCE POPS INTO
SUNDAY.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...STEINWEDEL
LONG TERM...MARSILI
AVIATION...JT
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
349 AM EDT MON MAY 7 2012
.SYNOPSIS...
LOW PRESSURE WILL MOVE ACROSS THE GREAT LAKES TUESDAY AND PUSH A
COLD FRONT SOUTH OF THE OHIO VALLEY LATER WEDNESDAY. THIS WILL
BRING SHOWERS AND A FEW THUNDERSTORMS LATER MONDAY THROUGH
WEDNESDAY WITH COOLER TEMPERATURES BY MID WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A MEANDERING FRONTAL BOUNDARY CURRENTLY EXTENDS FROM THE SOUTHERN
PLAINS INTO THE LOWER GREAT LAKES WITH SEVERAL LOWS TRACKING DOWN
IT. EACH OF THESE LOWS IS TENDING TO BE A FOCAL POINT FOR
CONVECTIVE ACTIVITY ALONG THE FRONT...WITH SEVERAL CONVECTIVE BLOW
UPS FROM TEXAS NORTHWARD TO ILLINOIS AND EASTWARD INTO MICHIGAN.
EAST OF THIS FRONTAL BOUNDARY...A RIDGE OF HIGH PRESSURE IS
LARGELY IN CONTROL...WHICH INCLUDES OVER THE PITTSBURGH REGION.
HOWEVER...THE UPPER RIDGE HAS BEEN LARGELY DAMPENED...WITH
GENERALLY NORTHWESTERLY UPPER LEVEL FLOW PRESENT OVER THE FORECAST
AREA AT THIS TIME. GIVEN THIS STEERING FLOW...AND CONVECTIVE
TRENDS OVER LOWER MICHIGAN AND NORTHWESTERN OHIO...IT WOULD
CERTAINLY SEEM THAT SOME AMOUNT OF RESIDUAL SHOWER ACTIVITY COULD
TRACK...PARTICULARLY INTO THE WESTERN ZONES AND NORTHERN ZONES OF
THE FORECAST AREA...BY LATE THIS MORNING AND AFTERNOON.
HOWEVER...THE ORGANIZATION OF THIS ACTIVITY IS LIKELY TO BE LESS
THAN OPTIMAL. ADDITIONALLY...CONVECTIVE BLOW OFF HAS ALREADY
COVERED MUCH OF THE AREA. THIS SHOULD HELP TO KEEP CAPE VALUES A
BIT LOWER THIS AFTERNOON THAN THEY MIGHT OTHERWISE BE GIVEN A
FAIRLY WELL MIXED BOUNDARY LAYER WITH ROUGHLY 25 KTS AT 850 MB AND
850 MB TEMPERATURES ON THE ORDER OF 2C HIGHER THAN YESTERDAY.
GIVEN ADDITIONALLY CLOUD COVER...TEMPERATURES AND HENCE CAPE
VALUES SHOULD BE HELD BACK A BIT...AND GIVEN MEDIOCRE 0-6 KM SHEAR
VALUES THIS AFTERNOON...WHILE A FEW MARGINALLY SEVERE STORMS MAY
BE POSSIBLE OVER OHIO...THE FORECAST WILL NOT BE FEATURING ANY
MENTION OF SUCH ACTIVITY. FRIES
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
THE MORE CRITICAL PORTION OF THE FORECAST STARTS TUESDAY NIGHT AS
THE NEXT LARGE SCALE SYSTEM TRACKS TOWARD THE AREA. PREVIOUS MODEL
RUNS HAVE ALL STRUGGLED WITH THE TIMING OF THIS SYSTEM GIVEN THE
FAIRLY WEAK REFLECTION OF IT AT 500 MB AS A SUBTLE RIPPLE IN THE
HEIGHT FIELD BETWEEN A DEEPER NORTHERN STREAM TROUGH AND THE
DEPARTING RIDGE FROM THE WEEKEND. TIMING IS NOW COMING INTO A BIT
BETTER VIEW FAVORING A VERY SLOW PROGRESSION OF ITS ASSOCIATED
FRONTAL BOUNDARY FROM MONDAY EVENING RIGHT THROUGH THE ENTIRE DAY
ON TUESDAY. THE MODEL CONSENSUS SEEMS TO LIKE THE IDEA OF THE VORT
CURRENTLY OVER MISSOURI EJECTING TO THE EAST CONCURRENT WITH THE
FRONTAL PASSAGE ACROSS THE AREA. GIVEN NEARLY FRONT PARALLEL 500
MB FLOW...THE RESULT WILL BE VERY SLOW EASTWARD MOVEMENT OF THE
FRONT AS THIS OCCURS. AS A RESULT...THE DEEP LAYER OF INSTABILITY
EXTENDING FROM THE SURFACE UP BEYOND 500 MB IS LIKELY TO BE EASILY
FOCUSED AND HARNESSED BY THE MID-LEVEL VORT THAT WILL BE MOVING
THROUGH THE REGION. IF WE COUPLE THIS WITH THE FRONTOGENETICAL
FORCING THE FLUX OF GULF MOISTURE INTO THE REGION...THE STAGE
SEEMS TO BE SET GIVEN THE SLOW MOTION OF THE FRONTAL BOUNDARY FROM
SOME FAIRLY COPIOUS RAINFALL. THE MODEL CONSENSUS FAVORS ROUGHLY
1-2 INCHES OF RAIN FROM MONDAY NIGHT THROUGH TUESDAY ACROSS MUCH
OF THE CWA...WHICH WHILE IMPRESSIVE...IS STILL NOT ENOUGH TO FAVOR
A FLASH FLOOD WATCH ISSUANCE. THIS IS MAINLY BECAUSE THOSE 2 INCH
AMOUNTS WOULD NEED TO FALL IN AN HOUR OR TWO BEFORE MUCH CONCERN
WOULD EXIST...AND AT THIS TIME...IT IS FAR TOO DIFFICULT TO
DETERMINE IF THAT IS POSSIBLE GIVEN FRONTAL TIMING PROBLEMS AS
WELL AS UNCERTAINTY AS TO THE DEGREE OF INSTABILITY. FOR
NOW...HEAVY RAIN WAS CARRIED IN THE FORECAST FOR TUESDAY NIGHT TO
ALERT AS TO THE LIKELIHOOD OF A PERIOD OF HEAVIER RAINFALL ALONG
THE FRONTAL BOUNDARY.
THE COLD FRONT FINALLY DOES KICK SOUTHEAST OF THE AREA BY
WEDNESDAY AS THE NORTHERN STREAM DIPS WELL SOUTH OF WHERE IT HAS
TAKEN RESIDENCE IN RECENT WEEKS. AS THIS OCCURS...UPPER TROUGHING
BECOMES CENTERED OVER THE CWA FROM WEDNESDAY THROUGH THURSDAY.
WITH COLDER AIR ALOFT ENTERING THE PICTURE...INSTABILITY WILL
AGAIN BECOME FAIRLY COMMON. HOWEVER...IT IS LIKELY TO BE MUCH MORE
SHALLOW. BUFKIT PROFILES SUGGEST 100-300 J/KG CAPES WITH POSITIVE
AREA UNABLE TO GET MUCH ABOVE THE -5C ISOTHERM. AS A
RESULT...CHARGE SEPARATION IS UNLIKELY TO BE EFFICIENT ENOUGH TO
SUPPORT THUNDERSTORM DEVELOPMENT...HOWEVER IT WOULD SEEM GIVEN LAKE
MOISTURE INFLUENCE AS WELL AS FAIRLY STEEP LOW LEVEL LAPSE
RATES...SCATTERED SHOWERS SHOULD DEVELOP BY WEDNESDAY AFTERNOON.
MORE IMPORTANTLY WITH THE DIPPING SOUTH OF THE POLAR JET WILL BE
THE CHANGE IN TEMPERATURES. RECENT 850 MB TEMPERATURES HAVE BEEN
IN THE +11 TO +14C RANGE. BY WEDNESDAY AND THURSDAY...MODEL 850 MB
TEMPERATURES SHOULD FALL INTO THE +2 TO +5C RANGE. THIS SEEMS
LIKELY TO TRANSLATE INTO 15-20 DEGREES OF SURFACE COOLING RELATIVE
TO RECENT DAYS. ADDITIONALLY...WITH NIGHTTIME STABILIZATION AND
RADIATIONAL COOLING...THERE IS SOME CHANCE OF A RETURN TO FROSTY
CONDITIONS BY THURSDAY NIGHT IN SOME AREAS. FRIES
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE WILL THEN MOVE INTO THE OHIO VALLEY KEEPING THE
WEATHER DRY THROUGH SATURDAY.
A COLD FRONT IS PROGGED TO BRING SCATTERED SHOWERS SUNDAY.
TEMPERATURES ARE FORECAST TO BE A FEW DEGREES BELOW NORMAL THURSDAY
AND FRIDAY...WARMING TO SLIGHTLY ABOVE NORMAL FOR THE WEEKEND.
&&
.AVIATION /07Z MONDAY THROUGH FRIDAY/...
LOW CONFIDENCE FORECAST FOR TODAY. DECAYING COMPLEX TO THE NORTHWEST
CONTINUES TO PUSH CIRRUS CLOUDS OVER THE UPPER OHIO VALLEY. AN AREA
OF STRATUS HAS DEVELOPED OVER THE EASTERN APPALACHIANS AND HAS BEEN
TRYING TO DRIFT WESTWARD. HOWEVER, LL FLOW IS VERY WEAK AND USING
LATEST SAT PICS, RIDGES ARE HOLDING THE LOW CLOUDS AT BAY. FOR THE
FORECAST, WILL LEAVE OUT MENTION OF STRATUS AT ALL PORTS WITH THE
EXCEPTION OF DUJ. LATEST HRRR RUN IS SHOWING THE IFR STRATUS MAKING
IT TO DUJ SHORTLY AFTER ISSUANCE TIME AND REMAINING, THROUGH 12Z.
WILL GO WITH AN MVFR/IFR FORECAST AT DUJ, BUT WILL NEED TO MONITOR
CLOSELY OVERNIGHT.
MODELS ARE HAVING DIFFICULTY DECIDING WHAT TO DO WITH THE DECAYING
COMPLEX OVER THE WESTERN GREAT LAKES. CURRENT SAT AND RADAR PICS
SHOW THE ACTIVITY DISSIPATING QUICKLY. ADDITIONALLY, LATEST MODEL
RUNS ARE FORECASTING A STRENGTHENING OF THE MIDWEST RIDGE AS IT
MOVES EASTWARD THIS MORNING. HAVE VERY LITTLE CONFIDENCE IN HOW MUCH
ACTIVITY WILL DEVELOP TODAY. TRYING TO FOLLOW THE UL WAVES TO HELP
WITH TIMING AND PLACEMENT. THE WAVE ASSOCIATED WITH THE DYING
WESTERN COMPLEX MOVES ACROSS THE NORTH DURING THE POST-DAWN MORNING
HOURS. THE PROBLEM IS THAT IT IS RUNNING INTO THE UL RIDGE. WILL
INCLUDE A MENTION OF NON-RESTRICTIVE SHOWERS ACROSS THE NORTH THIS
MORNING. WITH THE LACK OF UL SUPPORT AND DEEP LAYERED MOISTURE, WILL
LEAVE OUT THE MENTION OF RAIN AT OTHER PORTS UNTIL LATE IN THE DAY,
AS THE FRONT APPROACHES.
.OUTLOOK...TONIGHT THROUGH THURSDAY...
RESTRICTIONS ARE EXPECTED TONIGHT AND THROUGH MUCH OF TUESDAY, AS A
COLD FRONT WILL SLOWLY MOVE THROUGH. LOW CONFIDENCE FORECAST FOR THE
REMAINDER OF THE OUTLOOK, AS A LARGE UL TROUGH WILL SETTLE INTO THE
UPPER OHIO VALLEY LATE WED AND THU.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS PITTSBURGH PA
107 AM EDT MON MAY 7 2012
.SYNOPSIS...
LOW PRESSURE WILL MOVE ACROSS THE GREAT LAKES TUESDAY AND PUSH A
COLD FRONT SOUTH OF THE OHIO VALLEY LATER WEDNESDAY. THIS WILL
BRING SHOWERS AND A FEW THUNDERSTORMS LATER MONDAY THROUGH
WEDNESDAY WITH COOLER TEMPERATURES BY MID WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
OVERNIGHT PERIOD STILL APPEARS TO BE DRY...WITH CLOUDS SLOWLY ON
THE INCREASE FROM BOTH THE WEST AND THE EAST. WITH DEWPOINTS
REMAINING IN THE LOW 60S ALONG THE RIDGES...EXPECT THAT LOW
STRATUS WILL DEVELOP BY DAYBREAK. RIGHT NOW THINKING THAT FOG
SHOULD NOT BE MUCH OF A CONCERN WITH STRATUS DEVELOPMENT.
FLOW WILL BECOME MORE SOUTHERLY BY MONDAY MORNING AS WARM FRONT
STRENGTHENS AND MOVES TOWARD I-80 WHILE LOW PRESSURE AND COLD
FRONT MOVE TO THE LOWER OHIO VALLEY. ISOLATED MORNING SHOWERS
POSSIBLE MONDAY BUT WIDESPREAD SHOWERS AND A FEW STORMS SHOULD
HOLD OFF UNTIL MID TO LATE AFTERNOON WITH DEEP MOISTURE AND LIFT
WITH APPROACHING SYSTEM. FAR WESTERN COUNTIES IN A SLIGHT RISK FOR
SEVERE LATE DAY MONDAY BUT THIS WILL DEPEND ON AMOUNT OF AVAILABLE
INSTABILITY. WILL MENTION IN HWO. MILD OVERNIGHT AND CONTINUED
ABOVE NORMAL MONDAY IN WARM ADVECTION.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
WIDESPREAD SHOWERS AND SOME THUNDERSTORMS MONDAY NIGHT INTO
TUESDAY AS SURFACE LOW MOVES INTO EASTERN GREAT LAKES WITH UPPER
LEVEL TROUGH DIGGING INTO THE OHIO VALLEY. COLD FRONT WILL BE
SLOWED A BUT TUESDAY AS UPPER TROUGH DIGS AND BRINGS UPPER FLOW
MORE PARALLEL TO FRONT FOR A TIME. AS SHORTWAVE AND SURFACE LOW
PUSHES TO NEW ENGLAND TUESDAY NIGHT FRONT WILL REACH SOUTH OF
MASON DIXON LINE WITH DECREASING RAIN CHANCES NORTHWEST TO
SOUTHEAST. MODELS IN DISAGREEMENT ON WHETHER ANOTHER WAVE WILL
FORM ON FRONT WEDNESDAY AND MOVE NORTHEAST TO PUSH HIGHER POPS
BACK NORTH AND WEST ACROSS REGION. DEEPENING TROUGH WITH HEIGHT
FALLS AT 500MB WILL ALLOW FOR INSTABILITY SHOWERS AT THE VERY
LEAST SO CHANCE POPS WEDNESDAY. TEMPERATURES WILL BEGIN A GRADUAL
COOL DOWN TUESDAY TRENDING BELOW NORMAL BY WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
SCATTERED SHOWERS ARE FORECAST TO TAPER OFF WEDNESDAY NIGHT AS A LOW
PRESSURE SYSTEM EXITS TO THE EAST. HIGH PRESSURE WILL THEN MOVE INTO
THE OHIO VALLEY THURSDAY...KEEPING THE WEATHER DRY THURSDAY
AFTERNOON THROUGH SATURDAY.
A COLD FRONT IS PROGGED TO BRING SCATTERED SHOWERS SUNDAY.
TEMPERATURES ARE FORECAST TO BE A FEW DEGREES BELOW NORMAL THURSDAY
AND FRIDAY...WARMING TO SLIGHTLY ABOVE NORMAL FOR THE WEEKEND.
&&
.AVIATION /05Z MONDAY THROUGH FRIDAY/...
LOW CONFIDENCE FORECAST FOR TODAY. DECAYING COMPLEX TO THE NORTHWEST
CONTINUES TO PUSH CIRRUS CLOUDS OVER THE UPPER OHIO VALLEY. AN AREA
OF STRATUS HAS DEVELOPED OVER THE EASTERN APPALACHIANS AND HAS BEEN
TRYING TO DRIFT WESTWARD. HOWEVER, LL FLOW IS VERY WEAK AND USING
LATEST SAT PICS, RIDGES ARE HOLDING THE LOW CLOUDS AT BAY. FOR THE
FORECAST, WILL LEAVE OUT MENTION OF STRATUS AT ALL PORTS WITH THE
EXCEPTION OF DUJ. LATEST HRRR RUN IS SHOWING THE IFR STRATUS MAKING
IT TO DUJ SHORTLY AFTER ISSUANCE TIME AND REMAINING, THROUGH 12Z.
WILL GO WITH AN MVFR/IFR FORECAST AT DUJ, BUT WILL NEED TO MONITOR
CLOSELY OVERNIGHT.
MODELS ARE HAVING DIFFICULTY DECIDING WHAT TO DO WITH THE DECAYING
COMPLEX OVER THE WESTERN GREAT LAKES. CURRENT SAT AND RADAR PICS
SHOW THE ACTIVITY DISSIPATING QUICKLY. ADDITIONALLY, LATEST MODEL
RUNS ARE FORECASTING A STRENGTHENING OF THE MIDWEST RIDGE AS IT
MOVES EASTWARD THIS MORNING. HAVE VERY LITTLE CONFIDENCE IN HOW MUCH
ACTIVITY WILL DEVELOP TODAY. TRYING TO FOLLOW THE UL WAVES TO HELP
WITH TIMING AND PLACEMENT. THE WAVE ASSOCIATED WITH THE DYING
WESTERN COMPLEX MOVES ACROSS THE NORTH DURING THE POST-DAWN MORNING
HOURS. THE PROBLEM IS THAT IT IS RUNNING INTO THE UL RIDGE. WILL
INCLUDE A MENTION OF NON-RESTRICTIVE SHOWERS ACROSS THE NORTH THIS
MORNING. WITH THE LACK OF UL SUPPORT AND DEEP LAYERED MOISTURE, WILL
LEAVE OUT THE MENTION OF RAIN AT OTHER PORTS UNTIL LATE IN THE DAY,
AS THE FRONT APPROACHES.
.OUTLOOK...TONIGHT THROUGH THURSDAY...
RESTRICTIONS ARE EXPECTED TONIGHT AND THROUGH MUCH OF TUESDAY, AS A
COLD FRONT WILL SLOWLY MOVE THROUGH. LOW CONFIDENCE FORECAST FOR THE
REMAINDER OF THE OUTLOOK, AS A LARGE UL TROUGH WILL SETTLE INTO THE
UPPER OHIO VALLEY LATE WED AND THU.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
639 PM CDT SUN MAY 6 2012
...MESOSCALE CONVECTIVE DISCUSSION...
.UPDATE...
/ISSUED 625 PM CDT SUN MAY 6 2012/
ISOLATED TO STRONG CONVECTION THAT DEVELOPED DURING THE MID AFTERNOON
HOURS HAD DIMINISHED LATE THIS AFTERNOON. HOWEVER CONVECTION WAS
CONTINUING TO EXPAND TO THE NORTH ACROSS WEST CENTRAL MISSOURI
JUST AHEAD OF A SOUTHWARD SAGGING COLD FRONT THAT EXTENDED FROM
NORTHERN MISSOURI INTO SOUTH CENTRAL KANSAS. ALSO OF INTEREST WAS
A EAST TO WEST OUTFLOW BOUNDARY ACROSS CENTRAL MISSOURI.
WILL BE CLOSELY MONITORING THE EVOLUTION OF CONVECTION ACROSS WEST
CENTRAL MISSOURI AS THIS MAY DEVELOP INTO A SMALL CONVECTIVE
COMPLEX AND MOVE SOUTHEAST INTO THE AREA AS SUGGESTED BY THE
CORFIDI VECTORS. THIS DEVELOPMENT MAY BE AIDED LATER THIS EVENING
BY A MODEST LOW LEVEL JET.
A FEW STRONG TO SEVERE STORMS WILL BE POSSIBLE LATER THIS EVENING
ACROSS CENTRAL MISSOURI INCLUDING THE TRUMAN LAKE AND LAKE OF THE
OZARKS REGIONS. THIS RISK MAY SPREAD SOUTH DURING THE NIGHT.
LOCALIZED DAMAGING WIND GUSTS AND LARGE HAIL WILL BE THE PRIMARY
HAZARDS.
WILL ALSO HAVE TO WATCH FOR THE POTENTIAL FOR TORRENTIAL RAINFALL
AND FLASH FLOODING GIVEN THE MOISTURE RICH AIR MASS.
THE FORECASTS WILL BE UPDATED THROUGH THE EVENING BASED ON RADAR
AND SHORT TERM MODEL TRENDS.
FOSTER
&&
.DISCUSSION...
//MESOSCALE DISCUSSION ISSUED AT 208 PM//
AN OUTFLOW BOUNDARY CONTINUES TO MOVE ACROSS SOUTHWEST
MISSOURI...AND WILL NEED TO BE WATCHED CLOSELY FOR SEVERE
THUNDERSTORM DEVELOPMENT.
AN EXTREMELY UNSTABLE ENVIRONMENT EXISTS ACROSS SOUTHERN AND CENTRAL
MISSOURI. RUC SUGGESTS THAT 4000 J/KG OF MIXED LAYER CAPE IS NOW
PRESENT FOR UPDRAFTS TO WORK WITH. THE ONE MITIGATING FACTOR IS
SHEAR VALUES...WHICH ARE VERY LOW. DEEP LAYER SHEAR IS ONLY ABOUT
10 TO 20 KNOTS...WHILE LOW LEVEL HELICITIES ARE UNDER 50 M2S2.
THE PRIMARY RISK WITH STORMS THAT DEVELOP WILL BE DAMAGING DOWNBURST
WINDS IN EXCESS OF 70 MPH...AND LARGE HAIL TO THE SIZE OF GOLF
BALLS. A 0-4KM THETA E DIFFERENTIAL RANGING BETWEEN 35 AND 40
DEGREES...SUGGESTS A HIGH LIKELIHOOD OF DOWNBURSTS.
CURRENTLY...THE LINE SEGMENT MOVING INTO BARRY COUNTY WILL HAVE A
HIGH RISK FOR PRODUCING DAMAGING WIND GUSTS. WE WILL NEED TO
MONITOR FOR IMPACTS OVER TABLE ROCK LAKE...AS MANY BOATERS ARE ON
THE LAKE THIS AFTERNOON. THIS STORM IS CATCHING ABOUT 25 KNOTS OF
0-3 KM SHEAR...WITH A NEAR PERPENDICULAR INTERACTION...WHICH COULD
INCREASE THE STRENGTH OF THE LINE SEGMENT FOR THE NEXT HOUR OR SO.
CRAMER
FOR TONIGHT...COLD FRONT WILL BE SLOWER TO MOVE INTO THE
AREA...BUT WILL BE THE SECONDARY FOCUS FOR STRONG TO SEVERE
CONVECTION WITH THIS SYSTEM. IN ADDITION...A WEAK SHORTWAVE WILL
TRACK EAST-NORTHEAST OUT OF OKLAHOMA THIS AFTERNOON INTO WESTERN
MISSOURI THIS EVENING INTO THE OVERNIGHT HOURS. THE SHORTWAVE AND
COLD FRONT WILL INTERACT WITH AN UNSTABLE ENVIRONMENT TO PRODUCE
STRONG TO SEVERE STORMS. SHEAR VALUES LOOK TO BE ON THE WEAK SIDE
HOWEVER WITH THE STRONG INSTABILITY AND LARGE THETA-E DIFFERENCES
WILL SEE A THREAT FOR DOWNBURSTS ALONG WITH LARGE HAIL. SEVERE
RISKS WILL BEGIN TO WEAKEN TOWARDS THE LATE EVENING INTO THE
OVERNIGHT HOURS AS THE INSTABILITY DIMINISHES.
THERE WILL ALSO BE A RISK OF TRAINING STORMS TONIGHT ALONG THE
FRONT AND COULD SEE SOME FLASH FLOODING DEVELOP IF THIS
OCCURS...ESPECIALLY OVER SOUTHEAST KANSAS INTO WEST CENTRAL
MISSOURI WHICH HAD THE HEAVIEST RAINFALL WITH THE PAST SYSTEM.
THUNDERSTORM CHANCES WILL CONTINUE INTO MONDAY AS THE FRONT WILL
SLOWLY TRACKS SOUTHEAST THROUGH THE AREA. THERE WILL REMAIN A RISK
OF SEVERE STORMS OVER SOUTH CENTRAL MISSOURI...ESPECIALLY DURING
THE LATE MORNING AND AFTERNOON HOURS WHERE THE INSTABILITY WILL
INCREASE AHEAD OF THE FRONT.
THE FRONT SHOULD CLEAR THE AREA BY MONDAY NIGHT WITH A STRONG
UPPER LEVEL TROUGH EXPECTED TO SWING SOUTHEAST THROUGH THE AREA
TUESDAY NIGHT AND WEDNESDAY. THIS SHOULD BRING A COOLER AND DRIER
AIR MASS TO THE AREA. NORTHWEST FLOW ALOFT WILL ESTABLISH OVER THE
FORECAST AREA FOR A GOOD PORTION OF THE REMAINDER OF THE WEEK
WHICH SHOULD KEEP THE COOLER TEMPERATURES OVER THE REGION.
THE NEXT SYSTEM TO AFFECT THE AREA WILL ARRIVE FRIDAY NIGHT INTO
THE WEEKEND WHICH WILL BRING THE NEXT CHANCE OF THUNDERSTORMS.
LINDENBERG
&&
.AVIATION...
/ISSUED 630 PM CDT SUN MAY 6 2012/
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP AND IMPACT AREA
TERMINALS LATER THIS EVENING AND OVERNIGHT AS A FRONT APPROACHES
FROM THE NORTH. THIS WILL RESULT IN AREAS OF MVFR CEILINGS AND
VISIBILITIES.
MVFR CEILINGS WILL BECOME MORE PREVALENT LATE TONIGHT AND MONDAY
MORNING AS THE FRONT PUSHES ACROSS THE REGION.
FOSTER
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
416 AM CDT MON MAY 7 2012
.SHORT TERM...CERTAINLY QUITE A CHANGE FROM THE PAST WEEK...WHICH
WAS MORE LIKE JULY WITH HIGH HUMIDITY AND SEVERAL EPISODES OF SEVERE
THUNDERSTORMS WITH LARGE HAIL. WE NOW HAVE SUB-40 DEGREE DEWPOINTS
WORKING INTO CENTRAL NEBRASKA FROM THE NORTHWEST ABOUT
NORTH/NORTHWEST WINDS. TEMPERATURES HAVE REMAINED UP A BIT TONIGHT
WITH COLD ADVECTION THANKS TO GOOD DECK OF MID/HIGH CLOUDS.
THE MAIN ISSUE TODAY IS A SMALL RISK FOR SPRINKLES IN SOME AREA...AND
THEN SOME CONCERN OF PATCHY FROST OVER THE NORTHWEST FORECAST AREA
TONIGHT. THOUGH LOW LEVEL DRY AIR WILL DEEPEN WITH TIME...THE FORECAST
AREA ASCENDS INTO A FAVORABLE RIGHT REAR QUADRANT OF 250MB JET STREAK
BY AFTERNOON. THIS FRONTOGENETIC TYPE FORCING IS CAPTIONED ON AT
LEAST A FEW MODELS...INCLUDING THE RUC RAPID REFRESH...WITH HINTS OF
MOISTURE TRYING TO SPILL NORTHEAST FROM COLORADO. BELIEVE ITS WORTH
A SPRINKLE MENTION AT THIS TIME FOR AREAS SOUTH OF INTERSTATE 80.
CHILLY CONDITIONS TONIGHT ARE MOST LIKELY IN THE NORTHWEST FORECAST
AREA...MAINLY NORTHWEST OF A LINE FROM ELWOOD...TO LOUP CITY...TO
GREELEY. AIR WILL BE DRY ENOUGH...WINDS PROBABLY LIGHT ENOUGH...TO
REACH NEAR THE 36 DEGREE LINE OR LOWER...WHICH WOULD SUPPORT FROST.
THE ISSUE MAY BE CLOUDS...AS SOME INCREASE/LINGERING CLOUDS COULD
REEK HAVOC WITH JUST WHAT AREAS ACTUALLY DROP THE LOWEST. WILL
MENTION SOME PATCHY FROST IN THE GOTHENBURG AREA...AND IN THE
HAZARDOUS WEATHER OUTLOOK...BUT NOT CONFIDENT ENOUGH TO ISSUE ANY
ADVISORY AT THIS TIME.
DESPITE SUNSHINE...A COOL START WILL LEAD TO A COOLISH DAY TUESDAY.
NORTH/NORTHWEST WINDS WILL KEEP THAT COOL FEEL IN THE AIR EVEN WITH
TEMPERATURES IN THE UPPER 60S TO LOWER 70S. THE WINDS WILL BE
STRONGEST ACROSS SOUTH CENTRAL NEBRASKA...AND GRADUALLY DROP OFF
THE FURTHER SOUTH ONE GOES. WITH HIGH PRESSURE SETTLING RIGHT ON THE
FORECAST TUESDAY NIGHT...ANOTHER RISK FOR PATCHY FROST COULD ARISE.
THAT APPEARS MOSTLY LIKELY IN THE NORTHEAST FORECAST AREA...MAINLY
NORTH AND EAST OF A YORK TO GREELEY LINE. THE WESTERN AREAS WILL
SEE JUST EVEN SOUTHERLY FLOW TO LIMIT COOLING IN THOSE AREAS.
WEDNESDAY AND WEDNESDAY WILL BE NICE WITH MAINLY CLEAR SKIES AND
SOUTHERLY FLOW GRADUALLY DEVELOPING THROUGHOUT THE DAY FROM WEST
TO EAST. HIGHS WEDNESDAY WILL BE RIGHT WHERE SHOULD BE FOR THIS
TIME OF YEAR...IN THE LOWER 70S. MORITZ
.LONG TERM...THURSDAY THROUGH SUNDAY. NEEDLESS TO SAY...IT LOOKS
LIKE THE MONTH OF MAY GOT ITS FIRST MULTI-DAY BOUT OF SEVERE WEATHER
OUT OF THE WAY QUITE EARLY...AS THERE ARE NO SYNOPTICALLY EVIDENT
THREATS FOR WIDESPREAD STRONG-SEVERE STORMS THROUGH AT LEAST THE
NEXT 7-9 DAYS PER THE LATEST 00Z GFS/ECMWF RUNS. THAT BEING
SAID...THERE ARE SOME CHANCES FOR SHOWERS/GENERALLY WEAK STORMS.
TEMP WISE...THESE 4 DAYS WILL GENERALLY BOUNCE AROUND WITHIN ROUGHLY
5 DEGREES EITHER SIDE OF NORMAL FOR MID-MAY.
STARTING OFF THURSDAY...THIS IS LOOKING LIKE THE WARMEST DAY OF
THE EXTENDED...AND NUDGED UP HIGHS VERY SLIGHTLY FROM PREVIOUS
FORECAST...PUTTING MOST AREAS IN THE 78-82 RANGE. IN THE MID-UPPER
LEVELS...THE TWO MAIN FEATURES ARE A COMPACT...CUT OFF LOW SLOWLY
MOVING INTO TX...AND A LARGER SCALE SHORTWAVE TROUGH CROSSING THE
NORTHERN ROCKIES. IN RESPONSE TO THE LATTER...HIGH PLAINS SURFACE
PRESSURE FALLS WILL INDUCE SOUTHERLY WINDS DURING THE DAY...AND
LIKELY A BIT BREEZY WITH SUSTAINED SPEEDS EASILY 15-20 MPH.
THURSDAY NIGHT...MODELS ARE IN DECENT AGREEMENT DRAGGING THE 500MB
SHORTWAVE TROUGH ALONG THE CANADIAN BORDER INTO THE ND AREA...AND
PUSHING A WELL-DEFINED SURFACE COLD FRONT SOUTHWARD INTO THE
REGION. AT THIS TIME...THE GFS IS A BIT FASTER/STRONGER WITH THIS
WAVE AND RESULTANT FRONTAL PASSAGE THAN THE ECMWF...AND DEVELOPS A
BAND OF PRECIP MAINLY ACROSS WESTERN NEB DURING THE NIGHT WITHIN
THE ENTRANCE REGION OF THE UPPER JET AND JUST BEHIND THE SURFACE
FRONT. ALTHOUGH ECMWF KEEPS ALL PRECIP NORTHWEST OF THE CWA
THROUGH THE NIGHT...WILL PLAY IT CLOSER TO PREVIOUS FORECAST AND
THE GFS SOLUTION WITH JUST A SLIGHT CHANCE OF SHOWERS/ISOLATED
STORMS ACROSS FAR NORTHWEST COUNTIES. INSTABILITY PROGS INDICATE
THAT EVEN A FEW HUNDRED J/KG OF ELEVATED CAPE MAY BE HARD TO COME
BY...SO AT THIS POINT WOULD THINK SMALL HAIL WOULD BE THE MOST ANY
STORMS COULD GENERATE.
FRIDAY INTO FRIDAY NIGHT...MODEL AGREEMENT REMAINS REASONABLY HIGH
FOR THIS TIME RANGE...AS THE NORTHERN SHORTWAVE CONTINUES TRACKING
TOWARD THE GREAT LAKES...AND THE SURFACE COLD FRONT PUSHES WELL
SOUTH THROUGH THE CWA. WELL OFF TO THE SOUTH...THE SLOW MOVING TX
MID-UPPER LOW SHOULD KEEP APPRECIABLE LOW LEVEL MOISTURE/INSTABILITY
WELL SOUTH OF THE CENTRAL PLAINS. THAT BEING SAID...MID LEVEL
SATURATION WITHIN THE ENTRANCE REGION OF THE UPPER JET SHOULD KEEP
AT LEAST THE POTENTIAL FOR RAIN SHOWERS GOING...AND HAVE 20-30
PERCENT CHANCES CWA-WIDE. DESPITE MEAGER INSTABILITY...WILL
MAINTAIN THUNDER WORDING BUT WILL KEEP IT AS ISOLATED AND WITH
SEEMINGLY VERY LITTLE RISK OF STRONG/SEVERE. TEMP-WISE...HIGHS
FRIDAY WILL BE A BIT TRICKY AS THE FRONT PUSHES IN...BUT WILL AIM
FOR MID 60S NORTHWEST TO MID 70S SOUTHEAST. HAVE FRIDAY NIGHT LOWS
WELL DOWN IN THE 40S ACROSS THE NORTHWEST 1/2 OF THE CWA.
SATURDAY INTO SATURDAY NIGHT...KEPT SLIGHT CHANCE POPS FOR MAINLY
LIGHT RAIN SHOWERS GOING...BUT PRIMARILY NEAR AND SOUTH OF THE
STATE LINE. LOWERED HIGHS FOR SATURDAY SLIGHTLY PER ALLBLEND MODEL
CONSENSUS...WITH ONLY MID-UPPER 60S CWA-WIDE. A SEASONABLY COOL
NIGHT FOLLOWS WITH MID-UPPER 40S CWA-WIDE.
FINALLY FOR SUNDAY...KEPT 20-30 POPS GOING ACROSS SOUTHERN
ZONES...BUT MODEL AGREEMENT HAS ALREADY FADED BY THEN...WITH GFS
KEEPING IT DRY...WHILE ECMWF BRINGS A BROAD MID LEVEL WAVE INTO
THE REGION IN DISORGANIZED NORTHWEST FLOW...BUT WITH BETTER PRECIP
CHANCES PRESUMABLY FOCUSING IN MORE FAVORED UPSLOPE AREAS TO THE
WEST. WILL AIM FOR LOW 70S CWA-WIDE FOR HIGH TEMPS. PFANNKUCH
&&
.PREV DISCUSSION... /ISSUED 1050 PM CDT SUN MAY 6 2012/
UPDATE...UPDATED THE FORECAST TONIGHT TO INCREASE SKY COVER AND
LOWER DEW POINTS...AND ALSO TO HOLD ON TO THE LINGERING SHOWERS IN
THE SOUTHEAST LONGER TONIGHT.
AVIATION...06Z KGRI TAF. WIND WILL BE THE BIGGEST ISSUE FOR THIS
FORECAST. NORTH WIND WILL PICK BACK UP AGAIN FOR MONDAY BY MID-
MORNING AS LOW-LEVEL LAPSE RATES INCREASE. THERE SHOULD BE A
CONSIDERABLE AMOUNT OF MID-LEVEL CLOUDINESS HANGING AROUND FOR
MOST IF NOT ALL OF THIS FORECAST. ANY SHOWER ACTIVITY SHOULD
REMAIN SOUTHEAST OF THE TERMINAL TONIGHT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1153 PM CDT SUN MAY 6 2012
.AVIATION...
06Z TAFS FOR KOFK...KOMA AND KLNK.
DRIER DEWPOINTS ARE MOVING IN FROM THE NORTH WITH VFR CONDTIONS
AND VARIABLE MID AND HIGH LEVEL CLOUDS THROUGH THE TAF PERIOD.
THERE IS A STORM SYSTEM OVER THE SOUTHWEST U.S. AND SHOULD LEAD TO
SOME THICKENING MID LEVEL CLOUDS MONDAY. THERE ARE SOME MODEL
DIFFERENCES ON HOW STRONG THE MOISTURE RETURN WILL BE. IF IT WILL
BE JUST CLOUDS OR POSSIBLY SOME LIGHT PRECIP. SO THIS WILL NEED TO
BE MONITORED. NORTH WINDS TONIGHT AT 5 TO 15KT WILL INCREASE AFTER
15Z TO 15 TO 20KTS WITH GUSTS TO 25KT DURING THE DAY MONDAY.
&&
.PREV DISCUSSION... /ISSUED 315 PM CDT SUN MAY 6 2012/
SHORT TERM...TONIGHT
UPPER AIR CHARTS FROM 12Z SHOWED THE FOLLOWING. AT 300 MB...PRIMARY
JETSTREAM STRETCHED FROM UTAH INTO ONTARIO WITH A JET MAX OF AROUND
90-100 KNOTS OVER NORTH DAKOTA. AT 500 MB...A FAIRLY TIGHT/COMPACT
CLOSED LOW WAS NOTED NEAR KGGW...CLOSE TO THE BORDER OF MONTANA AND
SASKATCHEWAN. 12 HOUR 500 MB HEIGHT FALL AT KGGW WAS 110 METERS BUT
THE ESTIMATED MAX VALUE WAS ABOUT 140 METERS A LITTLE FARTHER NORTH.
MODEST SOUTHWESTERLY FLOW WAS NOTED FROM THE DESERT SOUTHWEST INTO
THE NORTHERN PLAINS. DECENT MOISTURE WAS IN PLACE AT 850 MB...WITH
DEWPOINTS IN THE TEENS FROM KANSAS INTO ILLINOIS. AT THE SURFACE...
AN OCCLUDED FRONT CURVED FROM LOW PRESSURE OVER SASKATCHWAN INTO
MINNESOTA...THEN A COLD FRONT TRAILED SOUTH THROUGH WESTERN IOWA...
AND DOWN INTO WESTERN OKLAHOMA. SURFACE PATTERN ACROSS SOUTHEAST
NEBRASKA WAS SOMEWHAT AFFECTED/CONTAMINATED BY EARLIER MCS THAT
PRODUCED OUTFLOW.
ALTHOUGH THE MAIN SURFACE FRONT WILL CONTINUE TO PUSH SOUTHEAST OR
EAST TONIGHT...THERE IS STILL ENOUGH LINGERING ELEVATED MOISTURE AND
INSTABILITY OVER ABOUT THE SOUTHEASTERN 1/2 OF THE FORECAST AREA FOR
SCATTERED THUNDERSTORMS AT LEAST THROUGH MIDNIGHT. THIS IS CLOSER
TO THE 850 MB FRONT. 12Z NAM WAS MORE A BIT MORE AGRESSIVE WITH
PRECIPITATION COMPARED TO THE GFS. 17Z RUN OF THE HRRR THOUGH
SUGGESTED 12Z NAM WAS REASONABLE.
LONG TERM...MONDAY THROUGH SUNDAY.
TEMPERATURES WILL PROVIDE THE MAIN CHALLENGES THROUGH MUCH OF THE
WEEK WITH HIGHER CHANCES FOR SHOWERS/THUNDERSTORMS NOT ARRIVING
UNTIL ABOUT FRIDAY.
CLOSED LOW AT 500 MB WILL TRACK EASTWARD JUST NORTH OF THE BORDER OF
THE U.S. AND CANADA ON MONDAY...WHILE THE TROUGH ASSOCIATED WITH
IT TRACKS ACROSS THE NORTHERN AND CENTRAL PLAINS. IT APPEARS THAT
PRECIPITATION CHANCES WILL BE MINIMAL IN OUR AREA. SOME LIGHT
SHOWERS COULD LINGER IN FAR SOUTHEAST NEBRASKA PAST 6 AM...SO LEFT
A LOW POP THERE UNTIL ABOUT 9 AM. ON TUESDAY...FELT BETTER CHANCES
FOR SHOWERS WOULD STAY TO OUR NORTH OR NORTHEAST.
A RIDGE OF HIGH PRESSURE AT THE SURFACE WILL BUILD INTO THE AREA
MONDAY NIGHT INTO TUESDAY...SETTING THE STAGE FOR WHAT LOOKS LIKE A
COOL EARLY MORNING FOR WEDNESDAY. WENT SEVERAL DEGREES BELOW
GUIDANCE FOR LOWS TUESDAY NIGHT/WEDNESDAY MORNING WITH MAINLY CLEAR
SKIES AND LIGHT WINDS EXPECTED.
A MID TROPOSPHERIC RIDGE WILL BUILD ACROSS THE REGION WEDNESDAY
THROUGH THURSDAY WITH DRY CONDITIONS AND MILDER TEMPERATURES. MODELS
SHOW NEXT COLD FRONT APPROCHING THE AREA FROM THE NORTHWEST BY LATE
THURSDAY NIGHT. THEN HAVE LOW POPS FOR PARTS OF THE AREA INTO NEXT
WEEKEND.
MILLER
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
ZAPOTOCNY
AREA FORECAST DISCUSSION
NWS TULSA OK
1141 PM CDT SUN MAY 6 2012
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
VFR CONDITIONS ARE OCCURRING IN ADVANCE OF A COLD FRONT
THAT IS POISED TO MOVE INTO NORTHEAST OKLAHOMA. SHOWERS
AND THUNDERSTORMS CURRENTLY ALONG AND NEAR THE COLD FRONT
WILL MOVE INTO THE AREA OVERNIGHT AFFECTING THE NORTHEAST
OKLAHOMA AND NORTHWEST ARKANSAS TAF SITES OVERNIGHT INTO
EARLY MONDAY MORNING. MVFR TO IFR CONDITIONS WILL BE POSSIBLE
WITH THE THUNDERSTORMS. MVFR CEILINGS WILL MOVE INTO THE
REGION IN THE WAKE OF THE COLD FRONT. VFR CONDITIONS ARE EXPECTED
TO RETURN MONDAY AFTERNOON/EVENING.
&&
.PREV DISCUSSION... /ISSUED 921 PM CDT SUN MAY 6 2012/
..UPDATE...
DISCUSSION...
COLD FRONT CURRENTLY EXTENDING FROM EAST CENTRAL KANSAS SOUTHWARD
INTO SOUTHWEST OKLAHOMA HAS PROGRESSED ONLY SLOWLY EASTWARD THIS
EVENING...AND HAS RECENTLY BECOME THE FOCUS FOR EXPANDING
THUNDERSTORM COVERAGE ACROSS EASTERN KANSAS. 00Z KOUN SOUNDING
SAMPLED THE HIGHLY UNSTABLE YET CAPPED AIRMASS CURRENTLY IN PLACE.
GIVEN THE ABSENCE OF LARGE SCALE FORCING IN PLACE...THE FOCUS FOR
LIFT WILL REMAIN NEAR THE COLD FRONT. THE EVOLUTION OF CONVECTION
ALONG THE FRONT IS UNCLEAR AS SOME SHORT TERM MODEL SOLUTIONS
DEVELOP AN AGGRESSIVE COLD POOL WHICH SPREAD SOUTHEASTWARD DURING
THE EARLY MORNING HOURS. THE 00Z NAM IS IN THIS CAMP HOWEVER WE
QUESTION WHETHER IT IS RELEASING THE HIGH CAPE ENVIRONMENT TOO
EASILY...WITH LOCAL WRF RUNS MUCH LESS AGGRESSIVE IN SOUTHEASTWARD
DEVELOPMENT. THE HRRR SOLUTIONS HAVE BEEN SOMEWHAT CONSISTENT AND
OFFER A COMPROMISE WHICH SEEMS REASONABLE AT THIS POINT...AND
ALLOW CONVECTION TO SPREAD SOUTHEASTWARD OFF THE FRONT BUT
EVENTUALLY LIMIT THE SOUTHWARD ADVANCE DURING THE OVERNIGHT HOURS.
THUS THE UPDATED FORECAST WILL TRIP POPS ACROSS THE SOUTHERN HALF
OF THE FORECAST AREA AND RETAIN THE FOCUS FOR NORTHEAST OKLAHOMA
INTO FAR NORTHWEST ARKANSAS. THE STABILIZING BOUNDARY LAYER LOOKS
TO KEEP THE HIGHEST INSTABILITY FROM BEING REALIZED...HOWEVER
POOLING DEEPER MOISTURE NEAR THE FRONTAL ZONE WILL RETAIN
SUFFICIENT ELEVATED INSTABILITY TO WARRANT A SEVERE WEATHER RISK
OVERNIGHT. OVERNIGHT LOW TEMPS LOOK ON TRACK ASSUMING SOME TYPE OF
OUTFLOW COOLS LOCATIONS AHEAD OF THE FRONTAL POSITION BEFORE
SUNRISE.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...10
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1155 PM CDT SUN MAY 6 2012
.AVIATION...
MAIN AVIATION CONCERN IS STILL THE EXPECTED SPREAD AND DEVELOPMENT
OF LOW STRATUS ACROSS THE REGION EARLY MONDAY MORNING. LATEST GUIDANCE
IS SLIGHTLY MORE PESSIMISTIC AND WE HAVE ADJUSTED THE TAFS TO SHOW
A LONGER DURATION OF MVFR CEILINGS. A PERIOD OF IFR CEILINGS AND
PERHAPS EVEN SOME LIGHT -DZ ARE POSSIBLE AS WELL. CEILINGS MAY
STILL LIFT TO VFR BY MIDDAY BUT CONFIDENCE HAS DECREASED. SHRA AND
TSRA CHANCES ARE POSSIBLE AT KLBB AT THE VERY END OF THE TAF PERIOD.
&&
.PREV DISCUSSION... /ISSUED 629 PM CDT SUN MAY 6 2012/
AVIATION...
VFR CONDITIONS EXPECTED TO CONTINUE UNTIL 07Z-08Z...AFTER WHICH
LOW STRATUS IS FORECAST TO EXPAND SOUTH FROM THE PANHANDLES AND
AFFECT KLBB AND KCDS WITH MVFR CEILINGS...AND POSSIBLY A PERIOD OF
IFR CEILINGS AT KLBB EARLY MONDAY MORNING. THE CEILINGS SHOULD
SLOWLY LIFT AT BOTH TERMINALS ABOVE MVFR BY LATE MORNING OR MIDDAY
MONDAY...WITH WX CONDITIONS THEN EXPECTED TO DETERIORATE MONDAY
NIGHT AFTER 0Z. NE SFC WINDS BETWEEN 10 TO 18 KTS WILL PREVAIL.
PREV DISCUSSION... /ISSUED 444 PM CDT SUN MAY 6 2012/
UPDATE...
QUICK UPDATE TO ADD AN ISOLATED THUNDERSTORM MENTION FOR THE NEXT
COUPLE OF HOURS ACROSS THE EXTREME SOUTHEAST ZONES...WHERE HIGH-
BASED STORMS WERE DEVELOPING. NO OTHER CHANGES MADE TO THE
FORECAST ATTM.
PREV DISCUSSION... /ISSUED 257 PM CDT SUN MAY 6 2012/
SHORT TERM...
COLD FRONT HAS SLOWED THIS AFTN AND AS OF 19Z EXTENDED ALONG A LINE
FROM SEMINOLE-POST-PADUCAH NORTHWEST OF A DRYLINE FROM NEAR LAKE ALAN
HENRY TO GUTHRIE. ENHANCED CONVERGENCE WHERE THESE TWO BOUNDARIES
MEET IS EVIDENT ON LAPS DATA...HOWEVER A LACK OF CU THUS FAR
CONFIRMS CAPPING IS STILL QUITE ROBUST. HRRR SEEMS AWFUL BULLISH IN
CONVECTING NEAR KING AND STONEWALL COUNTIES BY 20Z. TEND TO BELIEVE
IF STORMS MATERIALIZE THEY WILL BE DELAYED IN TIME AND DISPLACED
FARTHER EAST...SO POPS WERE LEFT SILENT FOR NOW.
TONIGHT...THE AXIS OF A SURFACE HIGH WILL SHARPEN SSW INTO ERN NM
ALLOWING WINDS AROUND 850MB TO VEER NELY AND BEGIN TAPPING A RICHER
FIELD OF MOISTURE PRESENTLY IN NWRN OK. LOW CLOUDS ALREADY IN THE
CENTRAL TX PANHANDLE SHOULD EXPAND SOUTH TONIGHT IN RESPONSE TO THIS
PROCESS.
MONDAY...INITIAL COOL SURFACE RIDGING IS FORECAST TO WEAKEN IN
RESPONSE TO INCREASING WARM ADVECTION AND PRESSURE FALLS FROM SRN NM
INTO THE PERMIAN BASIN. DRIVING FORCE BEHIND THIS IS TIED TO AN
APPROACHING UPPER TROUGH CURRENTLY NEAR BAJA CA AND AN ASSOCIATED
TROPOPAUSE JET STREAK DOWNSTREAM. BRUNT OF THIS FORCING WILL NOT
AFFECT OUR CWA UNTIL THE FOLLOWING PERIOD...HOWEVER SUSTAINED LIGHT
ELY UPSLOPE FLOW THROUGHOUT THE LOWEST 5K FEET COMBINED WITH AN
ELEVATED BUT SHARPENING BAROCLINIC ZONE APPEAR SUFFICIENT FOR
CONVECTION IN ERN NM BY MIDDAY. FORECAST SOUNDINGS HERE BY LATE AFTN
INDICATE SBCAPE AND ELEVATED CAPE OF 500-1000 J/KG EMBEDDED WITHIN
STRONG 0-6KM BULK SHEAR OF 50-60 KNOTS. CURRENT THINKING IS STORMS
IN NM COULD THREATEN THE WRN SOUTH PLAINS BY LATE AFTN WITH A
CONDITIONAL THREAT OF SOME BEING SEVERE. DID REMOVE POP MENTION OFF
THE CAPROCK TOMORROW AS LIFT HERE APPEARS MUCH TOO SHALLOW TO
OVERCOME A STOUT EML AROUND 750MB. WITH STRATUS EXPECTED TO LINGER
MUCH OF THE DAY...TEMPS AREA WIDE WILL FALL BELOW NORMAL FOR THE
FIRST TIME SINCE MID APRIL!
LONG TERM...
THE CLOSED LOW PROGGED TO BE PINCHED OFF FROM THE UL TROF EDGING
ACROSS THE ROCKIES WILL DIVE SOUTH OUT OF UT INTO NRN MEXICO THRU
WED EVENING. FROM THERE GUIDANCE HAS COME TO BETTER AGREEMENT WITH
THE TRACK OF THE LOW AS IT PUSHES EASTWARD INTO WTX...ALBEIT A SLOW
PROGRESSION. THIS COMBINED WITH A QUASI-STATIONARY FRONT TO THE
SOUTH...POSSIBLE AS FAR SOUTH AS THE RGV...WILL CONTRIBUTE TO
CONTINUED PRECIP CHANCES EACH DAY DURING THE WEEK.
THE FIRST AND BEST PRECIP CHANCE REMAINS ON TUE AS A SECONDARY 850
FRONT PUSHES THRU THE AREA AS THE SFC RIDGE BUILDS IN OVER THE
PANHANDLE. NAM/GFS AGREE UPON SOME 305K ISENTROPIC UPGLIDE AOA 12Z
TUE. THIS COMBINED WITH THE CONTINUED UL DIVERGENT REGION OVER THE
REGION TUE...THE BEST CHANCES FOR HEAVY PRECIP LOOKS TO REMAIN IN
THE MORNING HOURS...WITH CHANCES TRENDING DOWN FROM THERE AS THE SFC
RIDGE SETTLES IN TO THE NORTH. THIS EVENT CONTINUES TO LOOK LIKE A
DESCENT RAIN MAKER...WITH ONLY LIMIT INSTABILITY /GENERALLY UNDER
200 J/KG MUCAPE/. THEREFORE...HAVE ONCE AGAIN LOWER THUNDER TO ONLY
AN ISOLATED MENTION.
WED 00Z ON...THE BEST PRECIP CHANCES WILL BE TIED TO THE FRONT TO
THE SOUTH AND THE AFOREMENTIONED UL LOW EDGING EAST.
THEREFORE...MOST OF THE LATER HALF OF THE WEEK HAVE CONTINUED SLGT
CHANCE POPS MAINLY ACROSS THE SWRN ZONES. HOWEVER...BY THE WEEKEND
THERE REMAINS SOME SLIGHT DIFFERENCE ON SPEED AND TRACK OF THE UL
LOW OVER THE REGION AS WELL AS THE ONE OFF THE ERN CONUS.
THEREFORE...WILL CONTINUE ECMWF TREND FROM PREVIOUS THINKING.
MEADOWS
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 49 64 44 58 44 / 10 30 50 50 20
TULIA 52 66 48 60 45 / 10 20 40 40 20
PLAINVIEW 52 68 49 59 47 / 10 20 40 40 20
LEVELLAND 53 74 52 60 50 / 10 20 60 60 20
LUBBOCK 54 74 53 60 48 / 10 10 50 60 20
DENVER CITY 52 78 52 64 50 / 10 30 70 70 20
BROWNFIELD 52 76 52 60 50 / 10 20 60 70 20
CHILDRESS 59 75 54 70 50 / 10 10 30 40 20
SPUR 57 76 54 64 49 / 10 10 40 40 20
ASPERMONT 60 80 56 70 50 / 10 10 40 40 20
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
33
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
1147 PM CDT SUN MAY 6 2012
.DISCUSSION...SEE AVIATION SECTION BELOW.
&&
.AVIATION...VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH MUCH OF
TONIGHT WITH MVFR TOWARD MON MORNING AND BRIEF PERIODS OF IFR
CONDITIONS FROM ALI TO VCT DUE TO CIGS AND PATCHY FOG. VFR
CONDITIONS ARE EXPECTED TO RESUME BY MID TO LATE MON MORNING AND
CONTINUE THROUGH THE REMAINDER OF MON AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 712 PM CDT SUN MAY 6 2012/
DISCUSSION...SEE 00Z AVIATION DISCUSSION.
AVIATION...CONVECTION IS FIRING UP IN SOUTH CENTRAL TX...AND SOME
MODELS (TTU AND HRRR) BRING THIS CONVECTION INTO KVCT AREA.
CONFIDENCE IN THIS HAPPENING ARE NOT HIGH ENOUGH AT THIS TIME
(GIVEN WEAKER LOW LEVEL WINDS TONIGHT...INCREASING CIN/LOWER CAPES AND
LACK OF UPPER SUPPORT). THAT BEING SAID...EXPECTING MUCH LESS MID
AND HIGH CLOUD COVER TONIGHT...SO WILL BRING IN THE MVFR
CONDITIONS A BIT EARLIER...OVER KVCT AOA 03Z AND KCRP/KALI AOA
06Z. EXPECTING VFR AT KLRD (AND HAVE REMOVED THUNDER). HAVE ALSO
INCLUDED A BIT OF BR (ACTUALLY KEPT FROM PREVIOUS TAFS)...WITH
POSSIBLE IFR CIGS AT KALI. WILL HAVE MVFR CONDITIONS EAST OF KLRD
TIL ABOUT 17Z. AM EXPECTING LESS WIND TOMORROW AS WELL (WITH FRONT
TO THE NORTH)...BUT WINDS WILL BE A BIT GUSTY AT TIMES DURING THE
AFTERNOON SO HAVE A MENTION OF GUSTS (LESS THAN 25 KNOTS) FOR THE
AFTERNOON.
PREV DISCUSSION... /ISSUED 327 PM CDT SUN MAY 6 2012/
SHORT TERM (TONIGHT THROUGH MONDAY NIGHT)...MAIN FORECAST
CHALLENGE IN SHORT TERM PERIOD IS CONVECTIVE CHANCES TONIGHT AND
AGAIN MON NIGHT. SEVERAL BOUNDARIES WERE EMITTED LAST NIGHT FROM
MCS THAT REMAINED JUST TO OUR NORTH. ONE BOUNDARY HAS RECENTLY PUSHED
OFF THE LOWER TX COAST WHILE ANOTHER LOST ITS CHARACTERISTICS OVER
CRP CWA. SEA BREEZE IS TRYING TO PUSH INLAND BUT MAY NOT BE ABLE
TO COMPENSATE FOR SLIGHT CIN VALUES ACROSS COASTAL PLAINS...THUS
ISO CONVECTION MAY BE VERY LIMITED ACROSS THE EAST REMAINDER OF
THIS AFTERNOON. FOCUS FOR LATE AFTERNOON AND THIS EVENING TURNS TO
WESTERN ZONES WHERE CONVECTION MAY DEVELOP OR MOVE IN FROM OLD
MEX. SURFACE DRYLINE/TROUGH CURRENTLY EXTENDS FROM ACROSS EDWARDS
PLATEAU AND FARTHER SOUTH INTO MEX. CONVECTION IS ALREADY
DEVELOPING ALONG BOUNDARY AND IN HIGHER ELEVATIONS IN MEX AND SOME
OF THIS CONVECTION MAY APPROACH WESTERN ZONES THIS EVENING.
SEVERAL CONSECUTIVE RUNS OF HRRR WANT TO BRING CONVECTION THROUGH
WESTERN ZONES OVERNIGHT WHILE OTHER 4KM WRF RUNS WERE DRIER. DO NOT
WANT TO COMPLETELY DISCOUNT HRRR AS OTHER RUNS DID NOT HANDLE THIS
MORNING/S MCS AND RESULTANT MCV WELL AND THUS HAVE DECIDED TO GO
WITH LOW CHANCE POPS TONIGHT OUT WEST. ANY STORMS THAT OCCUR MAY
BECOME STRONG WITH AN ISOLATED SEVERE THREAT POSSIBLE. WILL ALSO
NEED TO WATCH FOR POTENTIAL CONVECTION ACROSS EWX CWA AS CORFIDI
VECTORS INDICATE POTENTIAL MOVEMENT INTO OUR NORTHERN ZONES. IF
CONVECTION DOES AFFECT CWA THERE IS A SLIGHT CHANCE IT MAY REACH
THE COASTAL PLAINS LATE TONIGHT BUT THOSE CHANCES ARE CURRENTLY
LOW AS CIN VALUES FARTHER EAST WILL BE INCREASING OVERNIGHT. FOR
MONDAY...MID LEVEL RIDGING SHOULD HELP KEEP S TX HOT WITH HIGHS
AROUND 100 ACROSS WESTERN ZONES AND 90S ACROSS THE EAST UNDER
PARTLY TO MOSTLY SUNNY SKIES IN THE AFTERNOON. GFS AND CMC WANT TO
DEVELOP CONVECTION TO OUR NW IN EWX CWA MON AFTERNOON WITH
CONVECTION MOVING SOUTHEAST TOWARDS OUR AREA DURING THE EVENING.
NAM AND ECMWF ARE LESS ROBUST AND KEEP MOST ACTIVITY TO OUR NORTH.
FOR NOW...GIVEN BETTER UPPER LEVEL DYNAMICS PROG TO EXIST...HAVE
GONE WITH CHANCE POPS ACROSS NW AREAS.
LONG TERM (TUESDAY THROUGH SUNDAY)...MAIN ISSUES FOR THE
EXTENDED PART OF THE FORECAST WILL BE CONVECTION THROUGHOUT THE
WEEK. PERIOD WILL START OF WILL UPPER LEVEL RIDGE MOVING EAST AND
DAMPENING AS UPPER LEVEL LOW DEEPENS OVER SOUTHERN CA/AZ. COLD
FRONT WILL BE MOVING SOUTHWARD ACROSS TEXAS DURING THE DAY ON
TUESDAY. MODELS PROG LEFT EXIT REGION OF UPPER JET TO BE
APPROACHING THE AREA AS WELL DURING THIS TIME. MOISTURE WILL BE IN
PLACE AS PWATS CLIMB TO ABOUT 1.4 TO 1.5 INCHES OVER SOUTH TEXAS.
THIS WILL LEAD TO SHOWERS AND STORMS DEVELOPING ALONG THE BOUNDARY
TUESDAY NIGHT INTO WEDNESDAY. NAM/GFS IN FAIRLY GOOD AGREEMENT ON
EVOLUTION OF THE FRONT SO WAS COMFORTABLE RAISING POPS FOR THESE
PERIOD. WILL CARRY 50 POPS OUT WEST TO 20 POPS OVER THE COASTAL
PLAINS TUESDAY NIGHT WITH 40 POPS OVER LAND ON WEDNESDAY.
CONVECTIVE ACTIVITY WILL BE HIGHLY DEPENDENT ON WHERE FRONT ENDS
UP AND HOW LONG IT LINGERS OVER THE CWA. THESE DETAILS WILL BE
FINE TUNED OVER THE NEXT SEVERAL DAYS. UPPER LOW WILL BE MOVING
OUT OF MEXICO AND WEST TEXAS TO THE EAST NORTHEAST THURSDAY INTO
FRIDAY. MOISTURE WILL STILL REMAIN OVER SOUTH TEXAS AS PWAT VALUES
CONTINUE TO BE ABOVE NORMAL FOR THIS TIME OF YEAR. SHOWER AND
THUNDERSTORM CHANCES WILL CONTINUE FOR THE SECOND HALF OF THE WORK
WEEK. HAVE ALSO RAISED POPS DURING THE THURSDAY NIGHT AND FRIDAY
TIME FRAME. OVERALL...A WET PERIOD MAY MATERIALIZE ACROSS SOUTH
TEXAS THIS UPCOMING WEEK WITH PERIODS OF LOCALLY HEAVY RAINFALL
POSSIBLE. AFTERNOON HIGH TEMPERATURES WEDNESDAY THROUGH FRIDAY
WILL BE AT OR BELOW NORMAL FOR THIS TIME OF YEAR DUE TO CLOUD
COVER AND PRECIP CHANCES. UPPER SYSTEM WILL BEGIN TO MOVE
NORTHEAST OF THE REGION ON SATURDAY...WITH RAIN CHANCES ENDING
FROM WEST TO EAST.
MARINE...SCEC CONDITIONS TO PERSIST TONIGHT THROUGH AT LEAST
MONDAY WITH LITTLE CHANGE EXPECTED TO SEA CONDITIONS. AREAS OF
HAZE FROM AGRICULTURAL FIRES IN MEXICO MAY EXIST MONDAY ACROSS THE
OPEN WATERS OF THE MIDDLE TEXAS COAST. A LATE SEASON COLD FRONT
AND STRONG UPPER LEVEL WEATHER DISTURBANCE MAY AFFECT THE AREA BY
THE MIDDLE OF THIS WEEK WITH SHOWER AND THUNDERSTORM CHANCES
INCREASING AT TIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 74 92 74 89 72 / 10 10 10 10 20
VICTORIA 70 92 72 87 70 / 10 10 10 20 20
LAREDO 75 101 75 94 72 / 10 10 20 10 40
ALICE 72 97 73 91 71 / 10 10 10 10 30
ROCKPORT 76 86 76 85 76 / 10 10 10 10 20
COTULLA 72 99 71 91 70 / 10 20 30 20 50
KINGSVILLE 74 96 75 90 73 / 10 10 10 10 20
NAVY CORPUS 75 86 76 86 75 / 10 10 10 10 20
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
TE/81...AVIATION
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
330 AM CDT MON MAY 7 2012
.TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM.
THE STRONG 250 MB JET MAX OF 120 KNOTS HAS PUSHED OFF TO SOUTHERN
QUEBEC WITH A WEAKER JET MAX IN THE UPSTREAM OF THE TROUGH THAT
EXTENDS FROM LAKE WINNIPEG TO THE CENTRAL ROCKIES. ONLY WEAK UPPER
DIVERGENCE TODAY ACROSS WISCONSIN...WHICH HEADS OFF TO THE EASTERN
GREAT LAKES LATE TONIGHT.
A WEAKENING 30 KNOT 700 MB FLOW ACROSS NORTHERN ILLINOIS AND THE
WISCONSIN BORDER AREA EARLY THIS MORNING DIMINISHES TO 10 KNOTS
JUST AFTER SUNRISE.
WEAK 700 MB UPWARD MOTION OF 2.2 MICROBARS/SEC ACROSS LAKE
MICHIGAN JUST AFTER SUNRISE NEAR THE WEAK 700 MB TROUGH AXIS. THEN
LITTLE LIFT LATER THIS MORNING AS AN OCCLUDED FRONT PUSHES EAST
ACROSS THE FORECAST AREA.
THE NAM AND THE 03Z LOCAL WRF KEEP MOST OF THE PRECIPITATION
ACROSS NORTHERN ILLINOIS EARLY THIS MORNING CLOSER TO THE SURFACE
BOUNDARY AND SURFACE LOW. THE NAM/LOCAL WRF/ RAP/AND HRRR ALL
BRING SOME SCATTERED LIGHT SHOWERS ACROSS THE FAR SOUTH THIS
MORNING.
STRONG 700 MB DRYING WILL OCCUR LATE THIS MORNING OVER NORTHWEST
SECTIONS OF THE FORECAST AREA...AND ACROSS ALL OF SOUTHERN
WISCONSIN THIS AFTERNOON. THE DRYING OCCURS AT 850 MB AS
WELL...ALTHOUGH SOME INCREASE IN RH AT 850 OCCURS OVER THE
NORTHERN SECTIONS TONIGHT AHEAD OF THE APPROACHING MID LEVEL
TROUGH THAT EXTENDS FROM THE MINNESOTA ARROWHEAD TO SOUTHEAST
SOUTH DAKOTA BY SUNRISE SATURDAY.
SURFACE DEWPOINTS ALSO DRY...ESPECIALLY TONIGHT AS THEY LOWER
INTO THE LOWER 40S.
.SHORT TERM...TUESDAY THROUGH WEDNESDAY NIGHT...FORECAST
CONFIDENCE IS MEDIUM TO HIGH.
SHORT TERM MODELS CONTINUE TO SHOW UPPER LEVEL TROUGH SWINGING
SOUTHEAST THROUGH THE REGION TUESDAY THROUGH WEDNESDAY. APPEARS
BEST CHANCES FOR SHOWERS WILL BE TUESDAY AFTERNOON INTO TUESDAY
EVENING...WITH BEST DIFFERENTIAL CYCLONIC VORTICITY ADVECTION
PASSING THROUGH. CHANCES LOWER LATER TUESDAY NIGHT INTO
WEDNESDAY...WITH SECONDARY VORTICITY MAXIMUM PASSING THROUGH THE
AREA.
AREA FORECAST SOUNDINGS SHOWING STEEP LOW TO MID LEVEL LAPSE
RATES TUESDAY AS THE TROUGH MOVES INTO THE REGION. NAM MORE ROBUST
ON MEAN LAYER CAPES THAN GFS...UP TO 200 J/KG.
HOWEVER...INSTABILITY BARELY REACHING 10 DEGREE BELOW ZERO CELSIUS
ISOTHERM NEEDED FOR CONVECTION. WILL CONTINUE TO MENTION LOW
CHANCES FOR THUNDER TUESDAY AFTERNOON DESPITE MIXED CONFIDENCE IN
ITS OCCURRENCE.
CONTINUED LOWER END POPS TUESDAY NIGHT INTO WEDNESDAY...ESPECIALLY
IN THE EASTERN PORTIONS OF THE AREA. TEMPERATURES WILL BE NEAR TO
JUST BELOW SEASONAL NORMALS DURING THIS TIME...WITH A LAKE BREEZE
EXPECTED WEDNESDAY AFTERNOON. HIGH PRESSURE PASSING OVER THE AREA
WEDNESDAY NIGHT WILL BRING QUIET WEATHER AND COOL TEMPERATURES.
.LONG TERM...THURSDAY THROUGH SUNDAY...FORECAST CONFIDENCE IS
MEDIUM.
ECMWF/GFS IN DECENT AGREEMENT DURING THIS PERIOD WITH FEATURES.
THEY SHOW UPPER RIDGING SHIFTING THROUGH THE REGION THURSDAY AND
THURSDAY NIGHT...WITH HIGH PRESSURE SLOWLY SLIDING SOUTHEAST OF
THE AREA. QUIET WEATHER IS EXPECTED TO CONTINUE...WITH
TEMPERATURES NEAR SEASONAL NORMALS.
GFS THEN BRINGS COLD FRONT SOUTHEAST THROUGH THE REGION QUICKER
THAN THE ECMWF...MAINLY FRIDAY AFTERNOON THROUGH FRIDAY EVENING.
ECMWF IS ABOUT 12 HOURS SLOWER WITH THIS FRONTAL PASSAGE.
VORTICITY MAXIMUM SLIDES THROUGH THE AREA WITH THE FRONT.
THUS...WENT WITH A CONSENSUS BLEND FOR POPS AND TEMPERATURES
FRIDAY THROUGH SATURDAY NIGHT.
MODELS THEN SHOW PASSING VORTICITY MAXIMA WITHIN WEST TO NORTHWEST
UPPER LEVEL FLOW. SOME DIFFERENCES WITH TIMING AND PLACEMENT OF
THESE FEATURES...SO WENT WITH CONSENSUS BLEND FOR POPS AND
TEMPERATURES DURING THIS PERIOD AS WELL.
&&
.AVIATION/12Z TAFS/...
EXPECT MVFR WITH SOME IFR/LIFR CIGS THIS MORNING. CEILINGS SHOULD
RISE TO VFR THIS AFTERNOON AS DRIER AIR MOVES IN BEHIND AN
OCCLUDED FRONT.
&&
.MARINE...
THE PERSISTENT EAST FLOW SHOULD BECOME NORTH THIS MORNING THEN
NORTHWEST TONIGHT. WINDS/WAVES WILL REMAIN BELOW SMALL CRAFT
CRITERIA.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...HENTZ
TUESDAY THROUGH SUNDAY...WOOD
AREA FORECAST DISCUSSION
NWS MIAMI FL
1014 AM EDT MON MAY 7 2012
.UPDATE...THE SHORT TERM FORECAST REMAINS ON TRACK. A WEAKENING
FRONTAL BOUNDARY WILL PUSH SOUTH BUT REMAIN NORTH OF THE LOCAL
AREA TODAY, ALONG WITH THE BEST MID LEVEL ENERGY. SLIGHT CHANCE
POPS FOR THUNDERSTORMS SEEM REASONABLE THIS AFTERNOON, ESPECIALLY
FROM THE LAKE REGION AND ACROSS PALM BEACH COUNTY.
&&
.PREV DISCUSSION... /ISSUED 720 AM EDT MON MAY 7 2012/
AVIATION...
CLOUDS WILL SLOWLY INCREASE ACROSS SOUTH FLORIDA OVER THE NEXT 24
HOURS AS DEEPER MOISTURE PUSHES IN FROM THE NORTH. SHRAS WILL BE
POSSIBLE ACROSS THE AREA TOWARD THE LATE AFTERNOON HOURS...KEPT
VCSH MENTION AT ALL EAST COAST SITES. OTHERWISE...EASTERLY WINDS
AROUND 10 KTS FROM EAST COAST SEA BREEZE THIS AFTERNOON SHOULD
SUBSIDE AFTER 00Z. AT KAPF A SOUTHWESTERLY SEA BREEZE WILL DEVELOP
BY THE LATE MORNING AND CONTINUE THROUGH THE EARLY EVENING.
PREV DISCUSSION... /ISSUED 416 AM EDT MON MAY 7 2012/
DISCUSSION...WATER VAPOR IMAGERY SHOWS A TROUGH IN PLACE OVER
THE DEEP SOUTH. THIS FEATURE WILL MOVE SOUTHEAST OVER THE NEXT FEW
DAYS, REPLACING THE RIDGE THAT HAS BEEN IN PLACE ACROSS SOUTH FL.
MEANWHILE, MOISTURE WILL INCREASE AS WELL. IN FACT, THIS IS
HAPPENING ALREADY WITH GPS MET DATA SHOWING A SLOW RISE IN PWATS
SINCE LAST EVENING INTO THE 1.2-1.4 INCH RANGE, THOUGH MIAMI IS
STILL HOLDING AT 1.1 INCHES. AS MOISTURE INCREASES A TAD ALONG
WITH TROUGHING ACROSS THE AREA TUE-THU, THE RESULT WILL BE AN
INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS, THOUGH CERTAINLY
NOT A WASHOUT. THEY WILL BE OF THE PULSE VARIETY DURING THE HEAT
OF THE DAY WITH FOCUS OVER THE INTERIOR-EAST COAST.
FOR THIS AFTERNOON, NOT AS HIGH OF CONFIDENCE IN A FEW
THUNDERSTORMS DEVELOPING AS COMPARED TO TUE-THU. HOWEVER, THIS
COULD OCCUR FROM THE INTERIOR TOWARDS THE WESTERN BROWARD METRO
AND ACROSS PALM BEACH COUNTY...SO HAVE SLIGHT CHANCE OF TSTORMS
ACROSS THIS AREA FOR THIS AFTERNOON. LATEST HRRR SHOWS JUST LIGHT
QPF OVER INLAND PALM BEACH/INLAND BROWARD DEVELOPING BY 4 PM WITH
MOST OF THE ACTION TO OUR NORTH OVER CENTRAL AND NORTH FL.
AS THE TROUGH MOVES IN OVERNIGHT, A FEW SHOWERS OR THUNDERSTORMS
COULD DEVELOP OVER THE GULF OF MEXICO, POSSIBLY MOVING ONSHORE THE
GULF COAST, SIGNALED SLIGHTLY BY THE ECMWF. SO ADDED SLIGHT CHANCE
POPS AFTER MIDNIGHT FOR THIS AREA. HIGHER CONFIDENCE IN SHOWER AND
TSTORM ACTIVITY DEVELOPING TUE- THU, AGAIN WITH FOCUS INTERIOR AND
EAST COAST DUE TO A WESTERLY STEERING FLOW.
GFS/ECMWF SHOW A WEAKENING COLD FRONT MOVING INTO SOUTH FL LATE
THU WHILE BECOMING DIFFUSE. BOTH GFS/ECMWF SHOW ANOTHER SHORTWAVE
MOVING INTO THE NORTHERN GULF NEXT WEEKEND, BUT WITH MOST OF THE
ACTIVE WEATHER OFF TO OUR NORTHWEST. SO MAINTAINED JUST SLIGHT
CHANCE POPS IN THE EXTENDED. TEMPS THROUGH THE PERIOD WILL REMAIN
SEASONABLY WARM.
MARINE...LIGHT WINDS WILL CONTINUE WITH SEAS GENERALLY 4 FT OR
LESS THROUGH THE PERIOD, EXCEPT POSSIBLY UP TO 5 FT OFF THE
NORTHERN PALM BEACH COAST TUE NIGHT ASSOCIATED WITH A SMALL NE
SWELL.
FIRE WEATHER...A FEW INTERIOR LOCALES SAW RH`S FALL TO JUST
BELOW 35 PERCENT YESTERDAY FOR A FEW HR. THE SLIGHT INCREASE IN
MOISTURE TODAY SHOULD KEEP RH`S ABOVE CRITICAL LEVELS TODAY AND
BEYOND.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 88 71 86 71 / 20 20 30 20
FORT LAUDERDALE 86 72 86 73 / 10 10 30 20
MIAMI 88 72 86 73 / 10 10 30 20
NAPLES 85 70 84 70 / 10 10 20 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
UPDATE...14/MJB
AREA FORECAST DISCUSSION
NWS MIAMI FL
720 AM EDT MON MAY 7 2012
.AVIATION...
CLOUDS WILL SLOWLY INCREASE ACROSS SOUTH FLORIDA OVER THE NEXT 24
HOURS AS DEEPER MOISTURE PUSHES IN FROM THE NORTH. SHRAS WILL BE
POSSIBLE ACROSS THE AREA TOWARD THE LATE AFTERNOON HOURS...KEPT
VCSH MENTION AT ALL EAST COAST SITES. OTHERWISE...EASTERLY WINDS
AROUND 10 KTS FROM EAST COAST SEA BREEZE THIS AFTERNOON SHOULD
SUBSIDE AFTER 00Z. AT KAPF A SOUTHWESTERLY SEA BREEZE WILL DEVELOP
BY THE LATE MORNING AND CONTINUE THROUGH THE EARLY EVENING.
&&
.PREV DISCUSSION... /ISSUED 416 AM EDT MON MAY 7 2012/
DISCUSSION...WATER VAPOR IMAGERY SHOWS A TROUGH IN PLACE OVER
THE DEEP SOUTH. THIS FEATURE WILL MOVE SOUTHEAST OVER THE NEXT FEW
DAYS, REPLACING THE RIDGE THAT HAS BEEN IN PLACE ACROSS SOUTH FL.
MEANWHILE, MOISTURE WILL INCREASE AS WELL. IN FACT, THIS IS
HAPPENING ALREADY WITH GPS MET DATA SHOWING A SLOW RISE IN PWATS
SINCE LAST EVENING INTO THE 1.2-1.4 INCH RANGE, THOUGH MIAMI IS
STILL HOLDING AT 1.1 INCHES. AS MOISTURE INCREASES A TAD ALONG
WITH TROUGHING ACROSS THE AREA TUE-THU, THE RESULT WILL BE AN
INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS, THOUGH CERTAINLY
NOT A WASHOUT. THEY WILL BE OF THE PULSE VARIETY DURING THE HEAT
OF THE DAY WITH FOCUS OVER THE INTERIOR-EAST COAST.
FOR THIS AFTERNOON, NOT AS HIGH OF CONFIDENCE IN A FEW
THUNDERSTORMS DEVELOPING AS COMPARED TO TUE-THU. HOWEVER, THIS
COULD OCCUR FROM THE INTERIOR TOWARDS THE WESTERN BROWARD METRO
AND ACROSS PALM BEACH COUNTY...SO HAVE SLIGHT CHANCE OF TSTORMS
ACROSS THIS AREA FOR THIS AFTERNOON. LATEST HRRR SHOWS JUST LIGHT
QPF OVER INLAND PALM BEACH/INLAND BROWARD DEVELOPING BY 4 PM WITH
MOST OF THE ACTION TO OUR NORTH OVER CENTRAL AND NORTH FL.
AS THE TROUGH MOVES IN OVERNIGHT, A FEW SHOWERS OR THUNDERSTORMS
COULD DEVELOP OVER THE GULF OF MEXICO, POSSIBLY MOVING ONSHORE THE
GULF COAST, SIGNALED SLIGHTLY BY THE ECMWF. SO ADDED SLIGHT CHANCE
POPS AFTER MIDNIGHT FOR THIS AREA. HIGHER CONFIDENCE IN SHOWER AND
TSTORM ACTIVITY DEVELOPING TUE- THU, AGAIN WITH FOCUS INTERIOR AND
EAST COAST DUE TO A WESTERLY STEERING FLOW.
GFS/ECMWF SHOW A WEAKENING COLD FRONT MOVING INTO SOUTH FL LATE
THU WHILE BECOMING DIFFUSE. BOTH GFS/ECMWF SHOW ANOTHER SHORTWAVE
MOVING INTO THE NORTHERN GULF NEXT WEEKEND, BUT WITH MOST OF THE
ACTIVE WEATHER OFF TO OUR NORTHWEST. SO MAINTAINED JUST SLIGHT
CHANCE POPS IN THE EXTENDED. TEMPS THROUGH THE PERIOD WILL REMAIN
SEASONABLY WARM.
MARINE...LIGHT WINDS WILL CONTINUE WITH SEAS GENERALLY 4 FT OR
LESS THROUGH THE PERIOD, EXCEPT POSSIBLY UP TO 5 FT OFF THE
NORTHERN PALM BEACH COAST TUE NIGHT ASSOCIATED WITH A SMALL NE
SWELL.
FIRE WEATHER...A FEW INTERIOR LOCALES SAW RH`S FALL TO JUST
BELOW 35 PERCENT YESTERDAY FOR A FEW HR. THE SLIGHT INCREASE IN
MOISTURE TODAY SHOULD KEEP RH`S ABOVE CRITICAL LEVELS TODAY AND
BEYOND.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 88 71 86 71 / 20 20 30 20
FORT LAUDERDALE 86 72 86 73 / 10 10 30 20
MIAMI 88 72 86 73 / 10 10 30 20
NAPLES 85 70 84 70 / 10 10 20 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...14/MJB
AVIATION/RADAR...84/AK
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
928 AM CDT MON MAY 7 2012
.DISCUSSION...
320 AM CDT
SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT...
TODAY AND TONIGHT...AN INVERTED TROUGH EXTENDS FROM NORTH CENTRAL
TEXAS THROUGH NORTHEASTERN ILLINOIS THIS MORNING. THE LOWS WARM
FRONT ARCS FROM SPRINGFIELD ILLINOIS...THROUGH DELAWARE COUNTY
INDIANA. CONVECTION HAS REMAINED ACTIVE OVERNIGHT INTO EARLY THIS
MORNING...ESPECIALLY ALONG AND NORTH OF THE WARM FRONT. A LARGE
OUTFLOW BOUNDARY IS PUSHING SOUTH AWAY FROM THE MAIN LINE OF
STORMS...WITH ISOLATED STORMS BEING INITIATED BY THE OUTFLOW
BOUNDARY. THE EVENT HAS TRANSITIONED FROM SEVERE WEATHER TO A
HEAVY RAIN/FLASH FLOODING DUE TO SLOW MOVING STORMS AND PW VALUES
BETWEEN 1.5 TO 2 INCHES.
THE MAIN LOW PASSES THROUGH CENTRAL ILLINOIS TODAY AS DOES THE
MOISTURE AXIS. WINDS FLIP TO NORTHWEST BEHIND THE LOW AND PW
VALUES DROP FROM AROUND 1.5 INCHES TO 0.75 INCHES LATE TONIGHT.
GIVEN THE NOCTURNAL CONVECTION AND CLOUDY FORECAST...KEPT TEMPS A
FEW DEGREES BELOW GUIDANCE. WITH LESS HEATING TOMORROW...NOT
EXPECTING AS MUCH CAPE. THE NAM CURRENTLY FEATURES A MAX CAPE OF
AROUND 2000 J/KG EARLY ALONG AND SOUTHEAST OF THE I-55 CORRIDOR
WITH VALUES DECLINING THROUGH THE DAY. GIVEN THE NAMS WET BIAS AND
THEREFORE TYPICAL OVERESTIMATION OF CAPE...THINKING 1500 J/KG OR
LESS IS MOST LIKELY. 0-6 KM SHEAR ALSO DECREASES AS THE INVERTED
TROUGH MOVES OFF...WITH 35 KT OR LESS THROUGHOUT THE REGION.
MODEL SOUNDINGS INDICATE WARM AIR WILL BE SEEPING IN ALOFT AHEAD OF
THE WARM FRONT. THE WARM AIR WILL CAUSE A CAP WHICH WILL FURTHER
HINDER STORM DEVELOPMENT AND THEREFORE SEVERE WEATHER. BASED ON
THE PARAMETERS...THINKING THUNDERSTORMS WILL BE MORE LIKELY
SOUTHEAST AND ALONG THE 1-55 CORRIDOR WHERE THE ENVIRONMENT IS
MORE FAVORABLE. MAIN THREAT WILL BE HEAVY RAIN...ESPECIALLY WITH
THE VERY MOIST AIR MASS OVERHEAD.
TONIGHT...WENT WITH THE QUICKER NAM AND GFS SOLUTIONS IN REGARD TO
THE NOCTURNAL PRECIP. EXPECTING PRECIP TO MOVE QUICKLY OFF TO THE
EAST BEHIND THE DEPARTING LOW...ESPECIALLY SINCE MOISTURE WILL BE
RETREATING RAPIDLY. STAYED WITH GUIDANCE ON OVERNIGHT LOWS. THE
NIGHT WILL START CLOUDY AND CLEAR OUT LATE...LEADING TO A SLOW
DROP IN TEMPS UNTIL THE SKY CLEARS.
TUESDAY...THE DAY STARTS OFF DRY BEHIND THE FRONT AND LOW PASSAGE.
THE UPPER LEVEL TROUGH SWINGS THROUGH WISCONSIN AND NORTHERN
ILLINOIS TUESDAY AFTERNOON AND EVENING. MODELS INDICATE CONVECTION
WILL FORM TUESDAY AFTERNOON ACROSS WISCONSIN. CAPE VALUES ARE
MEAGER AT BEST AND WITH THE TROUGH SINKING SOUTH OUT OF CANADA...AM
QUESTIONING HOW MUCH MOISTURE THE MODELS KEEP WITH THIS SYSTEM.
DOWNPLAYING THE PRECIP POTENTIAL IN THE LOT CWA...THINKING THE
MAJORITY OF PRECIP WILL DRY UP BEFORE ENTERING NORTHERN IL. ONCE
AGAIN WENT WITH GUIDANCE FOR TEMPS...AS THE DAY WILL BEGIN SUNNY
WITH INCREASING CLOUD COVER.
BOTH THE GFS NAM...AND THE ECMWF TO A LESSER EXTENT...SUGGEST A
MCS WILL FORM TUESDAY NIGHT IN EAST CENTRAL WI AND SINK SOUTH OVER
THE LAKE. WITH ALL 3 MODELS DEPICTING A SIMILAR STORY...DECIDED TO
PUT IN SLIGHT CHANCE TO CHANCE POPS FOR TUESDAY NIGHT...HOWEVER
CONFIDENCE IS LOW REGARDING WHERE THE ACTUAL MCS WOULD FORM IF AT
ALL.
WEDNESDAY...A DRY PATTERN BEGINS ON WEDNESDAY AS HIGH PRESSURE MOVES
IN FROM THE CENTRAL PLAINS. SLIGHTLY COOLER TEMPS EXPECTED WITH
NORTHWEST UPPER LEVEL FLOW OUT OF CANADA.
JEE
EXTENDED...THURSDAY THROUGH SUNDAY...
410 AM CDT
OVERALL...THE EXTENDED FORECAST LOOKS DRY WITH AVERAGE TEMPS. A
BROAD RIDGE SETS UP OVER THE GREAT PLAINS MID WEEK AND PASSES OVER
THE MISSISSIPPI RIVER VALLEY LATE IN THE WEEK. NEXT CHANCE OF
PRECIP ARRIVES FRIDAY NIGHT AS A SURFACE LOW PASSES NORTH OF THE
GREAT LAKES AND ITS COLD FRONT PASSES THROUGH THE AREA LATE FRIDAY
NIGHT. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO FORM ALONG THE
COLD FRONT AND PERSIST THROUGH THE EARLY PART OF SATURDAY. THE
ECMWF HAS THE BAND OF PRECIP MOVING THROUGH THE AREA FASTER THAN
THE GFS...BUT AT THIS DISTANCE...DECIDED TO KEEP PRECIP IN THE
FORECAST SPANNING BOTH FORECASTS.
FOR TEMPS...MAX TEMPS REMAIN AROUND THE CLIMATIC NORMAL...IN THE MID
60S TO LOW 70S. OVERNIGHT LOWS APPEAR TO REMAIN WELL ABOVE FREEZING
THROUGHOUT THE EXTENDED.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* RAIN THRU REST OF MORNING WITH MVFR AND TEMPO IFR.
* RATE OF IMPROVEMENT TO VFR THIS AFTERNOON.
* POSSIBLE WIND SHIFT TO OUT OF NE-ENE THIS AFTERNOON.
TRS
//DISCUSSION...UPDATED 14Z...
MID LEVEL LOW CURRENTLY MOVING E ACROSS NORTHERN IL PRODUCING -RA
OCNL RA AND ACCOMPANYING MVFR AND TEMPO IFR CONDITIONS TO REACH NE
IL AROUND 18Z AND THEN CONTINUE ACROSS FAR SOUTHERN LAKE MI AND
NORTHERN IND DURING THE REST OF THE AFTERNOON.
BACK EDGE OF -RA BASED ON BOTH MODEL FORECAST OF FEATURE POSITION AS
WELL AS STRAIGHT EXTRAPOLATION HAVE -RA ENDING CHI TERMINALS
17Z OR SO. LARGE AREA OF IFR CEILINGS ACROSS ALL BUT NW AND FAR W
CENTRAL WI EXTENDS DOWN TO E CENTRAL IA SO PREVAILING MVFR CIGS AT
17Z AND AND VFR AT 19Z MAY BE A BIT PREMATURE AND GOOD CHANCE WILL
HAVE TO DELAY FOR AT LEAST A FEW HRS.
SFC PRES FALL CENTER FOLLOWING SFC LOW OVER SOUTHERN LAKE MI WAS
OVER FAR NE IL AT 13Z AND LOCAL SFC WINDS HAD FALLEN OFF TO BLO
10KT. MAIN SFC LOW CENTERED OVER SOUTHERN IND PROGGED TO NE IND BY
18Z. NEWEST RUC13 AT NAM12 SHOW A SUBTLE SFC HI OVER FAR SOUTHERN
LAKE MI THIS AFTERNOON WITH SFC WINDS RESPONDING BY VEERING TO N
AND NE AND THUS TRENDS WILL HAVE TO BE WATCHED TO SE IF THIS
DEVELOPS... THOUGH EVEN IF IT DOES FORECAST WINDS SPEEDS ARE BLO
10 KT.
CHANCES OF TS LOW AND WILL CONT TO DECREASE TODAY AS STABLE
CONDITIONS TO ONLY BECOME MORE SO...ESPECIALLY IF LOW CLOUDS
LINGER WELL INTO THE AFTERNOON.
TRS
PREVIOUS DISCUSSION...UPDATED 12Z...
AREA OF RAIN WITH EMBEDDED THUNDERSTORMS ENTERING INTO NORTHWEST
IL HAS SLOWLY WEAKENED AND HAVE BACKED OFF THUNDER MENTION TO JUST
VCTS AS NEW DEVELOPMENT IS STILL POSSIBLE. BUT EXPECT BULK OF THE
ACTIVITY TO BE LIGHT/MODERATE RAIN THROUGH MID/LATE MORNING WITH A
FEW SHOWERS PERHAPS LINGERING INTO THE EARLY AFTERNOON.
LOW CIGS HAVE DEVELOPED BUT STILL APPEAR TO BE BOUNCING AROUND
QUITE A BIT. WITH THE SURFACE LOW NOW EAST OF CMI...WINDS HAVE
SHIFTED AROUND TO THE NORTHWEST AND THINK LIFR CIGS SHOULD LIFT
THROUGH IFR INTO LOW MVFR THIS MORNING THOUGH CONFIDENCE ON EXACT
CLOUD HEIGHTS AS WELL AS THEIR DURATION IS STILL LOW. POSSIBLE
MVFR CIGS COULD PERSIST INTO THIS AFTERNOON AND WILL NEED TO BE
MONITORED THIS MORNING.
AS NOTED...WINDS SHIFTED WESTERLY AND GUSTY IN A FEW LOCATIONS BUT
SHOULD DIMINISH OVER THE NEXT FEW HRS AS THEY TURN BACK MORE
NORTHERLY. WINDS REMAIN NORTHERLY INTO THIS AFTERNOON BUT MODELS
HINTING AT A WEAK RIDGE DEVELOPING ALONG THE WEST SIDE OF THE LAKE
BY EVENING WHICH MAY ALLOW WINDS TO SWING AROUND TO THE NORTHEAST.
NOT TOO CONFIDENT THAT WILL HAPPEN AND WHILE ITS NOT IN THE THIS
SET OF TAFS...IT REMAINS A POSSIBILITY. WINDS WILL THEN SHIFT BACK
AROUND LIGHT NORTHWESTERLY LATER THIS EVENING. CMS
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH CONFIDENCE RA PERSISTS THRU MORNING.
* HIGH CONFIDENCE MINIMAL THREAT FOR TS.
* HIGH CONFIDENCE PREVAILING LIFR AND TEMPO IFR THROUGH MORNING.
* MEDIUM CONFIDENCE IMPROVEMENT TO VFR BY MID AFTERNOON.
* HIGH CONFIDENCE WINDS REST OF A.M.
* MEDIUM CONFIDENCE WINDS P.M.
TRS
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
* TUESDAY NIGHT...CHANCE OF SHRA/MVFR LATE.
* WEDNESDAY...CHANCE OF SHRA. MVFR POSSIBLE EARLY.
* THURSDAY...VFR.
* FRIDAY...VFR. CHANCE OF SHRA FRIDAY NIGHT.
* SATURDAY...CHANCE OF SHRA/SLIGHT CHANCE OF TSRA.
* SUNDAY...VFR. CHANCE OF SHRA. CMS
&&
.MARINE...
317 AM...LOW PRESSURE OVER CENTRAL IL WILL LIFT NORTHEAST ACROSS
NORTHERN INDIANA TODAY REACHING LAKE ERIE TONIGHT. THERE COULD BE A
FEW HOUR PERIOD EARLY THIS MORNING WHERE WINDS OVER SOUTHERN LAKE
MICHIGAN GUST INTO THE 15-25 KT RANGE AS THE LOW APPROACHES WITH A
SOUTHEAST DIRECTION SHIFTING TO THE NORTHEAST THIS MORNING. WINDS
WILL THEN SHIFT NORTHERLY AND DIMINISH INTO THE 10-15 KT RANGE
THIS AFTERNOON. A WEAK RIDGE MAY ALLOW WINDS TO DIMINISH EVEN
FURTHER ALONG THE WESTERN SIDE OF THE LAKE. A SECOND LOW WILL MOVE
SOUTHEAST ACROSS THE NORTHERN LAKES TONIGHT AND MERGE WITH THE
FIRST LOW LIFTING NORTHEAST ACROSS THE EASTERN LAKES ON TUESDAY. A
COLD FRONT WILL THEN MOVE SOUTH ACROSS THE LAKE TUESDAY NIGHT INTO
WEDNESDAY MORNING WITH NORTHERLY WINDS POSSIBLY INCREASING TO
15-25 KT. A LARGE RIDGE OF HIGH PRESSURE WILL THEN BUILD EAST
ACROSS THE LAKES REGION WEDNESDAY NIGHT INTO THURSDAY. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS JACKSON KY
1056 AM EDT MON MAY 7 2012
.UPDATE...
ISSUED AT 1056 AM EDT MON MAY 7 2012
THE MODELS CONTINUE TO DIFFER ON HOW MUCH AREAL CONVECTIVE COVERAGE
WE WILL REALLY SEE TODAY. THE LATEST NAM HAS VERY LITTLE IF ANY
THROUGH 00Z...ALONG WITH THE SREF. THE HRRR SHOWS AT LEAST SCATTERED
IF NOT NUMEROUS COVERAGE AT TIMES. THE CURRENT VISIBLE SATELLITE DOES
REVEAL AN OUTFLOW BOUNDARY MOVING EAST THROUGH CENTRAL KENTUCKY...
POISED TO MOVE THROUGH EASTERN KENTUCKY THIS AFTERNOON CLOSER TO PEAK
HEATING. WHILE THIS FEATURE WILL LIKELY WEAKEN WITH TIME...IT COULD
PROVIDE ENOUGH OF A WEAKNESS IN THE CAP TO GET CONVECTION GOING. AS
SUCH...DECIDED TO RAISE POPS SOMEWHAT FURTHER EAST. THE ATMOSPHERE IS
MODERATELY UNSTABLE...SO A FEW STORMS COULD APPROACH SEVERE LIMITS...
ESPECIALLY IF SOME STORM INTERACTION CAN TAKE PLACE.
UPDATE ISSUED AT 750 AM EDT MON MAY 7 2012
UPDATED THE FORECAST TO REFLECT CURRENT CONDITIONS AND MODEL TRENDS.
ONLY MADE SOME MINOR ADJUSTMENTS TO THE TEMPERATURES...WINDS AND DEW
POINTS.
UPDATE ISSUED AT 455 AM EDT MON MAY 7 2012
UPDATED THE FORECAST TO REFLECT CURRENT CONDITIONS AND MODEL TRENDS.
ONLY MADE SOME MINOR ADJUSTMENTS TO THE TEMPERATURES AND DEW POINTS.
NO ZONE UPDATE WILL BE REQUIRED.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 301 AM EDT MON MAY 7 2012
THE MODELS ARE IN DECENT AGREEMENT WITH THE TIMING OF THIS NEXT
SYSTEM. THE TIMING OF THE ACTUAL FRONT MOVING THROUGH HAS BEEN SLIPPING
OVER THE LAST FEW MODEL RUNS. THE MODELS ARE ALL VERY SLOW TO
ACTUALLY PUSH THIS SYSTEM THROUGH THE AREA. CONSIDERING THE GOOD
MODEL AGREEMENT...CONFIDENCE IS HIGHER THAN NORMAL. THE BIG
QUESTION FOR THIS AFTERNOON IS WHETHER OR NOT THERE WILL BE ANY
TRIGGERS TO GET SOME THUNDERSTORMS POPPING. ALL THE MODELS ARE NOW
GENERATING PRECIPITATION OVER THE AREA...HOWEVER THERE IS A LACK OF ANY
WELL DEFINED TRIGGERS. ONCE ANY CELLS DEVELOP AND THERE ARE ANY
OUTFLOWS...THEN THE VERY UNSTABLE AIR WILL ALLOW FOR THUNDERSTORMS TO
KEEP GOING FOR A WHILE. THESE WILL BE PULSE TYPE THUNDERSTORMS THAT DO
NOT MOVE VERY FAST. AS SUCH...THERE MAY BE SOME ISSUES WITH NUISANCE
TYPE FLOODING WITH DITCHES AND LOW WATER CROSSINGS RUNNING FULL. THE
PRECIPITABLE WATER WILL BE ABOUT 1.41 INCHES...SO RAINFALL RATES OF
OVER 1 INCH PER HOUR WILL BE FAIRLY EASY TO OBTAIN. THE MAJOR FORCING
WOULD APPEAR TO BE MOVING ACROSS THE AREA AFTER MIDNIGHT. BACK END OF
THE SYSTEM WILL NOT BE MOVING THROUGH THE AREA WEDNESDAY AFTERNOON.
EXPECT THE RAIN TO CONTINUE OFF AND ON THROUGH TUESDAY. FOR
TEMPERATURES...KEPT PRETTY CLOSE TO THE MOS BLEND. THE HIGHS FOR
TODAY MAY BE TOO HIGH IF THE CONVECTION INITIATES BEFORE NOON AND
CAUSES A LOT OF CLOUD COVER BEFORE PEAK HEATING.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 329 AM EDT MON MAY 7 2012
MODELS REMAIN IN REMARKABLY GOOD AGREEMENT THROUGH THE PERIOD
BOOSTING CONFIDENCE WITH THE FORECAST THROUGH THE END OF THE WEEK.
WE BEGIN TUESDAY NIGHT WITH LINGERING POST FRONTAL SHOWERS AND A FEW
THUNDERSTORMS OVER ERN KY AS THE UPPER LEVEL TROF SLOWLY SWINGS
THROUGH THE GREAT LAKES. ON WEDNESDAY THE TROF CONTINUES PUSHING
THROUGH THE OHIO VALLEY WITH PRECIP GRADUALLY ENDING FROM WEST TO
EAST THROUGH THE DAY AS WELL. BY WEDNESDAY NIGHT...STRONG HIGH
PRESSURE OVER THE THE HEART OF NOAM IN CONCERT WITH A BUDDING NRN
STREAM RIDGE OVER THE SRN CANADIAN PLAINS DOWN THROUGH THE NRN
ROCKIES SHIFTS EAST AND WILL BEGIN A STRETCH OF DRY...QUIET WEATHER
WITH MODERATING TEMPERATURES THAT LOOKS TO CONTINUE THROUGH THE END
OF THE WEEK. TOWARDS THE TAIL END OF THE PERIOD...BOTH THE EURO AND
THE GFS BRING A WEAK COLD FRONT INTO THE OHIO VALLEY...A LITTLE
QUICKER IN THE GFS VERSION...AS A SRN STREAM TROF MIGRATES FROM TX
THROUGH THE GULF COAST STATES...OPENING UP A RETURN FLOW OF WARM...
MOIST GOMEX AIR INTO THE REGION. GIVEN THE GOOD AGREEMENT THIS FAR
OUT...WILL KEEP SOLID CHANCES FOR PRECIP FOR THE END OF THE PERIOD
AND INTO THE BEGINNING OF NEXT WEEK.
AS FOR TEMPERATURES...THE EXTENDED INITIALIZATION CAME IN WITH A
REASONABLE STARTING POINT...THOUGH DID KEEP SOME MINOR ELEVATION
BASED DIFFERENCES FOR THURSDAY AND FRIDAY NIGHTS WITH HIGH PRESSURE
MOVING IN OVERHEAD. ALSO GAVE A BOOST TO HIGHS ON FRIDAY GIVEN THE
EXPECTED CLEAR SKIES...AND TO LINE UP A LITTLE BETTER WITH
SURROUNDING OFFICES. THIS ESSENTIALLY RESULTED IN TEMPS RUNNING A
LITTLE BELOW NORMAL THROUGH THE WEEK BEFORE RETUNING TO MORE
CLIMATOLOGICAL NORMS FOR THE WEEKEND...WITH OVERNIGHT LOWS GENERALLY
FOLLOWING A SIMILAR TREND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 750 AM EDT MON MAY 7 2012
PATCHY DENSE VALLEY FOG SHOULD BE LIFTING BY 14Z. WE COULD SEE A FEW
ISOLATED SHOWERS AND THUNDERSTORMS DURING THE AFTERNOON. INCLUDED
VCTS IN THE TAFS. THIS EVENING THE STORMS WILL BECOME MORE
WIDESPREAD. THERE IS A THREAT FOR SOME OF THE STORMS TO BECOME
SEVERE. EXPECT MOSTLY VFR CONDITIONS...EXCEPT IN THE VICINITY OF THE
STORMS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...JJ
LONG TERM....MB
AVIATION...JJ
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1039 AM CDT MON MAY 7 2012
.UPDATE...ZFP/GRIDS IN VERY GOOD CONDITION SO ONLY MINOR TWEAKS
MADE AT THIS POINT. GUSTY WINDS SHOULD DEVELOP TODAY WITHIN
RELATIVE NARROW DRY SLOT AS MIXING LAYER DEEPENS AND MOMENTUM
TRANSFER INCREASES. PROGRESSIVE NATURE OF MID LVL THERMAL POOL
MAKES INSTABILITY CLOUD DEVELOPMENT FAIRLY RAPID. INSTABILITY
PARAMETERS ARE NOT VERY IMPRESSIVE WITH LATEST SREF SHOWING
HIGHEST PROBABILITY NEAR BORDERLAND/IRON RANGE THIS AFTN. WILL
LEAVE ISO TRW IN MOST OF PRECIP AREA TODAY AS FCST 85/50H LAPSE
RATES INCREASE TO GREATER THAN 6C/KM.
&&
.PREV DISCUSSION... /ISSUED 636 AM CDT MON MAY 7 2012/
UPDATE...
UPDATED THE FORECAST TO REFLECT THE LATEST CLOUD AND FOG TRENDS.
IT APPEARS THICKER FOG HAS FORMED ALONG THE NORTH SHORE...SO
ALTERED THE MORNING FORECAST FROM PATCHY FOG TO AREAS OF FOG FOR
THAT AREA. ALSO...THE LATEST HRRR AND NAM RUNS SUGGEST MORE
EXTENSIVE CLOUD COVER MOVING IN FROM THE WEST TODAY...SO INCREASED
CLOUD COVER INTO THIS AFTERNOON.
PREV DISCUSSION... /ISSUED 627 AM CDT MON MAY 7 2012/
AVIATION...12Z TAFS.
DRY SLOT WORKING ITS WAY ACROSS THE AREA EARLY IN THE TAF CYCLE
WILL PRESENT A BRIEF WINDOW OF VFR. LIFR/IFR CIGS/VSBYS WITH
PATCHY BR/FOG AHEAD OF THE DRY SLOT WILL EXIT THE AREA FAIRLY
QUICKLY. BEHIND THE DRY SLOT...MVFR CIGS WILL SPREAD ACROSS THE
TAF SITES WITH SOME GUSTY SFC WINDS FROM 16Z TO 22Z. SOME SHOWERS
MAY OCCUR AFTER 21Z AS SFC LOW AND UPPER LOW DROP THROUGH THE
AREA. UPSTREAM SFC OBS INDICATE THE SHOWERS WILL BE ISOLD AND HAVE
VCSH TO ACCOUNT FOR THIS ISOLD NATURE.
PREV DISCUSSION... /ISSUED 337 AM CDT MON MAY 7 2012/
SHORT TERM...[NOW - TUESDAY]
AT 0830Z...THERE WAS A SURFACE LOW AND AN ASSOCIATED MID/UPPER
LEVEL LOW CENTERED OVER SOUTHERN SASKATCHEWAN. AN ASSOCIATED
OCCLUDED FRONT STRETCHED SOUTHEAST THROUGH THE WESTERN FA. MUCH OF
THE FA WAS COVERED WITH VERY LOW OVERCAST STRATUS...AND IN
ADDITION BKN/OVC HIGH CLOUDS COVERED THE SOUTHEASTERN FA. THERE
WAS SOME FOG ACROSS THE NORTHLAND...WITH SOME RECENT REPORTS NEAR
THE BRAINERD LAKES AND TWIN PORTS AREAS. THE WINDS WERE MOSTLY
CALM OR VERY LIGHT AND VARIABLE...EXCEPT FOR DEVELOPING LIGHT
SOUTHERLY WINDS ACROSS THE NORTHERN AND WESTERN FA. TEMPERATURES
WERE IN THE 40S TO LOW 50S. THE RADAR INDICATED LINGERING SHOWERS
ACROSS THE EASTERN FA...NAMELY THE ARROWHEAD.
EARLY THIS MORNING...THE OCCLUDED FRONT WILL CONTINUE TO MOVE
EASTWARD THROUGH THE FA...AND THE SHOWERS IN THE EASTERN FA WILL
GRADUALLY MOVE OUT OF THE FA. THE VERY LOW STRATUS AND PATCHY FOG
MAY LINGER THROUGH AT LEAST DAWN.
TODAY...THE SURFACE AND MID/UPPER LEVEL LOWS IN SOUTHERN
SASKATCHEWAN WILL MOVE INTO NORTHERN MINNESOTA. MIXING WILL
INCREASE THIS MORNING WITH THE INCREASING WESTERLY WINDS. THIS
SHOULD BEGIN TO BURN OFF THE EARLY MORNING STRATUS AND PATCHY
FOG...AS WELL AS GIVE THE FA SOME MORNING SUNSHINE. PATCHY FOG MAY
LINGER THROUGH PART OF THE MORNING ACROSS THE EASTERN FA WHERE THE
WINDS WILL BE LIGHTEST. THE COLD AIR ALOFT AND THE RELATIVELY LOW
CONVECTIVE TEMPERATURES TODAY SHOULD RESULT IN PLENTY OF CUMULUS
CLOUDS DEVELOPING BY THIS AFTERNOON. THE MODELS ARE IN GOOD
AGREEMENT THAT THE NORTHERN AND WESTERN FA COULD GET RAIN
SHOWERS. MODEL SUPPORT FOR INSTABILITY IS LIMITED...ABOUT 300 J/KG
OR LESS...BUT ENOUGH TO WARRANT INCLUDING A MENTION OF ISOLATED
THUNDER WITH THE SHOWERS. THE MORNING SUNSHINE SHOULD ALLOW
TEMPERATURES TO CLIMB TO THE LOWER 60S ACROSS MOST OF THE FA.
TONIGHT...THE SURFACE AND MID/UPPER TROUGH WILL MOVE
SOUTHEASTWARDS THROUGH THE FA. EXPECT A CLOUDY AND COOL NIGHT WITH
CONTINUING CHANCES OF RAIN SHOWERS...MAINLY ACROSS THE NORTHERN
HALF OF THE FA.
TUESDAY...THE NEGATIVELY TILTED MID/UPPER LEVEL TROUGH WILL SWING
THROUGH THE GREAT LAKES REGION THROUGH THE DAY ON TUESDAY AND THE
ASSOCIATED STACKED SURFACE LOW WILL SLIDE SOUTH TO SOUTHEASTERN
MINNESOTA BY TUESDAY EVENING. FORECAST SOUNDINGS ARE QUITE
SATURATED THROUGH THE MID LEVELS THROUGH THE DAY AND INTO THE
EVENING. AS THAT LOW PRESSURE CENTER SWINGS SOUTH...THE FA WILL
REMAIN CLOUDY AND WET...BUT COOLER THAN PREVIOUS DAY. THE
SOUNDINGS TUESDAY AFTERNOON ALSO SHOW SOME WEAK CAPE VALUES ACROSS
THE AREA AS THE AFTERNOON HEATING PICKS UP. HAVE INCLUDED ISOLATED
THUNDER TO ADDRESS THIS.
LONG TERM...[TUESDAY NIGHT - SUNDAY]
A LONG WAVE TROF WILL CLEAR THE FA TUESDAY EVENING WHILE ONE MORE
PIECE OF ENERGY DROPS QUICKLY INTO THE AREA BEHIND IT. THESE
FEATURES WARRANT THE POPS CURRENTLY IN PLACE OVER THE EASTERN TWO
THIRDS OF THE AREA TUESDAY EVENING. AFTER 06Z WEDNESDAY, UPPER
LEVEL AND SFC RIDGING BUILD INTO THE FA WITH A CLEARING SKY. THE
SFC RIDGING MOVES TO THE SOUTHERN GREAT LAKES WHILE UPPER RIDGING
REMAINS OVER THE FA THROUGH THURSDAY. A SW RETURN FLOW SETS UP IN
THURSDAY AFTERNOON ALLOWING WARM, MOIST AIR TO ADVECT INTO THE
AREA. THURSDAY NIGHT FINDS A STRONG COLD FRONT MOVING TOWARDS THE
FA WITH THUNDERSTORMS IN THE VICINITY OF THE FRONT. THE GFS, GEM,
NOGAPS AND DGEX ARE THE FASTEST WITH THE FRONT WHILE THE 00Z ECMWF
IS SLOWEST. TRIED TO LEAN MORE TOWARD THE ECMWF AS ALL MODELS ARE
TOO QUICK TO BREAK DOWN RIDGING DOWNSTREAM. THIS TREND CONTINUES
ON FRIDAY AND KEPT THE SAME APPROACH. LEFT SOME POPS OVER THE
EASTERN THIRD OF THE FA FRIDAY NIGHT AS PCPN MAY LINGER BEHIND THE
DEPARTING FRONT WITH THE CAA. A QUASI-ZONAL FLOW SETS UP SATURDAY
AND SUNDAY. A WEAK SHORT WAVE CLIPS THE EASTERN PORTION OF THE FA
SUNDAY AND HAVE SMALL POPS TO ACCOUNT FOR ITS PASSAGE.
&&
.POINT TEMPS/POPS...
DLH 63 42 52 39 / 10 20 60 20
INL 59 41 55 35 / 50 50 50 10
BRD 63 43 55 40 / 20 20 60 10
HYR 68 42 54 38 / 10 10 60 30
ASX 64 42 50 38 / 10 20 60 30
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...CANNON
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
636 AM CDT MON MAY 7 2012
.UPDATE...
UPDATED THE FORECAST TO REFLECT THE LATEST CLOUD AND FOG TRENDS.
IT APPEARS THICKER FOG HAS FORMED ALONG THE NORTH SHORE...SO
ALTERED THE MORNING FORECAST FROM PATCHY FOG TO AREAS OF FOG FOR
THAT AREA. ALSO...THE LATEST HRRR AND NAM RUNS SUGGEST MORE
EXTENSIVE CLOUD COVER MOVING IN FROM THE WEST TODAY...SO INCREASED
CLOUD COVER INTO THIS AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 627 AM CDT MON MAY 7 2012/
AVIATION...12Z TAFS.
DRY SLOT WORKING ITS WAY ACROSS THE AREA EARLY IN THE TAF CYCLE
WILL PRESENT A BRIEF WINDOW OF VFR. LIFR/IFR CIGS/VSBYS WITH
PATCHY BR/FOG AHEAD OF THE DRY SLOT WILL EXIT THE AREA FAIRLY
QUICKLY. BEHIND THE DRY SLOT...MVFR CIGS WILL SPREAD ACROSS THE
TAF SITES WITH SOME GUSTY SFC WINDS FROM 16Z TO 22Z. SOME SHOWERS
MAY OCCUR AFTER 21Z AS SFC LOW AND UPPER LOW DROP THROUGH THE
AREA. UPSTREAM SFC OBS INDICATE THE SHOWERS WILL BE ISOLD AND HAVE
VCSH TO ACCOUNT FOR THIS ISOLD NATURE.
PREV DISCUSSION... /ISSUED 337 AM CDT MON MAY 7 2012/
SHORT TERM...[NOW - TUESDAY]
AT 0830Z...THERE WAS A SURFACE LOW AND AN ASSOCIATED MID/UPPER
LEVEL LOW CENTERED OVER SOUTHERN SASKATCHEWAN. AN ASSOCIATED
OCCLUDED FRONT STRETCHED SOUTHEAST THROUGH THE WESTERN FA. MUCH OF
THE FA WAS COVERED WITH VERY LOW OVERCAST STRATUS...AND IN
ADDITION BKN/OVC HIGH CLOUDS COVERED THE SOUTHEASTERN FA. THERE
WAS SOME FOG ACROSS THE NORTHLAND...WITH SOME RECENT REPORTS NEAR
THE BRAINERD LAKES AND TWIN PORTS AREAS. THE WINDS WERE MOSTLY
CALM OR VERY LIGHT AND VARIABLE...EXCEPT FOR DEVELOPING LIGHT
SOUTHERLY WINDS ACROSS THE NORTHERN AND WESTERN FA. TEMPERATURES
WERE IN THE 40S TO LOW 50S. THE RADAR INDICATED LINGERING SHOWERS
ACROSS THE EASTERN FA...NAMELY THE ARROWHEAD.
EARLY THIS MORNING...THE OCCLUDED FRONT WILL CONTINUE TO MOVE
EASTWARD THROUGH THE FA...AND THE SHOWERS IN THE EASTERN FA WILL
GRADUALLY MOVE OUT OF THE FA. THE VERY LOW STRATUS AND PATCHY FOG
MAY LINGER THROUGH AT LEAST DAWN.
TODAY...THE SURFACE AND MID/UPPER LEVEL LOWS IN SOUTHERN
SASKATCHEWAN WILL MOVE INTO NORTHERN MINNESOTA. MIXING WILL
INCREASE THIS MORNING WITH THE INCREASING WESTERLY WINDS. THIS
SHOULD BEGIN TO BURN OFF THE EARLY MORNING STRATUS AND PATCHY
FOG...AS WELL AS GIVE THE FA SOME MORNING SUNSHINE. PATCHY FOG MAY
LINGER THROUGH PART OF THE MORNING ACROSS THE EASTERN FA WHERE THE
WINDS WILL BE LIGHTEST. THE COLD AIR ALOFT AND THE RELATIVELY LOW
CONVECTIVE TEMPERATURES TODAY SHOULD RESULT IN PLENTY OF CUMULUS
CLOUDS DEVELOPING BY THIS AFTERNOON. THE MODELS ARE IN GOOD
AGREEMENT THAT THE NORTHERN AND WESTERN FA COULD GET RAIN
SHOWERS. MODEL SUPPORT FOR INSTABILITY IS LIMITED...ABOUT 300 J/KG
OR LESS...BUT ENOUGH TO WARRANT INCLUDING A MENTION OF ISOLATED
THUNDER WITH THE SHOWERS. THE MORNING SUNSHINE SHOULD ALLOW
TEMPERATURES TO CLIMB TO THE LOWER 60S ACROSS MOST OF THE FA.
TONIGHT...THE SURFACE AND MID/UPPER TROUGH WILL MOVE
SOUTHEASTWARDS THROUGH THE FA. EXPECT A CLOUDY AND COOL NIGHT WITH
CONTINUING CHANCES OF RAIN SHOWERS...MAINLY ACROSS THE NORTHERN
HALF OF THE FA.
TUESDAY...THE NEGATIVELY TILTED MID/UPPER LEVEL TROUGH WILL SWING
THROUGH THE GREAT LAKES REGION THROUGH THE DAY ON TUESDAY AND THE
ASSOCIATED STACKED SURFACE LOW WILL SLIDE SOUTH TO SOUTHEASTERN
MINNESOTA BY TUESDAY EVENING. FORECAST SOUNDINGS ARE QUITE
SATURATED THROUGH THE MID LEVELS THROUGH THE DAY AND INTO THE
EVENING. AS THAT LOW PRESSURE CENTER SWINGS SOUTH...THE FA WILL
REMAIN CLOUDY AND WET...BUT COOLER THAN PREVIOUS DAY. THE
SOUNDINGS TUESDAY AFTERNOON ALSO SHOW SOME WEAK CAPE VALUES ACROSS
THE AREA AS THE AFTERNOON HEATING PICKS UP. HAVE INCLUDED ISOLATED
THUNDER TO ADDRESS THIS.
LONG TERM...[TUESDAY NIGHT - SUNDAY]
A LONG WAVE TROF WILL CLEAR THE FA TUESDAY EVENING WHILE ONE MORE
PIECE OF ENERGY DROPS QUICKLY INTO THE AREA BEHIND IT. THESE
FEATURES WARRANT THE POPS CURRENTLY IN PLACE OVER THE EASTERN TWO
THIRDS OF THE AREA TUESDAY EVENING. AFTER 06Z WEDNESDAY, UPPER
LEVEL AND SFC RIDGING BUILD INTO THE FA WITH A CLEARING SKY. THE
SFC RIDGING MOVES TO THE SOUTHERN GREAT LAKES WHILE UPPER RIDGING
REMAINS OVER THE FA THROUGH THURSDAY. A SW RETURN FLOW SETS UP IN
THURSDAY AFTERNOON ALLOWING WARM, MOIST AIR TO ADVECT INTO THE
AREA. THURSDAY NIGHT FINDS A STRONG COLD FRONT MOVING TOWARDS THE
FA WITH THUNDERSTORMS IN THE VICINITY OF THE FRONT. THE GFS, GEM,
NOGAPS AND DGEX ARE THE FASTEST WITH THE FRONT WHILE THE 00Z ECMWF
IS SLOWEST. TRIED TO LEAN MORE TOWARD THE ECMWF AS ALL MODELS ARE
TOO QUICK TO BREAK DOWN RIDGING DOWNSTREAM. THIS TREND CONTINUES
ON FRIDAY AND KEPT THE SAME APPROACH. LEFT SOME POPS OVER THE
EASTERN THIRD OF THE FA FRIDAY NIGHT AS PCPN MAY LINGER BEHIND THE
DEPARTING FRONT WITH THE CAA. A QUASI-ZONAL FLOW SETS UP SATURDAY
AND SUNDAY. A WEAK SHORT WAVE CLIPS THE EASTERN PORTION OF THE FA
SUNDAY AND HAVE SMALL POPS TO ACCOUNT FOR ITS PASSAGE.
&&
.POINT TEMPS/POPS...
DLH 61 42 52 39 / 20 20 60 20
INL 61 41 55 35 / 40 50 50 10
BRD 63 43 55 40 / 20 20 60 10
HYR 67 42 54 38 / 10 10 60 30
ASX 64 42 50 38 / 10 20 60 30
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...GROCHOCINSKI
LONG TERM....GSF
AREA FORECAST DISCUSSION
NWS HASTINGS NE
559 AM CDT MON MAY 7 2012
.AVIATION...12Z KGRI TAF. VFR CEILING/VISIBILITY ARE FORECAST
THROUGH THE PERIOD...ALTHOUGH THE WEATHER WON`T NECESSARILY BE
COMPLETELY INACTIVE. A FAIRLY SOLID MID LEVEL CLOUD DECK WILL
DOMINATE MOST OF THE PERIOD...AND THERE ARE INCREASING SIGNS THAT
SPRINKLES OR A FEW PASSING LIGHT RAIN SHOWERS WILL AFFECT THE AREA
MAINLY DURING THE FIRST 12 HOURS. WILL FOREGO ANY PREVAILING OR
TEMPO PRECIPITATION GROUPS AT THIS TIME...BUT WILL INSERT A
VICINITY SHOWER MENTION. OTHERWISE...SURFACE WINDS WILL PREVAIL
FROM A NORTHWESTERLY DIRECTION THROUGH THE MAJORITY OF THE
PERIOD...WITH A BIT OF GUSTINESS FOR MUCH OF THE DAY WITH GUST
POTENTIAL TO AROUND 24KT BEFORE SUBSIDING FOR THE OVERNIGHT HOURS.
&&
.PREV DISCUSSION... /ISSUED 416 AM CDT MON MAY 7 2012/
SHORT TERM...CERTAINLY QUITE A CHANGE FROM THE PAST WEEK...WHICH
WAS MORE LIKE JULY WITH HIGH HUMIDITY AND SEVERAL EPISODES OF SEVERE
THUNDERSTORMS WITH LARGE HAIL. WE NOW HAVE SUB-40 DEGREE DEWPOINTS
WORKING INTO CENTRAL NEBRASKA FROM THE NORTHWEST ABOUT
NORTH/NORTHWEST WINDS. TEMPERATURES HAVE REMAINED UP A BIT TONIGHT
WITH COLD ADVECTION THANKS TO GOOD DECK OF MID/HIGH CLOUDS.
THE MAIN ISSUE TODAY IS A SMALL RISK FOR SPRINKLES IN SOME AREA...AND
THEN SOME CONCERN OF PATCHY FROST OVER THE NORTHWEST FORECAST AREA
TONIGHT. THOUGH LOW LEVEL DRY AIR WILL DEEPEN WITH TIME...THE FORECAST
AREA ASCENDS INTO A FAVORABLE RIGHT REAR QUADRANT OF 250MB JET STREAK
BY AFTERNOON. THIS FRONTOGENETIC TYPE FORCING IS CAPTIONED ON AT
LEAST A FEW MODELS...INCLUDING THE RUC RAPID REFRESH...WITH HINTS OF
MOISTURE TRYING TO SPILL NORTHEAST FROM COLORADO. BELIEVE ITS WORTH
A SPRINKLE MENTION AT THIS TIME FOR AREAS SOUTH OF INTERSTATE 80.
CHILLY CONDITIONS TONIGHT ARE MOST LIKELY IN THE NORTHWEST FORECAST
AREA...MAINLY NORTHWEST OF A LINE FROM ELWOOD...TO LOUP CITY...TO
GREELEY. AIR WILL BE DRY ENOUGH...WINDS PROBABLY LIGHT ENOUGH...TO
REACH NEAR THE 36 DEGREE LINE OR LOWER...WHICH WOULD SUPPORT FROST.
THE ISSUE MAY BE CLOUDS...AS SOME INCREASE/LINGERING CLOUDS COULD
REEK HAVOC WITH JUST WHAT AREAS ACTUALLY DROP THE LOWEST. WILL
MENTION SOME PATCHY FROST IN THE GOTHENBURG AREA...AND IN THE
HAZARDOUS WEATHER OUTLOOK...BUT NOT CONFIDENT ENOUGH TO ISSUE ANY
ADVISORY AT THIS TIME.
DESPITE SUNSHINE...A COOL START WILL LEAD TO A COOLISH DAY TUESDAY.
NORTH/NORTHWEST WINDS WILL KEEP THAT COOL FEEL IN THE AIR EVEN WITH
TEMPERATURES IN THE UPPER 60S TO LOWER 70S. THE WINDS WILL BE
STRONGEST ACROSS SOUTH CENTRAL NEBRASKA...AND GRADUALLY DROP OFF
THE FURTHER SOUTH ONE GOES. WITH HIGH PRESSURE SETTLING RIGHT ON THE
FORECAST TUESDAY NIGHT...ANOTHER RISK FOR PATCHY FROST COULD ARISE.
THAT APPEARS MOSTLY LIKELY IN THE NORTHEAST FORECAST AREA...MAINLY
NORTH AND EAST OF A YORK TO GREELEY LINE. THE WESTERN AREAS WILL
SEE JUST EVEN SOUTHERLY FLOW TO LIMIT COOLING IN THOSE AREAS.
WEDNESDAY AND WEDNESDAY WILL BE NICE WITH MAINLY CLEAR SKIES AND
SOUTHERLY FLOW GRADUALLY DEVELOPING THROUGHOUT THE DAY FROM WEST
TO EAST. HIGHS WEDNESDAY WILL BE RIGHT WHERE SHOULD BE FOR THIS
TIME OF YEAR...IN THE LOWER 70S.
LONG TERM...THURSDAY THROUGH SUNDAY. NEEDLESS TO SAY...IT LOOKS
LIKE THE MONTH OF MAY GOT ITS FIRST MULTI-DAY BOUT OF SEVERE WEATHER
OUT OF THE WAY QUITE EARLY...AS THERE ARE NO SYNOPTICALLY EVIDENT
THREATS FOR WIDESPREAD STRONG-SEVERE STORMS THROUGH AT LEAST THE
NEXT 7-9 DAYS PER THE LATEST 00Z GFS/ECMWF RUNS. THAT BEING
SAID...THERE ARE SOME CHANCES FOR SHOWERS/GENERALLY WEAK STORMS.
TEMP WISE...THESE 4 DAYS WILL GENERALLY BOUNCE AROUND WITHIN ROUGHLY
5 DEGREES EITHER SIDE OF NORMAL FOR MID-MAY.
STARTING OFF THURSDAY...THIS IS LOOKING LIKE THE WARMEST DAY OF
THE EXTENDED...AND NUDGED UP HIGHS VERY SLIGHTLY FROM PREVIOUS
FORECAST...PUTTING MOST AREAS IN THE 78-82 RANGE. IN THE MID-UPPER
LEVELS...THE TWO MAIN FEATURES ARE A COMPACT...CUT OFF LOW SLOWLY
MOVING INTO TX...AND A LARGER SCALE SHORTWAVE TROUGH CROSSING THE
NORTHERN ROCKIES. IN RESPONSE TO THE LATTER...HIGH PLAINS SURFACE
PRESSURE FALLS WILL INDUCE SOUTHERLY WINDS DURING THE DAY...AND
LIKELY A BIT BREEZY WITH SUSTAINED SPEEDS EASILY 15-20 MPH.
THURSDAY NIGHT...MODELS ARE IN DECENT AGREEMENT DRAGGING THE 500MB
SHORTWAVE TROUGH ALONG THE CANADIAN BORDER INTO THE ND AREA...AND
PUSHING A WELL-DEFINED SURFACE COLD FRONT SOUTHWARD INTO THE
REGION. AT THIS TIME...THE GFS IS A BIT FASTER/STRONGER WITH THIS
WAVE AND RESULTANT FRONTAL PASSAGE THAN THE ECMWF...AND DEVELOPS A
BAND OF PRECIP MAINLY ACROSS WESTERN NEB DURING THE NIGHT WITHIN
THE ENTRANCE REGION OF THE UPPER JET AND JUST BEHIND THE SURFACE
FRONT. ALTHOUGH ECMWF KEEPS ALL PRECIP NORTHWEST OF THE CWA
THROUGH THE NIGHT...WILL PLAY IT CLOSER TO PREVIOUS FORECAST AND
THE GFS SOLUTION WITH JUST A SLIGHT CHANCE OF SHOWERS/ISOLATED
STORMS ACROSS FAR NORTHWEST COUNTIES. INSTABILITY PROGS INDICATE
THAT EVEN A FEW HUNDRED J/KG OF ELEVATED CAPE MAY BE HARD TO COME
BY...SO AT THIS POINT WOULD THINK SMALL HAIL WOULD BE THE MOST ANY
STORMS COULD GENERATE.
FRIDAY INTO FRIDAY NIGHT...MODEL AGREEMENT REMAINS REASONABLY HIGH
FOR THIS TIME RANGE...AS THE NORTHERN SHORTWAVE CONTINUES TRACKING
TOWARD THE GREAT LAKES...AND THE SURFACE COLD FRONT PUSHES WELL
SOUTH THROUGH THE CWA. WELL OFF TO THE SOUTH...THE SLOW MOVING TX
MID-UPPER LOW SHOULD KEEP APPRECIABLE LOW LEVEL MOISTURE/INSTABILITY
WELL SOUTH OF THE CENTRAL PLAINS. THAT BEING SAID...MID LEVEL
SATURATION WITHIN THE ENTRANCE REGION OF THE UPPER JET SHOULD KEEP
AT LEAST THE POTENTIAL FOR RAIN SHOWERS GOING...AND HAVE 20-30
PERCENT CHANCES CWA-WIDE. DESPITE MEAGER INSTABILITY...WILL
MAINTAIN THUNDER WORDING BUT WILL KEEP IT AS ISOLATED AND WITH
SEEMINGLY VERY LITTLE RISK OF STRONG/SEVERE. TEMP-WISE...HIGHS
FRIDAY WILL BE A BIT TRICKY AS THE FRONT PUSHES IN...BUT WILL AIM
FOR MID 60S NORTHWEST TO MID 70S SOUTHEAST. HAVE FRIDAY NIGHT LOWS
WELL DOWN IN THE 40S ACROSS THE NORTHWEST 1/2 OF THE CWA.
SATURDAY INTO SATURDAY NIGHT...KEPT SLIGHT CHANCE POPS FOR MAINLY
LIGHT RAIN SHOWERS GOING...BUT PRIMARILY NEAR AND SOUTH OF THE
STATE LINE. LOWERED HIGHS FOR SATURDAY SLIGHTLY PER ALLBLEND MODEL
CONSENSUS...WITH ONLY MID-UPPER 60S CWA-WIDE. A SEASONABLY COOL
NIGHT FOLLOWS WITH MID-UPPER 40S CWA-WIDE.
FINALLY FOR SUNDAY...KEPT 20-30 POPS GOING ACROSS SOUTHERN
ZONES...BUT MODEL AGREEMENT HAS ALREADY FADED BY THEN...WITH GFS
KEEPING IT DRY...WHILE ECMWF BRINGS A BROAD MID LEVEL WAVE INTO
THE REGION IN DISORGANIZED NORTHWEST FLOW...BUT WITH BETTER PRECIP
CHANCES PRESUMABLY FOCUSING IN MORE FAVORED UPSLOPE AREAS TO THE
WEST. WILL AIM FOR LOW 70S CWA-WIDE FOR HIGH TEMPS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...MORITZ
LONG TERM/AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1107 AM CDT MON MAY 7 2012
.DISCUSSION...
320 AM CDT
SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT...
TODAY AND TONIGHT...AN INVERTED TROUGH EXTENDS FROM NORTH CENTRAL
TEXAS THROUGH NORTHEASTERN ILLINOIS THIS MORNING. THE LOWS WARM
FRONT ARCS FROM SPRINGFIELD ILLINOIS...THROUGH DELAWARE COUNTY
INDIANA. CONVECTION HAS REMAINED ACTIVE OVERNIGHT INTO EARLY THIS
MORNING...ESPECIALLY ALONG AND NORTH OF THE WARM FRONT. A LARGE
OUTFLOW BOUNDARY IS PUSHING SOUTH AWAY FROM THE MAIN LINE OF
STORMS...WITH ISOLATED STORMS BEING INITIATED BY THE OUTFLOW
BOUNDARY. THE EVENT HAS TRANSITIONED FROM SEVERE WEATHER TO A
HEAVY RAIN/FLASH FLOODING DUE TO SLOW MOVING STORMS AND PW VALUES
BETWEEN 1.5 TO 2 INCHES.
THE MAIN LOW PASSES THROUGH CENTRAL ILLINOIS TODAY AS DOES THE
MOISTURE AXIS. WINDS FLIP TO NORTHWEST BEHIND THE LOW AND PW
VALUES DROP FROM AROUND 1.5 INCHES TO 0.75 INCHES LATE TONIGHT.
GIVEN THE NOCTURNAL CONVECTION AND CLOUDY FORECAST...KEPT TEMPS A
FEW DEGREES BELOW GUIDANCE. WITH LESS HEATING TOMORROW...NOT
EXPECTING AS MUCH CAPE. THE NAM CURRENTLY FEATURES A MAX CAPE OF
AROUND 2000 J/KG EARLY ALONG AND SOUTHEAST OF THE I-55 CORRIDOR
WITH VALUES DECLINING THROUGH THE DAY. GIVEN THE NAMS WET BIAS AND
THEREFORE TYPICAL OVERESTIMATION OF CAPE...THINKING 1500 J/KG OR
LESS IS MOST LIKELY. 0-6 KM SHEAR ALSO DECREASES AS THE INVERTED
TROUGH MOVES OFF...WITH 35 KT OR LESS THROUGHOUT THE REGION.
MODEL SOUNDINGS INDICATE WARM AIR WILL BE SEEPING IN ALOFT AHEAD OF
THE WARM FRONT. THE WARM AIR WILL CAUSE A CAP WHICH WILL FURTHER
HINDER STORM DEVELOPMENT AND THEREFORE SEVERE WEATHER. BASED ON
THE PARAMETERS...THINKING THUNDERSTORMS WILL BE MORE LIKELY
SOUTHEAST AND ALONG THE 1-55 CORRIDOR WHERE THE ENVIRONMENT IS
MORE FAVORABLE. MAIN THREAT WILL BE HEAVY RAIN...ESPECIALLY WITH
THE VERY MOIST AIR MASS OVERHEAD.
TONIGHT...WENT WITH THE QUICKER NAM AND GFS SOLUTIONS IN REGARD TO
THE NOCTURNAL PRECIP. EXPECTING PRECIP TO MOVE QUICKLY OFF TO THE
EAST BEHIND THE DEPARTING LOW...ESPECIALLY SINCE MOISTURE WILL BE
RETREATING RAPIDLY. STAYED WITH GUIDANCE ON OVERNIGHT LOWS. THE
NIGHT WILL START CLOUDY AND CLEAR OUT LATE...LEADING TO A SLOW
DROP IN TEMPS UNTIL THE SKY CLEARS.
TUESDAY...THE DAY STARTS OFF DRY BEHIND THE FRONT AND LOW PASSAGE.
THE UPPER LEVEL TROUGH SWINGS THROUGH WISCONSIN AND NORTHERN
ILLINOIS TUESDAY AFTERNOON AND EVENING. MODELS INDICATE CONVECTION
WILL FORM TUESDAY AFTERNOON ACROSS WISCONSIN. CAPE VALUES ARE
MEAGER AT BEST AND WITH THE TROUGH SINKING SOUTH OUT OF CANADA...AM
QUESTIONING HOW MUCH MOISTURE THE MODELS KEEP WITH THIS SYSTEM.
DOWNPLAYING THE PRECIP POTENTIAL IN THE LOT CWA...THINKING THE
MAJORITY OF PRECIP WILL DRY UP BEFORE ENTERING NORTHERN IL. ONCE
AGAIN WENT WITH GUIDANCE FOR TEMPS...AS THE DAY WILL BEGIN SUNNY
WITH INCREASING CLOUD COVER.
BOTH THE GFS NAM...AND THE ECMWF TO A LESSER EXTENT...SUGGEST A
MCS WILL FORM TUESDAY NIGHT IN EAST CENTRAL WI AND SINK SOUTH OVER
THE LAKE. WITH ALL 3 MODELS DEPICTING A SIMILAR STORY...DECIDED TO
PUT IN SLIGHT CHANCE TO CHANCE POPS FOR TUESDAY NIGHT...HOWEVER
CONFIDENCE IS LOW REGARDING WHERE THE ACTUAL MCS WOULD FORM IF AT
ALL.
WEDNESDAY...A DRY PATTERN BEGINS ON WEDNESDAY AS HIGH PRESSURE MOVES
IN FROM THE CENTRAL PLAINS. SLIGHTLY COOLER TEMPS EXPECTED WITH
NORTHWEST UPPER LEVEL FLOW OUT OF CANADA.
JEE
EXTENDED...THURSDAY THROUGH SUNDAY...
410 AM CDT
OVERALL...THE EXTENDED FORECAST LOOKS DRY WITH AVERAGE TEMPS. A
BROAD RIDGE SETS UP OVER THE GREAT PLAINS MID WEEK AND PASSES OVER
THE MISSISSIPPI RIVER VALLEY LATE IN THE WEEK. NEXT CHANCE OF
PRECIP ARRIVES FRIDAY NIGHT AS A SURFACE LOW PASSES NORTH OF THE
GREAT LAKES AND ITS COLD FRONT PASSES THROUGH THE AREA LATE FRIDAY
NIGHT. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO FORM ALONG THE
COLD FRONT AND PERSIST THROUGH THE EARLY PART OF SATURDAY. THE
ECMWF HAS THE BAND OF PRECIP MOVING THROUGH THE AREA FASTER THAN
THE GFS...BUT AT THIS DISTANCE...DECIDED TO KEEP PRECIP IN THE
FORECAST SPANNING BOTH FORECASTS.
FOR TEMPS...MAX TEMPS REMAIN AROUND THE CLIMATIC NORMAL...IN THE MID
60S TO LOW 70S. OVERNIGHT LOWS APPEAR TO REMAIN WELL ABOVE FREEZING
THROUGHOUT THE EXTENDED.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* -RA ENDING 17Z-18Z.
* RATE OF IMPROVEMENT FROM MVFR TO VFR THIS AFTERNOON.
* POSSIBLE VEERING WIND TO OUT OF NNE FOR EARLY AFTERNOON...THEN
BACKING TO NNW AGAIN LATE AFTERNOON.
TRS
//DISCUSSION...UPDATED 14Z...
MID LEVEL LOW CURRENTLY MOVING E ACROSS NORTHERN IL PRODUCING -RA
OCNL RA AND ACCOMPANYING MVFR AND TEMPO IFR CONDITIONS TO REACH NE
IL AROUND 18Z AND THEN CONTINUE ACROSS FAR SOUTHERN LAKE MI AND
NORTHERN IND DURING THE REST OF THE AFTERNOON.
BACK EDGE OF -RA BASED ON BOTH MODEL FORECAST OF FEATURE POSITION AS
WELL AS STRAIGHT EXTRAPOLATION HAVE -RA ENDING CHI TERMINALS
17Z OR SO. LARGE AREA OF IFR CEILINGS ACROSS ALL BUT NW AND FAR W
CENTRAL WI EXTENDS DOWN TO E CENTRAL IA SO PREVAILING MVFR CIGS AT
17Z AND AND VFR AT 19Z MAY BE A BIT PREMATURE AND GOOD CHANCE WILL
HAVE TO DELAY FOR AT LEAST A FEW HRS.
SFC PRES FALL CENTER FOLLOWING SFC LOW OVER SOUTHERN LAKE MI WAS
OVER FAR NE IL AT 13Z AND LOCAL SFC WINDS HAD FALLEN OFF TO BLO
10KT. MAIN SFC LOW CENTERED OVER SOUTHERN IND PROGGED TO NE IND BY
18Z. NEWEST RUC13 AT NAM12 SHOW A SUBTLE SFC HI OVER FAR SOUTHERN
LAKE MI THIS AFTERNOON WITH SFC WINDS RESPONDING BY VEERING TO N
AND NE AND THUS TRENDS WILL HAVE TO BE WATCHED TO SE IF THIS
DEVELOPS... THOUGH EVEN IF IT DOES FORECAST WINDS SPEEDS ARE BLO
10 KT.
CHANCES OF TS LOW AND WILL CONT TO DECREASE TODAY AS STABLE
CONDITIONS TO ONLY BECOME MORE SO...ESPECIALLY IF LOW CLOUDS
LINGER WELL INTO THE AFTERNOON.
TRS
PREVIOUS DISCUSSION...UPDATED 12Z...
AREA OF RAIN WITH EMBEDDED THUNDERSTORMS ENTERING INTO NORTHWEST
IL HAS SLOWLY WEAKENED AND HAVE BACKED OFF THUNDER MENTION TO JUST
VCTS AS NEW DEVELOPMENT IS STILL POSSIBLE. BUT EXPECT BULK OF THE
ACTIVITY TO BE LIGHT/MODERATE RAIN THROUGH MID/LATE MORNING WITH A
FEW SHOWERS PERHAPS LINGERING INTO THE EARLY AFTERNOON.
LOW CIGS HAVE DEVELOPED BUT STILL APPEAR TO BE BOUNCING AROUND
QUITE A BIT. WITH THE SURFACE LOW NOW EAST OF CMI...WINDS HAVE
SHIFTED AROUND TO THE NORTHWEST AND THINK LIFR CIGS SHOULD LIFT
THROUGH IFR INTO LOW MVFR THIS MORNING THOUGH CONFIDENCE ON EXACT
CLOUD HEIGHTS AS WELL AS THEIR DURATION IS STILL LOW. POSSIBLE
MVFR CIGS COULD PERSIST INTO THIS AFTERNOON AND WILL NEED TO BE
MONITORED THIS MORNING.
AS NOTED...WINDS SHIFTED WESTERLY AND GUSTY IN A FEW LOCATIONS BUT
SHOULD DIMINISH OVER THE NEXT FEW HRS AS THEY TURN BACK MORE
NORTHERLY. WINDS REMAIN NORTHERLY INTO THIS AFTERNOON BUT MODELS
HINTING AT A WEAK RIDGE DEVELOPING ALONG THE WEST SIDE OF THE LAKE
BY EVENING WHICH MAY ALLOW WINDS TO SWING AROUND TO THE NORTHEAST.
NOT TOO CONFIDENT THAT WILL HAPPEN AND WHILE ITS NOT IN THE THIS
SET OF TAFS...IT REMAINS A POSSIBILITY. WINDS WILL THEN SHIFT BACK
AROUND LIGHT NORTHWESTERLY LATER THIS EVENING. CMS
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH CONFIDENCE -RA ENDS 17Z-18Z TIME FRAME.
* HIGH CONFIDENCE MINIMAL TO NIL THREAT FOR TS.
* HIGH CONFIDENCE PREVAILING MVFR TEMPO IFR TIL EARLY AFTERNOON.
* MEDIUM CONFIDENCE IMPROVEMENT TO VFR BY MID AFTERNOON.
* HIGH CONFIDENCE SFC WINDS GENERALLY BLO 10KT.
* MEDIUM CONFIDENCE WIND DIR NNW-NNE THRU AFTERNOON.
TRS
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
* TUESDAY NIGHT...CHANCE OF SHRA/MVFR LATE.
* WEDNESDAY...CHANCE OF SHRA. MVFR POSSIBLE EARLY.
* THURSDAY...VFR.
* FRIDAY...VFR. CHANCE OF SHRA FRIDAY NIGHT.
* SATURDAY...CHANCE OF SHRA/SLIGHT CHANCE OF TSRA.
* SUNDAY...VFR. CHANCE OF SHRA. CMS
&&
.MARINE...
317 AM...LOW PRESSURE OVER CENTRAL IL WILL LIFT NORTHEAST ACROSS
NORTHERN INDIANA TODAY REACHING LAKE ERIE TONIGHT. THERE COULD BE A
FEW HOUR PERIOD EARLY THIS MORNING WHERE WINDS OVER SOUTHERN LAKE
MICHIGAN GUST INTO THE 15-25 KT RANGE AS THE LOW APPROACHES WITH A
SOUTHEAST DIRECTION SHIFTING TO THE NORTHEAST THIS MORNING. WINDS
WILL THEN SHIFT NORTHERLY AND DIMINISH INTO THE 10-15 KT RANGE
THIS AFTERNOON. A WEAK RIDGE MAY ALLOW WINDS TO DIMINISH EVEN
FURTHER ALONG THE WESTERN SIDE OF THE LAKE. A SECOND LOW WILL MOVE
SOUTHEAST ACROSS THE NORTHERN LAKES TONIGHT AND MERGE WITH THE
FIRST LOW LIFTING NORTHEAST ACROSS THE EASTERN LAKES ON TUESDAY. A
COLD FRONT WILL THEN MOVE SOUTH ACROSS THE LAKE TUESDAY NIGHT INTO
WEDNESDAY MORNING WITH NORTHERLY WINDS POSSIBLY INCREASING TO
15-25 KT. A LARGE RIDGE OF HIGH PRESSURE WILL THEN BUILD EAST
ACROSS THE LAKES REGION WEDNESDAY NIGHT INTO THURSDAY. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
347 PM EDT MON MAY 7 2012
.SHORT TERM...
TONIGHT...TUESDAY...TUESDAY NIGHT...
CONVECTIVE REDEVELOPMENT NOT FULLY MATERIALIZING YET AS AIRMASS
STRUGGLES TO RECOVER FROM EARLIER RAINS. KIWX RADAR SHOWING LONE
CONVECTIVE CELL JUST SOUTH OF THE CWA NEAR MUNCIE. KIND RADAR
INDICATING ADDL DEVELOPMENT NOW BEGINNING TO TAKE SHAPE FURTHER
SOUTH. WATER VAPOR IMAGERY AND LATEST RUC ANALYSIS SHOWING WEAK
SHORT WAVE APPROACHING THE AREA SO STILL HOLDING OUT HOPE FOR MORE
ORGANIZED PRECIP THIS EVENING AS SFC LOW AND FRONTAL BOUNDARY
CONTINUE TO MOVE EASTWARD...BUT HAVE DROPPED POPS OVER THE EASTERN
CWA AND OPTED FOR SCT WORDING. WILL KEEP MENTION OF THUNDER IN THE
SE CWA AS LATEST LAPS DATA ALONG WITH SPC MESO ANALYSIS HAS CAPES
NUDGING UP OVER 1000J/KG INTO JAY COUNTY. VIS SAT ALSO SHOWING
CLOUDS THINNING OUT FROM MARION TO LIMA SO FURTHER LATE AFTN
DESTABILIZATION EXPECTED. 12Z MODELS A LITTLE SLOWER IN MOVING
SYSTEM OUT SO WILL HANG ON TO SMALL CHANCE IN SE CWA TILL 12Z TUE.
REST OF THE SHORT TERM WILL FEATURE CAA PATTERN AS UPPER LOW DROPS
INTO THE NORTHERN GREAT LAKES. SHOULD STILL GET TO AROUND NORMAL FOR
HIGHS TUESDAY AS 850MB THERMAL TROUGH DELAYED UNTIL TUE NITE/WED AM.
EXPECT AN INCREASE IN CLOUD COVER TUE NITE AS UPPER TROUGH SINKS
FURTHER SOUTH ALONG WITH SECONDARY COLD FRONT.
&&
.LONG TERM...WEDNESDAY THROUGH MONDAY
AN UPPER LEVEL SPEED MAX DIGGING SOUTHWARD ACROSS THE UPPER MIDWEST
AND UPPER MS VALLEY WILL ALLOW UPPER TROUGH TO SHIFT SOUTHEAST INTO
THE GREAT LAKES REGION BY WEDNESDAY MORNING. MOISTURE WILL BE
RELATIVELY UNIMPRESSIVE WITH THIS SYSTEM AND THUS MAIN PRECIP CHANCE
IS EXPECTED TO BE CONFINED TO ASSOCIATED WEAK LOW LEVEL CONVERGENCE
AXIS THAT WILL BE DROPPING SOUTHWARD ACROSS THE AREA ON WEDNESDAY.
MID LEVEL COLD POOL IS EXPECTED TO SHIFT SOUTHEAST ACROSS LOWER
MICHIGAN INTO WEDNESDAY NIGHT. SOME WEAK SFC BASED INSTABILITY IS
POSSIBLE ON WEDNESDAY AFTERNOON ESPECIALLY ACROSS NORTHEAST PORTIONS
OF THE FORECAST AREA CLOSER TO THESE COOLER MID LEVEL PROFILES. WILL
HOLD OFF ON ANY TS INCLUSION AT THIS POINT WITH SOME CONCERN THAT IF
SOME DEEPER MIXING IS REALIZED...THIS COULD LIMIT ANY SFC BASED
INSTABILITY. CHANCE OF PRECIP TO COME TO AN END WEDNESDAY EVENING AS
THIS UPPER TROUGH SHIFTS EAST. BROAD LOW LEVEL ANTICYCLONE WILL THEN
OVERSPREAD THE REGION FOR THURSDAY AND FRIDAY SETTING UP A FEW QUIET
DAYS TO END THE WEEK.
LOW LEVEL ANTICYCLONE WILL BE VERY SLOW TO SHIFT EAST AS UPPER RIDGE
TO THE WEST AMPLIFIES AS IT APPROACHES THE GREAT LAKES REGION FRIDAY
IN RESPONSE TO NEXT PROGRESSIVE EASTERN PACIFIC TROUGH TRACKING INTO
THE NORTHERN PLAINS. MOISTURE RETURN IN ADVANCE OF THIS PACIFIC
TROUGH WILL BE SOMEWHAT ROUNDABOUT DUE TO PRESENCE OF DEPARTING
ANTICYCLONE TO THE SOUTHEAST. THIS SHOULD CONFINE ANY LOW LEVEL
MOISTURE RETURN OF CONSEQUENCE TO A FAIRLY NARROW CORRIDOR IN
ADVANCE OF ASSOCIATED COLD FRONTAL BOUNDARY. WHILE SOME SLIGHT
TIMING DIFFERENCES PERSIST WITH THIS FRONT...CHARACTERISTIC OF LARGE
SCALE FLOW AND GOOD AGREEMENT AMONGST MEDIUM RANGE MODELS HANDLING
THIS NEXT EASTERN PACIFIC TROUGH STILL LEND ENOUGH CONFIDENCE TO
MAINTAIN LOW CHANCE POPS FOR FRIDAY NIGHT INTO SUNDAY. ONCE FRONTAL
TIMING BECOMES BETTER RESOLVED WILL LIKELY BE ABLE TO CONTRACT THE
DURATION OF THESE POPS. HAVE OMITTED THUNDER AT THIS TIME GIVEN SOME
UNCERTAINTIES AS TO EXTENT OF LOW LEVEL MOISTURE RETURN BUT THIS
WILL ALSO NEED TO BE REASSESSED IN LATER FORECASTS. SOME SLIGHT
MODERATION IN TEMPERATURES EXPECTED FOR FRIDAY IN ADVANCE OF THIS
FRONT...BUT OVERALL TEMPERATURES NEAR SEASONABLE LEVELS ARE EXPECTED
THROUGH THE PERIOD. A RETURN TO DRY CONDITIONS EXPECTED FOR EARLY
NEXT WEEK AS THIS SYSTEM DEPARTS TO THE EAST.
&&
.AVIATION...
KIWX RADAR SHOWING MAJORITY OF PRECIP OUT OF THE CWA ATTM LEAVING
JUST SCATTERED SHOWERS OVER THE AREA TO BEGIN TAF PERIOD. SFC LOW
SLOWING MOVING ACROSS THE AREA AS REDEVELOPING SHOWERS OVER ILLINOIS
EXPECTED TO MOVE ACROSS BOTH TAF SITES LATE THIS AFTERNOON/EARLY
EVENING. AMPLE LOW LEVEL MOISTURE FROM EARLIER RAINS HAS IFR
CONDITIONS IN AND AROUND BOTH TAF SITES. CIGS SHOULD IMPROVE
SLIGHTLY AS PRECIP MOVES IN BUT THEN EXPECT MVFR CIGS TO REMAIN OVER
THE AREA OVERNIGHT BEFORE DRIER AIR FINALLY BEGINS TO WORK INTO THE
AREA BY EARLY TUESDAY MORNING. MID LEVEL DRYING AND WEAK SFC FLOW
SHOULD ALSO ALLOW FOR MVFR VSBYS AT BOTH TAF SITES WITH FOG
DEVELOPMENT LATER TONIGHT.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...LOGSDON
LONG TERM...MARSILI
AVIATION...LOGSDON
AREA FORECAST DISCUSSION
NWS JACKSON KY
327 PM EDT MON MAY 7 2012
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 327 PM EDT MON MAY 7 2012
SCATTERED CONVECTION CONTINUES TO FIRE UP MAINLY ALONG AND SOUTH OF
THE HAL ROGERS PARKWAY AND HIGHWAY 80 CORRIDORS. THE RADAR REMAINS
PRETTY QUIET OFF TO THE WEST AND DESPITE THE HRRR INSISTENCE UPON
CONVECTION GETTING GOING IN WESTERN KENTUCKY AND TRANSLATING
EASTWARD...ITS HARD TO SEE ANYTHING ORGANIZED HITTING THE AREA
THROUGH AT LEAST EARLY THIS EVENING.
THE MODELS HAVE DECISIVELY SPED UP THE TIMING OF THE SURFACE AND
UPPER LEVEL FEATURES ON THE 12Z RUNS THROUGH THE SHORT TERM. AS
SUCH...HAVE EXITED EVERYTHING A BIT FASTER...ALTHOUGH AM HESITANT TO
BE TOO AGGRESSIVE AS THIS HAS NOT BEEN TREND WITH THIS SYSTEM LATELY.
SCATTERED CONVECTION SHOULD CONTINUE THROUGH EARLY THIS EVENING...AND
THEN WILL WIND DOWN TEMPORARILY WITH THE LOSS OF HEATING. MID-LEVEL
LAPSE RATES AND RADAR TRENDS CONTINUE TO UN-IMPRESS...SO WOULD BE
SURPRISED IF ANY STORMS BECOME THAT INTENSE. STILL...WILL HANG ONTO
AN ISOLATED SEVERE WORDING IN THE HWO THROUGH DUSK.
THE COLD FRONT AND BETTER MID-LEVEL FORCING WILL NUDGE TOWARDS THE
AREA LATER TONIGHT INTO EARLY TUESDAY MORNING...ALLOWING FOR MORE
WIDESPREAD PRECIPITATION COVERAGE. DEEPER MOISTURE WILL THEN
GRADUALLY EXIT DURING THE DAY ON TUESDAY...WITH SHOWERS DIMINISHING
FROM NORTHWEST TO SOUTHEAST INTO TUESDAY EVENING.
THE MAIN TROUGH AXIS WILL SHIFT THROUGH THE AREA ON WEDNESDAY...WITH
PERHAPS ENOUGH MOISTURE TO ALLOW FOR A FEW SHOWERS...ESPECIALLY ALONG
AND NORTH OF THE MOUNTAIN PARKWAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 327 PM EDT MON MAY 7 2012
THE MODELS ARE IN PRETTY GOOD AGREEMENT AT THE START OF THE EXTENDED
WITH A FAIRLY DEEP TROUGH CROSSING THE OHIO VALLEY AND A NEARLY
DISCONNECTED LOW MEANDERING OVER NORTHERN OLD MEXICO. THE TROUGH
WILL SWEEP THROUGH THE AREA WEDNESDAY NIGHT WITH SIMILAR TIMING AND
STRENGTH IN ALL MODELS...THOUGH THE ECMWF AND GFS DO SYNCH UP THE
BEST. ONCE THE AXIS GOES THROUGH EAST KENTUCKY...A NODE OF THE UPPER
LOW RESPONSIBLE WILL PIVOT THROUGH THE GREAT LAKES AND PASS BY TO
OUR NORTHEAST DURING THE DAY THURSDAY MARKING THE LAST OF THE LOWER
HEIGHTS FROM THIS SYSTEM. BROAD RIDGING THEN COMMENCES THROUGH THE
END OF THE WEEK AND START OF THE WEEKEND. THIS WILL BE IN RESPONSE
TO THE SLOW APPROACH OF THE LOST UPPER LOW TO THE SOUTHWEST. THE
REMAINS OF THIS LOW WILL DRIFT EAST THROUGH THE SOUTHERN PLAINS AND
RELEASE ITS WEAK ENERGY EAST INTO THE OHIO AND TENNESSEE VALLEYS FOR
MAINLY THE LATTER PART OF THIS WEEKEND. AT THE SAME TIME...ANOTHER
TROUGH WILL BE PUSHING SOUTH INTO THE NORTH PLAINS AND EVENTUALLY
INTO THE NORTHERN OHIO VALLEY ON SUNDAY. WEAK WAVES IN THE SOUTHERN
STREAM WILL PASS THROUGH THE BASE OF THIS TROUGH AND POTENTIALLY
AFFECT KENTUCKY HEADING INTO THE START OF THE NEW WORK WEEK. THE
MODELS BECOME INCREASINGLY MUDDLED WITH TIME SO THAT A BLEND IS THE
MOST SENSIBLE APPROACH FOR THE LATTER PARTS OF THE EXTENDED...WHILE
FOR THE BEGINNING THE ECMWF WAS PREFERRED.
SENSIBLE WEATHER WILL FEATURE THE SLOW DEPARTURE OF THE STALLED
FRONT JUST TO OUR EAST ON WEDNESDAY NIGHT...THOUGH A COUPLE OF
EVENING SHOWERS MAY LINGER IN FAR EASTERN PARTS OF KENTUCKY. THE
TROUGH AXIS PASSING THROUGH BY MIDDAY THURSDAY MAY GEN UP A FEW
BONUS SHOWERS...BUT FOR NOW HAVE LEFT IT DRY. COOL AND DRY HIGH
PRESSURE THEN PUSHES INTO THE REGION AND WILL KEEP THE WEATHER
SETTLED AND PLEASANT THROUGH THE START OF THE WEEKEND. THIS HIGH
MODERATES AND MOVES EAST BY LATE SATURDAY ALLOWING MORE MOISTURE AND
WARMTH TO RETURN TO EAST KENTUCKY. FOR SUNDAY THROUGH MONDAY...WEAK
LOW PRESSURE TO THE SOUTH...A NEW COLD FRONT STALLING TO THE NORTH
AND AMPLE MOISTURE IN PLACE SHOULD BE ENOUGH TO GENERATE MAINLY
DIURNALLY DRIVEN SCATTERED CONVECTION FOR THE END OF THE EXTENDED AS
A MORE NORMAL LATE SPRING/EARLY SUMMER PATTERN TAKES HOLD.
THE GRID LOAD CAME IN RATHER NICE...THOUGH DID NUDGE POPS DOWN
FOR MOST OF THE CWA FROM THURSDAY THROUGH SATURDAY. ALSO...ADDED THE
STANDARD TERRAIN DRIVEN DETAILS TO THE LOW TEMPERATURE GRIDS EACH
NIGHT FROM THURSDAY THROUGH SATURDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 206 PM EDT MON MAY 7 2012
SCATTERED SHOWERS AND THUNDERSTORMS WILL BE PREVALENT ACROSS EASTERN
KENTUCKY THROUGH THIS AFTERNOON. SOME OF THESE WILL COME PRETTY CLOSE
TO TERMINALS...HOWEVER HAVE CHOSEN TO STICK WITH VCTS FOR NOW.
BETTER COVERAGE OF SHOWERS AND THUNDERSTORMS WILL ARRIVE THIS EVENING
AND TONIGHT...WITH CEILINGS DROPPING BACK TO MVFR LATE TONIGHT INTO
TUESDAY MORNING...AND THEN EVEN IFR BY THE MID-MORNING HOURS ON
TUESDAY AS A COLD FRONT GRADUALLY MOVES THROUGH THE AREA.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GEOGERIAN
LONG TERM....GREIF
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS JACKSON KY
206 PM EDT MON MAY 7 2012
.UPDATE...
ISSUED AT 206 PM EDT MON MAY 7 2012
CONVECTION HAS STARTED TO FIRE UP...MAINLY ALONG AND SOUTH OF THE HAL
ROGERS PARKWAY AND HIGHWAY 80. THE LATEST MESO-ANALYSIS PAGE SHOWS
MID-LEVEL LAPSE RATES REMAINING PRETTY WEAK...SO THE SEVERE THREAT IS
LOWER...HOWEVER CAN NOT COMPLETELY RULE OUT AN ISOLATED ONE OR TWO
WITH SOME STORM INTERACTION SO WILL LEAVE THIS MENTION IN THE HWO FOR
NOW. MAINLY FRESHENED UP THE HOURLY TEMPERATURES AND DEW POINTS TO
BETTER MATCH OBSERVATIONAL TRENDS.
UPDATE ISSUED AT 1056 AM EDT MON MAY 7 2012
THE MODELS CONTINUE TO DIFFER ON HOW MUCH AREAL CONVECTIVE COVERAGE
WE WILL REALLY SEE TODAY. THE LATEST NAM HAS VERY LITTLE IF ANY
THROUGH 00Z...ALONG WITH THE SREF. THE HRRR SHOWS AT LEAST SCATTERED
IF NOT NUMEROUS COVERAGE AT TIMES. THE CURRENT VISIBLE SATELLITE DOES
REVEAL AN OUTFLOW BOUNDARY MOVING EAST THROUGH CENTRAL KENTUCKY...
POISED TO MOVE THROUGH EASTERN KENTUCKY THIS AFTERNOON CLOSER TO PEAK
HEATING. WHILE THIS FEATURE WILL LIKELY WEAKEN WITH TIME...IT COULD
PROVIDE ENOUGH OF A WEAKNESS IN THE CAP TO GET CONVECTION GOING. AS
SUCH...DECIDED TO RAISE POPS SOMEWHAT FURTHER EAST. THE ATMOSPHERE IS
MODERATELY UNSTABLE...SO A FEW STORMS COULD APPROACH SEVERE LIMITS...
ESPECIALLY IF SOME STORM INTERACTION CAN TAKE PLACE.
UPDATE ISSUED AT 750 AM EDT MON MAY 7 2012
UPDATED THE FORECAST TO REFLECT CURRENT CONDITIONS AND MODEL TRENDS.
ONLY MADE SOME MINOR ADJUSTMENTS TO THE TEMPERATURES...WINDS AND DEW
POINTS.
UPDATE ISSUED AT 455 AM EDT MON MAY 7 2012
UPDATED THE FORECAST TO REFLECT CURRENT CONDITIONS AND MODEL TRENDS.
ONLY MADE SOME MINOR ADJUSTMENTS TO THE TEMPERATURES AND DEW POINTS.
NO ZONE UPDATE WILL BE REQUIRED.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 301 AM EDT MON MAY 7 2012
THE MODELS ARE IN DECENT AGREEMENT WITH THE TIMING OF THIS NEXT
SYSTEM. THE TIMING OF THE ACTUAL FRONT MOVING THROUGH HAS BEEN SLIPPING
OVER THE LAST FEW MODEL RUNS. THE MODELS ARE ALL VERY SLOW TO
ACTUALLY PUSH THIS SYSTEM THROUGH THE AREA. CONSIDERING THE GOOD
MODEL AGREEMENT...CONFIDENCE IS HIGHER THAN NORMAL. THE BIG
QUESTION FOR THIS AFTERNOON IS WHETHER OR NOT THERE WILL BE ANY
TRIGGERS TO GET SOME THUNDERSTORMS POPPING. ALL THE MODELS ARE NOW
GENERATING PRECIPITATION OVER THE AREA...HOWEVER THERE IS A LACK OF ANY
WELL DEFINED TRIGGERS. ONCE ANY CELLS DEVELOP AND THERE ARE ANY
OUTFLOWS...THEN THE VERY UNSTABLE AIR WILL ALLOW FOR THUNDERSTORMS TO
KEEP GOING FOR A WHILE. THESE WILL BE PULSE TYPE THUNDERSTORMS THAT DO
NOT MOVE VERY FAST. AS SUCH...THERE MAY BE SOME ISSUES WITH NUISANCE
TYPE FLOODING WITH DITCHES AND LOW WATER CROSSINGS RUNNING FULL. THE
PRECIPITABLE WATER WILL BE ABOUT 1.41 INCHES...SO RAINFALL RATES OF
OVER 1 INCH PER HOUR WILL BE FAIRLY EASY TO OBTAIN. THE MAJOR FORCING
WOULD APPEAR TO BE MOVING ACROSS THE AREA AFTER MIDNIGHT. BACK END OF
THE SYSTEM WILL NOT BE MOVING THROUGH THE AREA WEDNESDAY AFTERNOON.
EXPECT THE RAIN TO CONTINUE OFF AND ON THROUGH TUESDAY. FOR
TEMPERATURES...KEPT PRETTY CLOSE TO THE MOS BLEND. THE HIGHS FOR
TODAY MAY BE TOO HIGH IF THE CONVECTION INITIATES BEFORE NOON AND
CAUSES A LOT OF CLOUD COVER BEFORE PEAK HEATING.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 329 AM EDT MON MAY 7 2012
MODELS REMAIN IN REMARKABLY GOOD AGREEMENT THROUGH THE PERIOD
BOOSTING CONFIDENCE WITH THE FORECAST THROUGH THE END OF THE WEEK.
WE BEGIN TUESDAY NIGHT WITH LINGERING POST FRONTAL SHOWERS AND A FEW
THUNDERSTORMS OVER ERN KY AS THE UPPER LEVEL TROF SLOWLY SWINGS
THROUGH THE GREAT LAKES. ON WEDNESDAY THE TROF CONTINUES PUSHING
THROUGH THE OHIO VALLEY WITH PRECIP GRADUALLY ENDING FROM WEST TO
EAST THROUGH THE DAY AS WELL. BY WEDNESDAY NIGHT...STRONG HIGH
PRESSURE OVER THE THE HEART OF NOAM IN CONCERT WITH A BUDDING NRN
STREAM RIDGE OVER THE SRN CANADIAN PLAINS DOWN THROUGH THE NRN
ROCKIES SHIFTS EAST AND WILL BEGIN A STRETCH OF DRY...QUIET WEATHER
WITH MODERATING TEMPERATURES THAT LOOKS TO CONTINUE THROUGH THE END
OF THE WEEK. TOWARDS THE TAIL END OF THE PERIOD...BOTH THE EURO AND
THE GFS BRING A WEAK COLD FRONT INTO THE OHIO VALLEY...A LITTLE
QUICKER IN THE GFS VERSION...AS A SRN STREAM TROF MIGRATES FROM TX
THROUGH THE GULF COAST STATES...OPENING UP A RETURN FLOW OF WARM...
MOIST GOMEX AIR INTO THE REGION. GIVEN THE GOOD AGREEMENT THIS FAR
OUT...WILL KEEP SOLID CHANCES FOR PRECIP FOR THE END OF THE PERIOD
AND INTO THE BEGINNING OF NEXT WEEK.
AS FOR TEMPERATURES...THE EXTENDED INITIALIZATION CAME IN WITH A
REASONABLE STARTING POINT...THOUGH DID KEEP SOME MINOR ELEVATION
BASED DIFFERENCES FOR THURSDAY AND FRIDAY NIGHTS WITH HIGH PRESSURE
MOVING IN OVERHEAD. ALSO GAVE A BOOST TO HIGHS ON FRIDAY GIVEN THE
EXPECTED CLEAR SKIES...AND TO LINE UP A LITTLE BETTER WITH
SURROUNDING OFFICES. THIS ESSENTIALLY RESULTED IN TEMPS RUNNING A
LITTLE BELOW NORMAL THROUGH THE WEEK BEFORE RETUNING TO MORE
CLIMATOLOGICAL NORMS FOR THE WEEKEND...WITH OVERNIGHT LOWS GENERALLY
FOLLOWING A SIMILAR TREND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 206 PM EDT MON MAY 7 2012
SCATTERED SHOWERS AND THUNDERSTORMS WILL BE PREVALENT ACROSS EASTERN
KENTUCKY THROUGH THIS AFTERNOON. SOME OF THESE WILL COME PRETTY CLOSE
TO TERMINALS...HOWEVER HAVE CHOSEN TO STICK WITH VCTS FOR NOW.
BETTER COVERAGE OF SHOWERS AND THUNDERSTORMS WILL ARRIVE THIS EVENING
AND TONIGHT...WITH CEILINGS DROPPING BACK TO MVFR LATE TONIGHT INTO
TUESDAY MORNING...AND THEN EVEN IFR BY THE MID-MORNING HOURS ON
TUESDAY AS A COLD FRONT GRADUALLY MOVES THROUGH THE AREA.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...JJ
LONG TERM....MB
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS DULUTH MN
1258 PM CDT MON MAY 7 2012
.AVIATION.../18Z TAF ISSUANCE/
A COMPLEX CLOUD FORECAST IS SHAPING UP OVER THE DURATION OF THE
TAF CYCLE. A DOUBLE LOW PRESSURE SYSTEM WILL GRADUALLY MORPH INTO
ONE MAIN LOW PRESSURE SYSTEM OVER THE NORTHERN GREAT LAKES THROUGH
THE TAF CYCLE. THE RESULT WILL BE A WEST TO EAST LOW PRESSURE
TROUGH THAT WILL HELP TO FOCUS SHOWERS AND LOWERING CLOUD HEIGHTS.
TODAY IT LOOKS LIKE ANY POSSIBLE MVFR CIGS/VSBYS WOULD BE CONFINED
TO THE KINL AREA. HOWEVER...MVFR AND SOME IFR CONDITIONS SHOULD
BECOME THE NORM ACROSS THE AREA TONIGHT AND INTO TUESDAY MORNING.
&&
.PREV DISCUSSION... /ISSUED 1039 AM CDT MON MAY 7 2012/
UPDATE...ZFP/GRIDS IN VERY GOOD CONDITION SO ONLY MINOR TWEAKS
MADE AT THIS POINT. GUSTY WINDS SHOULD DEVELOP TODAY WITHIN
RELATIVE NARROW DRY SLOT AS MIXING LAYER DEEPENS AND MOMENTUM
TRANSFER INCREASES. PROGRESSIVE NATURE OF MID LVL THERMAL POOL
MAKES INSTABILITY CLOUD DEVELOPMENT FAIRLY RAPID. INSTABILITY
PARAMETERS ARE NOT VERY IMPRESSIVE WITH LATEST SREF SHOWING
HIGHEST PROBABILITY NEAR BORDERLAND/IRON RANGE THIS AFTN. WILL
LEAVE ISO TRW IN MOST OF PRECIP AREA TODAY AS FCST 85/50H LAPSE
RATES INCREASE TO GREATER THAN 6C/KM.
PREV DISCUSSION... /ISSUED 636 AM CDT MON MAY 7 2012/
UPDATE...
UPDATED THE FORECAST TO REFLECT THE LATEST CLOUD AND FOG TRENDS.
IT APPEARS THICKER FOG HAS FORMED ALONG THE NORTH SHORE...SO
ALTERED THE MORNING FORECAST FROM PATCHY FOG TO AREAS OF FOG FOR
THAT AREA. ALSO...THE LATEST HRRR AND NAM RUNS SUGGEST MORE
EXTENSIVE CLOUD COVER MOVING IN FROM THE WEST TODAY...SO INCREASED
CLOUD COVER INTO THIS AFTERNOON.
PREV DISCUSSION... /ISSUED 627 AM CDT MON MAY 7 2012/
AVIATION...12Z TAFS.
DRY SLOT WORKING ITS WAY ACROSS THE AREA EARLY IN THE TAF CYCLE
WILL PRESENT A BRIEF WINDOW OF VFR. LIFR/IFR CIGS/VSBYS WITH
PATCHY BR/FOG AHEAD OF THE DRY SLOT WILL EXIT THE AREA FAIRLY
QUICKLY. BEHIND THE DRY SLOT...MVFR CIGS WILL SPREAD ACROSS THE
TAF SITES WITH SOME GUSTY SFC WINDS FROM 16Z TO 22Z. SOME SHOWERS
MAY OCCUR AFTER 21Z AS SFC LOW AND UPPER LOW DROP THROUGH THE
AREA. UPSTREAM SFC OBS INDICATE THE SHOWERS WILL BE ISOLD AND HAVE
VCSH TO ACCOUNT FOR THIS ISOLD NATURE.
PREV DISCUSSION... /ISSUED 337 AM CDT MON MAY 7 2012/
SHORT TERM...[NOW - TUESDAY]
AT 0830Z...THERE WAS A SURFACE LOW AND AN ASSOCIATED MID/UPPER
LEVEL LOW CENTERED OVER SOUTHERN SASKATCHEWAN. AN ASSOCIATED
OCCLUDED FRONT STRETCHED SOUTHEAST THROUGH THE WESTERN FA. MUCH OF
THE FA WAS COVERED WITH VERY LOW OVERCAST STRATUS...AND IN
ADDITION BKN/OVC HIGH CLOUDS COVERED THE SOUTHEASTERN FA. THERE
WAS SOME FOG ACROSS THE NORTHLAND...WITH SOME RECENT REPORTS NEAR
THE BRAINERD LAKES AND TWIN PORTS AREAS. THE WINDS WERE MOSTLY
CALM OR VERY LIGHT AND VARIABLE...EXCEPT FOR DEVELOPING LIGHT
SOUTHERLY WINDS ACROSS THE NORTHERN AND WESTERN FA. TEMPERATURES
WERE IN THE 40S TO LOW 50S. THE RADAR INDICATED LINGERING SHOWERS
ACROSS THE EASTERN FA...NAMELY THE ARROWHEAD.
EARLY THIS MORNING...THE OCCLUDED FRONT WILL CONTINUE TO MOVE
EASTWARD THROUGH THE FA...AND THE SHOWERS IN THE EASTERN FA WILL
GRADUALLY MOVE OUT OF THE FA. THE VERY LOW STRATUS AND PATCHY FOG
MAY LINGER THROUGH AT LEAST DAWN.
TODAY...THE SURFACE AND MID/UPPER LEVEL LOWS IN SOUTHERN
SASKATCHEWAN WILL MOVE INTO NORTHERN MINNESOTA. MIXING WILL
INCREASE THIS MORNING WITH THE INCREASING WESTERLY WINDS. THIS
SHOULD BEGIN TO BURN OFF THE EARLY MORNING STRATUS AND PATCHY
FOG...AS WELL AS GIVE THE FA SOME MORNING SUNSHINE. PATCHY FOG MAY
LINGER THROUGH PART OF THE MORNING ACROSS THE EASTERN FA WHERE THE
WINDS WILL BE LIGHTEST. THE COLD AIR ALOFT AND THE RELATIVELY LOW
CONVECTIVE TEMPERATURES TODAY SHOULD RESULT IN PLENTY OF CUMULUS
CLOUDS DEVELOPING BY THIS AFTERNOON. THE MODELS ARE IN GOOD
AGREEMENT THAT THE NORTHERN AND WESTERN FA COULD GET RAIN
SHOWERS. MODEL SUPPORT FOR INSTABILITY IS LIMITED...ABOUT 300 J/KG
OR LESS...BUT ENOUGH TO WARRANT INCLUDING A MENTION OF ISOLATED
THUNDER WITH THE SHOWERS. THE MORNING SUNSHINE SHOULD ALLOW
TEMPERATURES TO CLIMB TO THE LOWER 60S ACROSS MOST OF THE FA.
TONIGHT...THE SURFACE AND MID/UPPER TROUGH WILL MOVE
SOUTHEASTWARDS THROUGH THE FA. EXPECT A CLOUDY AND COOL NIGHT WITH
CONTINUING CHANCES OF RAIN SHOWERS...MAINLY ACROSS THE NORTHERN
HALF OF THE FA.
TUESDAY...THE NEGATIVELY TILTED MID/UPPER LEVEL TROUGH WILL SWING
THROUGH THE GREAT LAKES REGION THROUGH THE DAY ON TUESDAY AND THE
ASSOCIATED STACKED SURFACE LOW WILL SLIDE SOUTH TO SOUTHEASTERN
MINNESOTA BY TUESDAY EVENING. FORECAST SOUNDINGS ARE QUITE
SATURATED THROUGH THE MID LEVELS THROUGH THE DAY AND INTO THE
EVENING. AS THAT LOW PRESSURE CENTER SWINGS SOUTH...THE FA WILL
REMAIN CLOUDY AND WET...BUT COOLER THAN PREVIOUS DAY. THE
SOUNDINGS TUESDAY AFTERNOON ALSO SHOW SOME WEAK CAPE VALUES ACROSS
THE AREA AS THE AFTERNOON HEATING PICKS UP. HAVE INCLUDED ISOLATED
THUNDER TO ADDRESS THIS.
LONG TERM...[TUESDAY NIGHT - SUNDAY]
A LONG WAVE TROF WILL CLEAR THE FA TUESDAY EVENING WHILE ONE MORE
PIECE OF ENERGY DROPS QUICKLY INTO THE AREA BEHIND IT. THESE
FEATURES WARRANT THE POPS CURRENTLY IN PLACE OVER THE EASTERN TWO
THIRDS OF THE AREA TUESDAY EVENING. AFTER 06Z WEDNESDAY, UPPER
LEVEL AND SFC RIDGING BUILD INTO THE FA WITH A CLEARING SKY. THE
SFC RIDGING MOVES TO THE SOUTHERN GREAT LAKES WHILE UPPER RIDGING
REMAINS OVER THE FA THROUGH THURSDAY. A SW RETURN FLOW SETS UP IN
THURSDAY AFTERNOON ALLOWING WARM, MOIST AIR TO ADVECT INTO THE
AREA. THURSDAY NIGHT FINDS A STRONG COLD FRONT MOVING TOWARDS THE
FA WITH THUNDERSTORMS IN THE VICINITY OF THE FRONT. THE GFS, GEM,
NOGAPS AND DGEX ARE THE FASTEST WITH THE FRONT WHILE THE 00Z ECMWF
IS SLOWEST. TRIED TO LEAN MORE TOWARD THE ECMWF AS ALL MODELS ARE
TOO QUICK TO BREAK DOWN RIDGING DOWNSTREAM. THIS TREND CONTINUES
ON FRIDAY AND KEPT THE SAME APPROACH. LEFT SOME POPS OVER THE
EASTERN THIRD OF THE FA FRIDAY NIGHT AS PCPN MAY LINGER BEHIND THE
DEPARTING FRONT WITH THE CAA. A QUASI-ZONAL FLOW SETS UP SATURDAY
AND SUNDAY. A WEAK SHORT WAVE CLIPS THE EASTERN PORTION OF THE FA
SUNDAY AND HAVE SMALL POPS TO ACCOUNT FOR ITS PASSAGE.
&&
.POINT TEMPS/POPS...
DLH 63 42 52 39 / 10 20 60 20
INL 59 41 55 35 / 50 50 50 10
BRD 63 43 55 40 / 20 20 60 10
HYR 68 42 54 38 / 10 10 60 30
ASX 64 42 50 38 / 10 20 60 30
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...CANNON
LONG TERM....DAP
AVIATION...DAP
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1213 PM CDT MON MAY 7 2012
.AVIATION...18Z TAF. GENERALLY QUIET WEATHER WITH VFR CONDITIONS
ARE EXPECTED FOR THIS TAF PERIOD. COULD SEE A FEW SPRINKLES MOVE
INTO THE AREA...ASSOCIATED WITH AN AREA OF LIGHT RAIN SHIFTING
NORTHEAST OUT OF KANSAS...SO LEFT VCSH MENTION GOING THIS
AFTERNOON. EVEN IF THE TERMINAL AREA DOES SEE PRECIP...CLOUD
BASES ARE EXPECTED TO REMAIN IN THE MID/UPPER LEVELS. WITH SURFACE
HIGH PRESSURE SET UP TO THE WEST THROUGH THE TAF PERIOD...WIND
DIRECTION EXPECTED TO REMAIN PRIMARILY NORTHWESTERLY. SHOULD START
TO SEE DIMINISHING SPEEDS LATER THIS AFTERNOON AND THOUGH THE
OVERNIGHT HOURS...BEFORE BECOMING A BIT MORE GUSTY TOWARD THE END
OF THE TAF PERIOD.
&&
PREV DISCUSSION... /ISSUED 416 AM CDT MON MAY 7 2012/
SHORT TERM...CERTAINLY QUITE A CHANGE FROM THE PAST WEEK...WHICH
WAS MORE LIKE JULY WITH HIGH HUMIDITY AND SEVERAL EPISODES OF SEVERE
THUNDERSTORMS WITH LARGE HAIL. WE NOW HAVE SUB-40 DEGREE DEWPOINTS
WORKING INTO CENTRAL NEBRASKA FROM THE NORTHWEST ABOUT
NORTH/NORTHWEST WINDS. TEMPERATURES HAVE REMAINED UP A BIT TONIGHT
WITH COLD ADVECTION THANKS TO GOOD DECK OF MID/HIGH CLOUDS.
THE MAIN ISSUE TODAY IS A SMALL RISK FOR SPRINKLES IN SOME AREA...AND
THEN SOME CONCERN OF PATCHY FROST OVER THE NORTHWEST FORECAST AREA
TONIGHT. THOUGH LOW LEVEL DRY AIR WILL DEEPEN WITH TIME...THE FORECAST
AREA ASCENDS INTO A FAVORABLE RIGHT REAR QUADRANT OF 250MB JET STREAK
BY AFTERNOON. THIS FRONTOGENETIC TYPE FORCING IS CAPTIONED ON AT
LEAST A FEW MODELS...INCLUDING THE RUC RAPID REFRESH...WITH HINTS OF
MOISTURE TRYING TO SPILL NORTHEAST FROM COLORADO. BELIEVE ITS WORTH
A SPRINKLE MENTION AT THIS TIME FOR AREAS SOUTH OF INTERSTATE 80.
CHILLY CONDITIONS TONIGHT ARE MOST LIKELY IN THE NORTHWEST FORECAST
AREA...MAINLY NORTHWEST OF A LINE FROM ELWOOD...TO LOUP CITY...TO
GREELEY. AIR WILL BE DRY ENOUGH...WINDS PROBABLY LIGHT ENOUGH...TO
REACH NEAR THE 36 DEGREE LINE OR LOWER...WHICH WOULD SUPPORT FROST.
THE ISSUE MAY BE CLOUDS...AS SOME INCREASE/LINGERING CLOUDS COULD
REEK HAVOC WITH JUST WHAT AREAS ACTUALLY DROP THE LOWEST. WILL
MENTION SOME PATCHY FROST IN THE GOTHENBURG AREA...AND IN THE
HAZARDOUS WEATHER OUTLOOK...BUT NOT CONFIDENT ENOUGH TO ISSUE ANY
ADVISORY AT THIS TIME.
DESPITE SUNSHINE...A COOL START WILL LEAD TO A COOLISH DAY TUESDAY.
NORTH/NORTHWEST WINDS WILL KEEP THAT COOL FEEL IN THE AIR EVEN WITH
TEMPERATURES IN THE UPPER 60S TO LOWER 70S. THE WINDS WILL BE
STRONGEST ACROSS SOUTH CENTRAL NEBRASKA...AND GRADUALLY DROP OFF
THE FURTHER SOUTH ONE GOES. WITH HIGH PRESSURE SETTLING RIGHT ON THE
FORECAST TUESDAY NIGHT...ANOTHER RISK FOR PATCHY FROST COULD ARISE.
THAT APPEARS MOSTLY LIKELY IN THE NORTHEAST FORECAST AREA...MAINLY
NORTH AND EAST OF A YORK TO GREELEY LINE. THE WESTERN AREAS WILL
SEE JUST EVEN SOUTHERLY FLOW TO LIMIT COOLING IN THOSE AREAS.
WEDNESDAY AND WEDNESDAY WILL BE NICE WITH MAINLY CLEAR SKIES AND
SOUTHERLY FLOW GRADUALLY DEVELOPING THROUGHOUT THE DAY FROM WEST
TO EAST. HIGHS WEDNESDAY WILL BE RIGHT WHERE SHOULD BE FOR THIS
TIME OF YEAR...IN THE LOWER 70S.
LONG TERM...THURSDAY THROUGH SUNDAY. NEEDLESS TO SAY...IT LOOKS
LIKE THE MONTH OF MAY GOT ITS FIRST MULTI-DAY BOUT OF SEVERE WEATHER
OUT OF THE WAY QUITE EARLY...AS THERE ARE NO SYNOPTICALLY EVIDENT
THREATS FOR WIDESPREAD STRONG-SEVERE STORMS THROUGH AT LEAST THE
NEXT 7-9 DAYS PER THE LATEST 00Z GFS/ECMWF RUNS. THAT BEING
SAID...THERE ARE SOME CHANCES FOR SHOWERS/GENERALLY WEAK STORMS.
TEMP WISE...THESE 4 DAYS WILL GENERALLY BOUNCE AROUND WITHIN ROUGHLY
5 DEGREES EITHER SIDE OF NORMAL FOR MID-MAY.
STARTING OFF THURSDAY...THIS IS LOOKING LIKE THE WARMEST DAY OF
THE EXTENDED...AND NUDGED UP HIGHS VERY SLIGHTLY FROM PREVIOUS
FORECAST...PUTTING MOST AREAS IN THE 78-82 RANGE. IN THE MID-UPPER
LEVELS...THE TWO MAIN FEATURES ARE A COMPACT...CUT OFF LOW SLOWLY
MOVING INTO TX...AND A LARGER SCALE SHORTWAVE TROUGH CROSSING THE
NORTHERN ROCKIES. IN RESPONSE TO THE LATTER...HIGH PLAINS SURFACE
PRESSURE FALLS WILL INDUCE SOUTHERLY WINDS DURING THE DAY...AND
LIKELY A BIT BREEZY WITH SUSTAINED SPEEDS EASILY 15-20 MPH.
THURSDAY NIGHT...MODELS ARE IN DECENT AGREEMENT DRAGGING THE 500MB
SHORTWAVE TROUGH ALONG THE CANADIAN BORDER INTO THE ND AREA...AND
PUSHING A WELL-DEFINED SURFACE COLD FRONT SOUTHWARD INTO THE
REGION. AT THIS TIME...THE GFS IS A BIT FASTER/STRONGER WITH THIS
WAVE AND RESULTANT FRONTAL PASSAGE THAN THE ECMWF...AND DEVELOPS A
BAND OF PRECIP MAINLY ACROSS WESTERN NEB DURING THE NIGHT WITHIN
THE ENTRANCE REGION OF THE UPPER JET AND JUST BEHIND THE SURFACE
FRONT. ALTHOUGH ECMWF KEEPS ALL PRECIP NORTHWEST OF THE CWA
THROUGH THE NIGHT...WILL PLAY IT CLOSER TO PREVIOUS FORECAST AND
THE GFS SOLUTION WITH JUST A SLIGHT CHANCE OF SHOWERS/ISOLATED
STORMS ACROSS FAR NORTHWEST COUNTIES. INSTABILITY PROGS INDICATE
THAT EVEN A FEW HUNDRED J/KG OF ELEVATED CAPE MAY BE HARD TO COME
BY...SO AT THIS POINT WOULD THINK SMALL HAIL WOULD BE THE MOST ANY
STORMS COULD GENERATE.
FRIDAY INTO FRIDAY NIGHT...MODEL AGREEMENT REMAINS REASONABLY HIGH
FOR THIS TIME RANGE...AS THE NORTHERN SHORTWAVE CONTINUES TRACKING
TOWARD THE GREAT LAKES...AND THE SURFACE COLD FRONT PUSHES WELL
SOUTH THROUGH THE CWA. WELL OFF TO THE SOUTH...THE SLOW MOVING TX
MID-UPPER LOW SHOULD KEEP APPRECIABLE LOW LEVEL MOISTURE/INSTABILITY
WELL SOUTH OF THE CENTRAL PLAINS. THAT BEING SAID...MID LEVEL
SATURATION WITHIN THE ENTRANCE REGION OF THE UPPER JET SHOULD KEEP
AT LEAST THE POTENTIAL FOR RAIN SHOWERS GOING...AND HAVE 20-30
PERCENT CHANCES CWA-WIDE. DESPITE MEAGER INSTABILITY...WILL
MAINTAIN THUNDER WORDING BUT WILL KEEP IT AS ISOLATED AND WITH
SEEMINGLY VERY LITTLE RISK OF STRONG/SEVERE. TEMP-WISE...HIGHS
FRIDAY WILL BE A BIT TRICKY AS THE FRONT PUSHES IN...BUT WILL AIM
FOR MID 60S NORTHWEST TO MID 70S SOUTHEAST. HAVE FRIDAY NIGHT LOWS
WELL DOWN IN THE 40S ACROSS THE NORTHWEST 1/2 OF THE CWA.
SATURDAY INTO SATURDAY NIGHT...KEPT SLIGHT CHANCE POPS FOR MAINLY
LIGHT RAIN SHOWERS GOING...BUT PRIMARILY NEAR AND SOUTH OF THE
STATE LINE. LOWERED HIGHS FOR SATURDAY SLIGHTLY PER ALLBLEND MODEL
CONSENSUS...WITH ONLY MID-UPPER 60S CWA-WIDE. A SEASONABLY COOL
NIGHT FOLLOWS WITH MID-UPPER 40S CWA-WIDE.
FINALLY FOR SUNDAY...KEPT 20-30 POPS GOING ACROSS SOUTHERN
ZONES...BUT MODEL AGREEMENT HAS ALREADY FADED BY THEN...WITH GFS
KEEPING IT DRY...WHILE ECMWF BRINGS A BROAD MID LEVEL WAVE INTO
THE REGION IN DISORGANIZED NORTHWEST FLOW...BUT WITH BETTER PRECIP
CHANCES PRESUMABLY FOCUSING IN MORE FAVORED UPSLOPE AREAS TO THE
WEST. WILL AIM FOR LOW 70S CWA-WIDE FOR HIGH TEMPS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
354 PM CDT MON MAY 7 2012
.DISCUSSION...
ISOLATED THUNDERSTORMS THAT DEVELOPED ALONG THE BAY BREEZE THIS
AFTERNOON CONTINUE TO MOVE TO THE SOUTHWEST ACROSS BRAZORIA COUNTY
AND SHOULD MOVE OFFSHORE WITHIN THE NEXT COUPLE OF HOURS PER
LATEST HRRR RUNS. ADDITIONAL DEVELOPMENT INLAND IS POSSIBLE AS THE
OUTFLOW BOUNDARY FROM THIS ACTIVITY CONTINUES TO PUSH WESTWARD
ACROSS HARRIS COUNTY.
TO OUR WEST...THUNDERSTORMS CONTINUE TO INCREASE IN COVERAGE
ACROSS THE NORTHERN HILL COUNTRY ALONG AND AHEAD OF A COLD FRONT
MOVING SOUTHWARD THROUGH THE STATE. THIS ACTIVITY HAS SPREAD
EASTWARD OVER THE PAST FEW HOURS TO NEAR THE I-35 CORRIDOR AND
SHOULD CONTINUE TO DEVELOP EASTWARD OVER THE NEXT FEW HOURS. THIS
ACTIVITY WILL LIKELY MOVE INTO OUR CWA LATE THIS EVENING ALTHOUGH
SOME DEVELOPMENT ACROSS OUR NORTHERN COUNTIES THIS AFTERNOON IS
POSSIBLE AS THE AREA REMAINS GENERALLY UNCAPPED WITH TEMPERATURES
IN THE UPPER 80S AND LOW 90S. MODEL SOUNDINGS SUGGEST CAPE VALUES
OF 2500-3000 WITH LI VALUES BETWEEN -6 AND -9 ACROSS THE NORTHERN
HALF OF OUR REGION SO ANYTHING THAT DOES DEVELOP THIS AFTERNOON OR
EVENING HAS THE POTENTIAL TO BE SEVERE WITH DAMAGING WINDS AND
LARGE HAIL.
EXTENDED FORECAST REMAINS RELATIVELY UNCHANGED. PRECIPITATION WILL
CONTINUE TO INCREASE ACROSS THE REGION ON TUESDAY AS THE FRONTAL
BOUNDARY SAGS SOUTHWARD INTO THE REGION. THURSDAY LOOKS TO BE OUR
DRIEST DAY OF THE WEEK BEFORE A STRONG UPPER LEVEL LOW MOVES INTO
THE STATE. GOOD DIVERGENCE ALOFT AHEAD OF THIS SYSTEM SHOULD ALLOW
FOR FAIRLY WIDESPREAD PRECIPITATION FROM LATE THURSDAY NIGHT INTO
FRIDAY ACROSS OUR REGION. GFS CONTINUES TO BE MORE PROGRESSIVE
WITH MOVING THIS SYSTEM EAST OF THE AREA WHILE THE ECMWF CONTINUES
TO HOLD THE TROUGH AXIS WEST OF OUR AREA ON FRIDAY...MUCH THE SAME
AS ITS 00Z RUN. GIVEN THIS POSSIBILITY WILL GO AHEAD AND KEEP SOME
POPS LINGERING ACROSS THE REGION FOR SATURDAY. 38
&&
.MARINE...
LIGHT TO MODERATE ONSHORE WINDS WILL PERSIST UNTIL A COLD FRONT
MOVES SOUTHWARD AND STALLS NEAR THE COAST ON TUESDAY. MODERATE TO
POSSIBLY STRONG EAST TO NORTHEAST WINDS AND ELEVATED SEAS ARE
EXPECTED TO DEVELOP THURSDAY THROUGH SATURDAY WITH CAUTION OR
ADVISORY FLAGS ANTICIPATED. 42
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 71 83 64 80 59 / 50 60 50 20 20
HOUSTON (IAH) 72 85 68 81 62 / 20 30 50 30 20
GALVESTON (GLS) 73 83 74 81 69 / 10 20 40 40 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...38
AVIATION/MARINE...42
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1248 PM CDT MON MAY 7 2012
.UPDATE...DRIER AIR WORKING IN LOW-MID LEVELS HELPING TO ERODE STRATUS
FROM WEST TO EAST. THIS IS HAPPENING A BIT FASTER THAN ORIGINALLY
FORECAST SO HAD TO UPDATE TRENDS IN BOTH SKY COVER AND TEMPS. ALSO
WIPED OUT SHRA CHANCES THIS AFTERNOON EXCEPT IN THE FAR
SOUTHEAST...WHERE BETTER MOISTURE AND LOW LEVEL CONVERGENCE NEAR
SURFACE TROUGH MAY HELP SOME SHOWERS HANG ON INTO THE AFTERNOON.
&&
.AVIATION/18Z TAFS/...LIGHT RAIN WILL EXIT FAR SOUTHEAST WISCONSIN
BY THE THE MIDDLE OF THIS AFTERNOON AS LOW PRESSURE PULLS AWAY TO
THE EAST. MVFR CIGS TO LINGER INTO THE AFTERNOON...FINALLY
EXITING THE EAST EARLY THIS EVENING. SHOULD SEE VFR CONDITIONS
THEN THROUGH TONIGHT AND INTO TOMORROW.
UPPER WAVE EXPECTED TO DROP INTO SOUTHERN WISCONSIN TUESDAY
AFTERNOON...BRINGING A CHANCE OF RAIN SHOWERS WITH A FEW RUMBLES
OF THUNDER POSSIBLE AS WELL. ENOUGH DRY AIR IN THE LOWER LEVELS TO
SUGGEST THAT CIGS WILL STAY VFR AS THE WAVE MOVES THROUGH...THOUGH
MVFR CONDITIONS NOT OUT OF THE QUESTION WITHIN ANY HEFTIER
SHOWERS.
&&
.PREV DISCUSSION... /ISSUED 330 AM CDT MON MAY 7 2012/
TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM.
THE STRONG 250 MB JET MAX OF 120 KNOTS HAS PUSHED OFF TO SOUTHERN
QUEBEC WITH A WEAKER JET MAX IN THE UPSTREAM OF THE TROUGH THAT
EXTENDS FROM LAKE WINNIPEG TO THE CENTRAL ROCKIES. ONLY WEAK UPPER
DIVERGENCE TODAY ACROSS WISCONSIN...WHICH HEADS OFF TO THE EASTERN
GREAT LAKES LATE TONIGHT.
A WEAKENING 30 KNOT 700 MB FLOW ACROSS NORTHERN ILLINOIS AND THE
WISCONSIN BORDER AREA EARLY THIS MORNING DIMINISHES TO 10 KNOTS
JUST AFTER SUNRISE.
WEAK 700 MB UPWARD MOTION OF 2.2 MICROBARS/SEC ACROSS LAKE
MICHIGAN JUST AFTER SUNRISE NEAR THE WEAK 700 MB TROUGH AXIS. THEN
LITTLE LIFT LATER THIS MORNING AS AN OCCLUDED FRONT PUSHES EAST
ACROSS THE FORECAST AREA.
THE NAM AND THE 03Z LOCAL WRF KEEP MOST OF THE PRECIPITATION
ACROSS NORTHERN ILLINOIS EARLY THIS MORNING CLOSER TO THE SURFACE
BOUNDARY AND SURFACE LOW. THE NAM/LOCAL WRF/ RAP/AND HRRR ALL
BRING SOME SCATTERED LIGHT SHOWERS ACROSS THE FAR SOUTH THIS
MORNING.
STRONG 700 MB DRYING WILL OCCUR LATE THIS MORNING OVER NORTHWEST
SECTIONS OF THE FORECAST AREA...AND ACROSS ALL OF SOUTHERN
WISCONSIN THIS AFTERNOON. THE DRYING OCCURS AT 850 MB AS
WELL...ALTHOUGH SOME INCREASE IN RH AT 850 OCCURS OVER THE
NORTHERN SECTIONS TONIGHT AHEAD OF THE APPROACHING MID LEVEL
TROUGH THAT EXTENDS FROM THE MINNESOTA ARROWHEAD TO SOUTHEAST
SOUTH DAKOTA BY SUNRISE SATURDAY.
SURFACE DEWPOINTS ALSO DRY...ESPECIALLY TONIGHT AS THEY LOWER
INTO THE LOWER 40S.
SHORT TERM...TUESDAY THROUGH WEDNESDAY NIGHT...FORECAST
CONFIDENCE IS MEDIUM TO HIGH.
SHORT TERM MODELS CONTINUE TO SHOW UPPER LEVEL TROUGH SWINGING
SOUTHEAST THROUGH THE REGION TUESDAY THROUGH WEDNESDAY. APPEARS
BEST CHANCES FOR SHOWERS WILL BE TUESDAY AFTERNOON INTO TUESDAY
EVENING...WITH BEST DIFFERENTIAL CYCLONIC VORTICITY ADVECTION
PASSING THROUGH. CHANCES LOWER LATER TUESDAY NIGHT INTO
WEDNESDAY...WITH SECONDARY VORTICITY MAXIMUM PASSING THROUGH THE
AREA.
AREA FORECAST SOUNDINGS SHOWING STEEP LOW TO MID LEVEL LAPSE
RATES TUESDAY AS THE TROUGH MOVES INTO THE REGION. NAM MORE ROBUST
ON MEAN LAYER CAPES THAN GFS...UP TO 200 J/KG.
HOWEVER...INSTABILITY BARELY REACHING 10 DEGREE BELOW ZERO CELSIUS
ISOTHERM NEEDED FOR CONVECTION. WILL CONTINUE TO MENTION LOW
CHANCES FOR THUNDER TUESDAY AFTERNOON DESPITE MIXED CONFIDENCE IN
ITS OCCURRENCE.
CONTINUED LOWER END POPS TUESDAY NIGHT INTO WEDNESDAY...ESPECIALLY
IN THE EASTERN PORTIONS OF THE AREA. TEMPERATURES WILL BE NEAR TO
JUST BELOW SEASONAL NORMALS DURING THIS TIME...WITH A LAKE BREEZE
EXPECTED WEDNESDAY AFTERNOON. HIGH PRESSURE PASSING OVER THE AREA
WEDNESDAY NIGHT WILL BRING QUIET WEATHER AND COOL TEMPERATURES.
LONG TERM...THURSDAY THROUGH SUNDAY...FORECAST CONFIDENCE IS
MEDIUM.
ECMWF/GFS IN DECENT AGREEMENT DURING THIS PERIOD WITH FEATURES.
THEY SHOW UPPER RIDGING SHIFTING THROUGH THE REGION THURSDAY AND
THURSDAY NIGHT...WITH HIGH PRESSURE SLOWLY SLIDING SOUTHEAST OF
THE AREA. QUIET WEATHER IS EXPECTED TO CONTINUE...WITH
TEMPERATURES NEAR SEASONAL NORMALS.
GFS THEN BRINGS COLD FRONT SOUTHEAST THROUGH THE REGION QUICKER
THAN THE ECMWF...MAINLY FRIDAY AFTERNOON THROUGH FRIDAY EVENING.
ECMWF IS ABOUT 12 HOURS SLOWER WITH THIS FRONTAL PASSAGE.
VORTICITY MAXIMUM SLIDES THROUGH THE AREA WITH THE FRONT.
THUS...WENT WITH A CONSENSUS BLEND FOR POPS AND TEMPERATURES
FRIDAY THROUGH SATURDAY NIGHT.
MODELS THEN SHOW PASSING VORTICITY MAXIMA WITHIN WEST TO NORTHWEST
UPPER LEVEL FLOW. SOME DIFFERENCES WITH TIMING AND PLACEMENT OF
THESE FEATURES...SO WENT WITH CONSENSUS BLEND FOR POPS AND
TEMPERATURES DURING THIS PERIOD AS WELL.
AVIATION/12Z TAFS/...
EXPECT MVFR WITH SOME IFR/LIFR CIGS THIS MORNING. CEILINGS SHOULD
RISE TO VFR THIS AFTERNOON AS DRIER AIR MOVES IN BEHIND AN
OCCLUDED FRONT.
MARINE...
THE PERSISTENT EAST FLOW SHOULD BECOME NORTH THIS MORNING THEN
NORTHWEST TONIGHT. WINDS/WAVES WILL REMAIN BELOW SMALL CRAFT
CRITERIA.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...WIMBERLEY/DDV
TODAY/TONIGHT AND AVIATION/MARINE...HENTZ
TUESDAY THROUGH SUNDAY...WOOD