Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 05/08/12
AREA FORECAST DISCUSSION
NWS ALBANY NY
1040 PM EDT MON MAY 7 2012
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL MOVE NORTHEAST FROM THE OHIO VALLEY
TO THE EASTERN GREAT LAKES TONIGHT...LIFTING A WARM FRONT
TOWARDS OUR REGION. THE WARM FRONT AND ASSOCIATED LOW PRESSURE
SYSTEM ARE EXPECTED TO BRING A WIDESPREAD RAINFALL TO THE REGION
TONIGHT INTO TUESDAY EVENING WITH THE RAINFALL HEAVY AT TIMES FOR
NORTHERN PARTS OF THE AREA. SCATTERED SHOWERS AND COOL CONDITIONS
WILL PERSIST FOR WEDNESDAY AND THURSDAY...BEFORE HIGH PRESSURE
RETURNS MORE SUNSHINE AND SEASONABLE TEMPERATURES BACK IN TIME FOR
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
AS OF 1030 PM...LEADING EDGE OF THE RAIN-SHIELD WAS APPROACHING THE
HUDSON RIVER VALLEY. AT ITS CURRENT FORWARD RATE OF
PROGRESSION...EXPECTATION IS FOR THE RAIN TO IMPACT ADJACENT WESTERN
NEW ENGLAND COUNTIES /NORTH OF LITCHFIELD CT/ AROUND MIDNIGHT.
LATEST RAP AND HRRR HIRES MODELS CONTINUE TO SUGGEST A RAPID
INCREASE IN VERTICAL VELOCITIES AS THE LOW LEVEL JET AND ISENTROPIC
LIFT MAGNITUDES FURTHER ENHANCE PRECIP TOWARD MIDNIGHT ACROSS THE
CWFA. HAVE ADJUSTED HOURLY POPS/TEMPS/DEWPTS.
OTHERWISE...LOW PRESSURE IS CURRENTLY OVER WESTERN OHIO...AND WILL
BE SLOWLY MOVING TOWARDS THE EASTERN GREAT LAKES OVERNIGHT. A WARM
FRONT EXTENDING EASTWARD OUT OF THIS SFC LOW PRESSURE IS CURRENTLY
DRAPED ALONG THE I-80 CORRIDOR TOWARDS WESTERN PA...AND THIS WILL
BE LIFTING TOWARDS THE REGION. CLOUDS AHEAD OF THIS FRONT HAVE
ALREADY REACHED WESTERN AND SOUTHERN PARTS OF THE AREA...AND THESE
WILL BE INCREASING OVER THE NEXT SEVERAL HOURS FROM SOUTHWEST TO
NORTHEAST. STRONG ISENTROPIC LIFT...AIDED BY A POWERFUL LOW LEVEL
JET AT 850 HPA OF NEARLY 50 KTS...WILL ALLOW FOR A STEADY RAINFALL
TO BREAK OUT ACROSS THE AREA LATER THIS EVENING FROM SOUTHWEST TO
NORTHEAST. WITH THE SFC LOW SO FAR TO THE WEST OVERNIGHT...THE
BEST ISENTROPIC LIFT APPEARS TO BE FOCUSED OVER NORTHWESTERN PARTS
OF THE AREA. PWAT VALUES WERE ONLY 0.37 INCHES ON THIS MORNING/S
12 UTC KALY SOUNDING...BUT THEY RAPIDLY INCREASE TO NEARLY 1.25
INCHES BY LATE TONIGHT. WITH PLENTY OF MOISTURE ADVECTING IN ON
S-SW FLOW...THE RAINFALL WILL BE HEAVY AT TIMES LATE TONIGHT...ESP
IN SOUTHERLY FAVORED SLOPES OF THE HIGH TERRAIN OF THE
ADIRONDACKS.
WE HAVEN/T MENTIONED THUNDER AT THIS TIME...AS SFC INSTABILITY
WILL BE LIMITED BY A STRONG LOW LEVEL INVERSION. ELEVATED
INSTABILITY LOOKS MARGINAL...WITH SHOWALTER VALUES REMAINING ABOVE
ZERO. THIS LOW LEVEL INVERSION AND THE ABSENCE OF ANY CONVECTION
SHOULD PREVENT THOSE STRONG WINDS AT 850 HPA FROM MIXING
DOWN. HOWEVER...THE WIND BELOW THE INVERSION HEIGHT AT 1500-2000
FEET LOOKS STRONG ENOUGH FOR SOME GUSTS OF 30-40 MPH IN AREAS OF
CHANNELED FLOW.
MIN TEMPS TONIGHT LOOK TO RANGE FROM THE MID 40S TO THE LOW 50S
ACROSS THE AREA.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
STEADY RAINFALL WILL BE ONGOING THROUGH MUCH OF THE DAY
TUESDAY...WITH THE HEAVIEST RAINFALL GENERALLY IN THE MORNING
HOURS FOR THE NORTHERN HALF OF THE AREA. SEE OUR HYDRO SECTION FOR
HOW THIS RAINFALL WILL AFFECT THE RIVERS AND STREAMS OF THE
REGION. SOUTHERLY WINDS WILL CONTINUE TO BE STRONG FOR AREAS OF
CHANNELED FLOW /SUCH AS THE HUDSON VALLEY/...WITH SOME GUSTS TO
AROUND 30 MPH POSSIBLE...MAINLY IN THE MORNING HOURS. THE WINDS
WON/T BE LINED UP AS WELL FOR STRONG GUSTS BY LATER IN THE
DAY...AS THE WINDS ALOFT START TO SHIFT TO SW...WITH CONTINUED
SOUTHERLY WINDS AT THE SFC. WITH THE CLOUDS AND PRECIP ON
TUESDAY...TEMPS WON/T RISE MUCH...WITH MAX TEMPS IN THE MID 50S TO
MID 60S.
THE STORM/S COLD FRONT WILL BE MOVING THROUGH THE AREA ON TUESDAY
EVENING. THE 12 UTC NAM12 SHOWS SOME ELEVATED INSTABILITY...SO
HAVE INTRODUCED A SLIGHT CHC FOR THUNDERSTORMS ALONG WITH RAIN
SHOWERS FOR THE AREA. BEHIND THE STORM/S COLD FRONT...THE THREAT
FOR THUNDER WILL END AND MOST AREAS WILL START TO DRY OUT...BUT
WILL LINGER A CHC FOR RAIN SHOWERS OR SPRINKLES...ESP FOR UPSLOPE
FAVORED AREAS. MIN TEMPS ON TUESDAY NIGHT WILL RANGE FROM THE MID
40S TO MID 50S.
PLENTY OF CLOUDS WILL CONTINUE ACROSS THE AREA INTO WEDNESDAY.
HOWEVER...BROAD SW FLOW SHOULD ALLOW FOR TEMPS TO BE A LITTLE
WARMER...WITH MAX TEMPS RANGING FROM THE MID 60S TO MID 70S. SOME
SUN MAY BREAK OUT BY AFTN...BUT IT STILL WILL BE MOSTLY CLOUDY FOR
MUCH OF THE DAY. WILL CONTINUE A CHC FOR RAIN SHOWERS WITH A
SECONDARY COLD FRONT MOVING ACROSS THE AREA BY LATE IN THE DAY. WITH
THE UPPER TROUGH MOVING TOWARDS THE AREA...THIS WILL CONTINUE THE
THREAT FOR SOME SCT SHOWERS EVEN INTO WED NIGHT. MIN TEMPS WED NIGHT
WILL RANGE FROM THE UPPER 30S ACROSS THE CENTRAL ADIRONDACKS TO NEAR
50 FOR THE MID HUDSON VALLEY.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
TRENDS CONTINUE TO FAVOR A MORE EASTWARD ADJUSTMENT TO THE SURFACE
LOW AS UPPER TROUGH AMPLIFIES OVER THE GREAT LAKES REGION AND NEW
ENGLAND. THIS WILL KEEP THE PATTERN RATHER UNSETTLED AS THE
COMBINATION OF THE COLD POOL ALOFT AND CYCLONIC FLOW TO WARRANT THE
CHANCE POPS THURSDAY INTO FRIDAY.
RIDGE AXIS IS EXPECTED TO MOVE INTO THE REGION TO START THE WEEKEND
WITH MOCLR SKIES AND SEASONABLE TO SLIGHT ABOVE SEASONABLE
TEMPERATURES. OUR ADJACENT WESTERN NEW ENGLAND COUNTIES HAVE THE
POTENTIAL TO SEE A LITTLE ADDITIONAL CLOUD COVER AS THIS REGION
COULD BE IN CLOSER PROXIMITY TO THE DEPARTING UPPER LOW OVER THE
GULF OF MAINE.
LATER INTO THE WEEKEND...A SHORT WAVE IS FORECAST TO TRACK ALONG THE
U.S./CANADIAN BORDER AND APPROACH THE WESTERN GREAT LAKES REGION.
HOWEVER...THIS WILL INTERACT WITH THE STRONG DOWNSTREAM RIDGE AXIS
/OVER OUR REGION/ AND A DRIER ATMOSPHERIC PROFILE. EXPECTATIONS ARE
FOR THIS FRONTAL BOUNDARY TO EITHER WEAKEN OR REDUCE THE PRECIP
POTENTIAL FOR THE REGION. AT THIS TIME...WE WILL REDUCE POPS TO
SLIGHT CHANCE AND KEEP THOSE POPS INTO THE DACKS AND WESTERN MOHAWK
VALLEY.
OVERALL...TEMPS FOR THE LONG TERM PERIOD LOOK NEAR TO SLIGHTLY
ABOVE NORMAL...AND PCPN BELOW NORMAL.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AT 18Z/MONDAY...THE FIRST ISSUANCE OF KPSF (PITTSFIELD MA) TAF.
DETERIORATING CONDITIONS THIS EVENING AS CURRENT VFR CONDITIONS WILL
BECOME MVFR TOWARD 03Z WITH RAIN. THE CHANCE FOR IFR CONDITIONS
LOOKS LOW AT THE MOMENT BASED ON UPSTREAM OBSERVATIONS AND WE WILL
NOT INCLUDE IN THE TAFS AT THIS TIME. MORE OF A GROWING CONCERN IS
THE POTENTIAL FOR LLWS. NCEP MODEL SUITE SUGGESTS THE LOW LEVEL
JET INCREASES WITH 30-40KTS AOA 2K FEET OVERNIGHT INTO MOST OF THE
DAYLIGHT HOURS ON TUESDAY. HENCE...WE WILL NOW INCLUDE LLWS AT ALL
TAF SITES WITH LOW END MVFR CIGS.
.OUTLOOK...
TUE NT-THU...VFR-MVFR. CHC -SHRA.
THU NT-SAT...VFR. NO SIG WX.
&&
.FIRE WEATHER...
A WIDESPREAD SOAKING RAIN EVENT /WET FLAG CONDITIONS/ WILL TAKE
PLACE TONIGHT INTO TUESDAY EVENING...WITH LINGERING SHOWERS
POSSIBLE THROUGH AT LEAST THURSDAY. THESE CLOUDY AND DAMP CONDITIONS
WILL KEEP RH VALUES NEAR 100 PERCENT TONIGHT THROUGH WEDNESDAY
MORNING...WITH VALUES MAINLY OVER 50 PERCENT BY WEDNESDAY
AFTERNOON. SOUTHERLY WINDS WILL BE GUSTY AT TIMES...ESP LATE
TONIGHT INTO WEDNESDAY MORNING...WITH SOUTHERLY CHANNELED FAVORED
AREAS SEEING GUSTS UP OVER 30 MPH AT TIMES. WINDS WILL SWITCH TO A
WNW DIRECTION BY WEDNESDAY AFTERNOON AT 5-15 MPH.
&&
.HYDROLOGY...
LOW PRESSURE WILL MOVE FROM THE OHIO VALLEY TOWARDS THE EASTERN
GREAT LAKES TONIGHT INTO TOMORROW. THIS WILL ALLOW FOR A
WIDESPREAD RAIN EVENT ACROSS THE REGION...WITH THE HEAVIEST RAIN
IN NORTHERN PARTS OF THE AREA...ESP SOUTHERLY FAVORED SLOPES OF
THE SOUTHERN AND WESTERN ADIRONDACKS. QPF AMOUNTS RANGE FROM 0.75
INCHES ACROSS THE LOWER/MIDDLE HOUSATONIC VALLEY...TO NEARLY 2.00
INCHES ACROSS THE SRN/CENTRAL ADIRONDACKS. SIGNIFICANT IN BANK RISES
ARE EXPECTED ON RIVERS AND STREAMS. HOWEVER...WITH THE TREES AND
VEGETATION NEARLY FULLY ACTIVE...AND THE RELATIVELY DRY SPRING
HAVING KEPT RIVERS AND STREAMS LOW ENOUGH TO HANDLE SOME FLOW...NO
FLOODING ISSUES ARE EXPECTED AT THIS TIME.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS
NEAR TERM...FRUGIS/BGM
SHORT TERM...FRUGIS
LONG TERM...BGM
AVIATION...BGM
FIRE WEATHER...FRUGIS
HYDROLOGY...FRUGIS
FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS ALBANY NY
744 PM EDT MON MAY 7 2012
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL MOVE NORTHEAST FROM THE OHIO VALLEY
TO THE EASTERN GREAT LAKES TONIGHT...LIFTING A WARM FRONT
TOWARDS OUR REGION. THE WARM FRONT AND ASSOCIATED LOW PRESSURE
SYSTEM ARE EXPECTED TO BRING A WIDESPREAD RAINFALL TO THE REGION
TONIGHT INTO TUESDAY EVENING WITH THE RAINFALL HEAVY AT TIMES FOR
NORTHERN PARTS OF THE AREA. SCATTERED SHOWERS AND COOL CONDITIONS
WILL PERSIST FOR WEDNESDAY AND THURSDAY...BEFORE HIGH PRESSURE
RETURNS MORE SUNSHINE AND SEASONABLE TEMPERATURES BACK IN TIME FOR
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
AS OF 730 PM...LEADING EDGE OF THE RAIN-SHIELD WAS APPROACHING THE
CATSKILLS AND WESTERN MOHAWK VALLEY. AT ITS CURRENT FORWARD RATE
OF PROGRESSION...EXPECTATION IS FOR THE RAIN TO IMPACT THE CAPITAL
REGION AROUND 10 PM LOCAL TIME. LATEST RAP AND HRRR CONTINUE TO
SUGGEST A RAPID INCREASE IN VERTICAL VELOCITIES AS THE LOW LEVEL
JET AND ISENTROPIC LIFT MAGNITUDES TOWARD MIDNIGHT ACROSS EASTERN
NY. HAVE ADJUSTED TIMING OF THE POPS/WX AND HOURLY TEMPS.
OTHERWISE...LOW PRESSURE IS CURRENTLY OVER WESTERN OHIO...AND WILL
BE SLOWLY MOVING TOWARDS THE EASTERN GREAT LAKES OVERNIGHT. A WARM
FRONT EXTENDING EASTWARD OUT OF THIS SFC LOW PRESSURE IS CURRENTLY
DRAPED ALONG THE I-80 CORRIDOR TOWARDS WESTERN PA...AND THIS WILL
BE LIFTING TOWARDS THE REGION. CLOUDS AHEAD OF THIS FRONT HAVE
ALREADY REACHED WESTERN AND SOUTHERN PARTS OF THE AREA...AND THESE
WILL BE INCREASING OVER THE NEXT SEVERAL HOURS FROM SOUTHWEST TO
NORTHEAST. STRONG ISENTROPIC LIFT...AIDED BY A POWERFUL LOW LEVEL
JET AT 850 HPA OF NEARLY 50 KTS...WILL ALLOW FOR A STEADY RAINFALL
TO BREAK OUT ACROSS THE AREA LATER THIS EVENING FROM SOUTHWEST TO
NORTHEAST. WITH THE SFC LOW SO FAR TO THE WEST OVERNIGHT...THE
BEST ISENTROPIC LIFT APPEARS TO BE FOCUSED OVER NORTHWESTERN PARTS
OF THE AREA. PWAT VALUES WERE ONLY 0.37 INCHES ON THIS MORNING/S
12 UTC KALY SOUNDING...BUT THEY RAPIDLY INCREASE TO NEARLY 1.25
INCHES BY LATE TONIGHT. WITH PLENTY OF MOISTURE ADVECTING IN ON
S-SW FLOW...THE RAINFALL WILL BE HEAVY AT TIMES LATE TONIGHT...ESP
IN SOUTHERLY FAVORED SLOPES OF THE HIGH TERRAIN OF THE
ADIRONDACKS.
WE HAVEN/T MENTIONED THUNDER AT THIS TIME...AS SFC INSTABILITY
WILL BE LIMITED BY A STRONG LOW LEVEL INVERSION. ELEVATED
INSTABILITY LOOKS MARGINAL...WITH SHOWALTER VALUES REMAINING ABOVE
ZERO. THIS LOW LEVEL INVERSION AND THE ABSENCE OF ANY CONVECTION
SHOULD PREVENT THOSE STRONG WINDS AT 850 HPA FROM MIXING
DOWN. HOWEVER...THE WIND BELOW THE INVERSION HEIGHT AT 1500-2000
FEET LOOKS STRONG ENOUGH FOR SOME GUSTS OF 30-40 MPH IN AREAS OF
CHANNELED FLOW.
MIN TEMPS TONIGHT LOOK TO RANGE FROM THE MID 40S TO THE LOW 50S
ACROSS THE AREA.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
STEADY RAINFALL WILL BE ONGOING THROUGH MUCH OF THE DAY
TUESDAY...WITH THE HEAVIEST RAINFALL GENERALLY IN THE MORNING
HOURS FOR THE NORTHERN HALF OF THE AREA. SEE OUR HYDRO SECTION FOR
HOW THIS RAINFALL WILL AFFECT THE RIVERS AND STREAMS OF THE
REGION. SOUTHERLY WINDS WILL CONTINUE TO BE STRONG FOR AREAS OF
CHANNELED FLOW /SUCH AS THE HUDSON VALLEY/...WITH SOME GUSTS TO
AROUND 30 MPH POSSIBLE...MAINLY IN THE MORNING HOURS. THE WINDS
WON/T BE LINED UP AS WELL FOR STRONG GUSTS BY LATER IN THE
DAY...AS THE WINDS ALOFT START TO SHIFT TO SW...WITH CONTINUED
SOUTHERLY WINDS AT THE SFC. WITH THE CLOUDS AND PRECIP ON
TUESDAY...TEMPS WON/T RISE MUCH...WITH MAX TEMPS IN THE MID 50S TO
MID 60S.
THE STORM/S COLD FRONT WILL BE MOVING THROUGH THE AREA ON TUESDAY
EVENING. THE 12 UTC NAM12 SHOWS SOME ELEVATED INSTABILITY...SO
HAVE INTRODUCED A SLIGHT CHC FOR THUNDERSTORMS ALONG WITH RAIN
SHOWERS FOR THE AREA. BEHIND THE STORM/S COLD FRONT...THE THREAT
FOR THUNDER WILL END AND MOST AREAS WILL START TO DRY OUT...BUT
WILL LINGER A CHC FOR RAIN SHOWERS OR SPRINKLES...ESP FOR UPSLOPE
FAVORED AREAS. MIN TEMPS ON TUESDAY NIGHT WILL RANGE FROM THE MID
40S TO MID 50S.
PLENTY OF CLOUDS WILL CONTINUE ACROSS THE AREA INTO WEDNESDAY.
HOWEVER...BROAD SW FLOW SHOULD ALLOW FOR TEMPS TO BE A LITTLE
WARMER...WITH MAX TEMPS RANGING FROM THE MID 60S TO MID 70S. SOME
SUN MAY BREAK OUT BY AFTN...BUT IT STILL WILL BE MOSTLY CLOUDY FOR
MUCH OF THE DAY. WILL CONTINUE A CHC FOR RAIN SHOWERS WITH A
SECONDARY COLD FRONT MOVING ACROSS THE AREA BY LATE IN THE DAY.
WITH THE UPPER TROUGH MOVING TOWARDS THE AREA...THIS WILL CONTINUE THE
THREAT FOR SOME SCT SHOWERS EVEN INTO WED NIGHT. MIN TEMPS WED
NIGHT WILL RANGE FROM THE UPPER 30S ACROSS THE CENTRAL ADIRONDACKS
TO NEAR 50 FOR THE MID HUDSON VALLEY.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
TRENDS CONTINUE TO FAVOR A MORE EASTWARD ADJUSTMENT TO THE SURFACE
LOW AS UPPER TROUGH AMPLIFIES OVER THE GREAT LAKES REGION AND NEW
ENGLAND. THIS WILL KEEP THE PATTERN RATHER UNSETTLED AS THE
COMBINATION OF THE COLD POOL ALOFT AND CYCLONIC FLOW TO WARRANT THE
CHANCE POPS THURSDAY INTO FRIDAY.
RIDGE AXIS IS EXPECTED TO MOVE INTO THE REGION TO START THE WEEKEND
WITH MOCLR SKIES AND SEASONABLE TO SLIGHT ABOVE SEASONABLE
TEMPERATURES. OUR ADJACENT WESTERN NEW ENGLAND COUNTIES HAVE THE
POTENTIAL TO SEE A LITTLE ADDITIONAL CLOUD COVER AS THIS REGION
COULD BE IN CLOSER PROXIMITY TO THE DEPARTING UPPER LOW OVER THE
GULF OF MAINE.
LATER INTO THE WEEKEND...A SHORT WAVE IS FORECAST TO TRACK ALONG THE
U.S./CANADIAN BORDER AND APPROACH THE WESTERN GREAT LAKES REGION.
HOWEVER...THIS WILL INTERACT WITH THE STRONG DOWNSTREAM RIDGE AXIS
/OVER OUR REGION/ AND A DRIER ATMOSPHERIC PROFILE. EXPECTATIONS ARE
FOR THIS FRONTAL BOUNDARY TO EITHER WEAKEN OR REDUCE THE PRECIP
POTENTIAL FOR THE REGION. AT THIS TIME...WE WILL REDUCE POPS TO
SLIGHT CHANCE AND KEEP THOSE POPS INTO THE DACKS AND WESTERN MOHAWK
VALLEY.
OVERALL...TEMPS FOR THE LONG TERM PERIOD LOOK NEAR TO SLIGHTLY
ABOVE NORMAL...AND PCPN BELOW NORMAL.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AT 18Z/MONDAY...THE FIRST ISSUANCE OF KPSF (PITTSFIELD MA) TAF.
DETERIORATING CONDITIONS THIS EVENING AS CURRENT VFR CONDITIONS WILL
BECOME MVFR TOWARD 03Z WITH RAIN. THE CHANCE FOR IFR CONDITIONS
LOOKS LOW AT THE MOMENT BASED ON UPSTREAM OBSERVATIONS AND WE WILL
NOT INCLUDE IN THE TAFS AT THIS TIME. MORE OF A GROWING CONCERN IS
THE POTENTIAL FOR LLWS. NCEP MODEL SUITE SUGGESTS THE LOW LEVEL
JET INCREASES WITH 30-40KTS AOA 2K FEET OVERNIGHT INTO MOST OF THE
DAYLIGHT HOURS ON TUESDAY. HENCE...WE WILL NOW INCLUDE LLWS AT ALL
TAF SITES WITH LOW END MVFR CIGS.
.OUTLOOK...
TUE NT-THU...VFR-MVFR. CHC -SHRA.
THU NT-SAT...VFR. NO SIG WX.
&&
.FIRE WEATHER...
A WIDESPREAD SOAKING RAIN EVENT /WET FLAG CONDITIONS/ WILL TAKE
PLACE TONIGHT INTO TUESDAY EVENING...WITH LINGERING SHOWERS
POSSIBLE THROUGH AT LEAST THURSDAY. THESE CLOUDY AND DAMP CONDITIONS
WILL KEEP RH VALUES NEAR 100 PERCENT TONIGHT THROUGH WEDNESDAY
MORNING...WITH VALUES MAINLY OVER 50 PERCENT BY WEDNESDAY
AFTERNOON. SOUTHERLY WINDS WILL BE GUSTY AT TIMES...ESP LATE
TONIGHT INTO WEDNESDAY MORNING...WITH SOUTHERLY CHANNELED FAVORED
AREAS SEEING GUSTS UP OVER 30 MPH AT TIMES. WINDS WILL SWITCH TO A
WNW DIRECTION BY WEDNESDAY AFTERNOON AT 5-15 MPH.
&&
.HYDROLOGY...
LOW PRESSURE WILL MOVE FROM THE OHIO VALLEY TOWARDS THE EASTERN
GREAT LAKES TONIGHT INTO TOMORROW. THIS WILL ALLOW FOR A
WIDESPREAD RAIN EVENT ACROSS THE REGION...WITH THE HEAVIEST RAIN
IN NORTHERN PARTS OF THE AREA...ESP SOUTHERLY FAVORED SLOPES OF
THE SOUTHERN AND WESTERN ADIRONDACKS. QPF AMOUNTS RANGE FROM 0.75
INCHES ACROSS THE LOWER/MIDDLE HOUSATONIC VALLEY...TO NEARLY 2.00
INCHES ACROSS THE SRN/CENTRAL ADIRONDACKS. SIGNIFICANT IN BANK
RISES ARE EXPECTED ON RIVERS AND STREAMS. HOWEVER...WITH THE TREES AND
VEGETATION NEARLY FULLY ACTIVE...AND THE RELATIVELY DRY SPRING
HAVING KEPT RIVERS AND STREAMS LOW ENOUGH TO HANDLE SOME FLOW...NO
FLOODING ISSUES ARE EXPECTED AT THIS TIME.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS
NEAR TERM...FRUGIS/BGM
SHORT TERM...FRUGIS
LONG TERM...BGM
AVIATION...BGM
FIRE WEATHER...FRUGIS
HYDROLOGY...FRUGIS
FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1028 PM EDT MON MAY 7 2012
.SYNOPSIS...
HIGH PRESSURE WILL EXTEND SOUTH FROM OFF THE NEW ENGLAND COAST
THROUGH WEDNESDAY. A COLD FRONT WILL DISSIPATE SOUTH OF THE REGION
THROUGH TONIGHT. A COLD FRONT IS EXPECTED TO MOVE THROUGH FROM THE
WEST WEDNESDAY NIGHT FOLLOWED BY HIGH PRESSURE INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TUESDAY/...
NEARLY ALL OF THE PRECIPITATION HAS DISSIPATED ACROSS THE AREA.
CANNOT RULE OUT A FEW SHOWERS OVERNIGHT FROM ALONG THE SAVANNAH
RIVER AND POINTS SOUTH...BUT THINK THAT MOST LOCALS WILL STAY DRY
AS DEPICTED BY LATEST HRRR AND CHS WRF. LOW TEMPERATURES LOOK ON
TRACK AND ONLY MADE SOME MINOR ADJUSTMENTS TO HOURLY TEMPERATURES
THIS EVENING BASED ON CURRENT READINGS. WITH FAIRLY DEEP MOISTURE
IN PLACE...ESPECIALLY ACROSS GEORGIA ZONES...MAINTAINED QUITE A
BIT OF CLOUD COVER TONIGHT...ESPECIALLY ALONG AND SOUTH OF THE
SAVANNAH RIVER.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
HIGH PRESSURE NORTHEAST OF THE REGION WILL WEAKEN AND SHIFT
NORTHEAST ON TUESDAY. THE LOW-LEVEL FLOW WILL REMAIN ONSHORE OVER
SOUTHEAST GA...AND EVENTUALLY BECOME ONSHORE OVER SOUTHERN SC DURING
THE AFTERNOON. LOW-LEVEL INSTABILITY AND LIFTED INDICES WILL BE
GREATER ACROSS SOUTHEAST GA FOR MUCH OF THE DAY...ALONG WITH GREATER
PRECIPITABLE WATER CONTENT. SCATTERED SHOWERS AND THUNDERSTORMS ARE
AGAIN EXPECTED TO DEVELOP ON TUESDAY WITH THE GREATEST COVERAGE OVER
SOUTHEAST GA. WE MAINTAINED A SIMILAR POP SCHEME TO WHAT WE HAVE
TODAY DUE TO A RELATIVELY MINOR CHANGE IN PATTERN. HIGH TEMPS AGAIN
ONLY EXPECTED TO REACH THE LOWER 80S DUE TO EXTENSIVE LOW-LEVEL
CLOUDINESS.
BETTER COVERAGE OF SHOWERS AND THUNDERSTORMS IS EXPECTED WEDNESDAY
AS A COLD FRONT EVENTUALLY PUSHES THROUGH THE AREA. ALTHOUGH WE ARE
NOT SEEING MUCH IN THE WAY OF SHORTWAVE ENERGY MOVING THROUGH...
SOME UPPER JET COUPLING COMBINED WITH A JUICY LOW-LEVEL AIRMASS AND
COOLING TEMPS ALOFT WILL CREATE AN ENVIRONMENT MORE CONDUCIVE TO
CONVECTION. THE APPROACH OF THE COLD FRONT ITSELF WILL FURTHER
ENHANCE PRECIPITATION COVERAGE...SO WE HAVE POPS INCREASING INTO THE
LIKELY RANGE DURING THE AFTERNOON. THERE STILL LOOKS TO BE SOME
SEVERE WEATHER POTENTIAL GIVEN LIFTED INDICES DROPPING BELOW -4C AND
CAPES AROUND 1500 J/KG...ALONG WITH 20-25 M2/S2 OF 0-4 KM BULK
SHEAR. WILL DEFER TO THE OVERNIGHT SHIFT BEFORE ADDING TO THE
HAZARDOUS WEATHER OUTLOOK SINCE A NEW OUTLOOK WILL THEN BE AVAILABLE
FROM THE STORM PREDICTION CENTER.
THE FRONT SHOULD PUSH THROUGH WEDNESDAY NIGHT WITH DRYING WEATHER
FOR THURSDAY. DUE TO DOWNSLOPE FLOW...TEMPS ON THURSDAY WILL STILL
BE IN THE LOWER 80S.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
SURFACE HIGH PRESSURE TO DOMINATE THROUGH THE END OF THE WEEK...WITH
DRY CONDITIONS AND TEMPERATURES MAINLY BELOW NORMAL. THERE COULD BE
SOME SHOWERS SATURDAY PUSHING ASHORE AS THE HIGH TRANSITIONS OFF THE
MID ATLANTIC COAST BUT TOO EARLY TO INCLUDE MENTION. HAVE LOW RAIN
CHANCES FOR SUNDAY AS DEEPER MOISTURE LOOKS TO BEGIN MOVING IN AHEAD
OF A COLD FRONT TO THE WEST AND POSSIBLE LOW PRESSURE IN THE GULF OF
MEXICO.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
TOUGH FORECAST FOR KCHS AND ESPECIALLY KSAV OVERNIGHT AND INTO
EARLY TUESDAY MORNING.
FOR KSAV...ALREADY HAD A BRIEF PERIOD OF MVFR CIGS THIS EVENING
AND EVEN THOUGH THE LOW CEILINGS HAVE SCATTERED OUT FOR THE TIME
BEING...NEARBY OBSERVATIONS OF MVFR CIGS AND MODEL DATA SHOWING
DEEP MOISTURE IN PLACE WITH AN ONSHORE FLOW LIKELY TO RESULT IN
PERIODS OF MVFR CIGS OFF AND ON ALL NIGHT AND INTO TUESDAY
MORNING. THE MOST LIKELY PERIOD OF MVFR CIGS AS WELL AS SOME MVFR
VSBY AT KSAV WILL BE FROM ABOUT 09Z THROUGH 13Z. CANNOT RULE OUT
IFR CIGS...BUT AT THIS TIME DO NOT HAVE ENOUGH CONFIDENCE IN THIS
OCCURRING TO INCLUDE IT IN THE FORECAST. IT IS ALSO POSSIBLE THAT
THE THREAT FOR MVFR CIGS COULD LAST UNTIL 14 OR PERHAPS EVEN
15Z...ALTHOUGH AT THE PRESENT TIME THE CHANCES OF THIS OCCURRING
SEEM QUITE LOW.
FOR KCHS...FEEL THAT VFR CONDITIONS WILL PREVAIL THROUGH 00Z
WEDNESDAY. HOWEVER...THERE IS SOME POTENTIAL FOR MVFR CIGS MAINLY LATE
TONIGHT/EARLY TUESDAY. IF SKIES WERE TO BECOME CLEAR OR PARTLY
CLOUDY FOR A TIME TONIGHT THERE WOULD ALSO BE A THREAT FOR SOME
MVFR VSBYS. AT THE PRESENT TIME FEEL THE CHANCE OF EITHER OF THIS
OCCURRING IS TOO LOW TO INCLUDE IN THE FORECAST.
EXTENDED AVIATION OUTLOOK...MVFR CONDS POSSIBLE EARLY TUE/WED DUE
TO LOW CLOUDS/FOG. GOOD POSSIBILITY OF SHOWERS/THUNDERSTORMS BY
WEDNESDAY AFTERNOON INTO THE EARLY EVENING IN ASSOCIATION WITH A
COLD FRONT.
&&
.MARINE...
EVEN THOUGH THERE WAS A SURGE IN WINDS ACROSS SOME OF THE SOUTH
CAROLINA WATERS EARLIER THIS EVENING...THE WINDS HAVE BACKED OFF
SOME AND WIND AND SEAS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT
ADVISORY THRESHOLDS THROUGH THE NIGHT. MODERATE ONSHORE WINDS
WILL PERSIST TONIGHT. SEAS WILL RANGE 2-4 NEARSHORE WATERS AND
4-5 FT OFFSHORE WATERS.
TUESDAY THROUGH SATURDAY...ATLANTIC HIGH PRESSURE THROUGH WEDNESDAY
WITH A COLD FRONT TO PUSH THROUGH WEDNESDAY NIGHT. HIGH PRESSURE IS
THEN EXPECTED THROUGH THE END OF THE WEEK. ALTHOUGH THERE WILL BE A
SURGE IN WINDS ASSOCIATED WITH THE FRONT...CONDITIONS ARE EXPECTED
TO REMAIN BELOW ADVISORY LEVELS THROUGH THE PERIOD.
&&
.TIDES/COASTAL FLOODING...
LATE THIS EVENING TIDES ARE MAXING OUT NEAR 8.0 FEET AT CHARLESTON
AND AROUND 9.9 FEET AT FORT PULASKI. WILL CONTINUE WITH THE
COASTAL FLOOD WARNING UNTIL 2 AM...ALTHOUGH THE WARNING WILL
LIKELY BE ABLE TO BE DROPPED EARLY. PLEASE SEE THE LOCAL STORM
REPORTS FOR FLOODING IMPACTS FROM THE HIGH TIDES THIS EVENING.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...COASTAL FLOOD WARNING UNTIL 2 AM EDT TUESDAY FOR GAZ117-119-
139-141.
SC...COASTAL FLOOD WARNING UNTIL 2 AM EDT TUESDAY FOR SCZ048>052.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...MTE
SHORT TERM...JRL
LONG TERM...JRL/RJB
AVIATION...MTE
MARINE...JRL/MTE
TIDES/COASTAL FLOODING...MTE
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
1000 PM EDT MON MAY 7 2012
.UPDATE...
THE MAJORITY OF THE CONVECTIVE DEVELOPMENT HAS BEEN WANING ACROSS
THE FORECAST AREA TONIGHT... THOUGH THERE STILL HAS BEEN LINGERING
SHOWERS AND STORMS ALONG SOME CONVERGING OUTFLOW BOUNDARIES SOUTH
OF KFFC. HRRR STILL HOLDS ON TO SOME REDEVELOPMENT IN THE NORTH AFTER
06Z LIKELY DUE TO THE INFLUENCE OF AN UPPER LEVEL SHORTWAVE AHEAD
OF THE COLD FRONTAL PASSAGE. WILL NEED TO MONITOR THIS ON THE
OVERNIGHT. KEPT CHANCE POPS OVERNIGHT FOR MOST AREAS WITH LIKELY
POPS STARTING IN THE NORTHWEST DURING THE EARLY MORNING HOURS.
ALSO RAISED POPS EARLY WEDNESDAY MORNING BASED ON PROGGED
POSITIONING OF THE COLD FRONT SUGGESTED BY MAJORITY OF GUIDANCE.
TWEAKED WINDS SOME TO VEER A BIT EARLIER OUT OF THE SOUTHWEST
AHEAD OF THE FRONT. ALL ELSE SEEMED TO BE ON TRACK.
03
&&
.PREV DISCUSSION...
SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
/ISSUED 350 PM EDT MON MAY 7 2012/
AREA OF SHOWERS THAT DEVELOPED OVER EASTERN GEORGIA HAS DEVELOPED
INTO A LINE BETWEEN ATL AND AHN...STRETCHING SOUTHWARD AND EAST OF
MCN. CLOUD COVERAGE HAS HELPED TO LIMIT INSTABILITY ACROSS THAT AREA
BUT WITH SOME BREAKS IN THE CLOUDS...HAVE STARTED TO SEE INCREASED
THUNDER. AS THIS AREA DRIFTS TOWARD THE EAST...THE WESTERN HALF OF
THE CWA SHOULD BECOME MORE ACTIVE EARLY THIS EVENING AND CAN ALREADY
SEE SOME CELLS DEVELOPING ACROSS THAT AREA. THE WESTERN HALF OF THE
CWA WOULD ALSO BE THE FOCUS FOR THE STRONGER STORMS AS SLIGHTLY
LESSER CLOUD COVERAGE HAS ALLOWED FOR GREATER DESTABILIZATION.
OVERNIGHT...THE FOCUS WILL SHIFT TO THE NORTHWEST AS A SHORTWAVE
MOVES INTO NORTHWEST GEORGIA. BEFORE THIS SHIFTS ACROSS THE
MOUNTAINS AND WASHES OUT THOUGH IT WILL HELP TO ENHANCE THE CHANCE
OF PRECIPITATION ACROSS THE NORTH TONIGHT. FRONT MOVES INTO
NORTHWEST GEORGIA ON TUESDAY AND THIS WILL HELP TO ONCE AGAIN KEEP
THE FOCUS OF ACTIVITY ACROSS NORTH GEORGIA. WITH DECENT
INSTABILITY...MU CAPE VALUES OF 2000 J/KG...BUT WEAK SHEAR /BOTH 0-1
AND 0-6KM/...MAIN THREAT WITH STORMS WOULD BE DAMAGING WIND AND
HAIL. CANT RULE OUT A FEW SEVERE STORMS ON TUESDAY...BUT AT THIS
POINT NOT EXPECTING A WIDESPREAD SEVERE EVENT. FRONT WILL WEAKEN
OVERNIGHT ON TUESDAY AS IT DRIFTS INTO CENTRAL GEORGIA SO HAVE
SHOWED TREND OF DECREASING POPS.
MAX TEMPS ON TUESDAY ARE ON THE LOWER SIDE OF GUIDANCE DUE TO
EXPECTED CLOUD COVERAGE...OTHERWISE TEMPS ARE CLOSE TO GUIDANCE.
LONG TERM /WEDNESDAY THROUGH MONDAY/...
LATEST ROUND OF EXTENDED RANGE GUIDANCE INDICATES CONTINUED GOOD
AGREEMENT IN TIMING OF NEXT FRONTAL SYSTEM WITH THE GFS JUST
SLIGHTLY FASTER ALTHOUGH WX EFFECTS ARE NEGLIGIBLE. CONTINUED
THUNDERSTORM CHANCES INTO WEDNESDAY ALTHOUGH INSTABILITY AXIS RACES
EAST AHEAD OF FRONT AND OVERALL INSTABILITY LOOKS LESS THAN THAT
ON TUESDAY. CONTINUED LIMITED SHEAR PROFILE AND EXPECTED MAINLY
HAIL AND ISOLATED WIND THREAT.
HIGH PRESSURE AND A DRY FORECAST LOOK TO BE ON TAP BEHIND THE
FRONT THURSDAY THROUGH SATURDAY. THOUGH...BOTH GFS AD ECMWF SHOW
SOME INCREASE IN DEEPER MOISTURE SATURDAY NIGHT INTO SUNDAY AS A
WEAK LOW PRESSURE SYSTEM LIFTS NORTHEAST FROM THE GULF AND A COLD
FRONT DRIFTS SOUTHWARD FROM THE OH/TN VALLEY REGION. WILL KEEP
SATURDAY NIGHT DRY FOR NOW...BUT HAVE INTRODUCED SLIGHT CHANCE
POPS FOR MUCH OF THE AREA SUNDAY WITH THESE FEATURES POSSIBLY
BEGINNING TO AFFECT THE STATE.
COOLER BEHIND THE FRONT WITH MODELS ADVERTISING TEMPS BACK TO
MORE NORMAL LEVELS.
DEESE
&&
.AVIATION...
00Z UPDATE...
MOSTLY MVFR TO VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. CONVECTIVE
ACTIVITY HAS BEEN LINGERING AROUND THE MAJORITY OF THE TAF SITES
THIS EVENING SO HAVE MAINTAINED VCSH MENTION AND TEMPO GROUP FOR
TSRA UNTIL 02Z... WHILE KEEPING KAHN DRY UNTIL LATER TUESDAY.
LIGHT WINDS AND LOW LEVEL MOISTURE WILL AGAIN BRING THE CHANCE FOR
SOME PATCHY FOG IN THE EARLY MORNING HOURS AND CIGS LOOK TO LOWER
TO NEAR 0VC010 AFTER 08Z. SOUTHEASTERLY WINDS SHOULD VEER TO
SOUTHWESTERLY BY ABOUT 13Z AND REMAIN LESS THAN 10KTS. BETTER
CHANCE FOR TSRA WILL RETURN BY 18Z WITH FRONT APPROACHING SO
INCLUDED PROB30. GUSTS UP TO 18KTS ARE POSSIBLE NEAR KATL BY 18Z
ALSO.
//ATL CONFIDENCE...00Z UPDATE...
MEDIUM CONFIDENCE ON PRECIPITATION TIMING.
HIGH CONFIDENCE ON ALL ELSE.
03
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 63 79 63 83 / 30 60 50 60
ATLANTA 64 80 65 81 / 40 60 50 60
BLAIRSVILLE 61 75 59 74 / 60 60 60 70
CARTERSVILLE 64 80 60 79 / 50 60 50 70
COLUMBUS 66 86 67 86 / 40 60 50 60
GAINESVILLE 62 77 62 80 / 50 60 60 70
MACON 62 84 64 87 / 20 50 50 60
ROME 64 82 61 79 / 60 60 50 60
PEACHTREE CITY 62 81 62 81 / 40 60 50 60
VIDALIA 66 87 67 89 / 20 50 50 60
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...FIEUX/03
LONG TERM....DEESE
AVIATION...03
AREA FORECAST DISCUSSION
NWS LINCOLN IL
833 PM CDT MON MAY 7 2012
.DISCUSSION...
ISSUED 826 PM CDT MON MAY 7 2012
COLD FRONT HAS SHIFTED SOUTH OF THE FORECAST AREA EARLY THIS
EVENING WITH ONLY A FEW SHOWERS LEFT BEHIND OVER FAR SOUTHEAST IL.
HIGH PRESSURE ACRS THE PLAINS WILL SHIFT EAST INTO THE MIDWEST
OVERNIGHT BRINGING DRIER AIR EAST WITH IT. DEW POINTS ALREADY
HAVE DROPPED INTO THE UPPER 40S OVER PARTS OF WEST CENTRAL IL AND
EXPECT THAT TREND TO WORK ITS WAY EAST OVER THE REMAINDER OF THE
FORECAST AREA TONIGHT. THE DRIER AIR WILL NOT ARRIVE INTO THE
EAST UNTIL THE PRE-DAWN HOURS SO THE COMBINATION OF CLEARING
SKIES AND ABUNDANT LOW LEVEL MOISTURE LEFT OVER FROM THE RAINFALL
OF THE PAST SEVERAL DAYS WILL LEAD TO SOME PATCHY FOG MAINLY
EAST OF I-55. THE LAST FEW RUNS OF THE 3KM HRRR MODEL SUGGEST
AREAS ALONG AND EAST OF I-57 HAVE THE BETTER CHANCE OF SEEING
SOME FOG LATE TONIGHT SO WILL INCLUDE IN THE OVERNIGHT HOURS.
OTHERWISE...OTHER THAN THE USUAL ADJUSTMENTS IN THE EARLY EVE
TEMPERATURE TRENDS...THE REST OF THE FORECAST IS IN GOOD SHAPE.
SMITH
&&
.AVIATION...
ISSUED 625 PM CDT MON MAY 7 2012
VFR CONDITIONS WILL OVERSPREAD THE ENTIRE AREA THIS EVENING. BAND
OF MVFR CIGS WITH SOME LOCAL IFR WILL GRADUALLY SHIFT TO THE EAST
AND SOUTH OVER THE NEXT SEVERAL HOURS AS HIGH PRESSURE STARTS TO
BUILD IN FROM THE NORTHWEST. THE BETTER COVERAGE OF SHOWERS AND
THUNDERSTORMS HAS CONTINUED TO SHIFT WELL OFF TO THE EAST AND
SOUTH OF THE TAF SITES EARLY THIS EVENING. ONCE CMI CLEARS OUT
BY 05Z...WE SHOULD SEE VFR CONDITIONS CONTINUE THRU THE REMAINDER
OF THE FORECAST PERIOD. SFC WINDS WILL BE OUT OF THE NORTHWEST
AT 5 TO 10 KTS TONIGHT...AND NORTHWEST AT 10 TO 15 KTS ON TUESDAY.
SMITH
&&
.PREV DISCUSSION...
ISSUED 241 PM CDT MON MAY 7 2012
AFTER THE RECENT STRETCH OF ACTIVE WEATHER...A COOLER/DRIER
PATTERN WILL TAKE HOLD THROUGH THE REST OF THE WEEK.
SHORT TERM...TONIGHT THROUGH THURSDAY
SLOW-MOVING COLD FRONT CURRENTLY ALONG THE I-70 CORRIDOR WILL
SAG SOUTHWARD THIS EVENING...POTENTIALLY TRIGGERING A FEW SHOWERS
AND THUNDERSTORMS ACROSS THE E/SE KILX CWA. 18Z MESO-ANALYSIS SHOWS
MUCAPE VALUES OF 1500 TO 2000J/KG ACROSS SOUTHEAST ILLINOIS...WITH
EVEN HIGHER INSTABILITY PARAMETERS NOTED FURTHER EAST INTO THE OHIO
RIVER VALLEY. DESPITE DECENT INSTABILITY AND PRESENCE OF FORCING
MECHANISM...0-6KM BULK SHEAR REMAINS VERY WEAK. AS A RESULT...AM
ONLY EXPECTING SCATTERED THUNDERSTORM DEVELOPMENT ALONG/AHEAD OF
THE FRONT LATE THIS AFTERNOON INTO THE EVENING. WILL CARRY LOW
CHANCE POPS ALONG AND SOUTHEAST OF A CHAMPAIGN TO SHELBYVILLE LINE
THROUGH MIDNIGHT...THEN WILL GO DRY EVERYWHERE AFTER MIDNIGHT AS
THE BOUNDARY SINKS SOUTH OF THE OHIO RIVER. SKIES WILL INITIALLY
BE MOSTLY CLOUDY...BUT WILL GRADUALLY CLEAR FROM NORTHWEST TO
SOUTHEAST. OVERNIGHT LOWS WILL MAINLY BE IN THE LOWER TO MIDDLE
50S...BUT WILL REMAIN NEAR THE 60 DEGREE MARK ACROSS THE
CLOUD-COVERED FAR SE CWA.
CLOSED UPPER LOW CURRENTLY SPINNING OVER SOUTHERN MANITOBA WILL
WEAKEN INTO AN OPEN WAVE AS IT TRACKS E/SE INTO THE GREAT LAKES
OVER THE NEXT 24 TO 36 HOURS. AHEAD OF THIS FEATURE...MOSTLY SUNNY
AND WARM CONDITIONS WILL PREVAIL ON TUESDAY...WITH HIGHS REACHING
THE LOWER TO MIDDLE 70S. MAY SEE SOME INCREASE IN CLOUDINESS
ACROSS THE FAR NORTH LATE IN THE DAY...BUT ALL IN ALL...SHOULD BE
A MOSTLY SUNNY DAY. ALL MODELS TAKE WAVE INTO THE EASTERN GREAT
LAKES/OHIO RIVER VALLEY BY WEDNESDAY EVENING...WITH A FEW
SOLUTIONS HINTING AT SOME DIURNAL SHOWERS WEDNESDAY AFTERNOON. GFS
SEEMS TO BE THE MOST AGGRESSIVE WITH PRECIP ACROSS NEARLY THE
ENTIRE AREA...WHILE NAM IS COMPLETELY DRY. DESPITE WEAKENING
NATURE OF SYSTEM AND LACK OF DEEP MOISTURE...CYCLONIC FLOW ALOFT
AND MODERATELY STEEP LAPSE RATES WILL YIELD PARTLY SUNNY SKIES
ACROSS THE E/NE CWA...WITH PERHAPS A FEW ISOLATED SHOWERS. FURTHER
WEST...MOSTLY SUNNY AND DRY CONDITIONS WILL PERSIST.
UPPER WAVE WILL SHIFT TOWARD NEW ENGLAND ON THURSDAY...AS UPPER
RIDGING BEGINS TO BUILD INTO THE REGION FROM THE WEST. THANKS TO
RISING UPPER HEIGHTS AND THE PRESENCE OF SURFACE HIGH
PRESSURE...ABUNDANT SUNSHINE AND TEMPS IN THE 70S WILL BE THE RULE
FOR THURSDAY.
LONG TERM...FRIDAY THROUGH MONDAY
UPPER RIDGE WILL BUILD INTO THE MIDWEST FOR FRIDAY AND
SATURDAY...ENSURING THE CONTINUATION OF WARM AND DRY WEATHER INTO
THE FIRST HALF OF THE WEEKEND. STILL SOME MODEL DISAGREEMENT ON
HOW FAST RIDGE BREAKS DOWN AND NEXT COLD FRONT APPROACHES...WITH
THE GFS BEING FASTER THAN THE ECMWF. RECENT TREND HAS BEEN TO SLOW
THIS PROCESS...SO WILL TREND TOWARD THE ECMWF FOR THE WEEKEND
FORECAST. AS SUCH...WILL ONLY MENTION A LOW CHANCE POP ACROSS THE
FAR NORTH ON SATURDAY...WITH WARM AND DRY WEATHER ELSEWHERE AROUND
CENTRAL AND SOUTHEAST ILLINOIS. AFTER THAT...FRONT WILL SLOWLY
SETTLE SOUTHWARD...BRINGING A CHANCE FOR SCATTERED SHOWERS/STORMS
FOR SATURDAY NIGHT AND SUNDAY. RAIN CHANCES MAY EVEN LINGER INTO
MONDAY IF ECMWF VERIFIES...BUT HAVE MAINTAINED A DRY FORECAST FOR
MONDAY AT THIS TIME...UNTIL BETTER MODEL AGREEMENT IS ACHIEVED.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1222 PM CDT SUN MAY 6 2012
.DISCUSSION...
ISSUED 1030 AM CDT SUN MAY 6 2012
10 AM SFC MAP PLACED A NORTHWARD MOVING WARM FRONT JUST SOUTH OF
I-74. SOUTH OF THE BOUNDARY SOUTHERLY WINDS WERE TRANSPORTING LOW 70S
DEWPOINTS INTO CENTRAL IL. COMBINATION OF VERY WARM/HUMID BOUNDARY
LAYER AND STEEP LAPSE RATES/COOL AIR ALOFT WILL LEAD TO A VERY
UNSTABLE AIRMASS THIS AFTERNOON WITH SURFACE BASED CAPES IN EXCESS
OF 4K J/KG ACROSS THE WESTERN THIRD OF THE CWA. ONE POSSIBLE
MITIGATING FACTOR FOR SEVERE STORMS AT LEAST THROUGH MID AFTERNOON
WILL BE INITIALLY VERY WEAK WIND FIELDS ALOFT. DEEP LAYER SHEAR
SHOULD INCREASE LATE THIS AFTERNOON AND EVENING BASED ON FORECAST
SOUNDINGS...AHEAD OF A SHORT WAVE AND COLD FRONT TO OUR WEST.
THROUGH MID AFTERNOON WILL WATCH FOR CONVECTION AHEAD OF A
WEAKENING THUNDERSTORM COMPLEX MOVING INTO SE IA...AND ALSO ANY
DEVELOPMENT ACROSS THE NRN CWA ALONG AND AHEAD OF THE NORTHWARD
MOVING WARM FRONT. STILL APPEARS BEST TIMEFRAME FOR SEVERE STORMS
WILL BE AFTER 6 PM IN THE WEST. VERY WARM AND HUMID AFTERNOON ON
TAP WITH HIGHS NEAR 90 IN THE FAR SW.
&&
.AVIATION...
ISSUED 1222 PM CDT SUN MAY 6 2012
TIMING OF CONVECTION DIFFICULT TO PIN DOWN AT THIS POINT...BUT
FROM LATE THIS AFTERNOON THROUGH THE REMAINDER OF THIS TAF CYCLE
PERIODIC STORMS WILL ROAM THE AREA. CURRENT THINKING HAS INITIAL
ROUND OF STORMS DEVELOPING OVER WESTERN IL LATE THIS AFTERNOON
ALONG REMNANT OUTFLOW BOUNDARY AND SLOWLY TRACKING EAST/SOUTHEAST
THIS EVENING. ADDITIONAL STORMS SHOULD FORM ALONG A COLD FRONT
CURRENTLY IN IA/MO...WHICH WOULD AFFECT US DURING THE OVERNIGHT
HOURS. STORMS MAY CONTINUE INTO MONDAY MORNING AS THE FRONT SLOWLY
PUSHES ACROSS THE STATE. NOT TOO CONFIDENT IN ANY PARTICULAR
TIMEFRAME FOR STORMS TO IMPACT A PARTICULAR TAF SITE SO LEFT VCTS
FOR NOW. WARM FRONT HAS PUSHED NORTH OF THE AREA THIS
AFTERNOON...SO SOUTHERLY WINDS WILL CONTINUE INTO EARLY EVENING.
AROUND 00Z WINDS WILL BECOME LIGHTER AND BACK MORE TO THE ESE
AHEAD OF THE SURFACE LOW WHICH WILL BE SHIFTING INTO MO. ANOTHER
WIND SHIFT TO THE NORTHWEST IS EXPECTED FROM 10-14Z MONDAY AS THE
COLD FRONT PUSHES THROUGH THE STATE.
25
&&
.PREV DISCUSSION...
ISSUED 257 AM CDT SUN MAY 6 2012
FRONTAL BOUNDARY HAS NOT REALLY MOVED OVER THE LAST SEVERAL
HOURS...EXTENDING FROM NORTHWEST IOWA TO NEAR SPRINGFIELD AND
SOUTHEAST INTO SOUTH CENTRAL INDIANA. DEW POINTS IN THE 65-70F
RANGE WERE POOLING ALONG THIS BOUNDARY. SOME LIGHT FOG WAS
OBSERVED NORTH OF THE FRONT WITH VISIBILITIES OF 3-5 MILES. LARGE
MCS STRETCHING FROM CENTRAL MINNESOTA INTO NORTHERN NEBRASKA HAS
PUSHED INTO FAR NORTHWEST IOWA.
SEVERE WEATHER POTENTIAL THROUGH MONDAY REMAINS THE PRIMARY
FORECAST CONCERN.
SHORT TERM...TODAY THROUGH MONDAY...
NORTHWARD SPREAD OF THE WARM SECTOR MAY BE TEMPERED BY THE
INFLUENCES OF THE MCS DEBRIS...BUT SHOULD GET FAR ENOUGH NORTH TO
CLEAR OUR NORTHERN CWA TOWARD MIDDAY. INSTABILITY SHOULD NOT BE A
PROBLEM AS CAPES APPROACH 3000 J/KG BY MIDDAY AND CONVECTIVE
INHIBITION VALUES WANE. TIMING OF THE CONVECTION IS THE TRICKY
PART...WITH THE HRRR LEANING TOWARD EARLY AFTERNOON DEVELOPMENT
WEST OF THE MISSISSIPPI RIVER...AND THE NAM AND LOCAL WRF MODELS
FROM ST LOUIS AND CHICAGO NWS OFFICES BRINGING SOME OF THE MCS
REMNANTS INTO THE NORTHERN CWA LATE THIS MORNING. ATTENDANT COLD
FRONT IS LIKELY TO MOVE INTO THE NORTHWEST CWA EARLY THIS
EVENING...CONTINUING THE STORM THREAT OVERNIGHT. MOST OF THE CWA
REMAINS IN A SLIGHT RISK OF SEVERE WEATHER...EXCEPT EAST OF
I-57...WHERE SEVERE THREAT MAY BE VERY LATE TONIGHT OR MONDAY
MORNING INSTEAD. HAVE CONTINUED WITH RAIN CHANCES MAINLY WEST OF
I-55 THIS AFTERNOON...AND OVERSPREADING THE REMAINDER OF THE CWA
THIS EVENING. HEAVIEST RAIN THREAT LOOKS TO BE JUST TO OUR
NORTH...BUT WILL NEED TO WATCH THE FAR NORTHERN CWA WHICH HAD 1-3
INCHES OF RAIN THURSDAY NIGHT AND FRIDAY MORNING FOR ANY POTENTIAL
HYDROLOGICAL CONCERNS. TIMING OF FRONTAL PASSAGE ON MONDAY SHOULD
BE EARLY AFTERNOON ACROSS THE EASTERN CWA...AND HAVE KEPT LIKELY
POPS GOING IN THAT AREA DURING THE DAY...DIMINISHING IN THE
EVENING.
TEMPERATURE-WISE...WILL LIKELY SEE HIGHS DEEP INTO THE 80S OVER
THE ENTIRE FORECAST AREA...POTENTIALLY NUDGING 90 ACROSS THE
SOUTHWEST CWA. MOST RECORDS TODAY ARE IN THE LOWER 90S AND LIKELY
JUST OUT OF REACH...ALTHOUGH SPRINGFIELD HAS A RECORD HIGH OF 88
WHICH IS IN JEOPARDY. WILL PROBABLY SEE SOME 80 DEGREE READINGS
AGAIN ACROSS THE SOUTHEAST ON MONDAY AHEAD OF THE FRONT...BUT THAT
WILL BE THE LAST OF THE 80S ACROSS OUR CWA FOR THE REMAINDER OF
THE WEEK.
LONG TERM...TUESDAY THROUGH SATURDAY...
A MUCH COOLER AND QUIETER REGIME SETS UP THE REMAINDER OF THE
WEEK. AN UPPER LOW...CURRENTLY LOCATED OVER FAR NORTH CENTRAL
MONTANA PER WATER VAPOR IMAGERY...SHOULD MOVE TO NEAR LAKE
SUPERIOR BY TUESDAY MORNING. ASSOCIATED SURFACE AND UPPER TROUGH
WILL SWING THROUGH THE GREAT LAKES TUESDAY AND WEDNESDAY...WITH
THE COLDER AIR ALOFT HELPING TO TRIGGER A FEW SHOWERS. STILL LOOKS
LIKE THE BEST SUPPORT FOR THIS WILL BE FURTHER TO OUR NORTH...BUT
HAVE INCLUDED SOME SLIGHT CHANCES ACROSS THE NORTHEAST CWA ON
WEDNESDAY AS THE TROUGH FULLY PUSHES THROUGH THE STATE.
UPPER RIDGING ACROSS THE ROCKIES AT MIDWEEK WILL RESULT IN A
NORTHWEST FLOW...AND BELOW NORMAL TEMPERATURES...FOR A COUPLE
DAYS IN OUR AREA. LONGER RANGE MODELS SHOWING THE RIDGING PUSHING
EASTWARD LATE IN THE WEEK...WITH A BIT OF MODERATION IN
TEMPERATURES. SURFACE HIGH PRESSURE OVER THE MIDWEST TO PROVIDE
FAIR WEATHER FOR THURSDAY AND FRIDAY...AHEAD OF A SHORTWAVE WHICH
WILL PUSH ACROSS THE NORTHERN STATES LATE IN THE WEEK. MOISTURE
RETURN IN OUR AREA WILL BE MEAGER AHEAD OF THIS SYSTEM...SO RAIN
CHANCES ARE NOT ESPECIALLY HIGH AT THIS TIME. HOWEVER...THE
NORTHWEST CWA SHOULD SEE A FEW SHOWERS AND THUNDERSTORMS BY
SATURDAY AFTERNOON.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1030 AM CDT SUN MAY 6 2012
.DISCUSSION...
ISSUED 1030 AM CDT SUN MAY 6 2012
10 AM SFC MAP PLACED A NORTHWARD MOVING WARM FRONT JUST SOUTH OF
I-74. SOUTH OF THE BOUNDARY SOUTHERLY WINDS WERE TRANSPORTING LOW 70S
DEWPOINTS INTO CENTRAL IL. COMBINATION OF VERY WARM/HUMID BOUNDARY
LAYER AND STEEP LAPSE RATES/COOL AIR ALOFT WILL LEAD TO A VERY
UNSTABLE AIRMASS THIS AFTERNOON WITH SURFACE BASED CAPES IN EXCESS
OF 4K J/KG ACROSS THE WESTERN THIRD OF THE CWA. ONE POSSIBLE
MITIGATING FACTOR FOR SEVERE STORMS AT LEAST THROUGH MID AFTERNOON
WILL BE INITIALLY VERY WEAK WIND FIELDS ALOFT. DEEP LAYER SHEAR
SHOULD INCREASE LATE THIS AFTERNOON AND EVENING BASED ON FORECAST
SOUNDINGS...AHEAD OF A SHORT WAVE AND COLD FRONT TO OUR WEST.
THROUGH MID AFTERNOON WILL WATCH FOR CONVECTION AHEAD OF A
WEAKENING THUNDERSTORM COMPLEX MOVING INTO SE IA...AND ALSO ANY
DEVELOPMENT ACROSS THE NRN CWA ALONG AND AHEAD OF THE NORTHWARD
MOVING WARM FRONT. STILL APPEARS BEST TIMEFRAME FOR SEVERE STORMS
WILL BE AFTER 6 PM IN THE WEST. VERY WARM AND HUMID AFTERNOON ON
TAP WITH HIGHS NEAR 90 IN THE FAR SW.
25
&&
.AVIATION...
ISSUED 655 AM CDT SUN MAY 6 2012...FOR THE 12Z TAFS
IFR FOG WILL AFFECT BMI/CMI FOR A COUPLE OF HOURS AT THE START OF THE
TAF PERIOD...WITH MVFR FOG AT DEC/PIA DURING THAT TIME. VERY HIGH
DEWPOINTS IN THE LOW TO MID 60S WILL SET THE STAGE FOR
THUNDERSTORMS TO ARRIVE LATER THIS AFTERNOON AND INTENSIFY AS THE
REACH THE TAF SITES THIS EVENING. THE EXACT TIMING FOR EACH
TERMINAL REMAINS IN QUESTION...SO WE LEFT A VCTS STARTING AT 23Z
FOR PIA AND PROGRESSED TO A 02Z ARRIVAL FOR CMI. LARGE HAIL AND
DAMAGING WINDS WILL BE POSSIBLE TONIGHT AS THE STORMS BECOME MORE
WIDESPREAD.
A WARM FRONT LIFTING NORTH TODAY SHOULD HELP SHIFT THE WIND
DIRECTION SLIGHTLY FROM AN ESE TO A SSE DIRECTION. WIND SPEEDS
THIS AFTERNOON SHOULD SUSTAIN IN THE 12-14KT RANGE WITH GUSTS TO
23-25KT RANGE.
THE COLD FRONT IS NOT EXPECTED TO ARRIVE UNTIL SOMETIME ON
MONDAY...WHICH IS OUTSIDE OF THIS TAF PERIOD. WE CAN NOT RULE OUT
SOME MVFR/IFR FOG LATER TONIGHT BEHIND THE LINE OF THUNDERSTORMS
AND AHEAD OF THE COLD FRONT.
SHIMON
&&
.PREV DISCUSSION...
ISSUED 257 AM CDT SUN MAY 6 2012
FRONTAL BOUNDARY HAS NOT REALLY MOVED OVER THE LAST SEVERAL
HOURS...EXTENDING FROM NORTHWEST IOWA TO NEAR SPRINGFIELD AND
SOUTHEAST INTO SOUTH CENTRAL INDIANA. DEW POINTS IN THE 65-70F
RANGE WERE POOLING ALONG THIS BOUNDARY. SOME LIGHT FOG WAS
OBSERVED NORTH OF THE FRONT WITH VISIBILITIES OF 3-5 MILES. LARGE
MCS STRETCHING FROM CENTRAL MINNESOTA INTO NORTHERN NEBRASKA HAS
PUSHED INTO FAR NORTHWEST IOWA.
SEVERE WEATHER POTENTIAL THROUGH MONDAY REMAINS THE PRIMARY
FORECAST CONCERN.
SHORT TERM...TODAY THROUGH MONDAY...
NORTHWARD SPREAD OF THE WARM SECTOR MAY BE TEMPERED BY THE
INFLUENCES OF THE MCS DEBRIS...BUT SHOULD GET FAR ENOUGH NORTH TO
CLEAR OUR NORTHERN CWA TOWARD MIDDAY. INSTABILITY SHOULD NOT BE A
PROBLEM AS CAPES APPROACH 3000 J/KG BY MIDDAY AND CONVECTIVE
INHIBITION VALUES WANE. TIMING OF THE CONVECTION IS THE TRICKY
PART...WITH THE HRRR LEANING TOWARD EARLY AFTERNOON DEVELOPMENT
WEST OF THE MISSISSIPPI RIVER...AND THE NAM AND LOCAL WRF MODELS
FROM ST LOUIS AND CHICAGO NWS OFFICES BRINGING SOME OF THE MCS
REMNANTS INTO THE NORTHERN CWA LATE THIS MORNING. ATTENDANT COLD
FRONT IS LIKELY TO MOVE INTO THE NORTHWEST CWA EARLY THIS
EVENING...CONTINUING THE STORM THREAT OVERNIGHT. MOST OF THE CWA
REMAINS IN A SLIGHT RISK OF SEVERE WEATHER...EXCEPT EAST OF
I-57...WHERE SEVERE THREAT MAY BE VERY LATE TONIGHT OR MONDAY
MORNING INSTEAD. HAVE CONTINUED WITH RAIN CHANCES MAINLY WEST OF
I-55 THIS AFTERNOON...AND OVERSPREADING THE REMAINDER OF THE CWA
THIS EVENING. HEAVIEST RAIN THREAT LOOKS TO BE JUST TO OUR
NORTH...BUT WILL NEED TO WATCH THE FAR NORTHERN CWA WHICH HAD 1-3
INCHES OF RAIN THURSDAY NIGHT AND FRIDAY MORNING FOR ANY POTENTIAL
HYDROLOGICAL CONCERNS. TIMING OF FRONTAL PASSAGE ON MONDAY SHOULD
BE EARLY AFTERNOON ACROSS THE EASTERN CWA...AND HAVE KEPT LIKELY
POPS GOING IN THAT AREA DURING THE DAY...DIMINISHING IN THE
EVENING.
TEMPERATURE-WISE...WILL LIKELY SEE HIGHS DEEP INTO THE 80S OVER
THE ENTIRE FORECAST AREA...POTENTIALLY NUDGING 90 ACROSS THE
SOUTHWEST CWA. MOST RECORDS TODAY ARE IN THE LOWER 90S AND LIKELY
JUST OUT OF REACH...ALTHOUGH SPRINGFIELD HAS A RECORD HIGH OF 88
WHICH IS IN JEOPARDY. WILL PROBABLY SEE SOME 80 DEGREE READINGS
AGAIN ACROSS THE SOUTHEAST ON MONDAY AHEAD OF THE FRONT...BUT THAT
WILL BE THE LAST OF THE 80S ACROSS OUR CWA FOR THE REMAINDER OF
THE WEEK.
LONG TERM...TUESDAY THROUGH SATURDAY...
A MUCH COOLER AND QUIETER REGIME SETS UP THE REMAINDER OF THE
WEEK. AN UPPER LOW...CURRENTLY LOCATED OVER FAR NORTH CENTRAL
MONTANA PER WATER VAPOR IMAGERY...SHOULD MOVE TO NEAR LAKE
SUPERIOR BY TUESDAY MORNING. ASSOCIATED SURFACE AND UPPER TROUGH
WILL SWING THROUGH THE GREAT LAKES TUESDAY AND WEDNESDAY...WITH
THE COLDER AIR ALOFT HELPING TO TRIGGER A FEW SHOWERS. STILL LOOKS
LIKE THE BEST SUPPORT FOR THIS WILL BE FURTHER TO OUR NORTH...BUT
HAVE INCLUDED SOME SLIGHT CHANCES ACROSS THE NORTHEAST CWA ON
WEDNESDAY AS THE TROUGH FULLY PUSHES THROUGH THE STATE.
UPPER RIDGING ACROSS THE ROCKIES AT MIDWEEK WILL RESULT IN A
NORTHWEST FLOW...AND BELOW NORMAL TEMPERATURES...FOR A COUPLE
DAYS IN OUR AREA. LONGER RANGE MODELS SHOWING THE RIDGING PUSHING
EASTWARD LATE IN THE WEEK...WITH A BIT OF MODERATION IN
TEMPERATURES. SURFACE HIGH PRESSURE OVER THE MIDWEST TO PROVIDE
FAIR WEATHER FOR THURSDAY AND FRIDAY...AHEAD OF A SHORTWAVE WHICH
WILL PUSH ACROSS THE NORTHERN STATES LATE IN THE WEEK. MOISTURE
RETURN IN OUR AREA WILL BE MEAGER AHEAD OF THIS SYSTEM...SO RAIN
CHANCES ARE NOT ESPECIALLY HIGH AT THIS TIME. HOWEVER...THE
NORTHWEST CWA SHOULD SEE A FEW SHOWERS AND THUNDERSTORMS BY
SATURDAY AFTERNOON.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
655 AM CDT SUN MAY 6 2012
.DISCUSSION...
ISSUED 257 AM CDT SUN MAY 6 2012
FRONTAL BOUNDARY HAS NOT REALLY MOVED OVER THE LAST SEVERAL
HOURS...EXTENDING FROM NORTHWEST IOWA TO NEAR SPRINGFIELD AND
SOUTHEAST INTO SOUTH CENTRAL INDIANA. DEW POINTS IN THE 65-70F
RANGE WERE POOLING ALONG THIS BOUNDARY. SOME LIGHT FOG WAS
OBSERVED NORTH OF THE FRONT WITH VISIBILITIES OF 3-5 MILES. LARGE
MCS STRETCHING FROM CENTRAL MINNESOTA INTO NORTHERN NEBRASKA HAS
PUSHED INTO FAR NORTHWEST IOWA.
SEVERE WEATHER POTENTIAL THROUGH MONDAY REMAINS THE PRIMARY
FORECAST CONCERN.
SHORT TERM...TODAY THROUGH MONDAY...
NORTHWARD SPREAD OF THE WARM SECTOR MAY BE TEMPERED BY THE
INFLUENCES OF THE MCS DEBRIS...BUT SHOULD GET FAR ENOUGH NORTH TO
CLEAR OUR NORTHERN CWA TOWARD MIDDAY. INSTABILITY SHOULD NOT BE A
PROBLEM AS CAPES APPROACH 3000 J/KG BY MIDDAY AND CONVECTIVE
INHIBITION VALUES WANE. TIMING OF THE CONVECTION IS THE TRICKY
PART...WITH THE HRRR LEANING TOWARD EARLY AFTERNOON DEVELOPMENT
WEST OF THE MISSISSIPPI RIVER...AND THE NAM AND LOCAL WRF MODELS
FROM ST LOUIS AND CHICAGO NWS OFFICES BRINGING SOME OF THE MCS
REMNANTS INTO THE NORTHERN CWA LATE THIS MORNING. ATTENDANT COLD
FRONT IS LIKELY TO MOVE INTO THE NORTHWEST CWA EARLY THIS
EVENING...CONTINUING THE STORM THREAT OVERNIGHT. MOST OF THE CWA
REMAINS IN A SLIGHT RISK OF SEVERE WEATHER...EXCEPT EAST OF
I-57...WHERE SEVERE THREAT MAY BE VERY LATE TONIGHT OR MONDAY
MORNING INSTEAD. HAVE CONTINUED WITH RAIN CHANCES MAINLY WEST OF
I-55 THIS AFTERNOON...AND OVERSPREADING THE REMAINDER OF THE CWA
THIS EVENING. HEAVIEST RAIN THREAT LOOKS TO BE JUST TO OUR
NORTH...BUT WILL NEED TO WATCH THE FAR NORTHERN CWA WHICH HAD 1-3
INCHES OF RAIN THURSDAY NIGHT AND FRIDAY MORNING FOR ANY POTENTIAL
HYDROLOGICAL CONCERNS. TIMING OF FRONTAL PASSAGE ON MONDAY SHOULD
BE EARLY AFTERNOON ACROSS THE EASTERN CWA...AND HAVE KEPT LIKELY
POPS GOING IN THAT AREA DURING THE DAY...DIMINISHING IN THE
EVENING.
TEMPERATURE-WISE...WILL LIKELY SEE HIGHS DEEP INTO THE 80S OVER
THE ENTIRE FORECAST AREA...POTENTIALLY NUDGING 90 ACROSS THE
SOUTHWEST CWA. MOST RECORDS TODAY ARE IN THE LOWER 90S AND LIKELY
JUST OUT OF REACH...ALTHOUGH SPRINGFIELD HAS A RECORD HIGH OF 88
WHICH IS IN JEOPARDY. WILL PROBABLY SEE SOME 80 DEGREE READINGS
AGAIN ACROSS THE SOUTHEAST ON MONDAY AHEAD OF THE FRONT...BUT THAT
WILL BE THE LAST OF THE 80S ACROSS OUR CWA FOR THE REMAINDER OF
THE WEEK.
LONG TERM...TUESDAY THROUGH SATURDAY...
A MUCH COOLER AND QUIETER REGIME SETS UP THE REMAINDER OF THE
WEEK. AN UPPER LOW...CURRENTLY LOCATED OVER FAR NORTH CENTRAL
MONTANA PER WATER VAPOR IMAGERY...SHOULD MOVE TO NEAR LAKE
SUPERIOR BY TUESDAY MORNING. ASSOCIATED SURFACE AND UPPER TROUGH
WILL SWING THROUGH THE GREAT LAKES TUESDAY AND WEDNESDAY...WITH
THE COLDER AIR ALOFT HELPING TO TRIGGER A FEW SHOWERS. STILL LOOKS
LIKE THE BEST SUPPORT FOR THIS WILL BE FURTHER TO OUR NORTH...BUT
HAVE INCLUDED SOME SLIGHT CHANCES ACROSS THE NORTHEAST CWA ON
WEDNESDAY AS THE TROUGH FULLY PUSHES THROUGH THE STATE.
UPPER RIDGING ACROSS THE ROCKIES AT MIDWEEK WILL RESULT IN A
NORTHWEST FLOW...AND BELOW NORMAL TEMPERATURES...FOR A COUPLE
DAYS IN OUR AREA. LONGER RANGE MODELS SHOWING THE RIDGING PUSHING
EASTWARD LATE IN THE WEEK...WITH A BIT OF MODERATION IN
TEMPERATURES. SURFACE HIGH PRESSURE OVER THE MIDWEST TO PROVIDE
FAIR WEATHER FOR THURSDAY AND FRIDAY...AHEAD OF A SHORTWAVE WHICH
WILL PUSH ACROSS THE NORTHERN STATES LATE IN THE WEEK. MOISTURE
RETURN IN OUR AREA WILL BE MEAGER AHEAD OF THIS SYSTEM...SO RAIN
CHANCES ARE NOT ESPECIALLY HIGH AT THIS TIME. HOWEVER...THE
NORTHWEST CWA SHOULD SEE A FEW SHOWERS AND THUNDERSTORMS BY
SATURDAY AFTERNOON.
GEELHART
&&
.AVIATION...
ISSUED 655 AM CDT SUN MAY 6 2012...FOR THE 12Z TAFS
IFR FOG WILL AFFECT BMI/CMI FOR A COUPLE OF HOURS AT THE START OF THE
TAF PERIOD...WITH MVFR FOG AT DEC/PIA DURING THAT TIME. VERY HIGH
DEWPOINTS IN THE LOW TO MID 60S WILL SET THE STAGE FOR
THUNDERSTORMS TO ARRIVE LATER THIS AFTERNOON AND INTENSIFY AS THE
REACH THE TAF SITES THIS EVENING. THE EXACT TIMING FOR EACH
TERMINAL REMAINS IN QUESTION...SO WE LEFT A VCTS STARTING AT 23Z
FOR PIA AND PROGRESSED TO A 02Z ARRIVAL FOR CMI. LARGE HAIL AND
DAMAGING WINDS WILL BE POSSIBLE TONIGHT AS THE STORMS BECOME MORE
WIDESPREAD.
A WARM FRONT LIFTING NORTH TODAY SHOULD HELP SHIFT THE WIND
DIRECTION SLIGHTLY FROM AN ESE TO A SSE DIRECTION. WIND SPEEDS
THIS AFTERNOON SHOULD SUSTAIN IN THE 12-14KT RANGE WITH GUSTS TO
23-25KT RANGE.
THE COLD FRONT IS NOT EXPECTED TO ARRIVE UNTIL SOMETIME ON
MONDAY...WHICH IS OUTSIDE OF THIS TAF PERIOD. WE CAN NOT RULE OUT
SOME MVFR/IFR FOG LATER TONIGHT BEHIND THE LINE OF THUNDERSTORMS
AND AHEAD OF THE COLD FRONT.
SHIMON
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
259 AM CDT SUN MAY 6 2012
.DISCUSSION...
ISSUED 257 AM CDT SUN MAY 6 2012
FRONTAL BOUNDARY HAS NOT REALLY MOVED OVER THE LAST SEVERAL
HOURS...EXTENDING FROM NORTHWEST IOWA TO NEAR SPRINGFIELD AND
SOUTHEAST INTO SOUTH CENTRAL INDIANA. DEW POINTS IN THE 65-70F
RANGE WERE POOLING ALONG THIS BOUNDARY. SOME LIGHT FOG WAS
OBSERVED NORTH OF THE FRONT WITH VISIBILITIES OF 3-5 MILES. LARGE
MCS STRETCHING FROM CENTRAL MINNESOTA INTO NORTHERN NEBRASKA HAS
PUSHED INTO FAR NORTHWEST IOWA.
SEVERE WEATHER POTENTIAL THROUGH MONDAY REMAINS THE PRIMARY
FORECAST CONCERN.
SHORT TERM...TODAY THROUGH MONDAY...
NORTHWARD SPREAD OF THE WARM SECTOR MAY BE TEMPERED BY THE
INFLUENCES OF THE MCS DEBRIS...BUT SHOULD GET FAR ENOUGH NORTH TO
CLEAR OUR NORTHERN CWA TOWARD MIDDAY. INSTABILITY SHOULD NOT BE A
PROBLEM AS CAPES APPROACH 3000 J/KG BY MIDDAY AND CONVECTIVE
INHIBITION VALUES WANE. TIMING OF THE CONVECTION IS THE TRICKY
PART...WITH THE HRRR LEANING TOWARD EARLY AFTERNOON DEVELOPMENT
WEST OF THE MISSISSIPPI RIVER...AND THE NAM AND LOCAL WRF MODELS
FROM ST LOUIS AND CHICAGO NWS OFFICES BRINGING SOME OF THE MCS
REMNANTS INTO THE NORTHERN CWA LATE THIS MORNING. ATTENDANT COLD
FRONT IS LIKELY TO MOVE INTO THE NORTHWEST CWA EARLY THIS
EVENING...CONTINUING THE STORM THREAT OVERNIGHT. MOST OF THE CWA
REMAINS IN A SLIGHT RISK OF SEVERE WEATHER...EXCEPT EAST OF
I-57...WHERE SEVERE THREAT MAY BE VERY LATE TONIGHT OR MONDAY
MORNING INSTEAD. HAVE CONTINUED WITH RAIN CHANCES MAINLY WEST OF
I-55 THIS AFTERNOON...AND OVERSPREADING THE REMAINDER OF THE CWA
THIS EVENING. HEAVIEST RAIN THREAT LOOKS TO BE JUST TO OUR
NORTH...BUT WILL NEED TO WATCH THE FAR NORTHERN CWA WHICH HAD 1-3
INCHES OF RAIN THURSDAY NIGHT AND FRIDAY MORNING FOR ANY POTENTIAL
HYDROLOGICAL CONCERNS. TIMING OF FRONTAL PASSAGE ON MONDAY SHOULD
BE EARLY AFTERNOON ACROSS THE EASTERN CWA...AND HAVE KEPT LIKELY
POPS GOING IN THAT AREA DURING THE DAY...DIMINISHING IN THE
EVENING.
TEMPERATURE-WISE...WILL LIKELY SEE HIGHS DEEP INTO THE 80S OVER
THE ENTIRE FORECAST AREA...POTENTIALLY NUDGING 90 ACROSS THE
SOUTHWEST CWA. MOST RECORDS TODAY ARE IN THE LOWER 90S AND LIKELY
JUST OUT OF REACH...ALTHOUGH SPRINGFIELD HAS A RECORD HIGH OF 88
WHICH IS IN JEOPARDY. WILL PROBABLY SEE SOME 80 DEGREE READINGS
AGAIN ACROSS THE SOUTHEAST ON MONDAY AHEAD OF THE FRONT...BUT THAT
WILL BE THE LAST OF THE 80S ACROSS OUR CWA FOR THE REMAINDER OF
THE WEEK.
LONG TERM...TUESDAY THROUGH SATURDAY...
A MUCH COOLER AND QUIETER REGIME SETS UP THE REMAINDER OF THE
WEEK. AN UPPER LOW...CURRENTLY LOCATED OVER FAR NORTH CENTRAL
MONTANA PER WATER VAPOR IMAGERY...SHOULD MOVE TO NEAR LAKE
SUPERIOR BY TUESDAY MORNING. ASSOCIATED SURFACE AND UPPER TROUGH
WILL SWING THROUGH THE GREAT LAKES TUESDAY AND WEDNESDAY...WITH
THE COLDER AIR ALOFT HELPING TO TRIGGER A FEW SHOWERS. STILL LOOKS
LIKE THE BEST SUPPORT FOR THIS WILL BE FURTHER TO OUR NORTH...BUT
HAVE INCLUDED SOME SLIGHT CHANCES ACROSS THE NORTHEAST CWA ON
WEDNESDAY AS THE TROUGH FULLY PUSHES THROUGH THE STATE.
UPPER RIDGING ACROSS THE ROCKIES AT MIDWEEK WILL RESULT IN A
NORTHWEST FLOW...AND BELOW NORMAL TEMPERATURES...FOR A COUPLE
DAYS IN OUR AREA. LONGER RANGE MODELS SHOWING THE RIDGING PUSHING
EASTWARD LATE IN THE WEEK...WITH A BIT OF MODERATION IN
TEMPERATURES. SURFACE HIGH PRESSURE OVER THE MIDWEST TO PROVIDE
FAIR WEATHER FOR THURSDAY AND FRIDAY...AHEAD OF A SHORTWAVE WHICH
WILL PUSH ACROSS THE NORTHERN STATES LATE IN THE WEEK. MOISTURE
RETURN IN OUR AREA WILL BE MEAGER AHEAD OF THIS SYSTEM...SO RAIN
CHANCES ARE NOT ESPECIALLY HIGH AT THIS TIME. HOWEVER...THE
NORTHWEST CWA SHOULD SEE A FEW SHOWERS AND THUNDERSTORMS BY
SATURDAY AFTERNOON.
GEELHART
&&
.AVIATION...
ISSUED 1130 PM CDT SAT MAY 5 2012
CIGS AND VSBYS THE MAIN CONCERN...ESP ACRS THE NORTH OVERNIGHT.
SATELLITE DATA AND SURFACE OBS TO OUR NORTH SUGGEST LOW MVFR AND
IFR CIGS BEGINNING TO GET A BIT MORE OF A SOUTHWARD PUSH THAN
EARLIER EXPECTED THANKS TO AN OUTFLOW BOUNDARY FROM A COMPLEX
OF STORMS THAT MOVED ACRS SOUTHERN WISCONSIN THIS EVE. THE LOWER
CIGS LOOK TO BE ALONG AND NORTH OF I-80 WITH THE LAST FEW SATELLITE
LOOPS SUGGESTING THE SOUTHWARD PUSH HAS SLOWED SOMEWHAT. LOW LEVEL
WINDS ARE FORECAST TO GO MORE INTO AN ESE DIRECTION WHICH SHOULD
KEEP MOST OF THE CLOUDS ALONG AND NORTH OF A PIA TO BMI LINE.
VSBYS WILL LOWER TO MVFR AND POSSIBLY IFR AT BMI FOR A TIME AFTR 06Z
WITH 2 TO 4 MILES PREVAILING ELSEWHERE DURING THE EARLY MORNING
HOURS. WHAT FOG AND LOW CLOUDS WE HAVE SHOULD LIFT QUICKLY AFTR
13Z WITH VFR CONDITIONS PREVAILING THRU 00Z.
A COLD FRONT WILL APPROACH THE AREA LATE TOMORROW EVENING AND
OVERNIGHT BRINGING THE THREAT FOR SCATTERED THUNDERSTORMS TO THE
TAF SITES BUT COVERAGE IS UNCERTAIN AT THIS TIME SO WILL TRY TO
HIT THE TIMING WITH VCTS AT EACH SITE TOMORROW EVENING. SFC WINDS
WILL BE OUT OF THE EAST AROUND 10 KTS TONIGHT AND THEN WINDS WILL
VEER MORE INTO THE SOUTH TOMORROW WITH SPEEDS OF BETWEEN 12 AND
17 KTS...WITH FORECAST SOUNDINGS SUGGESTING WIND GUSTS UP TO 25 KTS
POSSIBLE IN THE AFTERNOON.
SMITH
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
737 PM EDT MON MAY 7 2012
.AVIATION...
CIGS AND VIS RESTRICTIONS WILL BE MAIN ISSUE AT TAF SITES THIS
PERIOD. SATELLITE AND SURFACE OBSERVATIONS INDICATE A RATHER CHAOTIC
PATTERN WITH CIGS JUMPING ALL OVER FROM IFR TO VFR. EXPECT THIS TO
TRANSITION TO MVFR THROUGH THE EVENING WITH OCCASIONAL IFR POSSIBLE
AT KSBN. CIGS SHOULD CONTINUE TO LOWER THROUGH THE NIGHT WITH MORE
IFR AT KSBN POSSIBLE AFTER 08Z WITH SATURATING LOWER LEVELS. ALSO
EXPECT VIS IN THE 3 TO 5 MILE RANGE WITH BR AND LIGHT WINDS.
CONDITIONS TO SLOWLY IMPROVE ON TUESDAY WITH MIXING BUT CU RULES
SUGGEST BROKEN TO OVERCAST CU FIELD POSSIBLE. KEPT THIS IN VFR RANGE
FOR NOW BUT COULD SIMPLY REMAIN MVFR DEPENDING ON HOW MORNING CLOUDS
MIX.
&&
.SHORT TERM...
TONIGHT...TUESDAY...TUESDAY NIGHT...
CONVECTIVE REDEVELOPMENT NOT FULLY MATERIALIZING YET AS AIRMASS
STRUGGLES TO RECOVER FROM EARLIER RAINS. KIWX RADAR SHOWING LONE
CONVECTIVE CELL JUST SOUTH OF THE CWA NEAR MUNCIE. KIND RADAR
INDICATING ADDL DEVELOPMENT NOW BEGINNING TO TAKE SHAPE FURTHER
SOUTH. WATER VAPOR IMAGERY AND LATEST RUC ANALYSIS SHOWING WEAK
SHORT WAVE APPROACHING THE AREA SO STILL HOLDING OUT HOPE FOR MORE
ORGANIZED PRECIP THIS EVENING AS SFC LOW AND FRONTAL BOUNDARY
CONTINUE TO MOVE EASTWARD...BUT HAVE DROPPED POPS OVER THE EASTERN
CWA AND OPTED FOR SCT WORDING. WILL KEEP MENTION OF THUNDER IN THE
SE CWA AS LATEST LAPS DATA ALONG WITH SPC MESO ANALYSIS HAS CAPES
NUDGING UP OVER 1000J/KG INTO JAY COUNTY. VIS SAT ALSO SHOWING
CLOUDS THINNING OUT FROM MARION TO LIMA SO FURTHER LATE AFTN
DESTABILIZATION EXPECTED. 12Z MODELS A LITTLE SLOWER IN MOVING
SYSTEM OUT SO WILL HANG ON TO SMALL CHANCE IN SE CWA TILL 12Z TUE.
REST OF THE SHORT TERM WILL FEATURE CAA PATTERN AS UPPER LOW DROPS
INTO THE NORTHERN GREAT LAKES. SHOULD STILL GET TO AROUND NORMAL FOR
HIGHS TUESDAY AS 850MB THERMAL TROUGH DELAYED UNTIL TUE NITE/WED AM.
EXPECT AN INCREASE IN CLOUD COVER TUE NITE AS UPPER TROUGH SINKS
FURTHER SOUTH ALONG WITH SECONDARY COLD FRONT.
&&
.LONG TERM...WEDNESDAY THROUGH MONDAY
AN UPPER LEVEL SPEED MAX DIGGING SOUTHWARD ACROSS THE UPPER MIDWEST
AND UPPER MS VALLEY WILL ALLOW UPPER TROUGH TO SHIFT SOUTHEAST INTO
THE GREAT LAKES REGION BY WEDNESDAY MORNING. MOISTURE WILL BE
RELATIVELY UNIMPRESSIVE WITH THIS SYSTEM AND THUS MAIN PRECIP CHANCE
IS EXPECTED TO BE CONFINED TO ASSOCIATED WEAK LOW LEVEL CONVERGENCE
AXIS THAT WILL BE DROPPING SOUTHWARD ACROSS THE AREA ON WEDNESDAY.
MID LEVEL COLD POOL IS EXPECTED TO SHIFT SOUTHEAST ACROSS LOWER
MICHIGAN INTO WEDNESDAY NIGHT. SOME WEAK SFC BASED INSTABILITY IS
POSSIBLE ON WEDNESDAY AFTERNOON ESPECIALLY ACROSS NORTHEAST PORTIONS
OF THE FORECAST AREA CLOSER TO THESE COOLER MID LEVEL PROFILES. WILL
HOLD OFF ON ANY TS INCLUSION AT THIS POINT WITH SOME CONCERN THAT IF
SOME DEEPER MIXING IS REALIZED...THIS COULD LIMIT ANY SFC BASED
INSTABILITY. CHANCE OF PRECIP TO COME TO AN END WEDNESDAY EVENING AS
THIS UPPER TROUGH SHIFTS EAST. BROAD LOW LEVEL ANTICYCLONE WILL THEN
OVERSPREAD THE REGION FOR THURSDAY AND FRIDAY SETTING UP A FEW QUIET
DAYS TO END THE WEEK.
LOW LEVEL ANTICYCLONE WILL BE VERY SLOW TO SHIFT EAST AS UPPER RIDGE
TO THE WEST AMPLIFIES AS IT APPROACHES THE GREAT LAKES REGION FRIDAY
IN RESPONSE TO NEXT PROGRESSIVE EASTERN PACIFIC TROUGH TRACKING INTO
THE NORTHERN PLAINS. MOISTURE RETURN IN ADVANCE OF THIS PACIFIC
TROUGH WILL BE SOMEWHAT ROUNDABOUT DUE TO PRESENCE OF DEPARTING
ANTICYCLONE TO THE SOUTHEAST. THIS SHOULD CONFINE ANY LOW LEVEL
MOISTURE RETURN OF CONSEQUENCE TO A FAIRLY NARROW CORRIDOR IN
ADVANCE OF ASSOCIATED COLD FRONTAL BOUNDARY. WHILE SOME SLIGHT
TIMING DIFFERENCES PERSIST WITH THIS FRONT...CHARACTERISTIC OF LARGE
SCALE FLOW AND GOOD AGREEMENT AMONGST MEDIUM RANGE MODELS HANDLING
THIS NEXT EASTERN PACIFIC TROUGH STILL LEND ENOUGH CONFIDENCE TO
MAINTAIN LOW CHANCE POPS FOR FRIDAY NIGHT INTO SUNDAY. ONCE FRONTAL
TIMING BECOMES BETTER RESOLVED WILL LIKELY BE ABLE TO CONTRACT THE
DURATION OF THESE POPS. HAVE OMITTED THUNDER AT THIS TIME GIVEN SOME
UNCERTAINTIES AS TO EXTENT OF LOW LEVEL MOISTURE RETURN BUT THIS
WILL ALSO NEED TO BE REASSESSED IN LATER FORECASTS. SOME SLIGHT
MODERATION IN TEMPERATURES EXPECTED FOR FRIDAY IN ADVANCE OF THIS
FRONT...BUT OVERALL TEMPERATURES NEAR SEASONABLE LEVELS ARE EXPECTED
THROUGH THE PERIOD. A RETURN TO DRY CONDITIONS EXPECTED FOR EARLY
NEXT WEEK AS THIS SYSTEM DEPARTS TO THE EAST.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...LOGSDON
LONG TERM...MARSILI
AVIATION...LASHLEY
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1221 PM CDT SUN MAY 6 2012
...UPDATED AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 117 AM CDT SUN MAY 6 2012
AT 00Z SUNDAY AN UPPER LEVEL TROUGH WHICH WAS ASSOCIATED WITH THE
RIGHT ENTRANCE REGION OF AN UPPER LEVEL JET EXTENDED FROM
NORTHEAST COLORADO INTO EASTERN WYOMING. A SURFACE COLD FRONT
EXTENDED FROM NORTHEAST COLORADO INTO NORTHEAST NEBRASKA. SOUTH OF
THIS COLD FRONT WARM MID LEVEL TEMPERATURES WERE PRESENT ACROSS
WESTERN KANSAS WITH KDDC INDICATING 700MB TEMPERATURES AT +13C. AS
OF 06Z SURFACE ANALYSIS INDICATED THIS COLD FRONT WAS ALREADY
SURGING SOUTHEAST TOWARDS WEST CENTRAL KANSAS WITH LOW CLOUDS AND
NORTHWEST WINDS AROUND 25KNOTS DEVELOPING IN ITS WAKE.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 117 AM CDT SUN MAY 6 2012
BASED ON 925-850MB MOISTURE PROFILES THE MODELS THIS MORNING
REMAIN IN GOOD AGREEMENT IN LOW LEVEL MOISTURE RETURNING TO
SOUTHWEST KANSAS BEHIND A COLD FRONT THAT WAS CURRENTLY MOVING
INTO WEST CENTRAL KANSAS. NAM AND GFS 300-305 IS ENTROPIC SURFACES
EVEN SUGGEST SOME WEAK LIFT WILL CONTINUE THROUGH 00Z MONDAY.
BASED ON THIS WEAK LIFT AND DEPTH OF THIS MOIST LAYER WILL KEEP A
MENTION OF DRIZZLE GOING THROUGH MUCH OF THE DAY, ESPECIALLY
NORTHEAST OF DODGE CITY WHERE THE ISENTROPIC LIFT IS A LITTLE
BETTER. GIVEN THE CHANCE FOR DRIZZLE ALONG WITH CLOUDY CONDITIONS
THE PREVIOUS FORECAST STILL LOOKS ON TRACK WITH AFTERNOON
TEMPERATURES RANGING FROM THE LOW TO MID 60S WITH THE EXCEPTION
BEING SOUTH CENTRAL KANSAS. WILL HAVE TO MONITOR HOW QUICKLY THIS
FRONT WILL CROSS SOUTH CENTRAL KANSAS EARLY THIS MORNING BUT AT
THIS TIME BASED ON 06Z SURFACE OBSERVATION ACROSS NORTHWEST KANSAS
IT APPEARS THAT THE NAM MAY BE A LITTLE SLOW SO ADJUSTING THE
TIMING OF THIS FRONT CLOSE TO THE HRRR WILL CONTINUE TO FAVOR
SLIGHTLY COOLER TEMPERATURES IN THE MEDICINE LODGE AREA THAN WHAT
THE NAM/GFS SUGGEST.
BOUNDARY LAYER AND 0-0.5KM LAYER WINDS BEHIND THIS COLD FRONT
ACROSS WESTERN KANSAS EARLY TODAY BOTH WERE FORECAST TO RANGE BETWEEN
30 AND 35 KNOTS BEHIND THIS FRONT. GIVEN THIS AND THE LOCATION OF
WHERE THE STRONGER LOW LEVEL WINDS ARE FORECAST TO BE BETWEEN 09Z
AND 15Z SUNDAY WILL KEEP CURRENT WIND ADVISORY AS IS FOR NOW.
MARGINAL WIND ADVISORY WINDS HOWEVER STILL APPEAR POSSIBLE A
LITTLE FURTHER SOUTHEAST, HOWEVER CONFIDENCE IS NOT HIGH ENOUGH AT
THIS TIME TO EXPAND THE PREVIOUS ADVISORY.
SURFACE HIGH PRESSURE WILL THEN BEGIN TO BUILD INTO THE ARE EARLY
TONIGHT AND 300-305 ISENTROPIC DOWN GLIDE DEVELOPS. LOW LEVEL
MOISTURE STILL PRESENT OVER WESTERN KANSAS THROUGH MUCH OF THE
NIGHT BUT GIVEN THE SUBSIDENCE/DOWN GLIDE SUGGESTED WILL BEGIN TO
SHOW A DECREASING TREND IN CLOUD COVER BY OR SHORTLY AFTER
MIDNIGHT...ESPECIALLY IN THE NORTH. IN AREAS WHERE THE SKIES ARE
EXPECTED TO CLEAR WILL TREND TOWARDS THE COOLER MET/MAV ON
TEMPERATURES WHILE FURTHER SOUTHEAST WILL CONTINUE TO FAVOR THE
WARMER MOSGUIDE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 340 AM CDT SUN MAY 6 2012
MONDAY:
A RATHER BROAD UPPER LEVEL TROUGH WILL BE WEST OF KANSAS MONDAY. WESTERN
KANSAS WILL BE IN A QUASI COUPLED JET REGION WITH THE LEFT EXIT REGION
OF A 250 HPA 70 KT JET ACROSS THE EASTERN SECTIONS OF THE DESERT SOUTHWEST
AND THE RIGHT ENTRANCE REGION OF A 250 HPA 65 KT JET ACROSS NEBRASKA.
AS A RESULT, HAVE KEPT POPS MAINLY ACROSS FAR SOUTHWEST KANSAS WHERE
BETTER LIFT WILL BE PRESENT VERSUS FURTHER EAST. NOT PARTICULARLY IMPRESSED
OVERALL AS MOST OF THE QPF SHOULD REMAIN ACROSS THE HIGHER TERRAIN ALSO
IN ASSOCIATION WITH OROGRAPHIC LIFT AND UPSLOPE FLOW IN A POST FRONTAL
ENVIRONMENT. A 1025 HPA HIGH WILL SLIDE DOWN THE PLAINS IN THE WAKE
OF THE AFOREMENTIONED FRONT. THIS AIRMASS WILL BE CHARACTERIZED AS PLEASANT
WITH 850 HPA TEMPERATURES NOT TOO WARM (~10-12 DEG C). UPPER 60S DEG
F TO LOWER 70S DEG F IS EXPECTED FOR THE BEGINNING OF THE WORKWEEK
WHICH IS JUST A HAIR BELOW CLIMATOLOGY.
TUESDAY:
THE DESERT SOUTHWEST SYSTEM WILL CONTINUE TO SINK SOUTHWARD INTO THE
BAJA REGION WHILE THE NORTHERN SYSTEM MOVES EAST. SOUTHWEST KANSAS WILL
BE LEFT IN A COL POINT AT THE UPPER LEVELS. AT THE SURFACE, THE COOL
HIGH PRESSURE CENTER WILL CONTINUE TO DOMINATE. RICH BOUNDARY MOISTURE
WILL BE ADVECTED WELL SOUTH INTO TEXAS WITH FAIRLY LOW DEWPOINTS ACROSS
THE SUNFLOWER STATE. AS A RESULT, OVERNIGHT LOWS INTO TUESDAY MORNING
WILL BE MAINLY IN THE 40S DEG F EXCEPT NEAR KP28 WHERE AROUND 50 DEG
F IS EXPECTED. LOW TEMPERATURES IN THE 40S DEG F ARE NEAR CLIMATOLOGY.
A LACK OF DYNAMICS ALOFT AND HIGH PRESSURE AT THE SURFACE WILL LEAD
TO A DRY FORECAST FOR TUESDAY.
WEDNESDAY/THURSDAY:
MAXIMUM TEMPERATURES WILL MODERATE WEDNESDAY WITH HIGHS IN THE MID 70S
DEG F OR ABOUT NEAR NORMAL AS THE COOL HIGH PRESSURE SLIDES OFF TO THE
EAST AND LEE TROUGHING AND RESULTANT WARM AIR ADVECTION DEVELOPS ACROSS
THE HIGH PLAINS. POPS WILL REMAIN NEAR ZERO AS THE 500 HPA RIDGE AXIS
SLIDES EAST THROUGH THE DAY AHEAD OF ANOTHER SHORTWAVE TROUGH MOVING
ONSHORE ACROSS THE PACIFIC NORTHWEST. THURSDAY WILL BE THE WARMEST DURING
MY PERIOD AS 850 HPA TEMPERATURES WARM INTO THE LOWER 20 DEG C AND LEE
TROUGHING STRENGTHENS WITH SOUTHERLY WINDS CONTINUING FROM THE SURFACE
AND THROUGH THE 850 HPA CONSTANT PRESSURE LAYER. RETURN OF RICH BOUNDARY
LAYER MOISTURE IS NOT EXPECTED AT THIS POINT AS A COLD FRONT WILL SCOUR
HIGHER DEWPOINTS SOUTHWARD ACROSS THE NORTHERN GULF OF MEXICO BASIN.
FRIDAY AND BEYOND:
THE FORECAST TURNS MORE UNSETTLED BY THE END OF NEXT WEEK ALTHOUGH UNCERTAINTY
IS PRETTY HIGH AS THIS POINT. PRECIPITATION MAY OCCUR EITHER FROM A
NORTHERN SYSTEM BRINGING IN A COLD FRONT OR FROM THE BAJA SYSTEM BRING
IN MOISTURE FROM THE SOUTH. AT THIS POINT, THE EXACT SOLUTION IS UNKNOWN.
PREFER THE DRIER SOLUTION FROM THE ECMWF. SHOWERS AND THUNDERSTORMS
WILL BE POSSIBLE AS LIFT AND MOISTURE ADVECTION INCREASES DURING THIS
PERIOD. EVEN IF YOU WERE TO BUY THE WETTER GFS SOLUTION, DEWPOINTS
RETURNING TO KANSAS ARE NOT THAT IMPRESSIVE FOR MAY - 50S DEG F.
DEWPOINTS IN THE 60S/70S DEG F ARE STILL FORECAST TO BE REMAIN WELL
SOUTH INTO THE GULF OF MEXICO. LASTLY, UPPER LEVEL JET DYNAMICS IS
ALSO WEAK WITH THE CUT OFF LOW REMAINING WELL SOUTH ACROSS TEXAS AND
THE STRONGER POLAR JET FORECAST WELL NORTH NEAR THE INTERNATIONAL
BORDER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1221 PM CDT SUN MAY 6 2012
MVFR CONDITIONS WILL BE OBSERVED ACROSS THE TAF SITES THIS
AFTERNOON AS LOW CLOUDS ENVELOP THE AREA AOA015. THIS IS DUE TO A
COLD FRONT THAT MOVED THROUGH THE AREA EARLY THIS MORNING CAUSING
LOWER AND MID LEVEL LIFT. A FEW SHOWERS WILL BE POSSIBLE AT THE
HAYS TERMINAL THIS AFTERNOON BUT HAVE ONLY PLACED VCSH DUE TO
UNCERTAINTY IN TIMING AND INTENSITY. WINDS WILL GENERALLY BE FROM
THE NORTH AROUND 25 KNOTS GUSTING TO OVER 30 KNOTS AT TIMES. WINDS
DECREASE THIS EVENING INTO THE OVERNIGHT HOURS AS THE PRESSURE
GRADIENT SLACKENS AND HIGH PRESSURE BUILDS INTO THE AREA. CLOUDS
AOA050 ARE FORECASTED TO BE OBSERVED THIS EVENING INTO THE
OVERNIGHT HOURS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 67 50 68 46 / 20 10 10 10
GCK 65 44 67 45 / 10 10 20 20
EHA 70 46 65 45 / 10 10 20 20
LBL 71 47 68 46 / 10 10 20 20
HYS 67 46 69 45 / 20 20 10 10
P28 79 57 71 50 / 20 20 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 3 PM CDT /2 PM MDT/ THIS AFTERNOON FOR
KSZ030-031-043>045-061>064-074>077-084>086.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...SUGDEN
AVIATION...HOVORKA
AREA FORECAST DISCUSSION
NWS TOPEKA KS
646 AM CDT SUN MAY 6 2012
...UPDATE TO AVIATION...
.DISCUSSION...
00Z UPPER AIR DATA AND RECENT WATER VAPOR IMAGERY SHOW THE MAIN
SYSTEM OF NOTE AS THE UPPER LOW SPINNING OVER THE NORTHERN ROCKIES
WITH ANOTHER SHORTWAVE TAKING SHAPE OVER SOUTHERN CALIFORNIA. 0Z
700MB RAOBS SUPPORT A WEAK MID LEVEL WAVE IN SOUTH CENTRAL
COLORADO. PRECIPITABLE WATER LEVELS IN THE CENTRAL AND SOUTHERN
PLAINS WERE COMMONLY IN THE 1-1.5 INCH RANGE...AROUND 150 PERCENT
OF NORMAL. 850MB DEWPOINTS FROM KTOP TO KOUN AND KFWD WERE AROUND
15C. 07Z SURFACE OBSERVATIONS PUT A COLD FRONT FROM SOUTHWEST
KANSAS INTO NORTHWEST IOWA WITH CONVECTION BECOMING MORE
WIDESPREAD IN RECENT HOURS JUST BEHIND IT.
MAIN SYNOPTIC BOUNDARY IS STILL PROGGED TO MOVE THROUGH TODAY FROM
NORTHWEST TO SOUTHEAST...BUT QUESTIONS ARISE WITH WHAT EFFECT THE
UPSTREAM CONVECTION WILL HAVE ON LOW LEVEL CONDITIONS. MODELS OF
VARIOUS SCALES ATTEMPT TO BRING AN OUTFLOW BOUNDARY THROUGH AROUND
MIDDAY...AND GIVEN INCREASING PRECIP IN NEBRASKA...THIS CANNOT BE
DISCOUNTED. ALSO...MID/HIGH CLOUD IS MAKING NORTHEAST PROGRESS OUT
OF TEXAS AND MAY LIMIT INSOLATION. DESPITE THESE CONCERNS...LITTLE
SHOULD CHANGE WITH LARGER SCALE THERMODYNAMICS WITH STEEP LAPSE
RATES UNDER VERY WARM/MOIST LOW LEVELS FOR AT LEAST HIGH INSTABILITY
TO REDEVELOP EVEN AFTER ANY EARLY DAY BOUNDARY/PRECIP COULD MOVE
THROUGH. WILL KEEP PRECIP CHANCES FAIRLY HIGH FOR ESPECIALLY
EASTERN AREAS WHERE MOISTURE/INSTABILITY SHOULD BE GREATER FOR MUCH
OF TODAY AND THIS EVENING. DEEP LAYER SHEAR STILL APPEARS TO BE ON
THE LOWER SIDE THOUGH SOME VEERING IN HEIGHT WILL BE IN PLACE FOR A
MAINLY PULSE EVENT WITH LARGE HAIL AND DOWNBURST WIND POTENTIAL.
PRECIPITABLE WATER VALUES BREACH 1.5 INCHES WITH MULTIPLE ROUNDS OF
PRECIP POSSIBLE TO PRODUCE LOCALLY HEAVY RAINS. WEAK MID LEVEL WAVE
SHOULD PASS THIS EVENING AS WELL FOR ELEVATED SHOWER CHANCES IN
WESTERN AREAS AS WELL. FRONT SHOULD DEEPEN ENOUGH FOR PRECIP TO EXIT
EAST CENTRAL KANSAS BY 12Z MONDAY. HAVE KEPT TODAYS TEMPS ON THE
MODERATE SIDE OF POSSIBILITIES WITH CONFIDENCE IN THE SPECIFICS LOW.
AFTER SKIES CLEAR MONDAY...MAINLY CLEAR AND SEASONABLE CONDITIONS
FOR MUCH OF THE COMING WEEK WITH SLOW MOVING NORTHERN STATES WAVE
MAKING EAST-SOUTHEAST PROGRESS THROUGH THE GREAT LAKES AND THE
CALIFORNIA WAVE CROSSING NORTHWEST MEXICO. REINFORCING SURFACE HIGH
PASSES THROUGH AROUND WEDNESDAY MORNING FOR POTENTIALLY THE COOLEST
TEMPS...THOUGH STILL IN THE 40S. HOW THE MEXICO WAVE AND THE NEXT
FASTER NORTHERN STREAM SYSTEM INTERACT FOR THE LATE WEEK IS MUCH TO
BE DETERMINED...BUT A LEAST SMALL PRECIP CHANCES ARE STILL IN ORDER.
65
&&
.AVIATION...
OUTFLOW BOUNDARY FROM NEBRASKA CONVECTION HAS MOVED THROUGH MHK
TERMINAL ALREADY AND LOWERING CIGS TO MVFR AND SHIFTING WINDS TO
THE NORTH. THIS SHOULD LAST UNTIL ABOUT 15Z THEN BECOME VFR AGAIN.
FURTHER EAST TO TOP AND FOE THE HRRR WASHES OUT THE BOUNDARY THIS
MORNING. WINDS MAY BECOME LIGHT AND VARIABLE THEN BECOME SOUTHEAST
TO SOUTH AGAIN. TIMING OF CONVECTION A LITTLE TRICKY AS MAIN COLD
FRONT WILL MOVE THROUGH LATER TODAY...WENT VCTS AFTER 18Z THEN
ADDED A TEMPO GROUP FOR TOP AND FOE WITH MVFR CIGS AND VSBYS.
CONVECTION SHOULD CLEAR THE TERMINALS BY 03Z WITH SOME -SHRA
THEREAFTER.
53
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
600 AM CDT SUN MAY 6 2012
...UPDATE TO AVIATION FOR 12Z TAFS...
.SYNOPSIS...
ISSUED AT 117 AM CDT SUN MAY 6 2012
AT 00Z SUNDAY AN UPPER LEVEL TROUGH WHICH WAS ASSOCIATED WITH THE
RIGHT ENTRANCE REGION OF AN UPPER LEVEL JET EXTENDED FROM
NORTHEAST COLORADO INTO EASTERN WYOMING. A SURFACE COLD FRONT
EXTENDED FROM NORTHEAST COLORADO INTO NORTHEAST NEBRASKA. SOUTH OF
THIS COLD FRONT WARM MID LEVEL TEMPERATURES WERE PRESENT ACROSS
WESTERN KANSAS WITH KDDC INDICATING 700MB TEMPERATURES AT +13C. AS
OF 06Z SURFACE ANALYSIS INDICATED THIS COLD FRONT WAS ALREADY
SURGING SOUTHEAST TOWARDS WEST CENTRAL KANSAS WITH LOW CLOUDS AND
NORTHWEST WINDS AROUND 25KNOTS DEVELOPING IN ITS WAKE.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 117 AM CDT SUN MAY 6 2012
BASED ON 925-850MB MOISTURE PROFILES THE MODELS THIS MORNING
REMAIN IN GOOD AGREEMENT IN LOW LEVEL MOISTURE RETURNING TO
SOUTHWEST KANSAS BEHIND A COLD FRONT THAT WAS CURRENTLY MOVING
INTO WEST CENTRAL KANSAS. NAM AND GFS 300-305 ISENTROPIC SURFACES
EVEN SUGGEST SOME WEAK LIFT WILL CONTINUE THROUGH 00Z MONDAY.
BASED ON THIS WEAK LIFT AND DEPTH OF THIS MOIST LAYER WILL KEEP A
MENTION OF DRIZZLE GOING THROUGH MUCH OF THE DAY, ESPECIALLY
NORTHEAST OF DODGE CITY WHERE THE ISENTROPIC LIFT IS A LITTLE
BETTER. GIVEN THE CHANCE FOR DRIZZLE ALONG WITH CLOUDY CONDITIONS
THE PREVIOUS FORECAST STILL LOOKS ON TRACK WITH AFTERNOON
TEMPERATURES RANGING FROM THE LOW TO MID 60S WITH THE EXCEPTION
BEING SOUTH CENTRAL KANSAS. WILL HAVE TO MONITOR HOW QUICKLY THIS
FRONT WILL CROSS SOUTH CENTRAL KANSAS EARLY THIS MORNING BUT AT
THIS TIME BASED ON 06Z SURFACE OBSERVATION ACROSS NORTHWEST KANSAS
IT APPEARS THAT THE NAM MAY BE A LITTLE SLOW SO ADJUSTING THE
TIMING OF THIS FRONT CLOSE TO THE HRRR WILL CONTINUE TO FAVOR
SLIGHTLY COOLER TEMPERATURES IN THE MEDICINE LODGE AREA THAN WHAT
THE NAM/GFS SUGGEST.
BOUNDARY LAYER AND 0-0.5KM LAYER WINDS BEHIND THIS COLD FRONT
ACROSS WESTERN KANSAS EARLY TODAY BOTH WERE FORECAST TO RANGE BETWEEN
30 AND 35 KNOTS BEHIND THIS FRONT. GIVEN THIS AND THE LOCATION OF
WHERE THE STRONGER LOW LEVEL WINDS ARE FORECAST TO BE BETWEEN 09Z
AND 15Z SUNDAY WILL KEEP CURRENT WIND ADVISORY AS IS FOR NOW.
MARGINAL WIND ADVISORY WINDS HOWEVER STILL APPEAR POSSIBLE A
LITTLE FURTHER SOUTHEAST, HOWEVER CONFIDENCE IS NOT HIGH ENOUGH AT
THIS TIME TO EXPAND THE PREVIOUS ADVISORY.
SURFACE HIGH PRESSURE WILL THEN BEGIN TO BUILD INTO THE ARE EARLY
TONIGHT AND 300-305 ISENTROPIC DOWN GLIDE DEVELOPS. LOW LEVEL
MOISTURE STILL PRESENT OVER WESTERN KANSAS THROUGH MUCH OF THE
NIGHT BUT GIVEN THE SUBSIDENCE/DOWN GLIDE SUGGESTED WILL BEGIN TO
SHOW A DECREASING TREND IN CLOUD COVER BY OR SHORTLY AFTER
MIDNIGHT...ESPECIALLY IN THE NORTH. IN AREAS WHERE THE SKIES ARE
EXPECTED TO CLEAR WILL TREND TOWARDS THE COOLER MET/MAV ON
TEMPERATURES WHILE FURTHER SOUTHEAST WILL CONTINUE TO FAVOR THE
WARMER MOSGUIDE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 340 AM CDT SUN MAY 6 2012
MONDAY:
A RATHER BROAD UPPER LEVEL TROUGH WILL BE WEST OF KANSAS MONDAY. WESTERN
KANSAS WILL BE IN A QUASI COUPLED JET REGION WITH THE LEFT EXIT REGION
OF A 250 HPA 70 KT JET ACROSS THE EASTERN SECTIONS OF THE DESERT SOUTHWEST
AND THE RIGHT ENTRANCE REGION OF A 250 HPA 65 KT JET ACROSS NEBRASKA.
AS A RESULT, HAVE KEPT POPS MAINLY ACROSS FAR SOUTHWEST KANSAS WHERE
BETTER LIFT WILL BE PRESENT VERSUS FURTHER EAST. NOT PARTICULARLY IMPRESSED
OVERALL AS MOST OF THE QPF SHOULD REMAIN ACROSS THE HIGHER TERRAIN ALSO
IN ASSOCIATION WITH OROGRAPHIC LIFT AND UPSLOPE FLOW IN A POST FRONTAL
ENVIRONMENT. A 1025 HPA HIGH WILL SLIDE DOWN THE PLAINS IN THE WAKE
OF THE AFOREMENTIONED FRONT. THIS AIRMASS WILL BE CHARACTERIZED AS PLEASANT
WITH 850 HPA TEMPERATURES NOT TOO WARM (~10-12 DEG C). UPPER 60S DEG
F TO LOWER 70S DEG F IS EXPECTED FOR THE BEGINNING OF THE WORKWEEK
WHICH IS JUST A HAIR BELOW CLIMATOLOGY.
TUESDAY:
THE DESERT SOUTHWEST SYSTEM WILL CONTINUE TO SINK SOUTHWARD INTO THE
BAJA REGION WHILE THE NORTHERN SYSTEM MOVES EAST. SOUTHWEST KANSAS WILL
BE LEFT IN A COL POINT AT THE UPPER LEVELS. AT THE SURFACE, THE COOL
HIGH PRESSURE CENTER WILL CONTINUE TO DOMINATE. RICH BOUNDARY MOISTURE
WILL BE ADVECTED WELL SOUTH INTO TEXAS WITH FAIRLY LOW DEWPOINTS ACROSS
THE SUNFLOWER STATE. AS A RESULT, OVERNIGHT LOWS INTO TUESDAY MORNING
WILL BE MAINLY IN THE 40S DEG F EXCEPT NEAR KP28 WHERE AROUND 50 DEG
F IS EXPECTED. LOW TEMPERATURES IN THE 40S DEG F ARE NEAR CLIMATOLOGY.
A LACK OF DYNAMICS ALOFT AND HIGH PRESSURE AT THE SURFACE WILL LEAD
TO A DRY FORECAST FOR TUESDAY.
WEDNESDAY/THURSDAY:
MAXIMUM TEMPERATURES WILL MODERATE WEDNESDAY WITH HIGHS IN THE MID 70S
DEG F OR ABOUT NEAR NORMAL AS THE COOL HIGH PRESSURE SLIDES OFF TO THE
EAST AND LEE TROUGHING AND RESULTANT WARM AIR ADVECTION DEVELOPS ACROSS
THE HIGH PLAINS. POPS WILL REMAIN NEAR ZERO AS THE 500 HPA RIDGE AXIS
SLIDES EAST THROUGH THE DAY AHEAD OF ANOTHER SHORTWAVE TROUGH MOVING
ONSHORE ACROSS THE PACIFIC NORTHWEST. THURSDAY WILL BE THE WARMEST DURING
MY PERIOD AS 850 HPA TEMPERATURES WARM INTO THE LOWER 20 DEG C AND LEE
TROUGHING STRENGTHENS WITH SOUTHERLY WINDS CONTINUING FROM THE SURFACE
AND THROUGH THE 850 HPA CONSTANT PRESSURE LAYER. RETURN OF RICH BOUNDARY
LAYER MOISTURE IS NOT EXPECTED AT THIS POINT AS A COLD FRONT WILL SCOUR
HIGHER DEWPOINTS SOUTHWARD ACROSS THE NORTHERN GULF OF MEXICO BASIN.
FRIDAY AND BEYOND:
THE FORECAST TURNS MORE UNSETTLED BY THE END OF NEXT WEEK ALTHOUGH UNCERTAINTY
IS PRETTY HIGH AS THIS POINT. PRECIPITATION MAY OCCUR EITHER FROM A
NORTHERN SYSTEM BRINGING IN A COLD FRONT OR FROM THE BAJA SYSTEM BRING
IN MOISTURE FROM THE SOUTH. AT THIS POINT, THE EXACT SOLUTION IS UNKNOWN.
PREFER THE DRIER SOLUTION FROM THE ECMWF. SHOWERS AND THUNDERSTORMS
WILL BE POSSIBLE AS LIFT AND MOISTURE ADVECTION INCREASES DURING THIS
PERIOD. EVEN IF YOU WERE TO BUY THE WETTER GFS SOLUTION, DEWPOINTS
RETURNING TO KANSAS ARE NOT THAT IMPRESSIVE FOR MAY - 50S DEG F.
DEWPOINTS IN THE 60S/70S DEG F ARE STILL FORECAST TO BE REMAIN WELL
SOUTH INTO THE GULF OF MEXICO. LASTLY, UPPER LEVEL JET DYNAMICS IS
ALSO WEAK WITH THE CUT OFF LOW REMAINING WELL SOUTH ACROSS TEXAS AND
THE STRONGER POLAR JET FORECAST WELL NORTH NEAR THE INTERNATIONAL
BORDER.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 600 AM CDT SUN MAY 6 2012
MVFR/IFR CIGS EXPECTED TODAY IN ASSOCIATION WITH POST FRONTAL STRATUS.
CIGS SHOULD IMPROVE TO VFR BY THE EARLY AFTERNOON. SECOND CONCERN IS
WINDS WHICH SHOULD BE IN THE NORTHERLY 20 TO 30 KT RANGE WITH GUSTS
35 TO 40 KT. THE STRONGEST WINDS ARE EXPECTED AT KGCK AND THE LOWEST
CIGS ARE EXPECTED AT KHYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 67 50 68 46 / 20 10 10 10
GCK 65 44 67 45 / 10 10 20 20
EHA 70 46 65 45 / 10 10 20 20
LBL 71 47 68 46 / 10 10 20 20
HYS 67 46 69 45 / 20 20 10 10
P28 79 57 71 50 / 20 20 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 3 PM CDT /2 PM MDT/ THIS AFTERNOON FOR
KSZ030-031-043>045-061>064-074>077-084>086.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...SUGDEN
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
340 AM CDT SUN MAY 6 2012
...UPDATE TO LONG TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 117 AM CDT SUN MAY 6 2012
AT 00Z SUNDAY AN UPPER LEVEL TROUGH WHICH WAS ASSOCIATED WITH THE
RIGHT ENTRANCE REGION OF AN UPPER LEVEL JET EXTENDED FROM
NORTHEAST COLORADO INTO EASTERN WYOMING. A SURFACE COLD FRONT
EXTENDED FROM NORTHEAST COLORADO INTO NORTHEAST NEBRASKA. SOUTH OF
THIS COLD FRONT WARM MID LEVEL TEMPERATURES WERE PRESENT ACROSS
WESTERN KANSAS WITH KDDC INDICATING 700MB TEMPERATURES AT +13C. AS
OF 06Z SURFACE ANALYSIS INDICATED THIS COLD FRONT WAS ALREADY
SURGING SOUTHEAST TOWARDS WEST CENTRAL KANSAS WITH LOW CLOUDS AND
NORTHWEST WINDS AROUND 25KNOTS DEVELOPING IN ITS WAKE.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 117 AM CDT SUN MAY 6 2012
BASED ON 925-850MB MOISTURE PROFILES THE MODELS THIS MORNING
REMAIN IN GOOD AGREEMENT IN LOW LEVEL MOISTURE RETURNING TO
SOUTHWEST KANSAS BEHIND A COLD FRONT THAT WAS CURRENTLY MOVING
INTO WEST CENTRAL KANSAS. NAM AND GFS 300-305 ISENTROPIC SURFACES
EVEN SUGGEST SOME WEAK LIFT WILL CONTINUE THROUGH 00Z MONDAY.
BASED ON THIS WEAK LIFT AND DEPTH OF THIS MOIST LAYER WILL KEEP A
MENTION OF DRIZZLE GOING THROUGH MUCH OF THE DAY, ESPECIALLY
NORTHEAST OF DODGE CITY WHERE THE ISENTROPIC LIFT IS A LITTLE
BETTER. GIVEN THE CHANCE FOR DRIZZLE ALONG WITH CLOUDY CONDITIONS
THE PREVIOUS FORECAST STILL LOOKS ON TRACK WITH AFTERNOON
TEMPERATURES RANGING FROM THE LOW TO MID 60S WITH THE EXCEPTION
BEING SOUTH CENTRAL KANSAS. WILL HAVE TO MONITOR HOW QUICKLY THIS
FRONT WILL CROSS SOUTH CENTRAL KANSAS EARLY THIS MORNING BUT AT
THIS TIME BASED ON 06Z SURFACE OBSERVATION ACROSS NORTHWEST KANSAS
IT APPEARS THAT THE NAM MAY BE A LITTLE SLOW SO ADJUSTING THE
TIMING OF THIS FRONT CLOSE TO THE HRRR WILL CONTINUE TO FAVOR
SLIGHTLY COOLER TEMPERATURES IN THE MEDICINE LODGE AREA THAN WHAT
THE NAM/GFS SUGGEST.
BOUNDARY LAYER AND 0-0.5KM LAYER WINDS BEHIND THIS COLD FRONT
ACROSS WESTERN KANSAS EARLY TODAY BOTH WERE FORECAST TO RANGE BETWEEN
30 AND 35 KNOTS BEHIND THIS FRONT. GIVEN THIS AND THE LOCATION OF
WHERE THE STRONGER LOW LEVEL WINDS ARE FORECAST TO BE BETWEEN 09Z
AND 15Z SUNDAY WILL KEEP CURRENT WIND ADVISORY AS IS FOR NOW.
MARGINAL WIND ADVISORY WINDS HOWEVER STILL APPEAR POSSIBLE A
LITTLE FURTHER SOUTHEAST, HOWEVER CONFIDENCE IS NOT HIGH ENOUGH AT
THIS TIME TO EXPAND THE PREVIOUS ADVISORY.
SURFACE HIGH PRESSURE WILL THEN BEGIN TO BUILD INTO THE ARE EARLY
TONIGHT AND 300-305 ISENTROPIC DOWN GLIDE DEVELOPS. LOW LEVEL
MOISTURE STILL PRESENT OVER WESTERN KANSAS THROUGH MUCH OF THE
NIGHT BUT GIVEN THE SUBSIDENCE/DOWN GLIDE SUGGESTED WILL BEGIN TO
SHOW A DECREASING TREND IN CLOUD COVER BY OR SHORTLY AFTER
MIDNIGHT...ESPECIALLY IN THE NORTH. IN AREAS WHERE THE SKIES ARE
EXPECTED TO CLEAR WILL TREND TOWARDS THE COOLER MET/MAV ON
TEMPERATURES WHILE FURTHER SOUTHEAST WILL CONTINUE TO FAVOR THE
WARMER MOSGUIDE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 340 AM CDT SUN MAY 6 2012
MONDAY:
A RATHER BROAD UPPER LEVEL TROUGH WILL BE WEST OF KANSAS MONDAY. WESTERN
KANSAS WILL BE IN A QUASI COUPLED JET REGION WITH THE LEFT EXIT REGION
OF A 250 HPA 70 KT JET ACROSS THE EASTERN SECTIONS OF THE DESERT SOUTHWEST
AND THE RIGHT ENTRANCE REGION OF A 250 HPA 65 KT JET ACROSS NEBRASKA.
AS A RESULT, HAVE KEPT POPS MAINLY ACROSS FAR SOUTHWEST KANSAS WHERE
BETTER LIFT WILL BE PRESENT VERSUS FURTHER EAST. NOT PARTICULARLY IMPRESSED
OVERALL AS MOST OF THE QPF SHOULD REMAIN ACROSS THE HIGHER TERRAIN ALSO
IN ASSOCIATION WITH OROGRAPHIC LIFT AND UPSLOPE FLOW IN A POST FRONTAL
ENVIRONMENT. A 1025 HPA HIGH WILL SLIDE DOWN THE PLAINS IN THE WAKE
OF THE AFOREMENTIONED FRONT. THIS AIRMASS WILL BE CHARACTERIZED AS PLEASANT
WITH 850 HPA TEMPERATURES NOT TOO WARM (~10-12 DEG C). UPPER 60SN DEG
F TO LOWER 70S DEG F IS EXPECTED FOR THE BEGINNING OF THE WORKWEEK WHICH
IS JUST A HAIR BELOW CLIMATOLOGY.
TUESDAY:
THE DESERT SOUTHWEST SYSTEM WILL CONTINUE TO SINK SOUTHWARD INTO THE
BAJA REGION WHILE THE NORTHERN SYSTEM MOVES EAST. SOUTHWEST KANSAS WILL
BE LEFT IN A COL POINT AT THE UPPER LEVELS. AT THE SURFACE, THE COOL
HIGH PRESSURE CENTER WILL CONTINUE TO DOMINATE. RICH BOUNDARY MOISTURE
WILL BE ADVECTED WELL SOUTH INTO TEXAS WITH FAIRLY LOW DEWPOINTS ACROSS
THE SUNFLOWER STATE. AS A RESULT, OVERNIGHT LOWS INTO TUESDAY MORNING
WILL BE MAINLY IN THE 40S DEG F EXCEPT NEAR KP28 WHERE AROUND 50 DEG
F IS EXPECTED. LOW TEMPERATURES IN THE 40S DEG F ARE NEAR CLIMATOLOGY.
A LACK OF DYNAMICS ALOFT AND HIGH PRESSURE AT THE SURFACE WILL LEAD
TO A DRY FORECAST FOR TUESDAY.
WEDNESDAY/THURSDAY:
MAXIMUM TEMPERATURES WILL MODERATE WEDNESDAY WITH HIGHS IN THE MID 70S
DEG F OR ABOUT NEAR NORMAL AS THE COOL HIGH PRESSURE SLIDES OFF TO THE
EAST AND LEE TROUGHING AND RESULTANT WARM AIR ADVECTION DEVELOPS ACROSS
THE HIGH PLAINS. POPS WILL REMAIN NEAR ZERO AS THE 500 HPA RIDGE AXIS
SLIDES EAST THROUGH THE DAY AHEAD OF ANOTHER SHORTWAVE TROUGH MOVING
ONSHORE ACROSS THE PACIFIC NORTHWEST. THURSDAY WILL BE THE WARMEST DURING
MY PERIOD AS 850 HPA TEMPERATURES WARM INTO THE LOWER 20 DEG C AND LEE
TROUGHING STRENGTHENS WITH SOUTHERLY WINDS CONTINUING FROM THE SURFACE
AND THROUGH THE 850 HPA CONSTANT PRESSURE LAYER. RETURN OF RICH BOUNDARY
LAYER MOISTURE IS NOT EXPECTED AT THIS POINT AS A COLD FRONT WILL SCOUR
HIGHER DEWPOINTS SOUTHWARD ACROSS THE NORTHERN GULF OF MEXICO BASIN.
FRIDAY AND BEYOND:
THE FORECAST TURNS MORE UNSETTLED BY THE END OF NEXT WEEK ALTHOUGH UNCERTAINTY
IS PRETTY HIGH AS THIS POINT. PRECIPITATION MAY OCCUR EITHER FROM A
NORTHERN SYSTEM BRINGING IN A COLD FRONT OR FROM THE BAJA SYSTEM BRING
IN MOISTURE FROM THE SOUTH. AT THIS POINT, THE EXACT SOLUTION IS UNKNOWN.
PREFER THE DRIER SOLUTION FROM THE ECMWF. SHOWERS AND THUNDERSTORMS
WILL BE POSSIBLE AS LIFT AND MOISTURE ADVECTION INCREASES DURING THIS
PERIOD. EVEN IF YOU WERE TO BUY THE WETTER GFS SOLUTION, DEWPOINTS
RETURNING TO KANSAS ARE NOT THAT IMPRESSIVE FOR MAY - 50S DEG F.
DEWPOINTS IN THE 60S/70S DEG F ARE STILL FORECAST TO BE REMAIN WELL
SOUTH INTO THE GULF OF MEXICO. LASTLY, UPPER LEVEL JET DYNAMICS IS
ALSO WEAK WITH THE CUT OFF LOW REMAINING WELL SOUTH ACROSS TEXAS AND
THE STRONGER POLAR JET FORECAST WELL NORTH NEAR THE INTERNATIONAL
BORDER.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1213 AM CDT SUN MAY 6 2012
04Z SURFACE ANALYSIS INDICATED A COLD FRONT MOVING SOUTH ACROSS
NORTHWEST KANSAS. THIS FRONT APPEARS TO BE MOVING QUICKER THAN
WHAT THE 00Z NAM OR 00Z GFS SUGGESTED. HRRR APPEARS TO BE MORE
REPRESENTATIVE SO WILL FOLLOW THE QUICKER HRRR ON TIMING OF WIND
SHIFT LATER THIS MORNING AS THIS FRONT CROSSES SOUTHWEST KANSAS.
GUSTY NORTH WINDS WILL DEVELOP BEHIND THIS FRONT EARLY SUNDAY
MORNING WITH SUSTAINED WINDS OF AROUND 25KTS POSSIBLE FOR SEVERAL
HOURS FOLLOWING FROPA. LOW CLOUDS, IFR CIGS, CAN ALSO BE EXPECTED
BEHIND THIS COLD FRONT EARLY SUNDAY. BASED ON ISENTROPIC LIFT
ALONG WITH THE DEPTH OF THIS MOIST LAYER SOME LIGHT DRIZZLE WILL
ALSO BE POSSIBLE. IFR CONDITIONS SHOULD BEGIN TO IMPROVE BY MID
AFTERNOON WITH LOW VFR CONDITIONS BECOMING POSSIBLE TOWARDS 00Z
MONDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 67 50 68 46 / 20 10 10 10
GCK 65 44 67 45 / 10 10 20 20
EHA 70 46 65 45 / 10 10 20 20
LBL 71 47 68 46 / 10 10 20 20
HYS 67 46 69 45 / 30 20 10 10
P28 79 57 71 50 / 20 20 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 3 PM CDT /2 PM MDT/ THIS AFTERNOON FOR
KSZ030-031-043>045-061>064-074>077-084>086.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...SUGDEN
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
129 AM CDT SUN MAY 6 2012
...UPDATED SYNOPSIS AND SHORT TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 117 AM CDT SUN MAY 6 2012
AT 00Z SUNDAY AN UPPER LEVEL TROUGH WHICH WAS ASSOCIATED WITH THE
RIGHT ENTRANCE REGION OF AN UPPER LEVEL JET EXTENDED FROM
NORTHEAST COLORADO INTO EASTERN WYOMING. A SURFACE COLD FRONT
EXTENDED FROM NORTHEAST COLORADO INTO NORTHEAST NEBRASKA. SOUTH OF
THIS COLD FRONT WARM MID LEVEL TEMPERATURES WERE PRESENT ACROSS
WESTERN KANSAS WITH KDDC INDICATING 700MB TEMPERATURES AT +13C. AS
OF 06Z SURFACE ANALYSIS INDICATED THIS COLD FRONT WAS ALREADY
SURGING SOUTHEAST TOWARDS WEST CENTRAL KANSAS WITH LOW CLOUDS AND
NORTHWEST WINDS AROUND 25KNOTS DEVELOPING IN ITS WAKE.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 117 AM CDT SUN MAY 6 2012
BASED ON 925-850MB MOISTURE PROFILES THE MODELS THIS MORNING
REMAIN IN GOOD AGREEMENT IN LOW LEVEL MOISTURE RETURNING TO
SOUTHWEST KANSAS BEHIND A COLD FRONT THAT WAS CURRENTLY MOVING
INTO WEST CENTRAL KANSAS. NAM AND GFS 300-305 ISENTROPIC SURFACES
EVEN SUGGEST SOME WEAK LIFT WILL CONTINUE THROUGH 00Z MONDAY.
BASED ON THIS WEAK LIFT AND DEPTH OF THIS MOIST LAYER WILL KEEP A
MENTION OF DRIZZLE GOING THROUGH MUCH OF THE DAY, ESPECIALLY
NORTHEAST OF DODGE CITY WHERE THE ISENTROPIC LIFT IS A LITTLE
BETTER. GIVEN THE CHANCE FOR DRIZZLE ALONG WITH CLOUDY CONDITIONS
THE PREVIOUS FORECAST STILL LOOKS ON TRACK WITH AFTERNOON
TEMPERATURES RANGING FROM THE LOW TO MID 60S WITH THE EXCEPTION
BEING SOUTH CENTRAL KANSAS. WILL HAVE TO MONITOR HOW QUICKLY THIS
FRONT WILL CROSS SOUTH CENTRAL KANSAS EARLY THIS MORNING BUT AT
THIS TIME BASED ON 06Z SURFACE OBSERVATION ACROSS NORTHWEST KANSAS
IT APPEARS THAT THE NAM MAY BE A LITTLE SLOW SO ADJUSTING THE
TIMING OF THIS FRONT CLOSE TO THE HRRR WILL CONTINUE TO FAVOR
SLIGHTLY COOLER TEMPERATURES IN THE MEDICINE LODGE AREA THAN WHAT
THE NAM/GFS SUGGEST.
BOUNDARY LAYER AND 0-0.5KM LAYER WINDS BEHIND THIS COLD FRONT
ACROSS WESTERN KANSAS EARLY TODAY BOTH WERE FORECAST TO RANGE BETWEEN
30 AND 35 KNOTS BEHIND THIS FRONT. GIVEN THIS AND THE LOCATION OF
WHERE THE STRONGER LOW LEVEL WINDS ARE FORECAST TO BE BETWEEN 09Z
AND 15Z SUNDAY WILL KEEP CURRENT WIND ADVISORY AS IS FOR NOW.
MARGINAL WIND ADVISORY WINDS HOWEVER STILL APPEAR POSSIBLE A
LITTLE FURTHER SOUTHEAST, HOWEVER CONFIDENCE IS NOT HIGH ENOUGH AT
THIS TIME TO EXPAND THE PREVIOUS ADVISORY.
SURFACE HIGH PRESSURE WILL THEN BEGIN TO BUILD INTO THE ARE EARLY
TONIGHT AND 300-305 ISENTROPIC DOWN GLIDE DEVELOPS. LOW LEVEL
MOISTURE STILL PRESENT OVER WESTERN KANSAS THROUGH MUCH OF THE
NIGHT BUT GIVEN THE SUBSIDENCE/DOWN GLIDE SUGGESTED WILL BEGIN TO
SHOW A DECREASING TREND IN CLOUD COVER BY OR SHORTLY AFTER
MIDNIGHT...ESPECIALLY IN THE NORTH. IN AREAS WHERE THE SKIES ARE
EXPECTED TO CLEAR WILL TREND TOWARDS THE COOLER MET/MAV ON
TEMPERATURES WHILE FURTHER SOUTHEAST WILL CONTINUE TO FAVOR THE
WARMER MOSGUIDE.
.LONG TERM...(TUESDAY MORNING THROUGH SATURDAY) ISSUED AT 349 PM CDT SAT
MAY 5 2012
AN UPPER-LEVEL LOW WILL BE SITUATED ACROSS THE DESERT SOUTHWEST FROM
TUESDAY INTO WEDNESDAY, WITH AN UPPER-LEVEL TROUGH MOVING FROM THE
UPPER MIDWEST INTO THE GREAT LAKES. DESPITE THE TROUGH DEVELOPING
ACROSS THE SOUTHWEST, WHICH IS OFTEN A FAVORABLE PATTERN FOR
PRECIPITATION ACROSS THE HIGH PLAINS IN MAY, SURFACE TO 850MB HIGH
PRESSURE IN THE WAKE OF THE GREAT LAKES TROUGH WILL MOVE SOUTHWARD
INTO THE CENTRAL PLAIN, SHUNTING THE LOW-LEVEL MOISTURE INTO THE
SOUTHERN PLAINS. ALSO, THE NORTHERN STREAM JET ENERGY WILL TEND TO
SUPPRESS THE SOUTHWESTERN UPPER-LEVEL TROUGH FURTHER SOUTH.
NEVERTHELESS, FRONTOGENESIS ALONG THE EXTREMITY OF THE UPPER MIDWEST
TROUGH, ALONG WITH SOME LOW TO MID-LEVEL MOISTURE, MAY PROMOTE
SHOWER DEVELOPMENT TUESDAY, ESPECIALLY IN FAR WESTERN KANSAS.
AS THE SOUTHWESTERN UPPER-LEVEL SYSTEM PROGRESSES ACROSS THE SOUTHERN
ROCKIES AND INTO TEXAS THROUGH THURSDAY AND FRIDAY, THE BULK (IF NOT
ALL) OF THE PRECIPITATION WILL STAY TO OUR SOUTH. THE BRUNT OF THE
COOLING WITH THE GREAT LAKES TROUGH IS PROGGED BY THE ECMWF/GEM TO
STAY TO OUR NORTH AND EAST. SO HIGH TEMPERATURES OUGHT TO STILL
REACH INTO THE 70S TUESDAY AND WEDNESDAY AND PERHAPS AS HIGH AS 80
BY THURSDAY, WITH LOWS IN THE MID 40S TO LOWER 50S. THESE TEMPERATURES
ARE SEASONABLE FOR EARLY MAY. EVEN AFTER THURSDAY, NO PARTICULARLY
STRONG COLD FRONTS OR HEAT WAVES ARE EXPECTED, WITH MAINLY A
CONTINUATION OF MODERATE TEMPERATURES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1213 AM CDT SUN MAY 6 2012
04Z SURFACE ANALYSIS INDICATED A COLD FRONT MOVING SOUTH ACROSS
NORTHWEST KANSAS. THIS FRONT APPEARS TO BE MOVING QUICKER THAN
WHAT THE 00Z NAM OR 00Z GFS SUGGESTED. HRRR APPEARS TO BE MORE
REPRESENTATIVE SO WILL FOLLOW THE QUICKER HRRR ON TIMING OF WIND
SHIFT LATER THIS MORNING AS THIS FRONT CROSSES SOUTHWEST KANSAS.
GUSTY NORTH WINDS WILL DEVELOP BEHIND THIS FRONT EARLY SUNDAY
MORNING WITH SUSTAINED WINDS OF AROUND 25KTS POSSIBLE FOR SEVERAL
HOURS FOLLOWING FROPA. LOW CLOUDS, IFR CIGS, CAN ALSO BE EXPECTED
BEHIND THIS COLD FRONT EARLY SUNDAY. BASED ON ISENTROPIC LIFT
ALONG WITH THE DEPTH OF THIS MOIST LAYER SOME LIGHT DRIZZLE WILL
ALSO BE POSSIBLE. IFR CONDITIONS SHOULD BEGIN TO IMPROVE BY MID
AFTERNOON WITH LOW VFR CONDITIONS BECOMING POSSIBLE TOWARDS 00Z
MONDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 64 50 69 48 / 20 10 20 20
GCK 61 44 68 47 / 10 10 20 20
EHA 63 46 66 47 / 10 10 30 20
LBL 64 47 69 47 / 10 10 20 20
HYS 64 46 70 49 / 30 20 10 10
P28 78 57 73 52 / 10 20 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 3 PM CDT /2 PM MDT/ THIS AFTERNOON FOR
KSZ030-031-043>045-061>064-074>077-084>086.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...FINCH
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1222 AM CDT SUN MAY 6 2012
...UPDATED AVIATION DISCUSSION...
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 942 PM CDT SAT MAY 5 2012
A COLD FRONT LOCATED ACROSS SOUTHERN NEBRASKA WAS AHEAD OF SCHEDULE
THIS EVENING. THE HIGH RESOLUTION RAPID REFRESH MODEL AND NAM
BRING THIS FRONT THROUGH DODGE CITY BY 5 AM. BOTH MODELS INDICATE LOW
STRATUS CLOUDS DEVELOPING AND THE NAM SHOWS THE LOW LEVEL CLOUD
DECK ABOUT 3000 FT THICK. THIS COULD LEAD TO AREAS OF DRIZZLE MUCH
OF THE DAY SUNDAY, ESPECIALLY FROM DODGE CITY NORTH AND EAST TO HAYS.
THIS MAKES SENSE BASED ON THE MOIST AIR MASS NORTH OF THE FRONT IN
NEBRASKA AND SOUTH DAKOTA WHERE DEWPOINTS WERE IN THE 50S TO LOWER
60S. A STRONGER COLD FRONT WAS MOVING THROUGH THE NEBRASKA
PANHANDLE AND INTO SOUTHERN SOUTH DAKOTA THIS EVENING AND THE
PASSAGE OF THIS FRONT WILL LEAD TO STEADY TEMPERATURES EVEN DURING
THE DAY SUNDAY. TEMPERATURES WERE LOWERED SEVERAL DEGREES TO MORE
REFLECT THE MAGNITUDE OF THE COOL AIR MASS. THE WIND ADVISORY WAS
STARTED EARLIER AT 08 UTC DUE TO THE FASTER ARRIVAL OF THE FRONT.
.LONG TERM...(TUESDAY MORNING THROUGH SATURDAY) ISSUED AT 349 PM CDT SAT
MAY 5 2012
AN UPPER-LEVEL LOW WILL BE SITUATED ACROSS THE DESERT SOUTHWEST FROM
TUESDAY INTO WEDNESDAY, WITH AN UPPER-LEVEL TROUGH MOVING FROM THE
UPPER MIDWEST INTO THE GREAT LAKES. DESPITE THE TROUGH DEVELOPING
ACROSS THE SOUTHWEST, WHICH IS OFTEN A FAVORABLE PATTERN FOR
PRECIPITATION ACROSS THE HIGH PLAINS IN MAY, SURFACE TO 850MB HIGH
PRESSURE IN THE WAKE OF THE GREAT LAKES TROUGH WILL MOVE SOUTHWARD
INTO THE CENTRAL PLAIN, SHUNTING THE LOW-LEVEL MOISTURE INTO THE
SOUTHERN PLAINS. ALSO, THE NORTHERN STREAM JET ENERGY WILL TEND TO
SUPPRESS THE SOUTHWESTERN UPPER-LEVEL TROUGH FURTHER SOUTH.
NEVERTHELESS, FRONTOGENESIS ALONG THE EXTREMITY OF THE UPPER MIDWEST
TROUGH, ALONG WITH SOME LOW TO MID-LEVEL MOISTURE, MAY PROMOTE
SHOWER DEVELOPMENT TUESDAY, ESPECIALLY IN FAR WESTERN KANSAS.
AS THE SOUTHWESTERN UPPER-LEVEL SYSTEM PROGRESSES ACROSS THE SOUTHERN
ROCKIES AND INTO TEXAS THROUGH THURSDAY AND FRIDAY, THE BULK (IF NOT
ALL) OF THE PRECIPITATION WILL STAY TO OUR SOUTH. THE BRUNT OF THE
COOLING WITH THE GREAT LAKES TROUGH IS PROGGED BY THE ECMWF/GEM TO
STAY TO OUR NORTH AND EAST. SO HIGH TEMPERATURES OUGHT TO STILL
REACH INTO THE 70S TUESDAY AND WEDNESDAY AND PERHAPS AS HIGH AS 80
BY THURSDAY, WITH LOWS IN THE MID 40S TO LOWER 50S. THESE TEMPERATURES
ARE SEASONABLE FOR EARLY MAY. EVEN AFTER THURSDAY, NO PARTICULARLY
STRONG COLD FRONTS OR HEAT WAVES ARE EXPECTED, WITH MAINLY A
CONTINUATION OF MODERATE TEMPERATURES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1213 AM CDT SUN MAY 6 2012
04Z SURFACE ANALYSIS INDICATED A COLD FRONT MOVING SOUTH ACROSS
NORTHWEST KANSAS. THIS FRONT APPEARS TO BE MOVING QUICKER THAN
WHAT THE 00Z NAM OR 00Z GFS SUGGESTED. HRRR APPEARS TO BE MORE
REPRESENTATIVE SO WILL FOLLOW THE QUICKER HRRR ON TIMING OF WIND
SHIFT LATER THIS MORNING AS THIS FRONT CROSSES SOUTHWEST KANSAS.
GUSTY NORTH WINDS WILL DEVELOP BEHIND THIS FRONT EARLY SUNDAY
MORNING WITH SUSTAINED WINDS OF AROUND 25KTS POSSIBLE FOR SEVERAL
HOURS FOLLOWING FROPA. LOW CLOUDS, IFR CIGS, CAN ALSO BE EXPECTED
BEHIND THIS COLD FRONT EARLY SUNDAY. BASED ON ISENTROPIC LIFT
ALONG WITH THE DEPTH OF THIS MOIST LAYER SOME LIGHT DRIZZLE WILL
ALSO BE POSSIBLE. IFR CONDITIONS SHOULD BEGIN TO IMPROVE BY MID
AFTERNOON WITH LOW VFR CONDITIONS BECOMING POSSIBLE TOWARDS 00Z
MONDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 52 69 48 70 / 10 20 20 10
GCK 50 68 47 70 / 10 20 20 20
EHA 48 66 47 68 / 10 30 20 20
LBL 50 69 47 68 / 10 20 20 20
HYS 51 70 49 71 / 10 10 10 10
P28 58 73 52 71 / 10 10 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 3 PM CDT /2 PM MDT/ THIS AFTERNOON FOR
KSZ030-031-043>045-061>064-074>077-084>086.
&&
$$
SHORT TERM...FINCH
LONG TERM...FINCH
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS JACKSON KY
1042 PM EDT MON MAY 7 2012
.UPDATE...
ISSUED AT 1042 PM EDT MON MAY 7 2012
AS EXPECTED...INSTABILITY HAS BEEN NON-EXISTENT INTO THE OVERNIGHT
HOURS. IT LOOKS LIKE A HEAVIER BAND OF RAIN IS SETTING UP ACROSS
CENTRAL KENTUCKY AND THIS COULD BRUSH OUR BLUEGRASS COUNTIES.
HOWEVER...THE BULK OF THE HEAVIER RAIN SHOULD STAY TO OUR WEST BASED
ON THE LATEST RADAR TRENDS. HOWEVER...PERIODIC RAIN SHOWERS WILL
STILL PUSH ACROSS MUCH OF EASTERN KENTUCKY THROUGH THE REMAINDER OF
THE NIGHT. ONLY CHANGES WERE TO BRING IN THE HIGHER POPS INTO THE
WEST A BIT QUICKER...BUT OTHERWISE...FORECAST IS IN GOOD SHAPE.
UPDATE ISSUED AT 816 PM EDT MON MAY 7 2012
CONVECTIVE ACTIVITY THIS EVENING HAS REALLY PUT THE CLAMPS ON
INSTABILITY AND THUNDER CHANCES ARE DIMINISHING QUICKLY OR HAVE
ALREADY LEFT. WITH MID LEVEL LAPSE RATES VERY POOR AND NO SURFACE
INSTABILITY TO SPEAK OF...PLAN TO REMOVE THUNDER FOR THE REST OF THE
NIGHT AND ALSO ON TUESDAY. STILL SOME THUNDER ACROSS NORTH CENTRAL
KENTUCKY...BUT THE SURFACE INSTABILITY IS STILL PRESENT OUT THAT
DIRECTION. MID LEVEL TROUGH STILL EXPECTED TO CROSS THE AREA LATE
TONIGHT INTO TUESDAY...PRODUCING WIDESPREAD SHOWER ACTIVITY. IT LOOKS
LIKE THE BEST FORCING WILL ARRIVE AFTER MIDNIGHT AND CONTINUE INTO
TUESDAY MORNING. COULD BE A PROLONG PERIOD OF RAIN SHOWER ACTIVITY
ACROSS THE SOUTHEAST WITH UPSLOPE FLOW TUESDAY MORNING INTO TUESDAY
AFTERNOON. RAINFALL AMOUNTS WITH THE LACK OF THUNDERSTORMS WILL BE
MUCH LIGHTER WHICH IS ALWAYS GOOD NEWS FOR THIS PART OF THE COUNTRY.
TEMPERATURES HAVE STARTED OFF FAIRLY COOL THIS EVENING...BUT WITH
DEWPOINTS IN THE 60S...THEY DO NOT HAVE MUCH ROOM TO FALL. THIS
SUGGEST THE POTENTIAL FOR SOME PATCHY FOG IN THE VALLEYS PRIOR TO THE
RAIN ARRIVING LATE TONIGHT.
&&
.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 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 816 PM EDT MON MAY 7 2012
A COLD FRONT WILL PUSH ACROSS THE AREA OVERNIGHT WITH RAIN SHOWERS
SPREADING OVER THE AREA. AS THIS FRONT PASSES THROUGH...CIGS ARE
EXPECTED TO DROP OFF QUICKLY WITH MVFR CIGS EARLY...THEN DROPPING TO
IFR ACROSS NORTHEAST KENTUCKY. THINGS MAY STAY MVFR ACROSS THE
SOUTHWEST AND WEST. THIS IFR/MVFR CIGS WILL SLOWLY IMPROVE BACK TO
VFR ON TUESDAY...BUT MAY TAKE A GOOD CHUNK OF THE DAY FOR THIS TO
HAPPEN. EXPECTATIONS ARE THAT VFR CONDITIONS WILL RETURN IN THE
AFTERNOON...BUT COULD PERSIST MUCH LONGER. RAIN SHOWERS WILL START
AFTER MIDNIGHT AND CONTINUE THROUGH TUESDAY MORNING BEFORE COMING TO
AN END IN THE AFTERNOON.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...GEOGERIAN
LONG TERM....GREIF
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS JACKSON KY
817 PM EDT MON MAY 7 2012
.UPDATE...
ISSUED AT 816 PM EDT MON MAY 7 2012
CONVECTIVE ACTIVITY THIS EVENING HAS REALLY PUT THE CLAMPS ON
INSTABILITY AND THUNDER CHANCES ARE DIMINISHING QUICKLY OR HAVE
ALREADY LEFT. WITH MID LEVEL LAPSE RATES VERY POOR AND NO SURFACE
INSTABILITY TO SPEAK OF...PLAN TO REMOVE THUNDER FOR THE REST OF THE
NIGHT AND ALSO ON TUESDAY. STILL SOME THUNDER ACROSS NORTH CENTRAL
KENTUCKY...BUT THE SURFACE INSTABILITY IS STILL PRESENT OUT THAT
DIRECTION. MID LEVEL TROUGH STILL EXPECTED TO CROSS THE AREA LATE
TONIGHT INTO TUESDAY...PRODUCING WIDESPREAD SHOWER ACTIVITY. IT LOOKS
LIKE THE BEST FORCING WILL ARRIVE AFTER MIDNIGHT AND CONTINUE INTO
TUESDAY MORNING. COULD BE A PROLONG PERIOD OF RAIN SHOWER ACTIVITY
ACROSS THE SOUTHEAST WITH UPSLOPE FLOW TUESDAY MORNING INTO TUESDAY
AFTERNOON. RAINFALL AMOUNTS WITH THE LACK OF THUNDERSTORMS WILL BE
MUCH LIGHTER WHICH IS ALWAYS GOOD NEWS FOR THIS PART OF THE COUNTRY.
TEMPERATURES HAVE STARTED OFF FAIRLY COOL THIS EVENING...BUT WITH
DEWPOINTS IN THE 60S...THEY DO NOT HAVE MUCH ROOM TO FALL. THIS
SUGGEST THE POTENTIAL FOR SOME PATCHY FOG IN THE VALLEYS PRIOR TO THE
RAIN ARRIVING LATE TONIGHT.
&&
.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 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 816 PM EDT MON MAY 7 2012
A COLD FRONT WILL PUSH ACROSS THE AREA OVERNIGHT WITH RAIN SHOWERS
SPREADING OVER THE AREA. AS THIS FRONT PASSES THROUGH...CIGS ARE
EXPECTED TO DROP OFF QUICKLY WITH MVFR CIGS EARLY...THEN DROPPING TO
IFR ACROSS NORTHEAST KENTUCKY. THINGS MAY STAY MVFR ACROSS THE
SOUTHWEST AND WEST. THIS IFR/MVFR CIGS WILL SLOWLY IMPROVE BACK TO
VFR ON TUESDAY...BUT MAY TAKE A GOOD CHUNK OF THE DAY FOR THIS TO
HAPPEN. EXPECTATIONS ARE THAT VFR CONDITIONS WILL RETURN IN THE
AFTERNOON...BUT COULD PERSIST MUCH LONGER. RAIN SHOWERS WILL START
AFTER MIDNIGHT AND CONTINUE THROUGH TUESDAY MORNING BEFORE COMING TO
AN END IN THE AFTERNOON.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...GEOGERIAN
LONG TERM....GREIF
AVIATION...KAS
AREA FORECAST DISCUSSION...UPDATED
NWS PADUCAH KY
652 PM CDT MON MAY 7 2012
.UPDATE...
ISSUED AT 641 PM CDT MON MAY 7 2012
AN INTERIM GRID REVISION WAS MADE TO BLEND CURRENT POP/WEATHER
WITH THE MODEL REFLECTIVITY FROM THE 3KM HRRR AND 4KM NMM VERSION
OF THE NAM-WRF GUIDANCE. THESE SETS OF HIGH RESOLUTION STORM
SCALE MODELS SUGGEST THAT THE MAIN BAND OF CONVECTION OVER THE
PENNYRILE REGION OF WEST KENTUCKY WILL SCOUR OUT THE DEEPEST
MOISTURE ALONG AND AHEAD OF THE COLD FRONT. THIS CONVECTION WAS
AIDED EARLIER IN THE AFTERNOON WITH A LOW/MIDDLE LEVEL CIRCULATION
RIDING NORTHEAST ALONG AND AHEAD OF THE FRONTAL BOUNDARY.
THE SECONDARY LINE OF DISORGANIZED CONVECTION MAY BE SUGGESTIVE OF
POST-FRONTAL ZONE OF LIFT IN THE 925-850 MB FRONTAL ZONE. THIS MAY
PERSIST INTO THE EVENING HOURS ACROSS THE WFO PAH FORECAST AREA.
GIVEN THE LIMITED INSTABILITY EXPECTED TONIGHT...MAY NEED TO RE-EVALUATE
THE MENTION OF THUNDERSTORMS IN THE GRIDDED FORECAST...WITH A
HIGHER POP ASSOCIATED WITH SHOWERS VERSUS THUNDERSTORMS.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 152 PM CDT MON MAY 7 2012
THIS MORNING`S SHOWERS/STORMS REALLY WORKED THE ATMOSPHERE OVER
AND CAPPED IT OFF WITH A NICE LAYERED DECK OF CLOUDINESS. THIS WAS
INHIBITING CONVECTION FROM REFIRING THUS FAR...AND LED TO THE SPC
DOWNGRADE FROM SLGT RISK TO SEE TEXT FOR OUR AREA.
EVEN SO...SATELLITE IS STARTING TO SHOW SOME HINTS AT THINNING OF
THIS MORNING`S COMPLEX CLOUDINESS. SURFACE OBS REVEAL THE ACTUAL
FRONTAL BOUNDARY STILL PERCHED JUST TO THE NORTH AND WEST OF THE
FA...AND RADAR MOSAIC DOES SHOW SOME ACTIVITY TRYING TO DEVELOP
ALONG IT. AS THE BOUNDARY MOVES IN THIS PM...WE WILL MONITOR FOR
STRONG STORM POTENTIAL. WHILE WE`VE BACKED OFF THE PREVIOUSLY
INHERITED LIKELY AND BETTER POPS...WE STILL WANT TO MAINTAIN AT
LEAST HIGH CHANCE CAT GOING UNTIL THE FRONT MAKES ITS PASS.
12Z MODELS INDICATE THE PASSAGE OF THE FRONT AND THE ASSOCIATED
UPPER WAVE WILL BE THIS EVENING...WITH PCPN ALL BUT THRU BY 06Z.
SOME LATE NIGHT LINGERING OF A SMALL POP IS POSSIBLE IN THE FARTHEST
SERN PTNS FA...BUT ALL SHOULD BE PCPN FREE BY 12Z TUESDAY...SO WE`LL
MAKE THAT MODIFICATION TO THE FORECAST AS WELL.
TUESDAY-WEDNESDAY NIGHT WILL SEE POST FRONTAL COOLING/DRYING AIRMASS
BRINGING PLEASANT RELIEF TO THE SUMMER-LIKE HEAT/HUMIDITY OF RECENT
DAYS PAST. UPPER TROF PASSAGE WED LOOKS FOR NOW TO KEEP PCPN CHANCES
NORTH AND EAST OF US...BUT SOMETHING TO KEEP AN EYE UPON.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 152 PM CDT MON MAY 7 2012
SURFACE HIGH PRESSURE AND RISING HEIGHTS ALOFT SHOULD KEEP THE
REGION DRY WITH SEASONAL TEMPERATURES THROUGH SATURDAY. MODELS
DRAG A FRONT ACROSS OUR CWA ON SATURDAY BUT DONT GENERATE ANY
PRECIP IN THE PROCESS. THEY DO HOWEVER INDICATE POST FRONTAL
PRECIP CHANCES SATURDAY NIGHT AND SUNDAY.
BEYOND THAT DRY CONDITIONS SHOULD RETURN THROUGH THE END OF THE
FORECAST CYCLE WITH SLIGHTLY MODERATING TEMPERATURES. THE ECMWF
SHOWS A WEAKNESS IN THE SURFACE AND UPPER LEVELS OVER SOUTHEAST
MISSOURI NEXT MONDAY AND GENERATES A BIT OF PRECIP THERE. SINCE
THE OTHER LONG RANGE MODELS KEEP THE SURFACE HIGH STRONGER AND
GENERATE NO PRECIP...WILL KEEP IT DRY FOR NOW.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 641 PM CDT MON MAY 7 2012
FOR THE 00Z TAF ISSUANCE...ATTEMPTED TO ADDRESS THE MEAN PERIODS
OF CONVECTION /SHOWERS OR THUNDERSTORMS/ DURING THE FIRST 6 HOURS
OF THE TAF FORECAST FOR EACH OF THE SITES. THIS WILL LIKELY BE THE
HIGHEST PROBABILITY PERIOD FOR MVFR CEILINGS BEHIND THE COLD
FRONT. BY 12Z-14Z TUESDAY...VFR CEILINGS AND VISIBILITIES ARE THE
RULE ACROSS ALL OF THE WFO PAH TAF SITES.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...SMITH
SHORT TERM...DH
LONG TERM....JP
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1145 AM EDT SUN MAY 6 2012
.SYNOPSIS...
ISSUED AT 400 AM EDT SUN MAY 6 2012
HIGH PRESSURE WILL RESULT IN DRY WEATHER ACROSS LOWER MICHIGAN
THROUGH MIDDAY SUNDAY. THE NEXT LOW PRESSURE SYSTEM WILL BRING A
CHANCE OF SHOWERS AND A FEW TSTORMS AS EARLY AS THIS AFTERNOON. RAIN
AND THUNDERSTORMS ARE LIKELY ACROSS OUR AREA TONIGHT INTO MONDAY. A
FEW SHOWERS WILL LINGER THROUGH MIDWEEK BEFORE HIGH PRESSURE BUILDS
IN AND BRINGS FAIR WEATHER LATE IN THE WEEK.
&&
.UPDATE...
ISSUED AT 1145 AM EDT SUN MAY 6 2012
I HAVE ONCE AGAIN UPDATED THE GRIDS AND ZONES TO REFLECT AN
INCREASED THREAT FOR MID TO LATE AFTERNOON THUNDERSTORMS OVER THE
WESTERN CWA. THE LATEST RUC DATA SHOWS THE CONVECTION IS FOLLOWING
THE 1000 TO 850 MOISTURE TRANSPORT VECTOR CONVERGENCE AXIS. THIS
AREA MOVES INTO SOUTHWEST LOWER MICHIGAN (NEAR AND WEST OF US-131)
BY 4 PM. THE ADJUSTED TIME TOOL INFO SLOWS THE ARRIVAL TO OUR
BEACHES ON LAKE MICHIGAN UNTIL 330 PM. WE WILL CONTINUE TO MONITOR
THIS SITUATION. THE RAP SHOWS THE LLJ WEAKEN AS IT MOVES INTO
SOUTHWEST MICHIGAN AND MOST UNSTABLE CAPE STRUGGLES TO MAKE US-31
EVEN BY 00Z. SO THE STORMS SHOULD WEAKEN BUT THE WESTERN SECTIONS
SHOULD AT LEAST SEE SOME SHOWERS MID TO LATE AFTERNOON.
.SHORT TERM...(TODAY THROUGH MONDAY AFTERNOON)
ISSUED AT 400 AM EDT SUN MAY 6 2012
SHORT TERM FCST CONCERNS INVOLVE TIMING OF RAIN/CONVECTION INTO OUR
AREA THIS AFTERNOON THROUGH MONDAY.
RGNL IR SAT/RADAR TRENDS AND A CONSENSUS OF 00Z SHORT RANGE GUIDANCE
ALL SUGGEST THAT DRY CONDITIONS WILL PREVAIL ACROSS OUR FCST AREA
THROUGH MIDDAY/EARLY AFTN.
WE WILL MAINTAIN CHC POPS FOR SHOWERS FOR PORTIONS OF OUR AREA THIS
AFTN AS A LARGE AREA OF RAIN AND TSTORMS OVER MN EARLY THIS MORNING
MOVES ESE INTO WI LATER THIS MORNING. RAIN MAY REACH OUR WESTERN
FCST AREA TOWARD MID AFTERNOON. CONVECTION WILL LIKELY BE
DISSIPATING AS SUGGESTED BY 00Z 4KM WRF-NMM SIM Z GUIDANCE. SO IT
SHOULD BE JUST DISSIPATING SHOWERS TRYING TO MOVE IN FROM THE WNW
TOWARD MID TO LATE AFTN... PERHAPS AN ISOLATED STORM DEPENDING ON
HOW WELL THE MCV HOLDS TOGETHER.
RAIN WILL INCREASE IN COVERAGE LATE TONIGHT THROUGH MONDAY ALONG
WITH SOME TSTORMS AS ELEVATED INSTABILITY INCREASES WITH H8 LI/S
FALLING TO AROUND 0 TO -1 OVERNIGHT THROUGH MONDAY. UPPER DIVERGENCE
IS ALSO FAVORABLE FOR SOME TSTORMS TONIGHT AND PRECIPITABLE WATER
VALUES RAMP UP TO AROUND 1.5 INCHES LATE TONIGHT THROUGH MONDAY
AFTN. SO WE WILL MAINTAIN LIKELY POPS TONIGHT/MONDAY.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 400 AM EDT SUN MAY 6 2012
EARLY WEEK SYSTEM WILL BE SLIDING JUST EAST OF THE AREA MONDAY
NIGHT...TAKING SHOWERS AND A FEW STORMS OFF TO THE EAST DURING THE
EVENING. EXPECT A DRY OVERNIGHT MONDAY NIGHT.
MAIN LONG TERM FEATURE WILL BE AN UPPER TROUGH SWINGING THROUGH THE
GREAT LAKES REGION MID WEEK. THE TROUGH PIVOTS IN FROM THE NORTHWEST
ON TUESDAY...CENTERED OVER THE FORECAST AREA TUESDAY NIGHT AND
WEDNESDAY. BEST CHANCES FOR SHOWERS ASSOCIATED WITH THE UPPER TROUGH
WILL COME TUESDAY NIGHT AND WEDNESDAY. OVERALL...MOISTURE DEPTH IS
NOT REAL IMPRESSIVE...SO HAVE CHANCE POPS IN THE FORECAST FOR
NOW...30/40 PCT.
DRY WEATHER SHOULD RETURN FOR WEDNESDAY NIGHT THROUGH FRIDAY AS
RIDGING BUILDS BACK INTO THE AREA. A FRONT APPROACHES AND MOVES
THROUGH FROM THE NORTHWEST FRIDAY NIGHT AND SATURDAY. CHANCE POPS
FOR SHOWERS FOR NOW AS A NARROW RIBBON OF MOISTURE MOVES THROUGH.
A COOLING TREND IS EXPECTED INTO MID WEEK AS THE UPPER TROUGH SWINGS
THROUGH. 850MB TEMPS DROP INTO THE 0 TO +4C RANGE. WEDNESDAY LOOKS
TO BE THE COOLEST DAY WITH HIGHS ONLY REACHING THE MID TO UPPER 50S
IN MOST SPOTS. SOUTHWEST FLOW BRINGS A RETURN OF WARMER AIR FOR
FRIDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 746 AM EDT SUN MAY 6 2012
VFR CEILINGS WITH BASES AROUND 3500FT WERE PREVALENT ACROSS
SOUTHWEST LOWER MICHIGAN AT 1130Z. MVFR CEILINGS WERE NOTED AT
KGRR AND KMKG. THE EXPECTATION IS THE MVFR CEILINGS WILL LIFT TO
VFR LEVELS BY 15Z...WITH VFR CONDITIONS PERSISTING THROUGH THE
AFTERNOON.
MAIN CONCERN TODAY WILL BE THE UPSTREAM SHOWERS AND THUNDERSTORMS
OVER WISCONSIN. IT WILL TAKE UNTIL ABOUT 18Z FOR THEM TO REACH
WESTERN LOWER MICHIGAN AT THE CURRENT PACE. THE SHOWERS AND STORMS
SHOULD OUT RUN BETTER INSTABILITY AND BEGIN TO DISSIPATE AS THEY
HIT LAKE MICHIGAN. ITS CONCEIVABLE SOME SHOWERS WILL SURVIVE AND
MOVE INTO THE AREA THIS AFTERNOON...BUT FEEL STORMS WILL HOLD OFF
UNTIL TONIGHT.
A BETTER CHANCE FOR SHOWERS AND STORMS EXISTS TONIGHT AFTER ABOUT
02Z...AS MOISTURE FEEDS INTO THE AREA ON SOUTHERLY WINDS ALOFT.
LOOK FOR MVFR CONDITIONS TO DEVELOP OVERNIGHT AS THE SHOWERS AND
STORMS BECOME MORE NUMEROUS.
&&
.MARINE...
ISSUED AT 400 AM EDT SUN MAY 6 2012
RATHER MINIMAL WAVE ACTION ANTICIPATED TODAY THROUGH TONIGHT INTO
MONDAY DUE TO OFFSHORE EASTERLY WINDS..
&&
.HYDROLOGY...
ISSUED AT 400 AM EDT SUN MAY 6 2012
LOW PRESSURE MOVING IN FROM THE WEST WILL BRING A CHANCE OF SHOWERS
THIS AFTERNOON FOLLOWED BY MORE WIDESPREAD RAINFALL AND TSTORMS
TONIGHT AND MONDAY. LOCALLY HEAVY RAINFALL IS POSSIBLE LATE TONIGHT
THROUGH MONDAY AS PRECIPITABLE WATER VALUES CLIMB TO AROUND 1.5
INCHES IN THAT TIME FRAME.
1000-850 MB MOISTURE TRANSPORT DOES NOT LOOK VERY IMPRESSIVE BUT
DEEPER MOISTURE DOES MOVE IN TONIGHT AND MONDAY. BASIN AVG QPF
AMOUNTS TONIGHT THROUGH MONDAY SHOULD AVERAGE AROUND A HALF AN INCH
TO AN INCH... WITH LOCALLY HIGHER VALUES TO TWO INCHES POSSIBLE.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...DUKE
AVIATION...DUKE
HYDROLOGY...LAURENS
MARINE...LAURENS
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
125 PM CDT SUN MAY 6 2012
.UPDATE...
UPDATED TO INCLUDE 18Z AVIATION DISCUSSION BELOW.
&&
.DISCUSSION...
MCS IS CURRENTLY ONGOING ACROSS THE CWA AND THERE IS STILL SOME
QUESTION AS TO REDEVELOPMENT POTENTIAL LATER THIS AFTERNOON. A
COLD FRONT WILL SLIDE THROUGH THE REGION SUNDAY NIGHT...WITH
COOLER AND DRIER WEATHER EXPECTED THIS WEEK. THE EXCEPTION WILL BE
TUESDAY...WHEN A POSITIVELY TILTED NORTHERN STREAM WAVE MOVES
ACROSS THE REGION...AND FRIDAY...WHEN ANOTHER COLD FRONT MOVES
THROUGH THE REGION.
TODAY...TRAILING STRATIFORM THUNDERSTORMS COMPLEX CONTINUES TO
MOVE EASTWARD AT A SLIGHTLY FASTER CLIP THAN SHORTRANGE MODELS
INDICATE. THE HRRR IS CONSISTENTLY ABOUT 2 HOURS TOO SLOW...AND
THE 00Z SPC WRF ABOUT AN HOUR TARDY ON ITS EASTWARD PROGRESSION.
AS THIS SYSTEM CLEARS OUT...COULD SEE SOME BOUNDARY LAYER
DESTABILIZATION THIS AFTERNOON NEAR THE IA/MN BORDER.
THIS INSTABILITY IN COMBINATION WITH SEVERAL OUTFLOW BOUNDARIES
AND SOUTHWESTERLY FLOW ALOFT WITH A FEW EMBEDDED WEAK SHORTWAVES
COULD BE THE FOCUS FOR ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS
THIS AFTERNOON. THE MARGINAL SHEAR AND CAPE VALUES SHOULD KEEP
THE SEVERE THREAT SOUTH AND EAST OF THE CWA.
SUNDAY NIGHT THROUGH SATURDAY...A SURFACE COLD FRONT WILL HAVE
PUSHED THROUGH THE REGION BY SUNDAY NIGHT...WITH MUCH DRIER AIR
IN PLACE BY MONDAY. SHOULD BE A DRY DAY...WITH A FEW AFTERNOON
CUMULUS DEVELOPING. ON TUESDAY THE UPPER LEVEL LOW DRIVING THE
AFOREMENTIONED SURFACE FRONT WILL SLIDE IN FROM THE NORTHWEST. A
WEAK SHORTWAVE WILL ROTATE AROUND THIS UPPER LEVEL LOW...AND COLD
H850 TEMPS WILL STREAM IN FROM THE NORTHWEST. THIS SHOULD SET THE
STAGE FOR A COOL OVERCAST DAY AND SOME AFTERNOON SHOWERS CENTERED
AROUND PEAK HEATING. FOR THE REST OF THE WEEK...HIGHLY AMPLIFIED
FLOW WILL BE THE NAME OF THE GAME. FOR STARTERS...UPPER LEVEL
SUBSIDENCE DOWNSTREAM OF A RIDGE CENTERED OVER MONTANA WILL CAUSE
AN AREA OF SURFACE HIGH PRESSURE TO BUILD OVER THE UPPER MIDWEST
ON WEDNESDAY. THIS WILL QUICKLY BE FOLLOWED BY AN UPPER LEVEL
TROUGH ON THURSDAY...WHICH WILL DEVELOP A SURFACE LOW OUT WEST AND
CAUSE SOUTHERLY WINDS AND WARM AIR ADVECTION TO MOVE ACROSS THE
REGION. AS THIS LOW TRACKS EASTWARD ON FRIDAY...EXPECT ANOTHER
CHANCE FOR SHOWERS AND THUNDERSTORMS MAINLY DURING THE AFTERNOON
HOURS. FINALLY...ANOTHER AREA OF SURFACE HIGH PRESSURE WILL BUILD
IN THE WAKE OF FRIDAY(S) SYSTEM...WHICH SHOULD LEAD TO A DRY
WEEKEND WITH SEASONAL TEMPERATURES.
&&
.AVIATION.../18Z TAF ISSUANCE/
OCCLUDED FRONT MAKING ITS WAY ACRS MN THIS AFTN WILL SHIFT INTO WI
THIS EVENING...FOLLOWED BY WEAK HIGH PRESSURE THROUGH THE DAY
TMRW. LOW CLOUDS WITH WEAK LOW LEVEL STEERING FLOW WILL PERSIST
THROUGH AT LEAST THE EVENING HRS. ALL SITES /EXCEPT KRWF DUE TO A
NARROW BINOVC CROSSING THE VICINITY/ INITIALIZED AT IFR OR LOWER
MVFR RANGE. CEILINGS ARE EXPECTED TO REMAIN LOW THROUGH THE
EVENING THEN AS DRIER AIR MOVES OVER...CEILINGS WILL SLOWLY
DISSIPATE TO SCATTERED COVERAGE THEN LIFT OUT TMRW. AM NOT
EXPECTING ANY PRECIP NOR ANY VSBY RESTRICTIONS...THOUGH IF SOME
SITES BECOME CALM THEN PATCHY FOG MAY DEVELOP DURING THE PRE-DAWN
HOURS. REGARDING WINDS... DIRECTIONS THROUGH THE REST OF THE DAY
INTO THE EVENING HOURS WILL BE DIFFICULT TO PIN DOWN. HAVE ALREADY
SEEN A VARIETY OF DIRECTIONS FROM KMSP WESTWARD...BUT WITH SPEEDS
AOB 7 KT... THERE SHOULD BE MINIMAL IMPACTS. DIRECTIONS SETTLE
DOWN IN THE 270-290 RANGE OVERNIGHT THROUGH TMRW WITH INCRG SPEEDS
AS THE LOW-LEVEL PRESSURE GRADIENT TIGHTENS.
MSP...CEILINGS IN THE 1200-1400FT RANGE WILL PERSIST AT MSP
THROUGH THE REST OF THE AFTN INTO THE EARLY EVE HOURS. CIGS WILL
LIFT SLIGHTLY BUT AM HAVING A HARD TIME BELIEVING CIGS WILL RISE
ABOVE 1700 FT BEFORE MIDNIGHT. AFTER MIDNIGHT...MVFR CIGS WILL
REMAIN BUT...BY THEN...WITH SOME LOWER MOISTURE BEING SCOURED OUT
WILL LOOK FOR CIGS TO RISE TO 2000-3000FT. LOW LEVEL MOISTURE WILL
CONTINUE TO DIMINISH WHILE MIXING INCREASES DUE TO AN INCOMING
TIGHTENED PRESSURE GRADIENT WHICH WILL ENHANCE SFC WINDS. WIND
DIRECTIONS WILL BE A BIT PROBLEMATIC THROUGH THE REST OF TODAY
INTO THIS EVENING WITH THE FRONT MOVING ACROSS. WINDS WILL VARY
FROM NW THRU NE WITH SPEEDS AOB 7 KT...THEN BECOME MORE W TO WNW
OVERNIGHT THROUGH TMRW WITH SPEEDS INCRG ABOVE 12 KT AFTER
DAYBREAK.
OUTLOOK...
MON NIGHT...VFR WITH NW WINDS 10-20 KT.
TUE...MVFR CONDITIONS WITH SCATTERED SHWRS/TSTMS.
WED-THU...VFR.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JPC
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
618 AM CDT SUN MAY 6 2012
.DISCUSSION...
MCS IS CURRENTLY ONGOING ACROSS THE CWA AND THERE IS STILL SOME
QUESTION AS TO REDEVELOPMENT POTENTIAL LATER THIS AFTERNOON. A
COLD FRONT WILL SLIDE THROUGH THE REGION SUNDAY NIGHT...WITH
COOLER AND DRIER WEATHER EXPECTED THIS WEEK. THE EXCEPTION WILL BE
TUESDAY...WHEN A POSITIVELY TILTED NORTHERN STREAM WAVE MOVES
ACROSS THE REGION...AND FRIDAY...WHEN ANOTHER COLD FRONT MOVES
THROUGH THE REGION.
TODAY...TRAILING STRATIFORM THUNDERSTORMS COMPLEX CONTINUES TO
MOVE EASTWARD AT A SLIGHTLY FASTER CLIP THAN SHORTRANGE MODELS
INDICATE. THE HRRR IS CONSISTENTLY ABOUT 2 HOURS TOO SLOW...AND
THE 00Z SPC WRF ABOUT AN HOUR TARDY ON ITS EASTWARD PROGRESSION.
AS THIS SYSTEM CLEARS OUT...COULD SEE SOME BOUNDARY LAYER
DESTABILIZATION THIS AFTERNOON NEAR THE IA/MN BORDER.
THIS INSTABILITY IN COMBINATION WITH SEVERAL OUTFLOW BOUNDARIES
AND SOUTHWESTERLY FLOW ALOFT WITH A FEW EMBEDDED WEAK SHORTWAVES
COULD BE THE FOCUS FOR ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS
THIS AFTERNOON. THE MARGINAL SHEAR AND CAPE VALUES SHOULD KEEP
THE SEVERE THREAT SOUTH AND EAST OF THE CWA.
SUNDAY NIGHT THROUGH SATURDAY...A SURFACE COLD FRONT WILL HAVE
PUSHED THROUGH THE REGION BY SUNDAY NIGHT...WITH MUCH DRIER AIR
IN PLACE BY MONDAY. SHOULD BE A DRY DAY...WITH A FEW AFTERNOON
CUMULUS DEVELOPING. ON TUESDAY THE UPPER LEVEL LOW DRIVING THE
AFOREMENTIONED SURFACE FRONT WILL SLIDE IN FROM THE NORTHWEST. A
WEAK SHORTWAVE WILL ROTATE AROUND THIS UPPER LEVEL LOW...AND COLD
H850 TEMPS WILL STREAM IN FROM THE NORTHWEST. THIS SHOULD SET THE
STAGE FOR A COOL OVERCAST DAY AND SOME AFTERNOON SHOWERS CENTERED
AROUND PEAK HEATING. FOR THE REST OF THE WEEK...HIGHLY AMPLIFIED
FLOW WILL BE THE NAME OF THE GAME. FOR STARTERS...UPPER LEVEL
SUBSIDENCE DOWNSTREAM OF A RIDGE CENTERED OVER MONTANA WILL CAUSE
AN AREA OF SURFACE HIGH PRESSURE TO BUILD OVER THE UPPER MIDWEST
ON WEDNESDAY. THIS WILL QUICKLY BE FOLLOWED BY AN UPPER LEVEL
TROUGH ON THURSDAY...WHICH WILL DEVELOP A SURFACE LOW OUT WEST AND
CAUSE SOUTHERLY WINDS AND WARM AIR ADVECTION TO MOVE ACROSS THE
REGION. AS THIS LOW TRACKS EASTWARD ON FRIDAY...EXPECT ANOTHER
CHANCE FOR SHOWERS AND THUNDERSTORMS MAINLY DURING THE AFTERNOON
HOURS. FINALLY...ANOTHER AREA OF SURFACE HIGH PRESSURE WILL BUILD
IN THE WAKE OF FRIDAY(S) SYSTEM...WHICH SHOULD LEAD TO A DRY
WEEKEND WITH SEASONAL TEMPERATURES.
&&
.AVIATION... /12Z TAF ISSUANCE/
BACK EDGE OF THE SHOWER/TSTM ACTIVITY OVER THE MIDWEST CONTINUE TO
SLOWLY MOVE EAST THROUGH EASTERN MN AND WESTERN WISCONSIN THIS
MORNING. EXPECT SOME ISOLATED THUNDERSTORMS TO LINGER INTO THE
AFTERNOON OVER PARTS OF WEST CENTRAL WISCONSIN...BEFORE THE PRECIP
FINALLY PUSH OUT EARLY THIS EVENING. AN UPPER LOW PRESSURE AREA
OVER THE NORTHERN PLAINS...WILL CONTINUE TO LIFT NORTHEAST AS DRIER
AIR BEGINS TO FILTER INTO WESTERN MN TODAY AND INTO WESTERN
WISCONSIN TONIGHT. IFR/MVFR CONDITIONS PREVAILING THROUGH MUCH OF
THE DAY. BECOMING VFR OVER WESTERN MINNESOTA THIS EVENING...AS HIGH
PRESSURE BUILDS OVER THE AREA. CONDITIONS IMPROVING OVER THE REST OF
THE FORECAST AREA TONIGHT.
KMSP...WIDESPREAD CEILINGS BELOW 1000 FEET AGL THIS MORNING...RAIN
SLOWLY MOVING OFF TO THE EAST BY EARLY AFTERNOON. WEATHER CONDITIONS
IMPROVING LATER TODAY...THEN BECOMING MOSTLY CLEAR SKIES AFTER
MIDNIGHT. WINDS EASTERLY 10-15 KNOTS...THEN BECOMING WESTERLY AROUND
10 KNOTS BY THIS EVENING.
OUTLOOK...
MONDAY...VFR WITH NORTHWEST WINDS 15-20KTS.
TUESDAY...MVFR CIGS POSSIBLE.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JRB/JVM
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
350 AM CDT SUN MAY 6 2012
.DISCUSSION...
MCS IS CURRENTLY ONGOING ACROSS THE CWA AND THERE IS STILL SOME
QUESTION AS TO REDEVELOPMENT POTENTIAL LATER THIS AFTERNOON. A
COLD FRONT WILL SLIDE THROUGH THE REGION SUNDAY NIGHT...WITH
COOLER AND DRIER WEATHER EXPECTED THIS WEEK. THE EXCEPTION WILL BE
TUESDAY...WHEN A POSITIVELY TILTED NORTHERN STREAM WAVE MOVES
ACROSS THE REGION...AND FRIDAY...WHEN ANOTHER COLD FRONT MOVES
THROUGH THE REGION.
TODAY...TRAILING STRATIFORM THUNDERSTORMS COMPLEX CONTINUES TO
MOVE EASTWARD AT A SLIGHTLY FASTER CLIP THAN SHORTRANGE MODELS
INDICATE. THE HRRR IS CONSISTENTLY ABOUT 2 HOURS TOO SLOW...AND
THE 00Z SPC WRF ABOUT AN HOUR TARDY ON ITS EASTWARD PROGRESSION.
AS THIS SYSTEM CLEARS OUT...COULD SEE SOME BOUNDARY LAYER
DESTABILIZATION THIS AFTERNOON NEAR THE IA/MN BORDER.
THIS INSTABILITY IN COMBINATION WITH SEVERAL OUTFLOW BOUNDARIES
AND SOUTHWESTERLY FLOW ALOFT WITH A FEW EMBEDDED WEAK SHORTWAVES
COULD BE THE FOCUS FOR ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS
THIS AFTERNOON. THE MARGINAL SHEAR AND CAPE VALUES SHOULD KEEP
THE SEVERE THREAT SOUTH AND EAST OF THE CWA.
SUNDAY NIGHT THROUGH SATURDAY...A SURFACE COLD FRONT WILL HAVE
PUSHED THROUGH THE REGION BY SUNDAY NIGHT...WITH MUCH DRIER AIR
IN PLACE BY MONDAY. SHOULD BE A DRY DAY...WITH A FEW AFTERNOON
CUMULUS DEVELOPING. ON TUESDAY THE UPPER LEVEL LOW DRIVING THE
AFOREMENTIONED SURFACE FRONT WILL SLIDE IN FROM THE NORTHWEST. A
WEAK SHORTWAVE WILL ROTATE AROUND THIS UPPER LEVEL LOW...AND COLD
H850 TEMPS WILL STREAM IN FROM THE NORTHWEST. THIS SHOULD SET THE
STAGE FOR A COOL OVERCAST DAY AND SOME AFTERNOON SHOWERS CENTERED
AROUND PEAK HEATING. FOR THE REST OF THE WEEK...HIGHLY AMPLIFIED
FLOW WILL BE THE NAME OF THE GAME. FOR STARTERS...UPPER LEVEL
SUBSIDENCE DOWNSTREAM OF A RIDGE CENTERED OVER MONTANA WILL CAUSE
AN AREA OF SURFACE HIGH PRESSURE TO BUILD OVER THE UPPER MIDWEST
ON WEDNESDAY. THIS WILL QUICKLY BE FOLLOWED BY AN UPPER LEVEL
TROUGH ON THURSDAY...WHICH WILL DEVELOP A SURFACE LOW OUT WEST AND
CAUSE SOUTHERLY WINDS AND WARM AIR ADVECTION TO MOVE ACROSS THE
REGION. AS THIS LOW TRACKS EASTWARD ON FRIDAY...EXPECT ANOTHER
CHANCE FOR SHOWERS AND THUNDERSTORMS MAINLY DURING THE AFTERNOON
HOURS. FINALLY...ANOTHER AREA OF SURFACE HIGH PRESSURE WILL BUILD
IN THE WAKE OF FRIDAY(S) SYSTEM...WHICH SHOULD LEAD TO A DRY
WEEKEND WITH SEASONAL TEMPERATURES.
&&
.AVIATION... /06Z TAF ISSUANCE/
LINE OF CONVECTION EXITING KSTC THROUGH KRWF IS MOVING NEAR 35 KNOTS.
THIS WILL IMPACT THE KMSP AND KRNH AIRFIELDS BETWEEN 07Z AND 09Z.
WEST TO NORTHWEST WINDS REACHING 35 KNOTS ARE POSSIBLE AS THIS
LINE MOVES THROUGH. AN EXTENSIVE AREA OF SHOWERS AND ISOLATED
THUNDERSTORMS WILL OCCUR IN THE WAKE OF THE LINE. KAXN WILL BE ON
THE WESTERN FRINGE. CEILINGS REMAIN A PROBLEM THROUGH THE TAF
PERIOD WITH BKN-OVC008-012 COMMON THROUGH AT LEAST 15Z WITH MVFR
CEILINGS DEVELOPING BY AFTERNOON...ALTHOUGH CONFIDENCE IS NOT
HIGH. SLOW IMPROVEMENT FROM MVFR TO VFR SUNDAY EVENING ALONG WITH
SURFACE WINDS BECOMING NORTHWEST.
KMSP...MAIN CONCERN IS CONVECTION MOVING THROUGH BY 09Z. SOME
THREAT FOR WEST TO NORTHWEST WINDS GUSTING TO 35 KNOTS. CEILINGS
MAY TEMPORARILY IMPROVE TO VFR WITH THE STORMS...BUT EXTENSIVE LOW
MVFR/IFR SHOULD FILL BACK IN BEHIND THIS ACTIVITY. SHOWERS AND
ISOLATED THUNDERSTORMS REMAIN POSSIBLE DURING THE LATE NIGHT
HOURS/SUNDAY MORNING WITH DRY WEATHER FOR THE AFTERNOON. CEILINGS
IMPROVING SUNDAY EVENING TO VFR ALONG WITH INCREASING NORTHWEST
WINDS.
OUTLOOK...
MONDAY...VFR WITH NORTHWEST WINDS 15-20KTS.
TUESDAY...MVFR CIGS POSSIBLE.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...FLASH FLOOD WATCH UNTIL 7 AM CDT THIS MORNING FOR BLUE EARTH-
BROWN-CARVER-CHIPPEWA-FARIBAULT-FREEBORN-KANDIYOHI-LAC QUI
PARLE-LE SUEUR-MARTIN-MCLEOD-MEEKER-NICOLLET-POPE-REDWOOD-
RENVILLE-RICE-SCOTT-SIBLEY-STEARNS-STEELE-STEVENS-SWIFT-
WASECA-WATONWAN-WRIGHT-YELLOW MEDICINE.
WI...NONE.
&&
$$
JRB/RAH
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
229 PM CDT SUN MAY 6 2012
.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...
PILOTS FLYING IN AND OUT OF THE SOUTHWEST MISSOURI AIRPORTS WILL
NEED TO MONITOR RADAR TRENDS THIS AFTERNOON...THIS EVENING...AND
THROUGH TONIGHT.
A COLD FRONT IS APPROACHING THE REGION...WHICH WILL TRIGGER
SCATTERED SHOWERS AND THUNDERSTORMS. ANY SHOWER OR THUNDERSTORM
THAT DIRECTLY IMPACTS AN AIRFIELD...COULD CAUSE SOME VERY GUSTY
WINDS...HEAVY RAIN...AND CLOUD TO GROUND LIGHTNING. THE
ENVIRONMENT THIS AFTERNOON AND EVENING WILL BE IDEAL FOR DOWNBURST
WIND GUSTS.
RAIN WILL EXIT THE REGION AFTER MIDNIGHT TONIGHT...GIVING WAY TO
FAIR WEATHER FOR SEVERAL DAYS STARTING TOMORROW MORNING.
AS THE FRONT SHIFTS THROUGH SOUTHERN MISSOURI TONIGHT...SURFACE
WINDS WILL SHIFT TO THE WEST AND NORTHWEST.
CRAMER
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
208 PM CDT SUN MAY 6 2012
...MESOSCALE CONVECTIVE DISCUSSION...
THE NATIONAL WEATHER SERVICE WILL BE MONITORING FOR SEVERE
THUNDERSTORM DEVELOPMENT THIS AFTERNOON AND THIS EVENING.
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
&&
.DISCUSSION...
IT LOOKS TO BE A MESSY NEXT 24 TO 36 HOURS ACROSS THE CWA AS
WEAKLY ORGANIZED CONVECTION MOVES THROUGH THE AREA. ONCE THIS
APPROACHING SYSTEM MOVES THROUGH HOWEVER...A COMFORTABLE STRETCH OF
SPRING WEATHER APPEARS TO BE ON TAP FOR THE REGION.
STARTING OUT EARLY THIS MORNING...RATHER COMPLEX BUT GENERALLY WEAK
SOUTHWEST FLOW IS IN PLACE ALOFT OVER THE AREA. AT THE
SURFACE...LOW PRESSURE CONTINUES TO ORGANIZE OVER THE HIGH
PLAINS...WITH EXPANSIVE SURFACE TROUGHING EXTENDING INTO THE
NORTHERN PLAINS ALONG A SHARPENING SURFACE FRONT. A LARGE LINEAR
MCS HAD DEVELOPED OVERNIGHT FROM NEBRASKA THROUGH MUCH OF SOUTHERN
MINNESOTA.
OUTFLOW HAS SURGED WELL AHEAD OF THIS CONVECTION AS OF 07Z THIS
MORNING...AND THIS BOUNDARY WILL LIKELY BE THE INITIAL FOCUS FOR
CONVECTION OVER THE SGF CWA BY MIDDAY. SUSPECT THAT THIS BOUNDARY
WILL BEGIN TO IMPINGE ON THE NORTHWESTERN PERIPHERY OF THE CWA
BETWEEN 18Z AND 21Z TODAY...ABOUT THE TIME THAT A VERY UNSTABLE
AIRMASS WILL BE EFFECTIVELY UNCAPPED. ONCE SURFACE INHIBITION
ERODES...LIFT ALONG THE OUTFLOW WILL HAVE A VERY WARM AND MOIST LOW
LEVEL AIRMASS AVAILABLE TO TAP INTO...WITH RATHER STEEP MID LEVEL LAPSE
RATES ALOFT. AS A RESULT...4000+ J/KG OF SFC CAPE WILL BE COMMON
OVER THE REGION...WITH FORECAST SOUNDINGS SUGGESTING NEARLY 1000
J/KG AVAILABLE THROUGH THE HAIL GROWTH LAYER. WHILE INSTABILITY
WILL BE HIGH TO EXTREME IN NATURE...OVERALL WEAK BULK SHEAR VALUES
(AROUND 20 KTS THROUGH 0-6 KM LAYER) WILL MAKE CONVECTIVE
ORGANIZATION DIFFICULT TO COME BY. WITH THAT IN MIND...DO BELIEVE
THE GREATEST SEVERE THREAT WILL BE FROM LARGE (PERHAPS VERY LARGE IN
A FEW INSTANCES) HAIL AS STORMS INITIALLY DEVELOP...AS WELL AS LOCALIZED
DOWNBURSTS DUE TO PRECIP LOADING PROCESSES. THE TORNADO THREAT
APPEARS QUITE LOW AT THIS TIME...THOUGH ANY STORM MERGERS AND/OR
BOUNDARY INTERACTIONS THAT MAY ACT TO LOCALLY INCREASE HELICITY
VALUES WILL NEED TO BE WATCHED VERY VERY CAREFULLY...DUE TO THE VERY
HIGH INSTABILITY ALREADY IN PLACE.
ALONG WITH THE SEVERE WEATHER THREAT...WILL ALSO NEED TO BE MINDFUL
OF HEAVY RAIN POTENTIAL. OVERALL STORM MOTIONS ARE EXPECTED TO BE
RATHER SLOW...AS WELL AS BOUNDARY-PARALLEL. WHEN COMBINED WITH PWAT
VALUES APPROACHING 2 INCHES...THIS SUGGESTS THAT HEAVY RAIN/FLASH
FLOODING COULD BE POSSIBLE IN AT LEAST A LOCALIZED FASHION. MOST
FAVORED AREA FOR THIS WILL BE WEST OF U.S. 65 AND NORTH OF
I-44...WHERE HEAVY RAIN FELL LAST WEEK. FOR THE REMAINDER OF THE
AREA...HOPEFULLY THIS WILL SIMPLY SERVE AS A MUCH NEEDED DOSE OF
RAINFALL.
MUCH OF TODAY`S INITIAL CONVECTION WILL BE WELL AHEAD OF THE
SYNOPTIC COLD FRONT...WHICH LOOKS TO SLOWLY MAKE ITS WAY ACROSS THE
CWA THROUGH MID MORNING MONDAY. RIGHT NOW...IT IS SOMEWHAT UNCLEAR
AS HOW CONVECTION WILL EVOLVE THROUGH THE OVERNIGHT HOURS INTO
MONDAY MORNING. SUSPECT THAT EITHER NEW OUTFLOW WILL SERVE AS THE
FOCUS...OR ELSE ADDITIONAL DEVELOPMENT WILL BE REALIZED ALONG THE
ACTUAL FRONT THROUGH THE OVERNIGHT HOURS. HAVE MAINTAINED HIGH POPS
THROUGH MONDAY MORNING TO ACCOUNT...THOUGH DO THINK THAT THE OVERALL
SEVERE WEATHER THREAT SHOULD DECREASE A BIT THROUGH THE OVERNIGHT
HOURS TONIGHT.
AS ALLUDED TO ABOVE...SYNOPTIC FRONT SHOULD FINALLY CLEAR THE CWA BY
MIDDAY MONDAY...WITH HIGH PRESSURE THEN TAKING CONTROL FOR MOST OF
THE REMAINDER OF THE WEEK. THIS LOOKS TO RESULT IN SOME OF THE MOST
COMFORTABLE CONDITIONS WE`VE SEEN IN QUITE A WHILE ACROSS THE
REGION...WITH NEAR NORMAL HIGHS IN THE LOW 70S AND LOW TEMPS IN THE
LOW 50S.
BOXELL
&&
.AVIATION...
PILOTS FLYING IN AND OUT OF THE SOUTHWEST MISSOURI AIRPORTS WILL
NEED TO MONITOR RADAR TRENDS THIS AFTERNOON...THIS EVENING...AND
THROUGH TONIGHT.
A COLD FRONT IS APPROACHING THE REGION...WHICH WILL TRIGGER
SCATTERED SHOWERS AND THUNDERSTORMS. ANY SHOWER OR THUNDERSTORM
THAT DIRECTLY IMPACTS AN AIRFIELD...COULD CAUSE SOME VERY GUSTY
WINDS...HEAVY RAIN...AND CLOUD TO GROUND LIGHTNING. THE
ENVIRONMENT THIS AFTERNOON AND EVENING WILL BE IDEAL FOR DOWNBURST
WIND GUSTS.
RAIN WILL EXIT THE REGION AFTER MIDNIGHT TONIGHT...GIVING WAY TO
FAIR WEATHER FOR SEVERAL DAYS STARTING TOMORROW MORNING.
AS THE FRONT SHIFTS THROUGH SOUTHERN MISSOURI TONIGHT...SURFACE
WINDS WILL SHIFT TO THE WEST AND NORTHWEST.
CRAMER
&&
.CLIMATE...
RECORD HIGHS AND WARM LOWS THROUGH THE WEEKEND...
MAY 6TH...
SITE...REC HIGH...REC WARM LOW
SGF....90/1952...73/2007
JLN....90/2007...73/1940
UNO....89/1949...69/2007
VIH....88/1956...68/2007
BOXELL
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
511 PM CDT SUN MAY 6 2012
.AVIATION...00Z KGRI TAF. WIND WILL BE THE BIGGEST ISSUE FOR THIS
FORECAST. NORTH WIND WILL CALM DOWN BY AROUND 02Z BUT WILL PICK
BACK UP AGAIN FOR MONDAY. 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 EAST OF THE TERMINAL
FOR THE MOST PART.
&&
.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...HEINLEIN
SHORT TERM...JCB
LONG TERM...ROSSI
AREA FORECAST DISCUSSION
NWS HASTINGS NE
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.
&&
.PREV DISCUSSION... /ISSUED 1224 PM CDT SUN MAY 6 2012/
AVIATION...18Z TAF. LOW CLOUDS CONTINUE TO MOVE THROUGH THE KGRI
TERMINAL AREA. THEY SHOULD BE LIFTING IN THE NEXT HOUR OR TWO AS
AN UPPER LEVEL WAVE MOVES TO THE EAST OF THE AREA THIS AFTERNOON.
A FEW SHOWERS HAVE DEVELOPED TO THE SOUTHWEST OF THE KGRI TERMINAL
AND WILL MOVE TOWARD THE KGRI TERMINAL EARLY THIS AFTERNOON. CLOUDS
SHOULD CONTINUE TO LIFT DURING THE AFTERNOON. WINDS WILL BE FROM
THE NORTH DECREASING AS THE SUN SETS AND INCREASING AGAIN IN THE
MORNING.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM/AVIATION...JCB
LONG TERM...ROSSI
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
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
&&
.AVIATION...
18Z TAFS FOR KOFK...KOMA AND KLNK.
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE EXPECTED TO
DEVELOP/BECOME MORE WIDESPREAD ACROSS EASTERN NEBRASKA THIS
AFTERNOON. ACTIVITY COULD LINGER INTO EARLY TONIGHT AT KLNK/KOMA
BUT THUNDERSTORMS SHOULD BE MOSTLY SE OF TAF SITES EARLY THIS
EVENING. CIGS SHOULD LIFT MOSTLY INTO UPPER REACHES OF MVFR
CATEGORY OR ABOVE 3K FT AGL BY MID AFTERNOON...BUT COULD BE
LOWERED BACK DOWN IN AND NEAR SHOWERS. FOUR-HOUR TEMPO GROUPS OF
THUNDERSTORMS WERE MENTIONED AT KLNK/KOMA WHEN BEST CHANCES WERE
BELIEVED TO EXIST...BUT SOME RISK REMAINS EITHER SIDE OF THAT
WINDOW. TSTM CHANCES APPEARED TOO LOW TO CARRY MENTION AT KOFK.
CHERMOK
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
956 AM CDT SUN MAY 6 2012
.UPDATE...
WIND SPEEDS HAVE DIMINISHED BELOW CRITERIA LEVEL THIS
MORNING...THUS WILL CANCEL THE ADVISORY EARLY...HOWEVER NORTHERLY
WINDS GUSTS TO 25 MPH MAY STILL BE POSSIBLE THROUGH EARLY
AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 640 AM CDT SUN MAY 6 2012/
AVIATION...
12Z TAFS.
RECENT MVFR CEILINGS HAVE BECOME SCT020 AT KLBF. VFR CEILING NEAR
BKN080 MAY BE SCT080 AT TIMES...ARE FORECAST FOR REMAINDER OF
KLBF TAF. ALSO VFR CONDITIONS FOR REMAINDER OF KVTN TAF. STRONGER
WINDS 34022G28KT AT KLBF UNTIL 18Z TO GRADUALLY DIMINISH THROUGH
THE AFTERNOON. THERE IS A SLIGHT CHANCE FOR RAIN SHOWERS OR AN
ISOLATED TSRA AT KLBF. WILL NOT MENTION ATTM...WITH NO RADAR
RETURNS AND RUC FORECAST DRY.
PREV DISCUSSION... /ISSUED 400 AM CDT SUN MAY 6 2012/
SYNOPSIS...
COLD FRONT HAS PUSHED INTO FAR NW CWA...AS OF 09Z. TEMPS IN THE
40S BEHIND THE FRONT ACROSS THE PANHANDLE...AND IN THE LOWER 30S
ACROSS MUCH OF WY. SECONDARY FRONT ALONG THE EASTERN ZONES. BOTH
BOUNDARIES ARE PRODUCING SOME RAIN SHOWERS...WITH MORE COVERAGE
AND A FEW LIGHTNING STRIKES WITH THE EASTERN ONE. NORTH WINDS HAVE
PICKED UP ACROSS THE AREA...WITH A FEW SITES CLOSE TO ADVISORY
CRITERIA...30 MPH.
DISCUSSION...
COLD FRONT WILL CONTINUE TO PUSH EAST ACROSS THE AREA THIS
MORNING. ISOLATED TO SCATTERED RAIN SHOWERS WILL FOLLOW NEAR THE
FRONT. ALSO MODELS INCREASE 850 MB WINDS THIS MORNING ACROSS SW
INTO CENTRAL NEB CLOSE TO 50 KTS. HAVING MIXED SOME HIGHER WINDS
TO THE SURFACE ALREADY...WENT AHEAD AND HOISTED A SHORT DURATION
WIND ADVISORY WHERE HIGHEST WINDS THIS MORNING AREA EXPECTED. HIGH
PRESSURE WILL BEGIN TO PUSH INTO THE REGION THIS AFTERNOON AND
TONIGHT...WHICH SHOULD DECREASE WINDS BELOW ADVISORY CRITERIA.
ALSO EXPECTED LINGERING SHOWERS POSSIBLY INTO THE EARLY AFTERNOON
HOURS. A BETTER SHOT FOR PRECIP WILL BE DURING THE MORNING HOURS.
HIGHS WILL HOLD NEAR OR BELOW NORMAL DUE TO AN INCREASE OF CLOUD
COVER...IN THE 60S.
TONIGHT INTO MID WEEK A GENERALLY QUITE WEATHER PATTERN DEVELOPS.
HIGHS IN THE 60S AND A FEW LOWER 70S. STORM TRACK TO THE NORTH
WITH DRY CONDITIONS TO PREVAIL OVER THE HIGH PLAINS...HOWEVER
COULD SEE SOME HIGH CLOUDS AT TIMES. WILL NEED TO MONITOR THE
CENTER OF THE SURFACE HIGH. CURRENT TRACK FROM THE MODELS VARY.
IF THE CENTER IS OVER THE CWA...TEMPS LIKELY TO DROP WELL INTO THE
30S BENEATH THE HIGH...WITH THE POTENTIAL FOR A FROST OR EVEN A
FREEZE HEADLINE. WILL CONTINUE TO MONITOR THE LOCATION OF THE
HIGH...HOWEVER FORECAST IS CONSERVATIVE AND ADDED SOME PATCHY
FROST IN THE FORECAST.
NEXT LARGE SYSTEM ARRIVES THURSDAY NIGHT INTO FRIDAY WITH THIS
BEING THE NEXT SHOT FOR WIDESPREAD PRECIP. AHEAD OF THE COLD
FRONT TEMPS SURGE INTO THE 70S AND A FEW LOW 80S. HOWEVER HEAT IS
SHORT LIVED WITH A RETURN TO MORE SEASONAL CONDITIONS FOR THE
WEEKEND...AROUND 70.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM/EXTENDED...MASEK
AVIATION...WFO LBF
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
640 AM CDT SUN MAY 6 2012
.AVIATION...
12Z TAFS.
RECENT MVFR CEILINGS HAVE BECOME SCT020 AT KLBF. VFR CEILING NEAR
BKN080 MAY BE SCT080 AT TIMES...ARE FORECAST FOR REMAINDER OF
KLBF TAF. ALSO VFR CONDITIONS FOR REMAINDER OF KVTN TAF. STRONGER
WINDS 34022G28KT AT KLBF UNTIL 18Z TO GRADUALLY DIMINISH THROUGH
THE AFTERNOON. THERE IS A SLIGHT CHANCE FOR RAIN SHOWERS OR AN
ISOLATED TSRA AT KLBF. WILL NOT MENTION ATTM...WITH NO RADAR
RETURNS AND RUC FORECAST DRY.
&&
.PREV DISCUSSION... /ISSUED 400 AM CDT SUN MAY 6 2012/
SYNOPSIS...
COLD FRONT HAS PUSHED INTO FAR NW CWA...AS OF 09Z. TEMPS IN THE
40S BEHIND THE FRONT ACROSS THE PANHANDLE...AND IN THE LOWER 30S
ACROSS MUCH OF WY. SECONDARY FRONT ALONG THE EASTERN ZONES. BOTH
BOUNDARIES ARE PRODUCING SOME RAIN SHOWERS...WITH MORE COVERAGE
AND A FEW LIGHTNING STRIKES WITH THE EASTERN ONE. NORTH WINDS HAVE
PICKED UP ACROSS THE AREA...WITH A FEW SITES CLOSE TO ADVISORY
CRITERIA...30 MPH.
DISCUSSION...
COLD FRONT WILL CONTINUE TO PUSH EAST ACROSS THE AREA THIS
MORNING. ISOLATED TO SCATTERED RAIN SHOWERS WILL FOLLOW NEAR THE
FRONT. ALSO MODELS INCREASE 850 MB WINDS THIS MORNING ACROSS SW
INTO CENTRAL NEB CLOSE TO 50 KTS. HAVING MIXED SOME HIGHER WINDS
TO THE SURFACE ALREADY...WENT AHEAD AND HOISTED A SHORT DURATION
WIND ADVISORY WHERE HIGHEST WINDS THIS MORNING AREA EXPECTED. HIGH
PRESSURE WILL BEGIN TO PUSH INTO THE REGION THIS AFTERNOON AND
TONIGHT...WHICH SHOULD DECREASE WINDS BELOW ADVISORY CRITERIA.
ALSO EXPECTED LINGERING SHOWERS POSSIBLY INTO THE EARLY AFTERNOON
HOURS. A BETTER SHOT FOR PRECIP WILL BE DURING THE MORNING HOURS.
HIGHS WILL HOLD NEAR OR BELOW NORMAL DUE TO AN INCREASE OF CLOUD
COVER...IN THE 60S.
TONIGHT INTO MID WEEK A GENERALLY QUITE WEATHER PATTERN DEVELOPS.
HIGHS IN THE 60S AND A FEW LOWER 70S. STORM TRACK TO THE NORTH
WITH DRY CONDITIONS TO PREVAIL OVER THE HIGH PLAINS...HOWEVER
COULD SEE SOME HIGH CLOUDS AT TIMES. WILL NEED TO MONITOR THE
CENTER OF THE SURFACE HIGH. CURRENT TRACK FROM THE MODELS VARY.
IF THE CENTER IS OVER THE CWA...TEMPS LIKELY TO DROP WELL INTO THE
30S BENEATH THE HIGH...WITH THE POTENTIAL FOR A FROST OR EVEN A
FREEZE HEADLINE. WILL CONTINUE TO MONITOR THE LOCATION OF THE
HIGH...HOWEVER FORECAST IS CONSERVATIVE AND ADDED SOME PATCHY
FROST IN THE FORECAST.
NEXT LARGE SYSTEM ARRIVES THURSDAY NIGHT INTO FRIDAY WITH THIS
BEING THE NEXT SHOT FOR WIDESPREAD PRECIP. AHEAD OF THE COLD
FRONT TEMPS SURGE INTO THE 70S AND A FEW LOW 80S. HOWEVER HEAT IS
SHORT LIVED WITH A RETURN TO MORE SEASONAL CONDITIONS FOR THE
WEEKEND...AROUND 70.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...WIND ADVISORY UNTIL 1 PM CDT
/NOON MDT/ THIS AFTERNOON FOR NEZ038-058-059-069>071.
&&
$$
SHORT TERM/EXTENDED...MASEK
AVIATION...ROBERG
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
130 AM CDT SUN MAY 6 2012
.AVIATION...
06Z TAFS. MVFR CEILINGS TO HOLD AT KVTN UNTIL 12Z...THEN BKN100.
MVFR CEILING WILL REACH KLBF BY 07Z AND ALSO PERSIST UNTIL 12Z.
WINDS 34015G25KTS THROUGH 00Z/7TH...TO DECOUPLE THEREAFTER. THERE
IS A SLIGHT CHANCE FOR RAIN SHOWERS AT KLBF UNTIL 18Z.
&&
.PREV DISCUSSION... /ISSUED 852 PM CDT SAT MAY 5 2012/
UPDATE...
STORMS HAVE BEEN SLOW TO DEVELOP THIS AFTN AND EVENING AS A STRONG
CAP HAS BEEN IN PLACE. THE CAP APPEARS TO HAVE WEAKENED SOME AFTER
SUNSET AND STORMS HAVE BEGUN TO FIRE ACROSS NCNTL NEB. THIS IS
CLOSE TO THE RUC13 SOLN WHICH WAS THE BASIS FOR A FCST UPDATE THIS
EVENING. WE ALSO SLOW THE DEPARTURE OF THE TSTMS OVERNIGHT AS THE
MODELS APPEAR TO BE TOO FAST AND CARRY LIKELY POPS ACROSS THE
NORTHEAST ZONES TIL MORNING.
HEAVY RAIN APPEARS TO BE THE OPERATIVE MODE IN ADDITION TO THE
SEVERE WEATHER THREAT. THE 310K MOISTURE TRANSPORT VECTORS IN THE
RUC13 ARE THROUGH THE ROOF AND PRECIPITABLE WATER IS FCST TO
APPROACH 1.5 INCHES. NESDIS HAS SENT TWO MESSAGES ALERTING NRN NEB
ABOUT THE POTENTIAL FOR HEAVY RAINFALL.
PREV DISCUSSION... /ISSUED 623 PM CDT SAT MAY 5 2012/
UPDATE...
AVIATION...
SCATTERED SEVERE THUNDERSTORMS MAY PERSIST UNTIL 12Z EAST OF
HIGHWAY 83. ISOLATED STRONG TO SEVERE THUNDESTORMS WEST OF HIGHWAY
83 SHOULD MOVE THROUGH BY 06Z. MVFR CIGS ARE EXPECTED WITH THE
PASSAGE OF A STRONG COLD FRONT CURRENTLY OVER NORTHEAST WYOMING.
VFR IS EXPECTED ALL AREAS BY 12Z. FLIGHT CONDITIONS WILL IMPROVE
FROM WEST TO EAST WITH THE PASSAGE OF THE COLD FRONT THIS EVENING
AND OVERNIGHT.
PREV DISCUSSION... /ISSUED 302 PM CDT SAT MAY 5 2012/
DISCUSSION...STRONG COLD FRONT PLOWS INTO WESTERN AND NORTH CENTRAL
NEB EARLY THIS EVENING...MOISTURE AND INSTABILITY POOLING JUST TO
THE NORTH OF A STATIONARY OUTFLOW BOUNDARY BISECTING THE
AREA...SHOULD ALLOW FOR TSTM DEVELOPMENT ALONG THE FRONT AS IT
MOVES SOUTHEAST. STORMS SHOULD MOVE SOUTHEAST OF THE AREA AFTER
MIDNIGHT AS NORTH WINDS INCREASE BEHIND THE FRONT.
IN THE WAKE OF THE STRONG COLD FRONTAL PASSAGE...MUCH COOLER AND
LESS HUMID CONDITIONS ARE EXPECTED FOR SUNDAY INTO MONDAY. BREEZY TO
WINDY CONDITIONS ARE ALSO EXPECTED SUNDAY MORNING IN THE WAKE OF THE
FRONT. STRONG COLD AIR ADVECTION...COUPLED WITH NAM MODEL FORECASTED
500 METER WINDS AROUND 30 KTS...COULD ALLOW FOR SOME SUSTAINED WINDS
AROUND 25 TO 30 MPH DURING THE MORNING. WINDS SHOULD DECREASE SOME
DURING THE AFTERNOON...AS THE PRESSURE GRADIENT RELAXES AND CAA
ADVECTION WEAKENS. A SECONDARY COLD FRONTAL SURGE IS EXPECTED
MONDAY...WITH NORTHWEST WINDS INCREASING AGAIN.
IN THE UPPER LEVELS...A STRONG UPPER LEVEL LOW...LOCATED ACROSS THE
NORTHERN PLAINS...WILL COMBINE WITH A DISTURBANCE DROPPING SOUTH
THROUGH THE NORTHERN ROCKIES...AND KEEP OUR AREA IN SOUTHWEST FLOW
ALOFT THOUGH MONDAY. WILL INCLUDE A SLIGHT CHANCE FOR SHOWERS ACROSS
FAR SOUTHWEST NEB AND INTO THE SOUTHERN NEB PANHANDLE AS THE
AFOREMENTIONED NORTHERN ROCKIES DISTURBANCE DIVES SOUTH. BEYOND
MONDAY...BOTH THE ECMWF AND GFS MODELS AGREE THAT THE NORTHERN
PLAINS UPPER LEVEL LOW WILL MOVE SOUTHEAST INTO THE GREAT LAKES
REGION. THIS TURNS THE UPPER FLOW TO NORTHWEST ALOFT TUESDAY AND
WEDNESDAY. WITH LIMITED LOW LEVEL MOISTURE...AND NO DISTINCT
SHORTWAVES NOTED WITHIN THE UPPER FLOW...EXPECTING MAINLY DRY
CONDITIONS. LATE IN THE WEEK...THE GREAT LAKES UPPER LEVEL LOW WILL
BE KICKED EAST AS A NEW NORTHERN STREAM ENERGY MOVES INTO SOUTHERN
CANADA. THIS SHOULD DRIVE ANOTHER COLD FRONT SOUTH INTO THE
AREA...ALONG WITH SLIGHT CHANCES FOR SHOWERS AND THUNDERSTORMS. AT
THIS TIME IT APPEARS THAT LIMITED LOW LEVEL MOISTURE SHOULD KEEP ANY
PRECIPITATION ISOLATED.
TEMPERATURE WISE...MILD CONDITIONS ARE ANTICIPATED SUNDAY THROUGH
TUESDAY...WITH HIGHS IN THE 60S. LOOKING AT THE FROST POTENTIAL FOR
MONDAY MORNING...APPEARS WINS WILL STAY UP ENOUGH TO PRECLUDE MUCH
THREAT. TUESDAY MORNING COULD BE A DIFFERENT STORY...AS SFC HIGH
PRESSURE WILL BE LOCATED JUST WEST OF THE AREA. THIS MAY ALLOW WINDS
ACROSS THE PANHANDLE TO GO NEARLY CALM...AND SOME FROST LOOKS
POSSIBLE IN THAT AREA. TEMPERATURES SHOULD BEGIN TO MODIFY...WITH
HIGHS IN THE 70S WEDNESDAY AND THURSDAY...BEFORE A COOL DOWN BACK
INTO THE 60S FRIDAY AND SATURDAY.
AVAIATION...FOR KVTN AND KLBF...SHORT TERM MODEL GUIDANCE IS
STRUGGLING WITH A SOUTHWARD ADVANCING BOUNDARY GENERATED FROM EARLY
CONVECTION ACROSS CENTRAL SOUTH DAKOTA. SINCE THE SHORT TERM
SOLUTIONS ARE STRUGGLING...CONFIDENCE REMAINS LOW TO MODERATE FOR
THE REMAINING TAF CYCLE...ESPECIALLY IN REGARDS TO STORM COVERAGE
THIS AFTERNOON AND WIND SPEED/DIRECTION. A WARM FRONT WILL LIFT
NORTH ACROSS NORTH CENTRAL NEBRASKA THIS AFTERNOON AND SHOULD
PROVIDE A FOCUS FOR STORM DEVELOPMENT...SOME OF WHICH MAY BE
SEVERE. AS OF NOW THE HIGHEST CONVECTIVE POTENTIAL REMAINS ACROSS
NORTH CENTRAL NEBRASKA...POSSIBLE AFFECTING THE KANW AND KONL
TERMINALS. FURTHER SOUTH HOWEVER...MODELS INDICATE AN ADVANCING
DRYLINE WHICH MAY SUPPORT ADDITIONAL STORM DEVELOPMENT. DUE TO THE
SPORADIC NATURE OF CONVECTIVE STORMS...AND THE FACT THE MODELS ARE
NOT CORRECTLY ASSESSING WHERE CONVECTIVE BOUNDARIES EXIST...FELT IT
WAS BEST TO MENTION IN THIS DISCUSSION AND LEAVE STORM MENTION OUT OF
THE OFFICIAL TAF FORECAST FOR KLBF AND KVTN FOR NOW. HOWEVER NOTE
THAT A VERY UNSTABLE ATMOSPHERE IS EXPECTED LATE THIS AFTERNOON
ALONG AND SOUTH OF THE WARM FRONT. LARGE HAIL...STRONG ERRATIC
THUNDERSTORM WIND GUSTS...AND POSSIBLY TORNADOES WOULD BE POSSIBLE
LATE THIS AFTERNOON/EARLY EVENING WITHIN THIS ENVIRONMENT.
ATTENTION NOW TURNS TO THE WIND POTENTIAL TONIGHT AND LATE IN THE
TAF FORECAST PERIOD. AN UPPER LEVEL WAVE CROSSING THE NORTHERN HIGH
PLAINS WILL DRAG A COLD FRONT THROUGH AREA EARLY THIS EVENING
/00Z-03Z AT VTN...AFTER 03Z AT LBF/. STRONG COLD AIR ADVECTION AND
PRESSURE RISES WILL ALLOW FOR GUSTY NORTHWEST WIND OVERNIGHT...WITH
GUSTS POSSIBLY EXCEEDING 30KTS. EXPECT WIND SPEEDS TO RELAX SOME
LATE IN THE TAF PERIOD /AFTER 15Z/. OTHERWISE STRATUS IS EXPECTED
BEHIND THE FRONTAL PASSAGE...SO IFR WOULD BE EXPECTED AT ALL AREA
TERMINALS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM/EXTENDED...WFO LBF
AVIATION...ROBERG
AREA FORECAST DISCUSSION
NWS RALEIGH NC
312 PM EDT SUN MAY 6 2012
.SYNOPSIS...
AN AREA OF HIGH PRESSURE OVER THE MID ATLANTIC WILL EXTEND SOUTHWARD
INTO THE CAROLINAS THROUGH MONDAY. A COLD FRONT WILL APPROACH THE
REGION LATE TUESDAY AND WEDNESDAY...BRINGING UNSETTLED WEATHER FOR
THE MIDDLE OF THE WEEK.
&&
.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 RESATURATE 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 /18Z SUNDAY THROUGH THURSDAY/...
AS OF 155 PM SUNDAY...
VISIBLE SATELLITE IMAGERY IS BEGINNING TO SHOW MORE BREAKS IN THE
WIDESPREAD STRATUS ACROSS CENTRAL NC...WITH MORE REPORTS OF BKN
1500-2500 CEILINGS AROUND THE AREA. THIS TREND WILL CONTINUE INTO
THE AFTERNOON...ALTHOUGH MVFR CEILINGS MAY REMAIN PREDOMINATE SINCE
THE BREAKS IN CLOUDS ARE SMALL AND VARIABLE FROM HOUR TO HOUR. A
STEADY NORTHEASTERLY WIND...STRONGER OVER EASTERN NC...WILL CONTINUE
INTO THE EVENING HOURS WHILE A WEAK LOW PRESSURE OFF THE CAROLINA
COAST DRIFTS AWAY FROM THE AREA.
TONIGHT..MODELS SHOW ANOTHER SURGE OF HIGH PRESSURE FROM THE MID
ATLANTIC COAST...WHICH MAY KEEP WINDS FROM GOING COMPLETELY CALM.
MOST GUIDANCE SHOWS A 3-5KT WIND OVERNIGHT..WHICH WOULD HELP TO KEEP
FOG FROM BEING WIDESPREAD AND DENSE...WITH BETTER POTENTIAL FOR
STRATUS. HOWEVER...MANY AREAS RECEIVED ONE TO TWO INCHES OF RAIN
LAST EVENING AND IT IS POSSIBLE THAT VSBYS WILL BE LOWER THAN WHAT
GUIDANCE GIVES. THUS...THERE IS HIGHER CONFIDENCE IN MVFR TO IFR
STRATUS AFTER MIDNIGHT...BUT IFR OR LOWER VSBYS CANNOT BE RULED
OUT. STRATUS SHOULD LIFT MUCH MORE QUICKLY MONDAY MORNING...WITH
VFR CONDITIONS POSSIBLE PRIOR TO 18Z.
OUTLOOK...
A CONTINUED MOIST AIRMASS OVER CENTRAL NC MAY PROMOTE
STRATUS/FOG AGAIN TUESDAY MORNING. A COLD FRONT WILL THEN APPROACH
THE REGION FROM THE NORTHWEST THROUGH THE MIDDLE OF THE
WEEK...LEADING TO UNSETTLED WEATHER AND THE POTENTIAL FOR ADVERSE
AVIATION CONDITIONS THROUGH THURSDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SMITH
NEAR TERM...SMITH
SHORT TERM...HARTFIELD
LONG TERM...HARTFIELD
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
305 PM EDT SUN MAY 6 2012
.SYNOPSIS...
AN AREA OF HIGH PRESSURE OVER THE MID ATLANTIC WILL EXTEND SOUTHWARD
INTO THE CAROLINAS THROUGH MONDAY. A COLD FRONT WILL APPROACH THE
REGION LATE TUESDAY AND WEDNESDAY...BRINGING UNSETTLED WEATHER FOR
THE MIDDLE OF THE WEEK.
&&
.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 RESATURATE 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/...
AS OF 320 AM SUNDAY...
LITTLE CHANGE REQUIRED TO FORECAST.
ICREASING CLOUD COVERAGE AND A STEADY S-SW FLOW SHOULD RESULT IN
MILD OVERNIGHT TEMPS IN THE 60S WITH MIN TEMPS LOWER 60S SOUTH AND
WEST AND UPPER 50S FAR NE.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 240 AM SUNDAY...
TUESDAY TROUGH WEDNESDAY NIGHT:
MID/UPPER LEVEL RIDGE AXIS IS EXPECTED TO BE TO THE EAST OF THE AREA
BY THE START OF THIS PERIOD... WHILE A MID/UPPER LEVEL DISTURBANCE
CENTERED ACROSS THE NORTH CENTRAL U.S./WESTERN GREAT LAKES REGION
BEGINS TO AMPLIFY AND TRANSLATE EASTWARD. THIS WILL ALLOW A COLD
FRONT TO APPROACH OUR REGION ON TUESDAY INTO TUESDAY NIGHT. AHEAD OF
THE FRONT EXPECT SOUTHERLY RETURN FLOW WILL HELP WARM TEMPS BACK
INTO THE UPPER 70S TO LOWER 80S. GIVEN THE IMPROVING INSTABILITY AND
POTENTIAL FOR WEAK MID/UPPER LEVEL ENERGY TO TRACK ACROSS THE AREA
IN GENERALLY WSW`EARLY FLOW... EXPECT WE CLOUD SEE SOME SHOWERS AND
THUNDERSTORMS DEVELOP IN THE AFTERNOON/EVENING... WITH THE HIGHEST
POTENTIAL (CHANCE) ACROSS THE WESTERN PIEDMONT. ALSO... WILL NEED TO
KEEP AN EYE ON A SLOW MOVING SHEAR AXIS TO THE SOUTH OF THE AREA ON
TUESDAY. BOTH THE NAM AND GFS OVER THE PAST COUPLE OF RUNS AT TIMES
HAVE SHOWN THIS FEATURE DRIFTING NORTHWARD AND AFFECTING PORTIONS OF
CENTRAL NC... ALLOWING FOR THE DEVELOPMENT OF SOME SHOWERS AND
STORMS ACROSS OUR SOUTH AND EAST. HOWEVER... GIVEN LACK OF MODEL
AGREEMENT AND RUN TO RUN CONSISTENCY... WILL KEEP HIGHEST POPS WEST
FOR NOW ON TUESDAY AND TUESDAY NIGHT. GIVEN THE MOSTLY CLOUDY/CLOUDY
SKIES COUPLED WITH THE APPROACHING FRONT... EXPECT LOW TEMPS
WEDNESDAY MORNING WILL BE IN THE MID 60S.
THE AFOREMENTIONED COLD FRONT IS EXPECTED TO MOVE THROUGH THE AREA
ON WEDNESDAY... WITH LOCATIONS ACROSS THE EASTERN HALF/TWO-THIRDS OF
CENTRAL NC POTENTIALLY EXPERIENCING WIDESPREAD SHOWERS AND STORMS...
AS THE FRONT WILL BE MOVING THROUGH THE EASTERN HALF/TWO-THIRDS OF
THE AREA DURING PEAK HEATING (AS IT STANDS NOW)... COUPLED WITH
LARGE SCALE LIFT . THUS... WILL CONTINUE CURRENT POP FORECAST...
CHANCE FAR WEST... TO LOW END LIKELY ACROSS THE REMAINDER OF THE
AREA ON WEDNESDAY. WITH REGARD TO THE POTENTIAL FOR STRONG TO SEVERE
STORMS... AT LEAST WEAK TO MODERATE INSTABILITY IS EXPECTED ACROSS
THE AREA... WITH DEEP LAYER SHEAR VALUES RANGING FROM 20-25 KTS
SOUTH TO 30-35 KTS NORTH. THUS... EXPECT WE COULD SEE SOME ORGANIZED
SHOWERS AND STORMS... WITH SOME POTENTIAL STRONG TO SEVERE STORMS.
HOWEVER... GIVEN RATHER WEAK LAPSE RATES AS PW`S ARE EXPECTED TO
RISE TO 1.5-1.75 INCHES ON WEDNESDAY... NOT SURE HOW MUCH IF ANY
SEVERE STORMS WE WILL HAVE. FOR NOW WILL GO WITH HIGHS ON WEDNESDAY
RANGING FROM 76-82 DEGREES IN A NW TO SE FASHION WITH MOSTLY CLOUDY
TO OVERCAST SKIES.
LEAD MID/UPPER LEVEL IMPULSE WITH THE ASSOCIATED COLD FRONT IS
PROGGED TO MOVE THROUGH THE AREA WEDNESDAY NIGHT/THURSDAY MORNING...
WITH TIMING OF PRECIP EXITING THE SYSTEM A LITTLE SLOWER THAN LAST
NIGHTS MODELS INDICATED (3-9 HOURS SLOWER). THUS... WILL CONTINUE AT
LEAST CHANCE POPS INTO EARLY THURSDAY MORNING ACROSS THE COASTAL
PLAIN. THE 12Z ECWMF WANTS TO LINGER CHANCE FOR PRECIP INTO PAST
SUNRISE THURSDAY EVEN. WILL NOT GO THIS SLOW... AND ELECT TO END
POPS ACROSS THE ENTIRE CWA BEFORE DAYBREAK THURSDAY. FOR NOW WILL GO
WITH OVERNIGHT LOWS RANGING FROM THE MID TO UPPER 50S.
THURSDAY THROUGH FRIDAY:
MID TO UPPER TROUGH AXIS IS EXCEPTED TO SLOWLY SHIFT EASTWARD ACROSS
THE AREA THURSDAY INTO FRIDAY... WITH THE CORE OF THE TROUGH
REMAINING TO THE NORTH/NORTHEAST OF THE AREA. THUS... WITH SURFACE
HIGH PRESSURE BUILDING ACROSS THE AREA THURSDAY INTO SATURDAY EXPECT
AT LEAST MOSTLY SUNNY/CLEAR TO PARTLY SUNNY/CLOUDY SKIES... WITH DRY
CONDITIONS. HIGHS AREA EXPECTED TO BE IN THE 70S... LOWS IN THE
50S.
SURFACE HIGH PRESSURE IS EXPECTED TO BUILD INTO THE AREA LATE WEEK
INTO THE WEEKEND... RESULTING IN A RETURN TO DRIER AND COOLER
WEATHER. HIGHS ARE GENERALLY EXPECTED TO BE IN THE 70S... LOWS IN
THE UPPER 40S TO 50S DURING THIS TIME FRAME.
&&
.AVIATION /18Z SUNDAY THROUGH THURSDAY/...
AS OF 155 PM SUNDAY...
VISIBLE SATELLITE IMAGERY IS BEGINNING TO SHOW MORE BREAKS IN THE
WIDESPREAD STRATUS ACROSS CENTRAL NC...WITH MORE REPORTS OF BKN
1500-2500 CEILINGS AROUND THE AREA. THIS TREND WILL CONTINUE INTO
THE AFTERNOON...ALTHOUGH MVFR CEILINGS MAY REMAIN PREDOMINATE SINCE
THE BREAKS IN CLOUDS ARE SMALL AND VARIABLE FROM HOUR TO HOUR. A
STEADY NORTHEASTERLY WIND...STRONGER OVER EASTERN NC...WILL CONTINUE
INTO THE EVENING HOURS WHILE A WEAK LOW PRESSURE OFF THE CAROLINA
COAST DRIFTS AWAY FROM THE AREA.
TONIGHT..MODELS SHOW ANOTHER SURGE OF HIGH PRESSURE FROM THE MID
ATLANTIC COAST...WHICH MAY KEEP WINDS FROM GOING COMPLETELY CALM.
MOST GUIDANCE SHOWS A 3-5KT WIND OVERNIGHT..WHICH WOULD HELP TO KEEP
FOG FROM BEING WIDESPREAD AND DENSE...WITH BETTER POTENTIAL FOR
STRATUS. HOWEVER...MANY AREAS RECEIVED ONE TO TWO INCHES OF RAIN
LAST EVENING AND IT IS POSSIBLE THAT VSBYS WILL BE LOWER THAN WHAT
GUIDANCE GIVES. THUS...THERE IS HIGHER CONFIDENCE IN MVFR TO IFR
STRATUS AFTER MIDNIGHT...BUT IFR OR LOWER VSBYS CANNOT BE RULED
OUT. STRATUS SHOULD LIFT MUCH MORE QUICKLY MONDAY MORNING...WITH
VFR CONDITIONS POSSIBLE PRIOR TO 18Z.
OUTLOOK...
A CONTINUED MOIST AIRMASS OVER CENTRAL NC MAY PROMOTE
STRATUS/FOG AGAIN TUESDAY MORNING. A COLD FRONT WILL THEN APPROACH
THE REGION FROM THE NORTHWEST THROUGH THE MIDDLE OF THE
WEEK...LEADING TO UNSETTLED WEATHER AND THE POTENTIAL FOR ADVERSE
AVIATION CONDITIONS THROUGH THURSDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SMITH
NEAR TERM...SMITH
SHORT TERM...HARTFIELD
LONG TERM...BSD
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
103 PM CDT SUN MAY 6 2012
.DISCUSSION...
MAIN UPDATES EARLY THIS AFTERNOON WERE TO ADJUST
SKY...TEMPS...AND POPS BASED ON LATEST OBSERVATIONS...TRENDS...AND
NEAR TERM MODEL OUTPUT.
STACKED LOW PRESSURE CONTINUES TO MOVE SLOWLY NORTHEAST ACROSS
SOUTHERN SASKATCHEWAN. WRAP AROUND MOISTURE INCREASING CLOUDS
WEST INTO CENTRAL...WITH RAIN SHOWERS AT THE MOMENT STILL OFF TO
OUR WEST ACROSS NORTH CENTRAL MONTANA ADVECTING EAST-SOUTHEAST
TOWARDS EASTERN MT. A FEW LIGHT RETURNS OVER NORTH CENTRAL ND.
CONTINUES TO SEEM THE BEST FORCING FOR SHOWERS THIS AFTERNOON
INTO THIS EVENING SHOULD BE CONFINED FROM WEST CENTRAL
ND...NORTHEAST INTO NORTH CENTRAL ND...WITH THE BEST CHANCES FOR
RAIN TODAY/THIS EVENING ACROSS THE NORTHWEST. THE HRRR MODEL
SUPPORTS LATEST RADAR AND LEANED TOWARDS ITS SOLUTION FOR THE NEXT
6-9 HOURS.
WIND ADVISORY STILL LOOKS GOOD SO PLAN NO ADJUSTMENTS TO
HEADLINES WITH THE AFTERNOON UPDATE.
&&
.AVIATION...
VFR WITH SOME SCATTERED MVFR CIGS IN EASTERN MONTANA CONTINUE TO
MOVE INTO WESTERN NORTH DAKOTA AND WILL AFFECT KISN/KDIK/KMOT FOR
THE REST OF THE DAY. VFR CIGS TO MOVE INTO KBIS AND KJMS THIS
AFTERNOON...THEN GRADUALLY MVFR CIGS AFT 06Z. THE MAIN AVIATION
IMPACT WILL BE THE WINDS. WESTERLY WINDS COULD GUST AS HIGH AS 40
KNOTS THIS AFTERNOON AND EARLY EVENING...MAINLY AT KISN/KDIK/KMOT
TAFS. SOME RAIN SHOWERS THIS AFTERNOON AT KISN BUT BETTER CHANCE
FROM 00Z-06Z. MVFR CIGS TO SPREAD OVER ALL TAF SITES EVENTUALLY AFT
06Z. BEGINNING 15Z MONDAY EXPECT NORTHWEST WINDS TO INCREASE AGAIN
TO ABOVE 23 KNOTS WITH DIMINISHING MVFR CIGS TO VFR.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 9 PM CDT /8 PM MDT/ THIS EVENING FOR
NDZ001>003-009>011-017>021-031>034-040>045.
&&
$$
UPDATE...NH
AVIATION...JV
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1103 AM EDT SUN MAY 6 2012
.SYNOPSIS...
A NEARLY STATIONARY FRONT WILL REMAIN OVER TENNESSEE AND GEORGIA
TODAY AND TONIGHT. EXPECT A COLD FRONT TO APPROACH FROM THE
MISSISSIPPI AND OHIO VALLEYS DURING THE FIRST HALF OF THE WEEK WITH
A GOOD MOIST FLOW FROM THE GULF. EXPECT DRIER...COOLER HIGH
PRESSURE TO BUILD ACROSS OUR AREA IN THE LAST HALF OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 AM EDT...THE LOW CLOUD SHIELD ON MOIST NE FLOW ACROSS THE
REGION IS STARTING TO LIFT A BIT...WITH SOME BREAKS SHOWING UP.
DESPITE THE NE FLOW...DEWPOINTS HAVE NOT DRIED UP VERY MUCH...SO
CUMULUS WILL LIKELY FILL IN TO PRODUCE MORE CLOUDS THAN NOT MOST
AREAS THIS AFTN. HAVE LOWERED MAXES A COUPLE OF DEGREES IN THE NC
PIEDMONT WHERE MORNING CLOUDS HAVE BEEN MOST ABUNDANT. WINDS SHOULD
CONTINUE TO VEER GRADUALLY TOWARD EASTERLY...WITH AN UPSLOPE
COMPONENT DEVELOPING INTO THE HIGHER TERRAIN. TRIGGERING SHOULD
OCCUR FIRST OVER THE MTNS...WITH THE FOCUS FOR CONVECTIVE
DEVELOPMENT THE EXTREME SE MTNS. SOME MESOSCALE MODELS ALSO DEPICT
ISOLD CONVECTION OUT OVER THE PIEDMONT EARLY THIS AFTN FROM FORCING
WITH THE UPPER VORT EMBEDDED IN THE RIDGE AXIS. THIS FORCING MAY BE
OVERDONE...AND THE MODELS ALSO DO NOT HAVE A GOOD HANDLE ON ANY
DIFFERENTIAL SFC HEATING. THE MAIN CHANGE HAS BEEN TO ADD A THUNDER
MENTION OVER MORE OF THE UPSTATE AND EXTEND IT TO THE NC FOOTHILLS
THIS AFTN. PROFILES ARE NOT ESPECIALLY FAVORABLE FOR SEVERE TSTMS
THIS AFTN...BUT SOME LOCALIZED HEAVY RAIN IS POSSIBLE IN WEAK
STEERING FLOW.
LOW CLOUDS AND MAYBE SOME FOG WILL DEVELOP TONIGHT ACROSS MUCH OF
THE FA...THOUGH THERE MAY BE ENOUGH DRY AIR OVER THE SOUTHERN AND
EASTERN FRINGE OF ZONES TO PREVENT CLOUDS FROM DEVELOPING IN THESE
AREAS. LIGHT SHRA OR DRIZZLE WILL BE POSSIBLE ACROSS THE
APPALACHIANS AS LIGHT UPSLOPE FLOW PERSISTS.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AT 230 AM SUNDAY...A BACK DOOR COLD FRONT WILL PUSH SOUTH ACROSS OUR
FORECAST AREA SUNDAY NIGHT AND REMAINS JUST TO OUR SOUTH BY MONDAY
MORNING. THE BEST UPPER FORCING AND MOISTURE ALONG THE FRONT WILL
REMAIN SOUTH OF OUR AREA ON MONDAY. HOWEVER...A WEAK EASTERLY
UPSLOPE FLOW AND ELEVATED INSTABILITY MAY TRIGGER SCATTERED
CONVECTION OVER NC/GA MOUNTAINS. SO LOW END CHANCE POP WAS MENTIONED
THERE WITH SLIGHT CHANCE OVER THE PIEDMONT. BY MONDAY
NIGHT...MOISTURE ASSOCIATED WITH THE FRONT RETURNS NORTH ACROSS THE
UPPER SAVANNAH RIVER VALLEY IN ADVANCE OF AN APPROACHING COLD FRONT
FROM THE NORTHWEST. THE FRONT WILL BECOME STATIONARY OVER THE
APPALACHIANS ON TUESDAY WHICH WILL PROVIDE GOOD UPPER FORCING AND
PLENTY OF MOISTURE INTO OUR CWA. THAT IN MIND...LIKELY POP WAS
MENTIONED OVER THE NORTHERN HALF OF OUR CWA AND HIGH END CHANCE POPS
ELSEWHERE ON TUESDAY. ALSO THUNDER WAS MENTIONED DUE TO DECENT
INSTABILITY. DAYTIME HIGH WILL DROP INTO THE UPPER 70S OVER THE
PIEDMONT MONDAY AND BACK INTO THE LOW 80S TUESDAY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 330 AM SUNDAY...THE LATEST MODELS INDICATE THAT AN UPPER
TROUGH OVER THE GREAT LAKES AREA WILL DROP INTO THE SOUTHEAST STATES
BY WEDNESDAY. AS A RESULT...THE FRONT IS EXPECTED TO PUSH SE ACROSS
OUR CWA EARLY WED AND OFF THE ATLANTIC COAST BY WED NIGHT. THEN
BROAD CANADIAN HIGH PRESSURE WILL BUILD INTO THE EASTERN CONUS AND
LINGERS THROUGH SAT FOR COOLER TEMPS AND DRY WEATHER ACROSS OUR
FORECAST AREA. DAYTIME HIGHS WILL REMAIN IN THE UPPER 70S OVER THE
PIEDMONT WITH 60S IN THE MOUNTAINS THROUGHOUT THE PERIOD.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
AT KCLT...THE LATEST HRRR RUN PLACES WEAK CONVECTIVE DEVELOPMENT IN
THE VICINITY OF KCLT 16Z TO 18Z...BUT THIS APPEARS TO BE DUE TO
MISPLACEMENT OF THE DIFFERENTIAL HEATING BOUNDARY AND POOR HANDLING
OF THE UPPER VORT MAX UNDER THE RIDGE. WILL KEEP KCLT FREE OF ANY
PERCIP/TSRA MENTION...WITH LOWER VFR CIGS THROUGH THE AFTN/EVENING.
LOW CIGS ARE LIKELY AGAIN TONIGHT...AND MODEL SOUNDINGS CONTINUE TO
IMPLY THAT A VERY LOW DECK MAY BE POSSIBLE DURING THE EARLY MORNING
HOURS. ANTICIPATE WINDS STAYING NE TO ENE THROUGH THE PERIOD.
ELSEWHERE...MVFR CIGS WILL STEADILY LIFT THROUGH 16Z...WITH VFR CIGS
LIKELY THROUGH THE AFTN AND EVENING HOURS. ANY CONVECTIVE POTENTIAL
APPEARS BEST NEAR KAVL CIRCA 18Z AS UPSLOPE FLOW DEVELOPS AND
INSTABILITY MAXIMIZES. WILL KEEP THE FOOTHILLS TAFS DRY AND FREE OF
TS FOR NOW. WINDS WILL GRADUALLY VEER TO THE E OR ENE BY EARLY
AFTN...EXCEPT SE AT KAVL. MODEL SOUNDINGS AND MOS GUIDANCE IMPLY
VERY LOW CIGS ACROSS THE REGION TNGT. THE CURRENT FORECAST MAY BE ON
THE OPTIMISTIC SIDE.
OUTLOOK...SCT MAINLY DIURNAL SHWRS/TSTMS MON...MAINLY MTNS. TSTM
COVERAGE WILL INCREASE TUE-WED WITH A FRONT. MUCH DRIER CONDITIONS
ARE EXPECTED BEHIND THE FRONT THU AND FRI. PATCHY FOG AND STRATUS
WILL BE PSBL MON-WED MORNING.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JOH
NEAR TERM...HG
SHORT TERM...JOH
LONG TERM...JOH
AVIATION...HG
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1039 PM CDT MON MAY 7 2012
.UPDATE...LATEST HRRR RUN SHOWS VERY LITTLE ADDITIONAL CONVECTIVE
DEVELOPMENT THIS EVENING AND OVERNIGHT, WITH MOST OF THE ACTIVITY
OCCURRING ALONG THE CUMBERLAND PLATEAU AND THEN MOVING EAST. AM
UPDATING THE PUBLIC FORECAST TO LOWER POP`S AGAIN.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
ROSE
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
700 PM CDT MON MAY 7 2012
.AVIATION...
CURRENT WEATHER ACROSS THE REGION IS VFR. CIRRUS CLOUDS FROM TSTMS
IN CENTRAL TEXAS BEGINNING TO SPREAD FROM WEST TO EAST ACROSS
AREA. EXPECT TSTMS TO OUR WEST TO CONTINUE MOVING EAST INTO KCLL
AND KUTS AROUND 05Z AND POSSIBLY INTO KCXO AROUND 08Z. MVFR CIGS
ARE POSSIBLE AT MOST OF THE SOUTHERN AND CENTRAL SITES AFTER 08Z
AND BECOMING WIDESPREAD AROUND 14Z. COLD FRONT EXPECTED TO ENTER
NW PORTION OF REGION AROUND 09Z AND MOVE SLOWLY SOUTHEST DURING
THE DAY WITH SCATTERED SHOWERS AND A FEW THUNDERSTORMS DEVELOPING
ALONG THE FRONT. THE FRONT SHOULD NEAR THE COAST AROUND 00Z
WEDNESDAY WITH SCATTERED SHOWERS CONINUING INLAND BEHIND THE
FRONT.
&&
.PREV DISCUSSION... /ISSUED 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...47
AVIATION/MARINE...34
AREA FORECAST DISCUSSION...UPDATED
NWS LUBBOCK TX
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 CORPUS CHRISTI TX
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.
&&
$$
RH/79/LK/84...SHORT TERM/MARINE
TB/78...LONG TERM
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
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 73 52 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.
&&
$$
93/40
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1242 PM CDT SUN MAY 6 2012
.AVIATION...
EXPECT NLY WINDS OF 15-20 KNOTS TO PREVAIL TODAY IN THE WAKE OF A
COLD FRONT NOW ENTERING THE LOW ROLLING PLAINS AND NRN PERMIAN
BASIN. UPTICK IN DEWPOINTS BEHIND THIS FRONT IS ALREADY YIELDING
MVFR CIGS IN THE CENTRAL PANHANDLE AND WE EXPECT CDS AND LBB TO
SEE SIMILAR LOW CIGS DEVELOP LATE TONIGHT AS EVEN RICHER MOISTURE
IN NWRN OKLAHOMA IS CHANNELED SSW. THERE IS A DISTINCT POSSIBILITY
THESE BKN-OVC CIGS MAY RISE TO VFR BY LATE MON MORNING SHOULD
ENOUGH MIXING DEVELOP...BUT PATTERN CLIMATOLOGY AND MOS GUIDANCE
FAVOR MVFR THRU AT LEAST 07/18Z.
&&
.PREV DISCUSSION... /ISSUED 936 AM CDT SUN MAY 6 2012/
UPDATE...
QUICK UPDATE THIS MORNING TO CAPTURE STRONGER WINDS BEHIND A COLD
FRONT STRETCHING FROM SRN BAILEY COUNTY NORTHEAST TO NRN BRISCOE
COUNTY AS OF 14Z. SUSTAINED NLY WINDS PER VARIOUS WEST TX MESONET
STATIONS IN THE SWRN PANHANDLE HAVE ALREADY REACHED IN EXCESS OF
30 MPH OCCASIONALLY THANKS TO 40 KNOTS AROUND 2K FT AGL AS SAMPLED
BY AMA`S VWP. THIS WINDS ARE LOCATED WITHIN A NORTHERLY LLJ AXIS
POISED ACROSS THE WRN PANHANDLE...BUT ARE PROGGED TO WEAKEN IN THE
COMING HOURS. WILL THEREFORE REFRAIN FROM ISSUING A WIND ADVISORY
AS THIS WINDOW LOOKS TO BE TOO SHORT LIVED AND MARGINAL IN NATURE.
ALTHOUGH THE FRONT IS RUNNING A BIT AHEAD OF SCHEDULE...IT IS
STILL EXPECTED TO ENCOUNTER RESISTANCE LATER ON AS THE PRE-FRONTAL
BOUNDARY LAYER BECOMES DEEPLY-MIXED ULTIMATELY SLOWING THE FRONT`S
PROGRESSION SOUTHWARD. DID LOWER MAX TEMPS BY SEVERAL DEGREES
ACROSS THE NWRN SOUTH PLAINS WHILE KEEPING REMAINING AREAS LARGELY
INTACT. LATEST NAM AND RUC INDICATE THIS BOUNDARY WILL STALL NEAR
OUR SRN BORDER BY MIDDAY BEFORE ACCELERATING SOUTH NEAR SUNSET AS
PRE-FRONTAL BOUNDARY LAYER DECOUPLING ENSUES. THIS SHOULD PREVENT
ELEVATED FIRE WEATHER CONDITIONS FROM DEVELOPING AS WINDS REMAIN
TOO MARGINAL TO FAN FIRES. NO OTHER UPDATES AT THIS TIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 76 47 68 43 57 / 10 10 20 50 50
TULIA 78 50 69 48 59 / 10 10 20 40 50
PLAINVIEW 81 51 70 49 58 / 10 10 20 40 50
LEVELLAND 88 53 72 49 59 / 10 10 20 60 60
LUBBOCK 88 55 72 50 59 / 10 10 20 50 60
DENVER CITY 92 53 76 49 63 / 0 10 20 70 70
BROWNFIELD 93 54 75 50 59 / 10 10 20 60 70
CHILDRESS 88 58 73 56 70 / 10 10 20 30 40
SPUR 97 56 74 52 64 / 10 10 20 40 50
ASPERMONT 102 61 76 56 71 / 10 10 20 40 50
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
93/40/93
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1057 AM CDT SUN MAY 6 2012
.DISCUSSION...COMPLEX FORECAST FOR TODAY. PER SURFACE ANALYSIS AND
VISIBLE SAT IMAGERY...THE OUTFLOW BOUNDARY FROM LAST NIGHT/S MCS
TO OUR NORTH IS CURRENTLY DRAPED FROM WEST TO EAST FROM JUST NORTH
OF LAREDO TO JUST SOUTH OF DOWNTOWN CORPUS CHRISTI. AN ADDITIONAL
BOUNDARY ON THE BACK SIDE OF AN MCV IS CURRENTLY INITIATING
ISOLATED CONVECTION ACROSS NE ZONES. MESO ANALYSIS PLACES A HIGHLY
UNSTABLE AIRMASS ACROSS MUCH OF S TX THIS MORNING AND WITH
BOUNDARIES IN THE AREA CAN NOT RULE OUT ISOLATED STORMS THE
REMAINDER OF THE DAY. ADDITIONAL STORM CHANCES MAY COME LATE THIS
AFTERNOON AND INTO THE EVENING ACROSS RIO GRANDE PLAINS AND
EVENTUALLY THE BRUSH COUNTRY. 12Z HRRR WANTS TO DEVELOP CONVECTION
ACROSS OLD MEX BY MID AFTERNOON WITH STRONG STORMS CROSSING THE
RIVER INTO CRP CWA BY LATE AFTERNOON. WILL CONTINUE TO MONITOR
SITUATION WITH FULL UPDATE COMING WITH MAIN AFTERNOON FORECAST
PACKAGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 92 74 92 74 89 / 20 10 10 10 10
VICTORIA 90 72 92 72 87 / 20 10 10 10 10
LAREDO 100 74 100 76 94 / 20 20 10 10 20
ALICE 97 73 97 73 91 / 20 10 10 10 10
ROCKPORT 86 76 87 76 85 / 10 10 10 10 10
COTULLA 99 71 99 72 90 / 20 20 10 20 20
KINGSVILLE 95 73 95 75 90 / 20 10 10 10 10
NAVY CORPUS 87 75 87 76 86 / 20 10 10 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
UPDATE...HART/79
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1019 AM CDT SUN MAY 6 2012
.UPDATE...
CHALLENGING FORECAST THIS MORNING REGARDING THUNDERSTORM POTENTIAL
LATER THIS AFTERNOON. REMNANTS OF LAST NIGHTS MCS REMAIN TO OUR
WEST WHERE AN MCV HAS FORMED AND SOME REDEVELOPMENT IS OCCURRING
ACROSS GONZALES COUNTY. 12Z NAM SOUNDINGS SUGGEST THE CAP IS
BREAKABLE ACROSS THE NORTHERN HALF OF SOUTHEAST TEXAS THIS
AFTERNOON WITH CAPE VALUES BETWEEN 1400-2000 J/KG AND LI`S OF -5
TO -7. THE 11Z AND 12Z HRRR FORECAST REFLECTIVITIES HAVE TRENDED
WELL WITH THE ACTIVITY ONGOING THIS MORNING AND SUGGEST AN OVERALL
DOWNWARD TREND IN ACTIVITY THIS MORNING BEFORE REDEVELOPING ACROSS
PORTIONS OF HARRIS AND MONTGOMERY COUNTIES LATER THIS AFTERNOON.
GIVEN THIS AND THE UNCAPPED PROFILE FOR IAH AT 21Z IN THE NAM
GUIDANCE HAVE GONE AHEAD AND RAISED POPS ACROSS THE REGION INTO
THE EVENING HOURS. HAVE ALSO INCLUDED A MENTION OF SEVERE
GENERALLY ALONG AND NORTH OF THE US 59 CORRIDOR AS INVERTED V
SIGNATURE ON THE FORECAST SOUNDINGS SUGGESTS THE POTENTIAL FOR
SOME DAMAGING WIND GUSTS WITH THESE THUNDERSTORMS. 38
&&
.PREV DISCUSSION... /ISSUED 641 AM CDT SUN MAY 6 2012/
AVIATION...
SHOWERS AND ISOLATED THUNDERSTORMS WERE DEVELOPING WEST OF KSGR
AND KLBX AT 1130Z...AND FELT THAT AT LEAST ISOLATED SHOWERS WERE
POSSIBLE FROM KHOU AND KSGR TO THE COAST THIS MORNING. THE MODELS
AGREED THAT A VORTICITY CENTER AT 500 MB WILL MOVE UP FROM NEAR
MATAGORDA BAY INTO SE TX. THE MODELS INDICATED THAT THE BEST
CHANCES FOR ISOLATED SHOWERS AND THUNDERSTORMS THIS AFTERNOON WILL
BE OVER THE WESTERN AND NORTHERN TERMINAL SITES OUTSIDE OF METRO
HOUSTON AND KGLS. OVERNIGHT TONIGHT THERE IS AN OUTSIDE CHANCE
FOR MVFR TO IFR CONDITIONS TO FORM...ESPECIALLY OUTSIDE OF THE BIG
AIRPORTS.
40
PREV DISCUSSION... /ISSUED 414 AM CDT SUN MAY 6 2012/
DISCUSSION...
AN MCS OVER CENTRAL TEXAS CONTINUES TO EDGE TOWARD SE TX THIS
MORNING. FEEL THIS AREA OF CONVECTION WILL WEAKEN BUT WILL LIKELY
BRING SOME RAIN TO PARTS OF JACKSON...WHARTON AND COLORADO
COUNTIES BEFORE FALLING APART. THE RESIDUAL BOUNDARY AND COLD POOL
WILL LIE CLOSE TO SOUTHEAST TEXAS THIS AFTERNOON AND MAY BECOME A
PLAYER FOR LATE AFTERNOON AND EARLY EVENING THUNDERSTORMS. THE
NAM12 FORECAST SOUNDINGS ARE CONDITIONALLY UNSTABLE WITH PW VALUES
EXCEEDING 1.7 INCHES...LAPSE RATES ABOVE 7.0 DEGREES AND CAPE
EXCEEDING 3000. THE AREA IS PROGGED TO BE CAPPED WITH A CONVECTIVE
TEMP NEAR 90. THE CAP LOOKS BREAKABLE OVER PARTS OF THE NORTHWEST
ZONES BY 21Z. CLOUD DEBRIS FROM THIS MCS MAY RETARD HEATING BUT
THINK THERE WILL BE ENOUGH BREAKS THIS AFTERNOON FOR MAX TEMPS TO
WARM INTO THE LOWER 90S OVER THE NORTH AND NORTHWEST PARTS OF
SOUTHEAST TEXAS. THE ECMWF SUPPORTS A BURST OF CONVECTION THIS
EVENING WHILE THE GFS KEEPS THE REGION CAPPED AND RAIN FREE. A
TOUGH CALL FOR SURE BUT WILL SIDE WITH THE NAM AND ADD CHANCE POPS
OVER THE NORTHWEST AND ALSO MENTION THE POTENTIAL FOR SEVERE
STORMS DUE TO THE LAPSE RATES AND INVERTED V SIGNATURE IN THE
SOUNDING. IF CLOUDS HANG IN...CONVECTIVE POTENTIAL FOR THIS
EVENING WILL BE NIL.
A PACIFIC COLD FRONT WILL SLOWLY CROSS SOUTHEAST TEXAS ON TUESDAY
AND WEDNESDAY. STILL SOME TIMING DIFFERENCES WITH THE GFS NOW THE
SLOWEST MODEL. RAIN CHANCES SHOULD BE INCREASING OVER THE NORTH ON
TUESDAY CLOSER TO THE BEST SURFACE CONVERGENCE. THIS AREA WILL
SHIFT SOUTH ON WEDNESDAY WITH THE BETTER RAIN CHANCES CLOSER TO
THE COAST. THE FRONT WILL BE OFF THE COAST ON THURSDAY AND
MOISTURE LEVELS DROP SO HAVE PARED POPS BACK. ONSHORE FLOW
REDEVELOPS RATHER QUICKLY THURSDAY NIGHT AS A POTENT UPPER LEVEL
LOW NEAR THE BIG BEND KICKS SLOWLY EAST. PW VALUES POP BACK UP TO
1.6 INCHES FOR FRIDAY AND UPPER LEVEL WINDS BECOME STRONGLY
DIVERGENT. RAIN CHANCES WILL INCREASE AHEAD OF THE UPPER TROUGH.
LONG RANGE MODELS SEEM TO PINGING THE SOUTHERN HALF OF THE REGION
AND AREAS OFFSHORE WITH THE HEAVIEST PRECIP. THE POSITION OF THE
UPPER LOW WOULD SEEM TO FAVOR AREAS A BIT FURTHER NORTH (INLAND).
THE ECMWF AND CANADIAN ARE FASTER THAN THE GFS AND LEANED TOWARD
THE FASTER SOLUTIONS...BRINGING THE RAIN ACROSS THE REGION ON
FRIDAY.
TEMPS WILL TREND COOLER AS THE WEEK PROGRESS AS HEIGHTS FALL AND
CLOUD COVER INCREASES. GFS AND ECMWF HINTING AT SOME 50S FOR
OVERNIGHT LOWS OVER THE EXTREME NORTHEAST ZONES BY NEXT SATURDAY.
43
MARINE...
MODERATE ONSHORE WINDS EARLY THIS MORNING ARE MAINLY IN RESPONSE TO
THE MCS APPROACHING THE MID TEXAS COASTAL AREAS FROM THE HILL
COUNTRY. THE MODELS ARE IN AGREEMENT WITH DECREASING WIND SPEEDS
LATER THIS MORNING. EXPECT WINDS TO BE UNDER CAUTION CRITERIA LATER
THIS MORNING THROUGH MID WEEK.
40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 92 72 89 70 83 / 30 30 20 20 40
HOUSTON (IAH) 90 72 90 71 87 / 20 20 10 10 30
GALVESTON (GLS) 85 76 85 74 84 / 20 10 10 10 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...38
AVIATION/MARINE...46
AREA FORECAST DISCUSSION...UPDATED
NWS LUBBOCK TX
936 AM CDT SUN MAY 6 2012
.UPDATE...
QUICK UPDATE THIS MORNING TO CAPTURE STRONGER WINDS BEHIND A COLD
FRONT STRETCHING FROM SRN BAILEY COUNTY NORTHEAST TO NRN BRISCOE
COUNTY AS OF 14Z. SUSTAINED NLY WINDS PER VARIOUS WEST TX MESONET
STATIONS IN THE SWRN PANHANDLE HAVE ALREADY REACHED IN EXCESS OF
30 MPH OCCASIONALLY THANKS TO 40 KNOTS AROUND 2K FT AGL AS SAMPLED
BY AMA`S VWP. THIS WINDS ARE LOCATED WITHIN A NORTHERLY LLJ AXIS
POISED ACROSS THE WRN PANHANDLE...BUT ARE PROGGED TO WEAKEN IN THE
COMING HOURS. WILL THEREFORE REFRAIN FROM ISSUING A WIND ADVISORY
AS THIS WINDOW LOOKS TO BE TOO SHORT LIVED AND MARGINAL IN NATURE.
ALTHOUGH THE FRONT IS RUNNING A BIT AHEAD OF SCHEDULE...IT IS
STILL EXPECTED TO ENCOUNTER RESISTANCE LATER ON AS THE PRE-FRONTAL
BOUNDARY LAYER BECOMES DEEPLY-MIXED ULTIMATELY SLOWING THE FRONT`S
PROGRESSION SOUTHWARD. DID LOWER MAX TEMPS BY SEVERAL DEGREES
ACROSS THE NWRN SOUTH PLAINS WHILE KEEPING REMAINING AREAS LARGELY
INTACT. LATEST NAM AND RUC INDICATE THIS BOUNDARY WILL STALL NEAR
OUR SRN BORDER BY MIDDAY BEFORE ACCELERATING SOUTH NEAR SUNSET AS
PRE-FRONTAL BOUNDARY LAYER DECOUPLING ENSUES. THIS SHOULD PREVENT
ELEVATED FIRE WEATHER CONDITIONS FROM DEVELOPING AS WINDS REMAIN
TOO MARGINAL TO FAN FIRES. NO OTHER UPDATES AT THIS TIME.
&&
.PREV DISCUSSION... /ISSUED 627 AM CDT SUN MAY 6 2012/
AVIATION...
SOUTHERLY WINDS EARLY THIS MORNING WILL QUICKLY SHIFT TO THE NORTH
AND BECOME BREEZY LATER THIS MORNING DUE TO A COLD FRONT. STRONG
WINDS ARE EXPECTED TO PERSIST FOR MUCH OF THE AFTERNOON AND LESSEN
LATE IN THE AFTERNOON BUT STILL REMAINING BREEZY OVERNIGHT
TONIGHT. BY EARLY MONDAY MORNING...LOW LEVEL MOISTURE WILL
INCREASE AND AS A RESULT LOW STRATUS MAY FORM AT BOTH TAF SITES
FROM NORTH TO SOUTH.
PREV DISCUSSION... /ISSUED 439 AM CDT SUN MAY 6 2012/
SHORT TERM...
UPPER LEVEL SHORT WAVE AXIS WILL MOVE OVER THE AREA TODAY HOWEVER
THERE WILL BE LITTLE LIFT ASSOCIATED WITH IT BY THE TIME IT REACHES
THE AREA. THE DRYLINE WILL NOT MAKE MUCH MORE WESTWARD MOVEMENT THIS
MORNING BEFORE MIXING EAST. REGARDLESS...THE COLD FRONT EXPECTED
LATER THIS MORNING WILL OVERTAKE THE DRYLINE. THE COLD FRONT WAS
ENTERING THE NORTHERN TEXAS PANHANDLE EARLY THIS MORNING AND IS
STILL ANTICIPATED TO MOVE THROUGH THE REGION FROM LATE MORNING INTO
THE LATE AFTERNOON. BECAUSE OF THIS...THERE WILL BE A SHARP GRADIENT
OF MAXIMUM TEMPERATURES THIS AFTERNOON. AREAS SOUTH OF THE FRONT BY
THE AFTERNOON WILL CONTINUE TO SEE 90S INTO THE LOWER 100S WITH
UPPER 70S IN THE SOUTHWESTERN TEXAS PANHANDLE. HOWEVER...ONE GOOD
THING IS THAT JUST ABOUT EVERYWHERE WILL SEE COOLER TEMPERATURES
THAN OBSERVED OVER THE PREVIOUS FEW DAYS. THE FRONT WILL ALSO BRING
IN MORE PLEASANT SURFACE DEW POINTS. ALL MODELS SHOW LOW LEVEL
MOISTURE/STRATUS SPILLING INTO THE AREA FROM THE NORTH BY EARLY
MONDAY MORNING. JDV
LONG TERM...
A SIGNIFICANT PATTERN CHANGE WILL RESULT IN A MUCH COOLER AND MORE
DAMP PATTERN EXPECTED TO PERSIST THE ENTIRE COMING WEEK...IF NOT
BEYOND. CHANGE WILL BE INITIATED BY STRONG UPPER LOW CHARGING EAST
ALONG THE US-CANADIAN BORDER THEN DEEPENING INTO SLOW MOVING UPPER
TROUGH OVER THE EASTERN US. MUCH COOLER WEST TO NORTHWEST FLOW
WILL FOLLOW EAST OF THE ROCKIES WITH A COOL SURFACE HIGH PRESSURE
RIDGE SETTLING SOUTHWARD INTO THE SOUTHERN PLAINS EARLY IN THE
WEEK. RAINFALL AMOUNTS IN THIS PATTERN REMAIN HIGHLY UNCERTAIN...
CONNECTED LARGELY TO MESO-SCALE FEATURES TOO DISTANT TO FULLY
ANTICIPATE AT THIS POINT. BUT THE MOST SIGNIFICANT RAINFALL DOES
SEEM MORE LIKELY JUST TO OUR SOUTH-SOUTHWEST WITH THIS PATTERN
NEARER TO A QUASI-STATIONARY FRONTAL BOUNDARY THAT SHOULD LIE SOUTH
OF THE PECOS...PERHAPS NEAR THE RIO GRANDE MUCH OF THE WEEK.
THIS SET-UP WILL ALLOW POTENTIAL FOR OVER-RUNNING ISENTROPIC LIFT
FROM A WEAK CONVECTIVE ENHANCED WAVE EXPECTED TO EDGE NORTHEAST
INTO OUR AREA LATE MONDAY NIGHT AND TUESDAY. THIS SYSTEM ALSO WILL
FEATURE DYNAMIC LIFT FROM UPPER DIVERGENCE AND FAVORABLE LEFT-EXIT
JET REGION...AS WELL AS RIGHT-ENTRANCE JET PASSING NORTH OF THE
AREA AT THE SAME TIME. LOWER LEVELS FAIRLY DRY IN TERMS OF SURFACE
DEWPOINTS...BUT AIRMASS SHOULD COOL TOWARDS SATURATION WITH THE
PERIOD OF LIFT EXPECTED AND MOISTENING FROM CONVECTIVE SHOWERS
SPREADING INTO THE AREA FROM THE SOUTH-SOUTHWEST LATE ON MONDAY.
WE HAVE INCREASED THUNDERSTORM MENTION TO MEDIUM AND HIGH CHANCE
LEVELS FOR MONDAY NIGHT AND TUESDAY. AND DROPPED HIGH TEMPERATURES
TUESDAY ANOTHER NOTCH WITH MOIST AND COOL CONDITIONS AND 1020+ MB
SURFACE HIGH PRESSURE RIDGE SETTLING INTO THE AREA. TEMPERATURES
TUESDAY AS MUCH AS 30 TO 40 DEGREES COOLER THAN EXPERIENCED FOR
THE PAST WEEK...JACKETS AND SWEATERS RETURN AND AC GETS A BREAK.
SHOWERS SHOULD BE ON THE DECLINE LATE TUESDAY WITH DEPARTING WEAK
UPPER WAVE.
WEDNESDAY APPEARS LIKELY TO REMAIN COOL WITH LESSER SHOWER
CHANCES AND MORE LIMITED DYNAMIC LIFT AND INSTABILITY...WHILE
SURFACE FRONT WILL REMAIN LOCKED FAR TO OUR SOUTH. THUNDERSTORMS
DEVELOPING NEAR THIS FRONT COULD TEND TO DRIFT NORTHEASTWARD WHICH
WILL SUPPORT SMALL CHANCE MENTION SPREADING INTO THE AREA LATE IN
THE DAY AND WEDNESDAY NIGHT.
THE NEXT SIGNIFICANT EVENT IS EXPECTED TO BE THE PASSAGE OF A
VERY SLOW MOVING CLOSED UPPER LOW FROM NORTHERN MEXICO ACROSS THE
RIO GRANDE INTO WEST TEXAS THURSDAY NIGHT AND PERSISTING IN THE
AREA JUST TO OUR SOUTH THROUGH FRIDAY OR FRIDAY NIGHT. THIS SYSTEM
SHOULD ADEQUATELY DESTABILIZE AIRMASS TO SUPPORT INCREASING
THUNDER CHANCES LATE THURSDAY THROUGH FRIDAY AT LEAST. BEYOND
FRIDAY...MODEL MESS STARTS TO DEVELOP THOUGH LEAN GIVEN AT THIS
POINT TOWARDS MAINTAINING A COOL NORTHWEST FLOW AT LEAST INTO THE
WEEKEND PER FAVORED ECMWF SOLUTION. WILL ADDRESS PRECIPITATION
POTENTIAL FOR NEXT WEEKEND WITH LATER FORECASTS. RMCQUEEN
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 76 47 68 47 63 / 10 10 20 50 50
TULIA 78 50 69 50 62 / 10 10 20 40 50
PLAINVIEW 81 51 70 50 62 / 10 10 20 40 50
LEVELLAND 88 53 72 51 64 / 10 10 20 50 50
LUBBOCK 88 55 72 52 64 / 10 10 20 40 50
DENVER CITY 92 53 76 52 63 / 0 10 20 60 50
BROWNFIELD 93 54 75 52 64 / 10 10 20 60 50
CHILDRESS 88 58 73 56 69 / 10 10 20 30 40
SPUR 97 56 74 54 66 / 10 10 20 40 50
ASPERMONT 102 61 76 57 68 / 10 10 20 40 50
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
93/40
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1134 PM CDT SAT MAY 5 2012
.DISCUSSION... SEE AVIATION DISCUSSION BELOW
&&
.AVIATION...
SHOWERS AND THUNDERSTORMS HAVE WEAKENED AND ARE CONFINED TO
MASON...SAN SABA...MCCULLOCH AND ONE ISOLATED SHOWER IN CONCHO
COUNTIES. SEVERE THUNDERSTORMS EARLIER TONIGHT HAVE WEAKENED AND
THE REMAINING SHOWER AREA IS MAINLY MODERATE RAIN AND A STEADILY
LOWERING LIGHTNING THREAT. CURRENTLY THE LINE OF SHOWERS IS MOVING
SOUTHEAST AND SHOULD EXIST THE FORECAST AREA WITHIN THE NEXT FEW
HOURS. THIS SHOWER AREA COMBINED WITH HIGH CLOUDS MOVING OVER THE
AREA FROM THE SOUTHWEST IS CAUSING OVERCAST HIGH CLOUDS OVER MOST
OF THE WARNING AREA. SOME PARTIAL CLEARING OF HIGH CLOUDS FROM
WEST TO EAST IS EXPECTED TOMORROW.
MOST AREAS WILL HAVE VFR FLYING CONDITIONS THE NEXT 24
HOURS...EXCEPT FOR COUNTIES WITH SHOWERS THE NEXT FEW HOURS.
FARTHER SOUTH FORMATION OF LOW CLOUDS OVERNIGHT INTO EARLY MORNING
HOURS PRIMARILY NEAR SONORA AND JUNCTION WILL RESULT IN MVFR OR
LOCALLY IFR CONDITIONS. WINDS WILL CONTINUE GENERALLY FROM THE
SOUTH AT LOW LEVELS AND AT THE SURFACE OVERNIGHT AND INTO TOMORROW
AND REMAIN MOSTLY LESS THAN 15 KTS.
&&
.PREV DISCUSSION... /ISSUED 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 / 30 10 20 20 30
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/99/99
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
545 PM CDT SUN MAY 6 2012
.SHORT TERM...THROUGH TUESDAY NIGHT
251 PM CDT SUN MAY 6 2012
MAIN FORECAST PROBLEM IS WITH THE RAIN CHANCES TONIGHT AND AGAIN
TUESDAY.
SURFACE ANALYSIS THIS AFTERNOON SHOWS A WEAK AREA OF LOW PRESSURE
OVER CENTRAL IOWA. A WARM FRONT EXTENDS EAST FROM THE LOW INTO
NORTHERN ILLINOIS. A TROUGH OF LOW PRESSURE EXTENDS SOUTHWEST TO
ANOTHER AREA OF LOW PRESSURE OVER OKLAHOMA. REGIONAL RADARS SHOW
MOST OF THE CONVECTIVE ACTIVITY IS CONFINED TO THE WARM SECTOR
SOUTH OF THE WARM FRONT AND EAST OF THE TROUGH OF LOW PRESSURE.
THE MAIN CONCERN FOR RAIN CHANCES TONIGHT IS WHERE WILL THE
CONVECTION REDEVELOP THROUGH THE REMAINDER OF THE AFTERNOON. THIS
MORNINGS MCS HAS KEPT THE WARM FRONT SOUTH OF THE FORECAST AREA
BUT RECENT TRENDS SUGGEST IT IS STARTING TO RETURN SLOWLY TO THE
NORTH. WINDS AT KAWG IN SOUTHEAST IOWA HAVE TURNED FROM THE
NORTHEAST TO THE SOUTHEAST. NOT SURE HOW FAR NORTH THE FRONT WILL
MAKE IT...BUT IT COULD GET CLOSE ENOUGH TO ALLOW SOME OVERRUNNING
ACTIVITY TO AFFECT THE SOUTHEAST PORTIONS OF THE FORECAST AREA.
LOOKING AT THE 06.14Z HRRR AND 06.12Z HI-RES ARW AND NMM...ALL
THESE MODELS SHOW THE DEVELOPING CONVECTION THIS AFTERNOON AND
EVENING STAYING SOUTH OF THE FORECAST AREA. THIS ADDS A LEVEL OF
UNCERTAINTY TO THE FORECAST BUT EXPECTING A SHORT WAVE TROUGH TO
COME OUT OF SOUTHERN KANSAS AND MOVE TOWARD NORTHERN ILLINOIS THIS
EVENING. THIS WOULD KEEP THE BEST FORCING SOUTH OF THE AREA ALONG
WITH MOST THE ACTIVITY LIKE THE HI-RES MODELS ARE SUGGESTING. HAVE
LOWERED THE RAIN CHANCES ACROSS THE ENTIRE AREA WITH THE IDEA THAT
THE ACTIVITY WILL PRIMARILY STAY TO THE SOUTH.
THE NEXT CHANCE OF RAIN THEN COMES TUESDAY AS THE UPPER LEVEL LOW
CURRENTLY OVER SOUTHERN SASKATCHEWAN DROPS SOUTHEAST ACROSS THE
GREAT LAKES. BOTH THE 06.12Z NAM AND GFS SHOW AT LEAST ONE SHORT
WAVE TROUGH ASSOCIATED WITH THE UPPER LEVEL LOW THAT WILL PRODUCE
ANYWHERE FROM 4 TO 12 PVU/S OF VORTICITY ADVECTION IN THE 500-300
MB LAYER. THIS FORCING COMBINED WITH THE CYCLONIC FLOW AROUND THE
LOW SHOULD BE ENOUGH TO GENERATE SCATTERED SHOWERS FOR MUCH OF THE
AREA. AS THE COLD POOL ALOFT COMES ACROSS THE AREA...500 MB
TEMPERATURES DROP TO AROUND -25C...LAPSE RATES SHOULD BECOME STEEP
ENOUGH TO SUPPORT SOME ISOLATED THUNDER AS WELL. NAM BUFKIT
SOUNDING FOR CENTRAL WISCONSIN SHOW THE POTENTIAL FOR LAPSE RATES
OF 7C/KM UP THROUGH AT LEAST 500 MB. THIS ACTIVITY IS THEN
EXPECTED TO DISSIPATE/MOVE OFF TO THE EAST TUESDAY EVENING AS THE
LOW MOVES AWAY AND THE LAPSE RATES DECREASE.
.LONG TERM...WEDNESDAY THROUGH SUNDAY
251 PM CDT SUN MAY 6 2012
HIGH PRESSURE WILL SET UP OVER THE UPPER MIDWEST AND PROVIDE SOME
DRY WEATHER FOR WEDNESDAY AND THURSDAY. THE GFS AND 06.12Z ECMWF
ARE IN PRETTY GOOD AGREEMENT OF BRINGING A COLD FRONT ACROSS THE
AREA FRIDAY AND SATURDAY WITH THE RAIN CHANCES MAINLY ALONG AND
BEHIND THE FRONT. SOME RAIN CHANCES WILL THEN LINGER THROUGH
SUNDAY AS THE UPPER LEVEL TROUGH AXIS MOVES ACROSS SOUTHERN CANADA
AND THE UPPER MIDWEST.
&&
.AVIATION...TONIGHT AND MONDAY
545 PM CDT SUN MAY 6 2012
MAIN CHALLENGES WITH THIS TAF CYCLE IS WITH THE LOW CEILINGS AND
WHETHER A BATCH OF SHOWERS CURRENTLY IN WESTERN IOWA MAKES IT INTO
THE TAF SITES. CEILINGS HAVE GENERALLY IMPROVED TO MVFR AT
1200-2500FT ACROSS MUCH OF THE REGION THOUGH THERE IS A BAND OF
IFR STRETCHING FROM NORTHERN WISCONSIN INTO CENTRAL MINNESOTA.
WINDS WILL GENERALLY BE OUT OF THE NORTH BEFORE A COLD FRONT
SLOWLY MOVES THROUGH OVERNIGHT AND BRINGS THEM OUT OF THE
NORTHWEST. AHEAD OF THE FRONT...SOME SHOWERS OR DRIZZLE COULD MOVE
IN LATER THIS EVENING AND BRING CEILINGS/VISIBILITY DOWN BRIEFLY.
INSTABILITY LOOKS TO DROP OFF QUICKLY TONIGHT...SO DO NOT THINK
THAT IF/WHEN THE SHOWERS MOVE IN THAT THEY WILL PRODUCE ANY
THUNDER. HOW FAST CEILINGS CLEAR TOMORROW MORNING IS THE NEXT
QUESTION FOR FORECAST GUIDANCE SUGGESTING THAT RST CLEARS OUT
AROUND 15Z WHILE LSE CLEARS AT 18Z. CEILINGS SHOULD STAY AT MVFR
OR POSSIBLY IFR OVERNIGHT UNTIL THIS CLEARING OCCURS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
251 PM CDT SUN MAY 6 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
251 PM CDT SUN MAY 6 2012
.SHORT TERM...THROUGH TUESDAY NIGHT
251 PM CDT SUN MAY 6 2012
MAIN FORECAST PROBLEM IS WITH THE RAIN CHANCES TONIGHT AND AGAIN
TUESDAY.
SURFACE ANALYSIS THIS AFTERNOON SHOWS A WEAK AREA OF LOW PRESSURE
OVER CENTRAL IOWA. A WARM FRONT EXTENDS EAST FROM THE LOW INTO
NORTHERN ILLINOIS. A TROUGH OF LOW PRESSURE EXTENDS SOUTHWEST TO
ANOTHER AREA OF LOW PRESSURE OVER OKLAHOMA. REGIONAL RADARS SHOW
MOST OF THE CONVECTIVE ACTIVITY IS CONFINED TO THE WARM SECTOR
SOUTH OF THE WARM FRONT AND EAST OF THE TROUGH OF LOW PRESSURE.
THE MAIN CONCERN FOR RAIN CHANCES TONIGHT IS WHERE WILL THE
CONVECTION REDEVELOP THROUGH THE REMAINDER OF THE AFTERNOON. THIS
MORNINGS MCS HAS KEPT THE WARM FRONT SOUTH OF THE FORECAST AREA
BUT RECENT TRENDS SUGGEST IT IS STARTING TO RETURN SLOWLY TO THE
NORTH. WINDS AT KAWG IN SOUTHEAST IOWA HAVE TURNED FROM THE
NORTHEAST TO THE SOUTHEAST. NOT SURE HOW FAR NORTH THE FRONT WILL
MAKE IT...BUT IT COULD GET CLOSE ENOUGH TO ALLOW SOME OVERRUNNING
ACTIVITY TO AFFECT THE SOUTHEAST PORTIONS OF THE FORECAST AREA.
LOOKING AT THE 06.14Z HRRR AND 06.12Z HI-RES ARW AND NMM...ALL
THESE MODELS SHOW THE DEVELOPING CONVECTION THIS AFTERNOON AND
EVENING STAYING SOUTH OF THE FORECAST AREA. THIS ADDS A LEVEL OF
UNCERTAINTY TO THE FORECAST BUT EXPECTING A SHORT WAVE TROUGH TO
COME OUT OF SOUTHERN KANSAS AND MOVE TOWARD NORTHERN ILLINOIS THIS
EVENING. THIS WOULD KEEP THE BEST FORCING SOUTH OF THE AREA ALONG
WITH MOST THE ACTIVITY LIKE THE HI-RES MODELS ARE SUGGESTING. HAVE
LOWERED THE RAIN CHANCES ACROSS THE ENTIRE AREA WITH THE IDEA THAT
THE ACTIVITY WILL PRIMARILY STAY TO THE SOUTH.
THE NEXT CHANCE OF RAIN THEN COMES TUESDAY AS THE UPPER LEVEL LOW
CURRENTLY OVER SOUTHERN SASKATCHEWAN DROPS SOUTHEAST ACROSS THE
GREAT LAKES. BOTH THE 06.12Z NAM AND GFS SHOW AT LEAST ONE SHORT
WAVE TROUGH ASSOCIATED WITH THE UPPER LEVEL LOW THAT WILL PRODUCE
ANYWHERE FROM 4 TO 12 PVU/S OF VORTICITY ADVECTION IN THE 500-300
MB LAYER. THIS FORCING COMBINED WITH THE CYCLONIC FLOW AROUND THE
LOW SHOULD BE ENOUGH TO GENERATE SCATTERED SHOWERS FOR MUCH OF THE
AREA. AS THE COLD POOL ALOFT COMES ACROSS THE AREA...500 MB
TEMPERATURES DROP TO AROUND -25C...LAPSE RATES SHOULD BECOME STEEP
ENOUGH TO SUPPORT SOME ISOLATED THUNDER AS WELL. NAM BUFKIT
SOUNDING FOR CENTRAL WISCONSIN SHOW THE POTENTIAL FOR LAPSE RATES
OF 7C/KM UP THROUGH AT LEAST 500 MB. THIS ACTIVITY IS THEN
EXPECTED TO DISSIPATE/MOVE OFF TO THE EAST TUESDAY EVENING AS THE
LOW MOVES AWAY AND THE LAPSE RATES DECREASE.
.LONG TERM...WEDNESDAY THROUGH SUNDAY
251 PM CDT SUN MAY 6 2012
HIGH PRESSURE WILL SET UP OVER THE UPPER MIDWEST AND PROVIDE SOME
DRY WEATHER FOR WEDNESDAY AND THURSDAY. THE GFS AND 06.12Z ECMWF
ARE IN PRETTY GOOD AGREEMENT OF BRINGING A COLD FRONT ACROSS THE
AREA FRIDAY AND SATURDAY WITH THE RAIN CHANCES MAINLY ALONG AND
BEHIND THE FRONT. SOME RAIN CHANCES WILL THEN LINGER THROUGH
SUNDAY AS THE UPPER LEVEL TROUGH AXIS MOVES ACROSS SOUTHERN CANADA
AND THE UPPER MIDWEST.
&&
.AVIATION...THROUGH 18Z MONDAY
1244 PM CDT SUN MAY 6 2012
LOOKS LIKE THE BEST THREAT FOR SHOWERS AND THUNDERSTORMS HAS
SHIFTED SOUTH OF THE KRST/KLSE TAF SITES. MEANWHILE...PLAN ON IFR
STRATUS AT KRST AND MVFR STRATUS AT KLSE CONTINUING INTO THIS
EVENING WITH GENERALLY LIGHT AND VARIABLE SURFACE WINDS. EXPECTING KLSE
TO SLIP INTO IFR STRATUS ALONG WITH KRST AFTER 04Z TONIGHT AS THE
MOIST BOUNDARY LAYER COOLS. AS A OCCLUDED FRONT MAKES PASSAGE EAST
OF THE AREA MONDAY MORNING...EXPECT CLOUDS TO SCATTER OUT AT KRST
AROUND 12Z WITH KLSE FOLLOWING SUIT AFTER 14Z. WINDS WILL ALSO
PICK UP SOME FROM THE NORTHWEST WITH GUSTS NEARING 20KT AT KRST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
251 PM CDT SUN MAY 6 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...DAS
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
329 AM CDT SUN MAY 6 2012
.TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM.
STRONG 250 MB JET MAX OF 130 KNOTS JUST NORTH OF THE UPPER GREAT
LAKES REGION. A WEAK UPPER RIDGE EXTENDS ACROSS THE MISSISSIPPI
RIVER VALLEY WITH AN UPPER TROUGH OVER THE NORTHERN ROCKIES. THE
RIDGE PUSHES SLOWLY EAST AS THE TROUGH APPROACHES THE NORTHERN
PLAINS LATE TONIGHT. THE STRONGEST UPPER DIVERGENCE OCCURS ACROSS
NORTHERN WISCONSIN CLOSER TO THE ENTRANCE REGION OF THE
JET...ALTHOUGH SOME UPPER DIVERGENCE REMAINS THROUGH MUCH OF THE
DAY AND INTO TONIGHT ACROSS SOUTHERN WISCONSIN.
MAIN MORNING CONCERN IS WITH THE MCS ACROSS MINNESOTA THAT IS
OCCURRING ON THE NOSE OF A MODERATE 850 TO 700 MB JET AROUND 35
KNOTS. THE 700 MB WIND MAX PUSHES INTO WISCONSIN THIS MORNING WITH
THE NOSE OF THE WIND MAX OVER NORTHERN WISCONSIN. MEANWHILE THE
850 MB JET WEAKENS AS IT PUSHES TOWARD WISCONSIN...BEFORE
INCREASING SLIGHTLY THIS AFTERNOON. THE STRONGEST MOISTURE
CONVERGENCE OCCURS NORTH NEAR THE 850 MB WARM FRONT THAT WILL
EXTEND ACROSS NORTHERN WISCONSIN THIS AFTERNOON. AT THE SURFACE
THE WARM FRONT WILL PUSH NORTH AND MAY PUSH INTO FAR SOUTH CENTRAL
WISCONSIN WHERE THE NAM HAS AROUND 1300 J/KG OF 0 TO 1 KM CAPE.
NORTHEAST AREAS AND ALONG LAKE MICHIGAN IN THE SOUTHEAST HAVE
LITTLE CAPE.
LATER TONIGHT THE SURFACE TROUGH/COLD FRONT WILL APPROACH AND PUSH
ACROSS MOST OF THE FORECAST AREA EXCEPT THE FAR EAST. HOWEVER A
WEAK LOW WILL MOVE ACROSS NORTHERN ILLINOIS AS THE WARM FRONT SAGS
BACK SOUTH.
THE 05Z RAPID REFRESH MODEL WEAKENS THE MINNESOTA MCS AND FOCUSES
MOST OF THE PRECIPITATION ACROSS NORTHWEST WISCONSIN WITH JUST
SOME SCATTERED SHOWERS OVER SOUTH CENTRAL WISCONSIN CLOSER TO THE
WEAK CONVERGENCE WITH THE DEVELOPING 850 MB SOUTHWEST FLOW. THE
LOCAL 03Z 4KM WRF MODEL IS MORE AGGRESSIVE AND TAKES THE MCS INTO
THE DELLS AREA AROUND 8 AM CDT AND KEEPS GOING BEFORE REACHING THE
KENOSHA AREA BY NOON CDT.
THE 03Z HRRR IS SOMEWHAT IN BETWEEN WITH A WEAKENING MCS AFFECTING
MAINLY CENTRAL WISCONSIN...ALTHOUGH A BAND OF
SHOWERS/THUNDERSTORMS DO AFFECT THE SOUTH.
FORECAST SOUNDINGS SHOW A MODERATE TO STRONG INVERSION BELOW 2 TO
3 THSD FT...EVEN IN THE SOUTHWEST AREAS THIS MORNING. MID LEVEL
LAPSE RATES ARE AROUND 7 TO 8 C/KM.
00Z NAM INDICATES A WEAKENING MCS THAT WILL AFFECT THE FORECAST
AREA THIS MORNING...THEN THE MAIN FOCUS OF PRECIPITATION SOUTH
ALONG THE SURFACE BOUNDARY AND NORTH ACROSS THE BETTER 850MB
CONVERGENCE... ALTHOUGH QPF OVER MUCH OF THE TIME PERIOD.
THIS APPEARS TO BE THE CONSENSUS SO WILL GO WITH HIGH POPS BUT
WITH NO SPECIAL WORDING. THE NORTH AREAS ACROSS MARQUETTE...GREEN
LAKE AND INTO FOND DU LAC COUNTY IS OF CONCERN DUE TO HEAVY RAIN
THERE A FEW DAYS AGO BUT FLASH FLOOD GUIDANCE VALUES HAVE
RECOVERED TO 2.5 INCH IN ONE HOUR TO 3.3 INCHES IN 6 HOURS...SO
WILL NOT ISSUE ANY FLASH FLOOD WATCHES.
AS FOR SEVERE THREAT...THE HIGHEST AREA ON THE LOCAL CWASP
PROBABILITIES RISE TO 70 PCT AT 18Z OVER SOUTHWEST WISCONSIN THEN
DROP TO 65 PERCENT ACROSS NORTHWEST ILLINOIS BY EARLY EVENING.
THIS MATCHES WELL WITH SPC SLIGHT RISK...AND IS IN AREA OF
MODERATE CAPE VALUES...AND IN THE AREA WHERE THE CAP SHOULD WEAKEN
THIS AFTERNOON. APPEARS HAIL AND TO A SOMEWHAT LESSER EXTENT HIGH
WINDS WILL BE THE THREATS.
TEMPERATURES WILL BE A LITTLE DIFFICULT SINCE THE STABLE COOL AIR
WILL COVER MUCH OF THE FORECAST AREA WITH THE POTENTIAL OF THE
SURFACE BOUNDARY APPROACHING THE FAR SOUTHWEST AREA.
.SHORT TERM...MONDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE IS
MEDIUM TO HIGH.
SHORT TERM MODELS IN DECENT AGREEMENT WITH PUSHING INVERTED TROUGH
THROUGH THE AREA MONDAY MORNING...ACCOMPANIED BY A SHORTWAVE
TROUGH CLIPPING THE AREA FROM THE SOUTH. WILL KEEP LIKELY POPS
GOING FOR THE MORNING ON MONDAY IN THE EAST...LOWER IN THE WEST.
COLD AIR ADVECTION THEN MOVES INTO THE AREA MONDAY
AFTERNOON...WHICH WILL GRADUALLY DRY OUT AIR COLUMN. TRENDED
DOWNWARD WITH POPS MONDAY AFTERNOON TO REFLECT THIS. TEMPERATURES
WILL BE NEAR OR SLIGHTLY ABOVE SEASONAL NORMALS INLAND...WITH
SOMEWHAT COOLER READINGS WITH ONSHORE FLOW NEAR THE LAKE.
MODEST COLD AIR ADVECTION CONTINUES MONDAY NIGHT...AND INTO
TUESDAY AND TUESDAY NIGHT. THIS SHOULD BRING ONLY SLIGHTLY COOLER
TEMPERATURES TO THE REGION. MAIN FEATURE WILL BE UPPER LEVEL
TROUGH SLIDING SOUTHEAST THROUGH THE REGION MONDAY NIGHT THROUGH
WEDNESDAY. NAM/GFS FORECAST SOUNDINGS FROM AROUND THE AREA SHOW
WEAK INSTABILITY DEVELOPING TUESDAY AFTERNOON...WITH SOME MOISTURE
AROUND 5000 FEET ABOVE GROUND LEVEL.
GIVEN STEEP LOW LEVEL LAPSE RATES WITH DAYTIME HEATING...WITH
DECENT MID LEVEL LAPSE RATES AS WELL...CONTINUED TO MENTION POPS
FOR SHOWERS. THUNDERSTORM CHANCES APPEAR SMALL GIVEN LACK OF
INSTABILITY REACHING BEYOND THE 10 DEGREE BELOW ZERO CELSIUS
LEVEL. FOR NOW...WILL CONTINUE TO MENTION SLIGHT CHANCES FOR
THUNDER...BUT CONFIDENCE IS MIXED. CONTINUED LOWER END POPS FOR
SHOWERS TUESDAY NIGHT INTO WEDNESDAY AS TROUGH MOVES THROUGH.
.LONG TERM...WEDNESDAY NIGHT THROUGH SATURDAY...FORECAST
CONFIDENCE IS MEDIUM TO HIGH.
ECMWF/GFS IN FAIRLY GOOD AGREEMENT WITH FEATURES IN THIS PERIOD.
THEY SHOW HIGH PRESSURE SLIDING SOUTHEAST ACROSS THE REGION
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...WITH AN UPPER LEVEL RIDGE
PASSING THROUGH. THIS SHOULD BRING QUIET WEATHER WITH SEASONABLE
TEMPERATURES.
NEXT WEATHER SYSTEM IS A COLD FRONT SHIFTING SOUTHEAST THROUGH
THE REGION FRIDAY INTO SATURDAY. MAIN UPPER TROUGH AND VORTICITY
MAXIMA REMAIN NORTH OF THE AREA...BUT ENOUGH MOISTURE AND UPWARD
VERTICAL MOTION WITH FRONT TO MENTION POPS FOR PORTIONS OF THIS
PERIOD.
&&
.AVIATION/12Z TAFS/...
EXPECT MVFR/IFR CIGS OVER MUCH OF THE FORECAST AREA. THE SURFACE
BOUNDARY WILL REMAIN SOUTH OF WISCONSIN FOR THE MOST PART...BUT
MAY TRY TO PUSH NEAR AREAS SOUTHWEST OF MADISON THIS AFTERNOON.
SOME SHOWERS/SCATTERED THUNDERSTORMS AS THE MINNESOTA MCS PUSHES
EAST...BUT IT SHOULD WEAKEN DUE TO THE MORE STABLE AIR OVER
WISCONSIN.
MORE REDEVELOPMENT EXPECTED THIS AFTERNOON/EVENING AS A FRONT
APPROACHES FROM THE WEST TONIGHT.
&&
.MARINE...
PERSISTENT EAST FLOW BUT WINDS SHOULD BE BELOW SMALL CRAFT
CRITERIA. THE WAVES SHOULD REMAIN BELOW CRITERIA. SOME
THUNDERSTORMS ARE ALSO POSSIBLE.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...HENTZ
MONDAY THROUGH SATURDAY...WOOD
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1221 AM EDT TUE MAY 8 2012
.SYNOPSIS...
HIGH PRESSURE OFF THE NORTHEAST COAST WILL DRIFT EAST. A WARM FRONT
WILL CROSS THE REGION LATE TONIGHT AND TUESDAY. A COLD FRONT WILL
SLOWLY APPROACH THE AREA TUESDAY NIGHT INTO WEDNESDAY AND CROSS THE
REGION LATE WEDNESDAY INTO WEDNESDAY NIGHT. LOW PRESSURE MAY FORM
ALONG THE FRONT AND PASS TO OUR EAST LATE WEDNESDAY NIGHT INTO
THURSDAY MORNING. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT
FOR THE END OF THE WEEK AND THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
NO BIG CHANGES HAVE BEEN MADE TO THE OVERNIGHT FORECAST. WE ARE
IN THE BREAK BETWEEN WAA SHOTS. HAVE CANCELLED THE CFA EARLY FOR
THE OCEAN FRONT AS THE HIGH TIDE HAS PASSED. AS IS NORMALLY THE
CASE WITH CONVECTION WHILE THE GENERAL THEME OF THE MODELS HAS
BEEN ALRIGHT, NO INDIVIDUAL MODEL IS HANDLING UPSTREAM CONVECTION
CLOSELY, ESPECIALLY THE ONGOING PCPN IN NORTHERN WEST VIRGINIA.
THUS WE HAVE MAINTAINED SOME CHANCE LATER TONIGHT AS FAR SOUTH AS
THE PHL SUBURBS. ONLY OTHER CHANGE WITH THE POPS BASED ON THE 18Z
AND HRRR MODEL DATA WAS TO PIVOT HIGHEST POPS ACROSS NORTHERN CWA
IN A MORE W TO E DIRECTION. OTHER THAN THE 18Z WRF- NMMB, NO OTHER
MODEL BRINGS THUNDER INTO OUR CWA. THE WRF-NMMB TENDS TO BE TOO
BULLISH WITH THUNDER, SO WITHOUT FURTHER MODEL CORROBORATION, IT
WAS NOT ADDED.
CLOUDS ARE STILL EXPANDING TO OUR SOUTH, SO NO ADJUSTMENTS HAVE
BEEN MADE TO SKY COVER. ALSO THIS SHOULD PRECLUDE MUCH FOG OUTSIDE
OF PCPN FROM OCCURRING. WITH THE SKY COVER AND SOME WIND
OVERNIGHT, TEMPERATURES SHOULD NOT MOVE MUCH FROM CURRENT LEVELS
AND THIS IS ALREADY REFLECTED IN THE GRIDS AND FORECAST.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/...
IT APPEARS THAT UNSETTLED WEATHER WILL BE STARTING DURING THIS TIME
FRAME. THIS IS COURTESY OF LOW PRESSURE MOVING FROM THE UPPER OHIO
VALLEY AND THE EASTERN GREAT LAKES INTO SOUTHEASTERN CANADA. AS THIS
OCCURS, A LOW-LEVEL JET WILL CONTINUE TO MOVE ACROSS OUR AREA AND
EVEN STRENGTHEN A BIT. THIS WILL GENERALLY DRIVE THE MAIN WAA PUSH
AND WARM FRONT TO OUR NORTH. HOWEVER, A COLD FRONT WILL BE ARRIVING
DURING THE AFTERNOON. IT APPEARS THAT AN INITIAL SURGE OF SHOWERS
WILL BE UP ACROSS OUR NORTHWEST ZONES AHEAD OF THE WARM FRONT. WE
THEN AWAIT FOR THE CONVECTION INDUCED BY THE COLD FRONT TO ARRIVE.
THE SURFACE DEW POINTS ARE NOT FORECAST TO RAPIDLY INCREASE DURING
THE DAY, THEREFORE NOT A LOT OF INSTABILITY IS FORECAST TO DEVELOP.
THE FORECAST SOUNDINGS DO IMPLY AT LEAST SOME ELEVATED INSTABILITY
OCCURRING, THEREFORE WE WILL CONTINUE WITH A MENTION OF AT LEAST
SOME THUNDER.
THE COLD FRONT ITSELF LOOKS TO BE FAIRLY SLOW TO ARRIVE, THEREFORE
WE SLOWLY DOWN THE POP INCREASE FROM WEST TO EAST AND TRIED TO SHOW
A TIGHTER GRADIENT AS WELL. THE EASTERN ZONES MAY END UP HAVING A
DRY DAY AS THE MAIN CONVECTION COULD TEND TO HANG BACK FOR AWHILE
WITH LITTLE OR NO DEVELOPMENT WELL IN ADVANCE. AS A RESULT, WE HELD
THE HIGHEST POPS ACROSS OUR FAR WESTERN ZONES.
THE PRESSURE GRADIENT IS FORECAST TO TIGHTEN IN ADVANCE OF THE COLD
FRONT AS HIGH PRESSURE IS TO OUR EAST. THIS ALONG WITH THE LOW-LEVEL
JET TO BE OVERHEAD WILL COMBINE WITH ENOUGH BOUNDARY LAYER HEATING
TO PROMOTE DEEPER VERTICAL MIXING. THIS IS EXPECTED TO RESULT IN A
BREEZE DAY DEVELOPING. THE BEST MIXING LOOKS TO OCCUR FARTHER
EASTWARD ACROSS THE CWA AS THESE LOCALES HAVE A BETTER CHC OF AT
LEAST SOME LONGER SURFACE HEATING. BASED ON THE FORECAST SOUNDINGS,
THE WIND GUSTS LOOK TO TOP OUT IN THE 25-30 MPH RANGE AT MOST
LOCALES. THE INCREASED WINDS MAY ALSO TRY AND LOWER THE SURFACE DEW
POINTS SOME, ESPECIALLY DURING PEAK MIXING.
AS FOR TEMPERATURES, WE STARTED WITH A MOS BLEND THE MADE SOME
TWEAKS ESPECIALLY ALONG THE COAST DUE TO THE SOUTHERLY FLOW AND ALSO
ACROSS THE NORTHWEST ZONES DUE TO THE IDEA OF MORE CLOUDS HERE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
THE 00Z NAM WAS MOST ROBUST WITH DEVELOPMENT OF LOW PRESSURE ALONG
THE FRONT DURING THE WEDNESDAY TO WEDNESDAY NIGHT TIME FRAME, BUT
THE 12Z RUN NOW RESEMBLES MORE THE 06Z AND 12Z GFS AND THE 00Z AND
12Z ECMWF. THEREFORE, ALTHOUGH THE FRONT MOVES SLOWLY, HAS DYNAMIC
SUPPORT AND HAS ACCESS TO GOOD MOISTURE, OUR CONCERN OVER FLOODING
HAS DIMINISHED A LITTLE. WE WILL CONTINUE TO CARRY THE MENTION OF
POSSIBLE HEAVY RAIN IN THE HWO FOR WEDNESDAY AND WEDNESDAY NIGHT.
TUESDAY NIGHT SHOULD SEE AN EXIT OF WARM-FRONTAL RAIN AS THE 300K
ISENTROPIC LIFT MOVES BY, BUT THEN WE START TO SEE THE COLD FRONT
APPROACH THE AREA WITH SUPPORT FROM AN UPPER JET, SOME MID LEVEL
Q-VECTOR CONVERGENCE AND ENERGY IN THE POSITIVELY TILTED MID LEVEL
TROUGH, SOME LOWER LEVEL FRONTOGENESIS, AND SOME SOLID LOW TO MID
LEVEL MOISTURE GIVEN H8 DEW POINTS AND H7 THETA E VALUES. THIS FRONT
PRESENTLY IS PROGGED TO MOVE ACROSS THE AREA LATE WEDNESDAY INTO
WEDNESDAY NIGHT. THAT THE NAM HAS TONED DOWN THE IMPULSE THAT MOVES
ALONG THE FRONT BY NO MEANS IS AN INDICATION THAT MID LEVEL ENERGY
WILL NOT GENERATE ANY IMPULSE WHATSOEVER ALONG IT. HENCE THE SLOW
MOVEMENT OF THE FRONT AND THE SIGNIFICANT RAINFALL FORECAST. IT
DOES, HOWEVER, SEEM THAT ALL FACTORS COME TOGETHER BEST ONCE THE
FRONT IS OFF THE COAST. REGARDING CONVECTION, THERE SHOULD BE ENOUGH
INSTABILITY AVAILABLE FOR THAT INTO WEDNESDAY EVENING. ALTHOUGH IT
LOOKS LIKE THE BEST CHANCE OF STRONG CONVECTION OCCURS TO OUR
SOUTHWEST, THERE ARE FAIR BULK SHEAR NUMBERS ON WEDNESDAY AFTERNOON
NORTHWEST (THE RIGHT REAR QUAD OF THE UPPER JET IS TO OUR NORTHWEST)
AND SOME INDICATION OF AT LEAST MARGINAL CAPES BEING AVAILABLE FOR
THAT SHEAR. SPC CONTINUES TO CARRY US IN A GENERAL TSTM OUTLOOK;
THERE IS AN OFF CHANCE THAT WILL BE ELEVATED WITH TIME.
ONCE THE MID LEVEL IMPULSE MOVES TO OUR EAST, THE MODELS AGREE ON
CUTTING IT OFF. THE CUTOFF MAY BE JUST FAR ENOUGH TO OUR NORTHEAST
TO RELIEVE US OF ANY CONCERN. WE`LL SEE ABOUT THAT, BUT WILL
MAINTAIN AN OPTIMISTIC FORECAST FOR NOW. AFTER THAT, THE NEXT
POTENTIAL FOR RAIN COMES WITH A COLD FRONT THAT APPROACHES LATE IN
THE WEEKEND. THE GFS MAY BE SUFFERING SOME CONVECTIVE FEEDBACK
ISSUES WITH THE FRONT, AND WE HAVE ELECTED TO KEEP THE FORECAST DRY
INTO MONDAY FOR NOW.
TEMPERATURES WILL START THE PERIOD ABOVE NORMAL AHEAD OF THE FRONT
(ESPECIALLY AT NIGHT), DROP TO SOMEWHAT BELOW NORMAL FOR A TIME
AFTER THE FRONT BEFORE GRADUALLY RISING BACK ABOVE NORMAL BY THE END
OF THE PERIOD.
&&
.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
GENERALLY VFR CONDITIONS ARE EXPECTED TO PREVAIL IN THIS TAF
PACKAGE FROM THE KPHL METRO AIRPORTS (I95 CORRIDOR) SEWD WITH
MVFR CONDITIONS AT TIMES AT TERMINALS AND AIRPORTS FARTHER TO THE
NORTHWEST.
FOR THIS EVENING THE FIRST SHOT OF LIGHT RAIN THAT AFFECTED MOSTLY
THE NORTHERN AIRPORTS IS THROUGH. VFR CIGS ARE EXPECTED TO
PREVAIL. HIGHEST CIGS AT KACY AND KMIV. LATER TONIGHT THE
REMNANTS OF ONGOING THUNDERSTORMS IN WESTERN PENNSYLVANIA SHOULD
AFFECT KRDG AND KABE WITH MVFR CIGS AND VSBYS AT TIMES. THEY ARE
GOING TO BE NEAR THE SOUTHERN EDGE OF THE SHOWERS (NO THUNDER BY
THE TIME THEY MOVE EAST) SO CONFIDENCE AS TO THEIR IMPACT IS LESS
THAN AVERAGE. HIGHEST CONFIDENCE ABOUT VFR CONDITIONS ARE AT KMIV
AND KACY.
ON TUESDAY DAY THE TERMINALS SHOULD SPEND A GOOD PART OF THE DAY
IN THE WARM SECTOR WITH CIGS STAYING OR RISING TO VFR LEVELS
DURING THE MORNING HOURS. FORECAST SOUNDINGS ARE SUPPORTING GUSTY
SOUTH WINDS RATHER QUICKLY DURING THE MORNING SHORTLY AFTER 12Z.
ON TUESDAY AFTERNOON CONDITIONS SHOULD DETERIORATE TO MVFR IN
SHOWERS AT KABE AND KRDG (CONFIDENCE IS TOO LOW TO INCLUDE THUNDER
PLUS THEIR COVERAGE IS NOT EXPECTED TO BE THAT WIDESPREAD), FASTER
AT AIRPORTS FARTHER TO THE NORTH, BUT SLOWER FOR THEM TO ARRIVE IN
THE KPHL AREA AIRPORTS WHERE VFR CONDITIONS ARE FORECAST. DITTO
FOR AIRPORTS AND TERMINALS FARTHER TO THE SOUTHEAST. GUSTY SOUTH
WINDS ARE FORECAST TO CONTINUE AND WOULD NOT BE THAT SURPRISED IF
SOME PEAK GUSTS EXCEED 30 KNOTS.
OUTLOOK...
TUESDAY NIGHT AND WEDNESDAY...MVFR CONDITIONS IN SHOWERS AND POSSIBLE
THUNDERSTORMS. LOCALIZED IFR CONDITIONS ARE POSSIBLE. CONFIDENCE IS
MODERATE. THERE IS A CHANCE OF LLWS ON TUESDAY NIGHT MORE SO
SOUTHEAST THAN NORTHWEST.
WEDNESDAY NIGHT...MVFR CONDITIONS IN SHOWERS AND POSSIBLE
THUNDERSTORMS. CONDITIONS MAY IMPROVE NORTHWEST OVERNIGHT.
CONFIDENCE IS LOW TO MODERATE.
THURSDAY AND THURSDAY NIGHT...MAINLY VFR. ISOLATED MVFR CONDITIONS
IN SHOWERS ARE POSSIBLE NORTH. A FRESH NORTHWEST BREEZE IS
ANTICIPATED FOR THURSDAY. CONFIDENCE IS MODERATE.
FRIDAY AND SATURDAY...VFR CONDITIONS ARE EXPECTED. CONFIDENCE IS
MODERATE.
&&
.MARINE...
HIGH PRESSURE DOWN THE MID ATLANTIC COAST TO START TONIGHT WILL
GRADUALLY SLIDE EASTWARD. THIS WILL ALLOW A WARM FRONT TO GRADUALLY
LIFT INTO OUR AREA THROUGH THE NIGHT. THE SOUTHEAST FLOW HAS TURNED
GUSTY ESPECIALLY IN DELAWARE BAY DUE TO THE WIND FUNNELING UP THE
BAY. THIS SHOULD CONTINUE INTO THIS EVENING, BUT GENERALLY REMAIN
UNDER 25 KNOTS. A LOW-LEVEL JET IS FORECAST TO ARRIVE, HOWEVER SOME
WARMING ALOFT MAY TEND TO KEEP THE MIXING TO A MINIMUM. THEREFORE, A
GRADUAL INCREASE IN THE SOUTHERLY FLOW TONIGHT. THE PRESSURE
GRADIENT TIGHTENS TUESDAY AS HIGH PRESSURE EASES TO THE EAST AND A
COLD FRONT SLOWLY APPROACHES FROM THE WEST. THE LOW-LEVEL JET IS
FORECAST TO INCREASE SOME THROUGH THE DAY, HOWEVER ENOUGH WARMING
JUST ABOVE THE SURFACE SHOULD TEND TO KNOCK DOWN THE MIXING TO SOME
EXTENT ESPECIALLY AWAY FROM THE COAST. HOWEVER, THE FORECAST
SOUNDINGS DO INDICATE THAT THE WINDS COULD NEAR 25 KNOTS TUESDAY AND
THE SOUTHERLY FLOW IS EXPECTED TO BUILD THE SEAS. THEREFORE, THE
SMALL CRAFT ADVISORY WILL GO INTO EFFECT AT 15Z TUESDAY.
OUTLOOK...
WITH A DECENT SOUTHERLY H925 JET PASSING OVERHEAD ON TUESDAY
NIGHT, WE`VE MAINTAINED THE ADVISORY LEVEL WINDS AND SEAS AHEAD OF
THE COLD FRONT. THERE ISN`T A VERY STRONG FLOW BEHIND THE COLD
FRONT UNTIL THAT FRONT STARTS TO PUT SOME DISTANCE BETWEEN ITSELF
AND OUR WATERS, SO WE MAY NOT SEE ADVISORY LEVEL WINDS IN ITS
WAKE. SEAS MAY TAKE LONGER TO SUBSIDE, AND WE MAY END UP EXTENDING
THE ADVISORY INTO WEDNESDAY. WE WON`T DO THAT NOW, HOWEVER, SINCE
THE FORECAST OF LOW PRESSURE ALONG THE FRONT IS NOT LOOKING QUITE
AS ROBUST AS IT ONCE DID. ONCE SEAS SUBSIDE, SUB-ADVISORY
CONDITIONS ARE EXPECTED INTO THE WEEKEND.
&&
.TIDES/COASTAL FLOODING...
WE ARE BEGINNING OUR DECLINE OFF THE PEAK OF THE ASTRONOMICAL HIGH
TIDES ASSOCIATED WITH THE PERIGEAN FULL MOON. NEVERTHELESS THERE
SHOULD BE SOME MINOR TIDAL FLOODING DURING THE OVERNIGHT INTO
TUESDAY MORNING (CHESAPEAKE BAY) HIGH TIDE CYCLE. WINDS ARE SLOWLY
VEERING MORE TO THE SOUTHEAST AND THIS ADDS OUR SIDE OF CHESAPEAKE
BAY TO THE LIST.
THE HIGHEST TIDAL DEPARTURES HAVE SHIFTED INTO UPPER DELAWARE BAY
AND CHESAPEAKE BAY THIS AFTERNOON (AROUND THREE QUARTERS OF A FOOT
ABOVE NORMAL) WITH LOWER DEPARTURES IN THE TIDAL DELAWARE RIVER AND
ALONG THE OCEAN (AROUND A THIRD OF A FOOT). THE LEAST AMOUNT OF
WIGGLE ROOM BETWEEN THE FORECAST ASTRONOMICAL HIGH TIDES AND ONGOING
DEPARTURES REMAIN ALONG THE OCEAN FRONT AND LOWER DELAWARE BAY WHERE
WE WILL KEEP THE ADVISORY GOING. IN THE UPPER HALF OF DELAWARE BAY
AS WELL AS THE TIDAL DELAWARE, WHERE THERE IS A LARGER GAP BETWEEN
THE NEEDED DEPARTURES AND PREDICTED ASTRONOMICAL TIDES, WE WILL KEEP
THE STATEMENT GOING. AFTER COORDINATING WITH WAKEFIELD, WE WILL
ISSUE A STATEMENT FOR CHESAPEAKE BAY FOR THE TUESDAY MORNING HIGH
TIDE CYCLE. WHILE CBOFS GUIDANCE TAKES BOTH CAMBRIDGE AND TOLCHESTER
TO THE MID LEVEL OF MINOR TIDAL FLOODING CATEGORIES, THE GUIDANCE
HAS BEEN TOO HOT BY AROUND HALF A FOOT. DOWNWARD ADJUSTING WE
SUSPECT TUESDAY MORNING`S HIGH TIDE WILL BE VERY CLOSE TO THE 3.5 FT
ABOVE MEAN LOWER LOW WATER INITIATION LEVEL FOR MINOR TIDAL
FLOODING.
OVERALL THE MDL STORM SURGE GUIDANCE HAS BEEN VERIFYING BETTER THAN
STEVENS OR THE SERIES OF OFS GUIDANCE WITH THIS SPRING TIDE CYCLE
SINCE SATURDAY.
ASTRONOMICAL TIDES STARTING DROPPING MORE ON TUESDAY AND BEYOND.
ALSO THE SOUTHERLY GRADIENT IS FORECAST TO WEAKEN. IF THIS TREND
CONTINUES, THIS WOULD DECREASE THE CHANCES FOR ADDITIONAL MINOR
TIDAL FLOODING WITH THE TUESDAY NIGHT INTO WEDNESDAY MORNING HIGH
TIDE CYCLE.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 5 AM EDT
WEDNESDAY FOR ANZ430-431-450>455.
&&
$$
SYNOPSIS...DELISI/HAYES
NEAR TERM...GIGI/NIERENBERG
SHORT TERM...GORSE
LONG TERM...DELISI
AVIATION...DELISI/GIGI
MARINE...DELISI/GORSE
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
200 AM EDT TUE MAY 8 2012
.UPDATE...
THE MAJORITY OF THE CONVECTIVE DEVELOPMENT HAS BEEN WANING ACROSS
THE FORECAST AREA TONIGHT... THOUGH THERE STILL HAS BEEN LINGERING
SHOWERS AND STORMS ALONG SOME CONVERGING OUTFLOW BOUNDARIES SOUTH
OF KFFC. HRRR STILL HOLDS ON TO SOME REDEVELOPMENT IN THE NORTH AFTER
06Z LIKELY DUE TO THE INFLUENCE OF AN UPPER LEVEL SHORTWAVE AHEAD
OF THE COLD FRONTAL PASSAGE. WILL NEED TO MONITOR THIS ON THE
OVERNIGHT. KEPT CHANCE POPS OVERNIGHT FOR MOST AREAS WITH LIKELY
POPS STARTING IN THE NORTHWEST DURING THE EARLY MORNING HOURS.
ALSO RAISED POPS EARLY WEDNESDAY MORNING BASED ON PROGGED
POSITIONING OF THE COLD FRONT SUGGESTED BY MAJORITY OF GUIDANCE.
TWEAKED WINDS SOME TO VEER A BIT EARLIER OUT OF THE SOUTHWEST
AHEAD OF THE FRONT. ALL ELSE SEEMED TO BE ON TRACK.
03
&&
.PREV DISCUSSION...
SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
/ISSUED 350 PM EDT MON MAY 7 2012/
AREA OF SHOWERS THAT DEVELOPED OVER EASTERN GEORGIA HAS DEVELOPED
INTO A LINE BETWEEN ATL AND AHN...STRETCHING SOUTHWARD AND EAST OF
MCN. CLOUD COVERAGE HAS HELPED TO LIMIT INSTABILITY ACROSS THAT AREA
BUT WITH SOME BREAKS IN THE CLOUDS...HAVE STARTED TO SEE INCREASED
THUNDER. AS THIS AREA DRIFTS TOWARD THE EAST...THE WESTERN HALF OF
THE CWA SHOULD BECOME MORE ACTIVE EARLY THIS EVENING AND CAN ALREADY
SEE SOME CELLS DEVELOPING ACROSS THAT AREA. THE WESTERN HALF OF THE
CWA WOULD ALSO BE THE FOCUS FOR THE STRONGER STORMS AS SLIGHTLY
LESSER CLOUD COVERAGE HAS ALLOWED FOR GREATER DESTABILIZATION.
OVERNIGHT...THE FOCUS WILL SHIFT TO THE NORTHWEST AS A SHORTWAVE
MOVES INTO NORTHWEST GEORGIA. BEFORE THIS SHIFTS ACROSS THE
MOUNTAINS AND WASHES OUT THOUGH IT WILL HELP TO ENHANCE THE CHANCE
OF PRECIPITATION ACROSS THE NORTH TONIGHT. FRONT MOVES INTO
NORTHWEST GEORGIA ON TUESDAY AND THIS WILL HELP TO ONCE AGAIN KEEP
THE FOCUS OF ACTIVITY ACROSS NORTH GEORGIA. WITH DECENT
INSTABILITY...MU CAPE VALUES OF 2000 J/KG...BUT WEAK SHEAR /BOTH 0-1
AND 0-6KM/...MAIN THREAT WITH STORMS WOULD BE DAMAGING WIND AND
HAIL. CANT RULE OUT A FEW SEVERE STORMS ON TUESDAY...BUT AT THIS
POINT NOT EXPECTING A WIDESPREAD SEVERE EVENT. FRONT WILL WEAKEN
OVERNIGHT ON TUESDAY AS IT DRIFTS INTO CENTRAL GEORGIA SO HAVE
SHOWED TREND OF DECREASING POPS.
MAX TEMPS ON TUESDAY ARE ON THE LOWER SIDE OF GUIDANCE DUE TO
EXPECTED CLOUD COVERAGE...OTHERWISE TEMPS ARE CLOSE TO GUIDANCE.
LONG TERM /WEDNESDAY THROUGH MONDAY/...
LATEST ROUND OF EXTENDED RANGE GUIDANCE INDICATES CONTINUED GOOD
AGREEMENT IN TIMING OF NEXT FRONTAL SYSTEM WITH THE GFS JUST
SLIGHTLY FASTER ALTHOUGH WX EFFECTS ARE NEGLIGIBLE. CONTINUED
THUNDERSTORM CHANCES INTO WEDNESDAY ALTHOUGH INSTABILITY AXIS RACES
EAST AHEAD OF FRONT AND OVERALL INSTABILITY LOOKS LESS THAN THAT
ON TUESDAY. CONTINUED LIMITED SHEAR PROFILE AND EXPECTED MAINLY
HAIL AND ISOLATED WIND THREAT.
HIGH PRESSURE AND A DRY FORECAST LOOK TO BE ON TAP BEHIND THE
FRONT THURSDAY THROUGH SATURDAY. THOUGH...BOTH GFS AD ECMWF SHOW
SOME INCREASE IN DEEPER MOISTURE SATURDAY NIGHT INTO SUNDAY AS A
WEAK LOW PRESSURE SYSTEM LIFTS NORTHEAST FROM THE GULF AND A COLD
FRONT DRIFTS SOUTHWARD FROM THE OH/TN VALLEY REGION. WILL KEEP
SATURDAY NIGHT DRY FOR NOW...BUT HAVE INTRODUCED SLIGHT CHANCE
POPS FOR MUCH OF THE AREA SUNDAY WITH THESE FEATURES POSSIBLY
BEGINNING TO AFFECT THE STATE.
COOLER BEHIND THE FRONT WITH MODELS ADVERTISING TEMPS BACK TO
MORE NORMAL LEVELS.
DEESE
&&
.AVIATION...
06Z UPDATE...
MIXED MVFR/IFR CONDITIONS EXPECTED ACROSS THE MAJORITY OF NORTH AND
CENTRAL GEORGIA BY 08Z... BECOMING MAINLY MVFR BY 15Z AND VFR BY
18Z. ISOLATED TO SCATTERED SHOWERS AND A FEW THUNDERSTORMS WILL
CONTINUE THROUGH 18Z...BECOMING MORE WIDESPREAD BETWEEN 18Z AND 02Z.
WINDS SOUTHEAST 3-6KT WILL BECOME SOUTHWEST 6-10KT BY 15Z AND WEST
TO NORTHWEST BY 00Z.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM CONFIDENCE.
20
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 63 79 63 83 / 30 60 50 60
ATLANTA 64 80 65 81 / 40 60 50 60
BLAIRSVILLE 61 75 59 74 / 60 60 60 70
CARTERSVILLE 64 80 60 79 / 50 60 50 70
COLUMBUS 66 86 67 86 / 40 60 50 60
GAINESVILLE 62 77 62 80 / 50 60 60 70
MACON 62 84 64 87 / 20 50 50 60
ROME 64 82 61 79 / 60 60 50 60
PEACHTREE CITY 62 81 62 81 / 40 60 50 60
VIDALIA 66 87 67 89 / 20 50 50 60
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...FIEUX/03
LONG TERM....DEESE
AVIATION...03
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1114 PM CDT MON MAY 7 2012
.DISCUSSION...
ISSUED 826 PM CDT MON MAY 7 2012
COLD FRONT HAS SHIFTED SOUTH OF THE FORECAST AREA EARLY THIS
EVENING WITH ONLY A FEW SHOWERS LEFT BEHIND OVER FAR SOUTHEAST IL.
HIGH PRESSURE ACRS THE PLAINS WILL SHIFT EAST INTO THE MIDWEST
OVERNIGHT BRINGING DRIER AIR EAST WITH IT. DEW POINTS ALREADY
HAVE DROPPED INTO THE UPPER 40S OVER PARTS OF WEST CENTRAL IL AND
EXPECT THAT TREND TO WORK ITS WAY EAST OVER THE REMAINDER OF THE
FORECAST AREA TONIGHT. THE DRIER AIR WILL NOT ARRIVE INTO THE
EAST UNTIL THE PRE-DAWN HOURS SO THE COMBINATION OF CLEARING
SKIES AND ABUNDANT LOW LEVEL MOISTURE LEFT OVER FROM THE RAINFALL
OF THE PAST SEVERAL DAYS WILL LEAD TO SOME PATCHY FOG MAINLY
EAST OF I-55. THE LAST FEW RUNS OF THE 3KM HRRR MODEL SUGGEST
AREAS ALONG AND EAST OF I-57 HAVE THE BETTER CHANCE OF SEEING
SOME FOG LATE TONIGHT SO WILL INCLUDE IN THE OVERNIGHT HOURS.
OTHERWISE...OTHER THAN THE USUAL ADJUSTMENTS IN THE EARLY EVE
TEMPERATURE TRENDS...THE REST OF THE FORECAST IS IN GOOD SHAPE.
SMITH
&&
.AVIATION...
ISSUED 1105 PM CDT MON MAY 7 2012
THREAT FOR FOG AND LOW CIGS FROM BMI TO DEC AND EAST A CONCERN
THRU 13Z TUESDAY. DRIER AIR CONTINUES TO SLOWLY EDGE EAST ACRS THE
STATE WITH TEMP-DEW POINT SPREADS RANGING FROM 10 DEGREES ACRS THE
WEST TO ZERO IN THE EAST WHERE SKIES HAVE JUST RECENTLY CLEARED.
WILL INCLUDE TEMPO GROUPS AT BMI...DEC AND CMI WHERE IT APPEARS
THE DRIER AIR WILL TAKE THE LONGEST TO GET TO OVERNIGHT. WINDS
HAVE DROPPED TO BELOW 7 KTS IN MOST OF THE FORECAST AREA SO THERE
MAY BE SOME LIGHT FOG IN AREAS TO THE WEST SUCH AS DEC AND BMI
OVERNIGHT AS WELL WITH THE LOWER DEW POINTS GETTING INTO PIA AND
SPI. WHAT FOG AND OR LOW CLOUDS WE SEE TONIGHT SHOULD BE GONE BY
13Z WITH VFR CONDITIONS EXPECTED FOR THE REMAINDER OF THE FORECAST
PERIOD. LIGHT MOSTLY NW WINDS TONIGHT WILL PICK UP IN SPEED FROM
THE WEST TO NORTHWEST AT 10 TO 15 KTS...WITH GUSTS AROUND 20
KTS...WHICH SHOULD DIMINISH TO LESS THAN 10 KTS BY 00Z.
SMITH
&&
.PREV DISCUSSION...
ISSUED 241 PM CDT MON MAY 7 2012
AFTER THE RECENT STRETCH OF ACTIVE WEATHER...A COOLER/DRIER
PATTERN WILL TAKE HOLD THROUGH THE REST OF THE WEEK.
SHORT TERM...TONIGHT THROUGH THURSDAY
SLOW-MOVING COLD FRONT CURRENTLY ALONG THE I-70 CORRIDOR WILL
SAG SOUTHWARD THIS EVENING...POTENTIALLY TRIGGERING A FEW SHOWERS
AND THUNDERSTORMS ACROSS THE E/SE KILX CWA. 18Z MESO-ANALYSIS SHOWS
MUCAPE VALUES OF 1500 TO 2000J/KG ACROSS SOUTHEAST ILLINOIS...WITH
EVEN HIGHER INSTABILITY PARAMETERS NOTED FURTHER EAST INTO THE OHIO
RIVER VALLEY. DESPITE DECENT INSTABILITY AND PRESENCE OF FORCING
MECHANISM...0-6KM BULK SHEAR REMAINS VERY WEAK. AS A RESULT...AM
ONLY EXPECTING SCATTERED THUNDERSTORM DEVELOPMENT ALONG/AHEAD OF
THE FRONT LATE THIS AFTERNOON INTO THE EVENING. WILL CARRY LOW
CHANCE POPS ALONG AND SOUTHEAST OF A CHAMPAIGN TO SHELBYVILLE LINE
THROUGH MIDNIGHT...THEN WILL GO DRY EVERYWHERE AFTER MIDNIGHT AS
THE BOUNDARY SINKS SOUTH OF THE OHIO RIVER. SKIES WILL INITIALLY
BE MOSTLY CLOUDY...BUT WILL GRADUALLY CLEAR FROM NORTHWEST TO
SOUTHEAST. OVERNIGHT LOWS WILL MAINLY BE IN THE LOWER TO MIDDLE
50S...BUT WILL REMAIN NEAR THE 60 DEGREE MARK ACROSS THE
CLOUD-COVERED FAR SE CWA.
CLOSED UPPER LOW CURRENTLY SPINNING OVER SOUTHERN MANITOBA WILL
WEAKEN INTO AN OPEN WAVE AS IT TRACKS E/SE INTO THE GREAT LAKES
OVER THE NEXT 24 TO 36 HOURS. AHEAD OF THIS FEATURE...MOSTLY SUNNY
AND WARM CONDITIONS WILL PREVAIL ON TUESDAY...WITH HIGHS REACHING
THE LOWER TO MIDDLE 70S. MAY SEE SOME INCREASE IN CLOUDINESS
ACROSS THE FAR NORTH LATE IN THE DAY...BUT ALL IN ALL...SHOULD BE
A MOSTLY SUNNY DAY. ALL MODELS TAKE WAVE INTO THE EASTERN GREAT
LAKES/OHIO RIVER VALLEY BY WEDNESDAY EVENING...WITH A FEW
SOLUTIONS HINTING AT SOME DIURNAL SHOWERS WEDNESDAY AFTERNOON. GFS
SEEMS TO BE THE MOST AGGRESSIVE WITH PRECIP ACROSS NEARLY THE
ENTIRE AREA...WHILE NAM IS COMPLETELY DRY. DESPITE WEAKENING
NATURE OF SYSTEM AND LACK OF DEEP MOISTURE...CYCLONIC FLOW ALOFT
AND MODERATELY STEEP LAPSE RATES WILL YIELD PARTLY SUNNY SKIES
ACROSS THE E/NE CWA...WITH PERHAPS A FEW ISOLATED SHOWERS. FURTHER
WEST...MOSTLY SUNNY AND DRY CONDITIONS WILL PERSIST.
UPPER WAVE WILL SHIFT TOWARD NEW ENGLAND ON THURSDAY...AS UPPER
RIDGING BEGINS TO BUILD INTO THE REGION FROM THE WEST. THANKS TO
RISING UPPER HEIGHTS AND THE PRESENCE OF SURFACE HIGH
PRESSURE...ABUNDANT SUNSHINE AND TEMPS IN THE 70S WILL BE THE RULE
FOR THURSDAY.
LONG TERM...FRIDAY THROUGH MONDAY
UPPER RIDGE WILL BUILD INTO THE MIDWEST FOR FRIDAY AND
SATURDAY...ENSURING THE CONTINUATION OF WARM AND DRY WEATHER INTO
THE FIRST HALF OF THE WEEKEND. STILL SOME MODEL DISAGREEMENT ON
HOW FAST RIDGE BREAKS DOWN AND NEXT COLD FRONT APPROACHES...WITH
THE GFS BEING FASTER THAN THE ECMWF. RECENT TREND HAS BEEN TO SLOW
THIS PROCESS...SO WILL TREND TOWARD THE ECMWF FOR THE WEEKEND
FORECAST. AS SUCH...WILL ONLY MENTION A LOW CHANCE POP ACROSS THE
FAR NORTH ON SATURDAY...WITH WARM AND DRY WEATHER ELSEWHERE AROUND
CENTRAL AND SOUTHEAST ILLINOIS. AFTER THAT...FRONT WILL SLOWLY
SETTLE SOUTHWARD...BRINGING A CHANCE FOR SCATTERED SHOWERS/STORMS
FOR SATURDAY NIGHT AND SUNDAY. RAIN CHANCES MAY EVEN LINGER INTO
MONDAY IF ECMWF VERIFIES...BUT HAVE MAINTAINED A DRY FORECAST FOR
MONDAY AT THIS TIME...UNTIL BETTER MODEL AGREEMENT IS ACHIEVED.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
138 AM EDT TUE MAY 8 2012
.AVIATION.../06Z TAFS/
WK SHRTWV MOVG EAST ACROSS THE AREA THIS EVE PROVIDING SUFFICIENT
LIFT COMBINED WITH LINGERING MOISTURE OVER NE INDIANA TO CAUSE
SHOWERS TO REDEVELOP ALONG AND A BIT TO THE NW OF SFC CDFNT OVER
NW OH INTO EAST CENTRAL INDIANA. THIS SHOULD BE SHORT LIVED AS
SHRTWV MOVES EAST WITH RAIN EXPECTED TO END BY 08Z AT FWA. TO THE
WEST... LIGHT WINDS/CLEARING ASSOCIATED WITH WK SFC RIDGE WAS
RESULTING IN DENSE FOG OVER NE IL. THIS SHOULD SPREAD EAST ACROSS
NRN INDIANA OVERNIGHT WITH CONDITIONS AT SBN EXPECTED TO LOWER TO
LIFR AND IFR AT FWA. DIURNAL HEATING SHOULD MIX OUT STRATUS/FOG BY
14-15Z WITH VFR CONDITIONS THEN EXPECTED FOR THE REMAINDER OF THE
DAY AND MONDAY EVE.
&&
.PREV DISCUSSION...
SHORT TERM...
TONIGHT...TUESDAY...TUESDAY NIGHT...
CONVECTIVE REDEVELOPMENT NOT FULLY MATERIALIZING YET AS AIRMASS
STRUGGLES TO RECOVER FROM EARLIER RAINS. KIWX RADAR SHOWING LONE
CONVECTIVE CELL JUST SOUTH OF THE CWA NEAR MUNCIE. KIND RADAR
INDICATING ADDL DEVELOPMENT NOW BEGINNING TO TAKE SHAPE FURTHER
SOUTH. WATER VAPOR IMAGERY AND LATEST RUC ANALYSIS SHOWING WEAK
SHORT WAVE APPROACHING THE AREA SO STILL HOLDING OUT HOPE FOR MORE
ORGANIZED PRECIP THIS EVENING AS SFC LOW AND FRONTAL BOUNDARY
CONTINUE TO MOVE EASTWARD...BUT HAVE DROPPED POPS OVER THE EASTERN
CWA AND OPTED FOR SCT WORDING. WILL KEEP MENTION OF THUNDER IN THE
SE CWA AS LATEST LAPS DATA ALONG WITH SPC MESO ANALYSIS HAS CAPES
NUDGING UP OVER 1000J/KG INTO JAY COUNTY. VIS SAT ALSO SHOWING
CLOUDS THINNING OUT FROM MARION TO LIMA SO FURTHER LATE AFTN
DESTABILIZATION EXPECTED. 12Z MODELS A LITTLE SLOWER IN MOVING
SYSTEM OUT SO WILL HANG ON TO SMALL CHANCE IN SE CWA TILL 12Z TUE.
REST OF THE SHORT TERM WILL FEATURE CAA PATTERN AS UPPER LOW DROPS
INTO THE NORTHERN GREAT LAKES. SHOULD STILL GET TO AROUND NORMAL FOR
HIGHS TUESDAY AS 850MB THERMAL TROUGH DELAYED UNTIL TUE NITE/WED AM.
EXPECT AN INCREASE IN CLOUD COVER TUE NITE AS UPPER TROUGH SINKS
FURTHER SOUTH ALONG WITH SECONDARY COLD FRONT.
LONG TERM...WEDNESDAY THROUGH MONDAY
AN UPPER LEVEL SPEED MAX DIGGING SOUTHWARD ACROSS THE UPPER MIDWEST
AND UPPER MS VALLEY WILL ALLOW UPPER TROUGH TO SHIFT SOUTHEAST INTO
THE GREAT LAKES REGION BY WEDNESDAY MORNING. MOISTURE WILL BE
RELATIVELY UNIMPRESSIVE WITH THIS SYSTEM AND THUS MAIN PRECIP CHANCE
IS EXPECTED TO BE CONFINED TO ASSOCIATED WEAK LOW LEVEL CONVERGENCE
AXIS THAT WILL BE DROPPING SOUTHWARD ACROSS THE AREA ON WEDNESDAY.
MID LEVEL COLD POOL IS EXPECTED TO SHIFT SOUTHEAST ACROSS LOWER
MICHIGAN INTO WEDNESDAY NIGHT. SOME WEAK SFC BASED INSTABILITY IS
POSSIBLE ON WEDNESDAY AFTERNOON ESPECIALLY ACROSS NORTHEAST PORTIONS
OF THE FORECAST AREA CLOSER TO THESE COOLER MID LEVEL PROFILES. WILL
HOLD OFF ON ANY TS INCLUSION AT THIS POINT WITH SOME CONCERN THAT IF
SOME DEEPER MIXING IS REALIZED...THIS COULD LIMIT ANY SFC BASED
INSTABILITY. CHANCE OF PRECIP TO COME TO AN END WEDNESDAY EVENING AS
THIS UPPER TROUGH SHIFTS EAST. BROAD LOW LEVEL ANTICYCLONE WILL THEN
OVERSPREAD THE REGION FOR THURSDAY AND FRIDAY SETTING UP A FEW QUIET
DAYS TO END THE WEEK.
LOW LEVEL ANTICYCLONE WILL BE VERY SLOW TO SHIFT EAST AS UPPER RIDGE
TO THE WEST AMPLIFIES AS IT APPROACHES THE GREAT LAKES REGION FRIDAY
IN RESPONSE TO NEXT PROGRESSIVE EASTERN PACIFIC TROUGH TRACKING INTO
THE NORTHERN PLAINS. MOISTURE RETURN IN ADVANCE OF THIS PACIFIC
TROUGH WILL BE SOMEWHAT ROUNDABOUT DUE TO PRESENCE OF DEPARTING
ANTICYCLONE TO THE SOUTHEAST. THIS SHOULD CONFINE ANY LOW LEVEL
MOISTURE RETURN OF CONSEQUENCE TO A FAIRLY NARROW CORRIDOR IN
ADVANCE OF ASSOCIATED COLD FRONTAL BOUNDARY. WHILE SOME SLIGHT
TIMING DIFFERENCES PERSIST WITH THIS FRONT...CHARACTERISTIC OF LARGE
SCALE FLOW AND GOOD AGREEMENT AMONGST MEDIUM RANGE MODELS HANDLING
THIS NEXT EASTERN PACIFIC TROUGH STILL LEND ENOUGH CONFIDENCE TO
MAINTAIN LOW CHANCE POPS FOR FRIDAY NIGHT INTO SUNDAY. ONCE FRONTAL
TIMING BECOMES BETTER RESOLVED WILL LIKELY BE ABLE TO CONTRACT THE
DURATION OF THESE POPS. HAVE OMITTED THUNDER AT THIS TIME GIVEN SOME
UNCERTAINTIES AS TO EXTENT OF LOW LEVEL MOISTURE RETURN BUT THIS
WILL ALSO NEED TO BE REASSESSED IN LATER FORECASTS. SOME SLIGHT
MODERATION IN TEMPERATURES EXPECTED FOR FRIDAY IN ADVANCE OF THIS
FRONT...BUT OVERALL TEMPERATURES NEAR SEASONABLE LEVELS ARE EXPECTED
THROUGH THE PERIOD. A RETURN TO DRY CONDITIONS EXPECTED FOR EARLY
NEXT WEEK AS THIS SYSTEM DEPARTS TO THE EAST.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...LOGSDON
LONG TERM...MARSILI
AVIATION...JT
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1127 PM CDT MON MAY 7 2012
.UPDATE...
ISSUED AT 1127 PM CDT MON MAY 7 2012
UPDATED THE AVIATION SECTION.
UPDATE ISSUED AT 641 PM CDT MON MAY 7 2012
AN INTERIM GRID REVISION WAS MADE TO BLEND CURRENT POP/WEATHER
WITH THE MODEL REFLECTIVITY FROM THE 3KM HRRR AND 4KM NMM VERSION
OF THE NAM-WRF GUIDANCE. THESE SETS OF HIGH RESOLUTION STORM
SCALE MODELS SUGGEST THAT THE MAIN BAND OF CONVECTION OVER THE
PENNYRILE REGION OF WEST KENTUCKY WILL SCOUR OUT THE DEEPEST
MOISTURE ALONG AND AHEAD OF THE COLD FRONT. THIS CONVECTION WAS
AIDED EARLIER IN THE AFTERNOON WITH A LOW/MIDDLE LEVEL CIRCULATION
RIDING NORTHEAST ALONG AND AHEAD OF THE FRONTAL BOUNDARY.
THE SECONDARY LINE OF DISORGANIZED CONVECTION MAY BE SUGGESTIVE OF
POST-FRONTAL ZONE OF LIFT IN THE 925-850 MB FRONTAL ZONE. THIS MAY
PERSIST INTO THE EVENING HOURS ACROSS THE WFO PAH FORECAST AREA.
GIVEN THE LIMITED INSTABILITY EXPECTED TONIGHT...MAY NEED TO RE-EVALUATE
THE MENTION OF THUNDERSTORMS IN THE GRIDDED FORECAST...WITH A
HIGHER POP ASSOCIATED WITH SHOWERS VERSUS THUNDERSTORMS.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 152 PM CDT MON MAY 7 2012
THIS MORNING`S SHOWERS/STORMS REALLY WORKED THE ATMOSPHERE OVER
AND CAPPED IT OFF WITH A NICE LAYERED DECK OF CLOUDINESS. THIS WAS
INHIBITING CONVECTION FROM REFIRING THUS FAR...AND LED TO THE SPC
DOWNGRADE FROM SLGT RISK TO SEE TEXT FOR OUR AREA.
EVEN SO...SATELLITE IS STARTING TO SHOW SOME HINTS AT THINNING OF
THIS MORNING`S COMPLEX CLOUDINESS. SURFACE OBS REVEAL THE ACTUAL
FRONTAL BOUNDARY STILL PERCHED JUST TO THE NORTH AND WEST OF THE
FA...AND RADAR MOSAIC DOES SHOW SOME ACTIVITY TRYING TO DEVELOP
ALONG IT. AS THE BOUNDARY MOVES IN THIS PM...WE WILL MONITOR FOR
STRONG STORM POTENTIAL. WHILE WE`VE BACKED OFF THE PREVIOUSLY
INHERITED LIKELY AND BETTER POPS...WE STILL WANT TO MAINTAIN AT
LEAST HIGH CHANCE CAT GOING UNTIL THE FRONT MAKES ITS PASS.
12Z MODELS INDICATE THE PASSAGE OF THE FRONT AND THE ASSOCIATED
UPPER WAVE WILL BE THIS EVENING...WITH PCPN ALL BUT THRU BY 06Z.
SOME LATE NIGHT LINGERING OF A SMALL POP IS POSSIBLE IN THE FARTHEST
SERN PTNS FA...BUT ALL SHOULD BE PCPN FREE BY 12Z TUESDAY...SO WE`LL
MAKE THAT MODIFICATION TO THE FORECAST AS WELL.
TUESDAY-WEDNESDAY NIGHT WILL SEE POST FRONTAL COOLING/DRYING AIRMASS
BRINGING PLEASANT RELIEF TO THE SUMMER-LIKE HEAT/HUMIDITY OF RECENT
DAYS PAST. UPPER TROF PASSAGE WED LOOKS FOR NOW TO KEEP PCPN CHANCES
NORTH AND EAST OF US...BUT SOMETHING TO KEEP AN EYE UPON.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 152 PM CDT MON MAY 7 2012
SURFACE HIGH PRESSURE AND RISING HEIGHTS ALOFT SHOULD KEEP THE
REGION DRY WITH SEASONAL TEMPERATURES THROUGH SATURDAY. MODELS
DRAG A FRONT ACROSS OUR CWA ON SATURDAY BUT DONT GENERATE ANY
PRECIP IN THE PROCESS. THEY DO HOWEVER INDICATE POST FRONTAL
PRECIP CHANCES SATURDAY NIGHT AND SUNDAY.
BEYOND THAT DRY CONDITIONS SHOULD RETURN THROUGH THE END OF THE
FORECAST CYCLE WITH SLIGHTLY MODERATING TEMPERATURES. THE ECMWF
SHOWS A WEAKNESS IN THE SURFACE AND UPPER LEVELS OVER SOUTHEAST
MISSOURI NEXT MONDAY AND GENERATES A BIT OF PRECIP THERE. SINCE
THE OTHER LONG RANGE MODELS KEEP THE SURFACE HIGH STRONGER AND
GENERATE NO PRECIP...WILL KEEP IT DRY FOR NOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1127 PM CDT MON MAY 7 2012
VARIABLE VFR DECK MOVING SOUTH ACROSS THE REGION WITH HIGH CLOUDS
HEADING EAST. WINDS SHOULD REMAIN LIGHT NORTHWEST THROUGH THE
NIGHT IN THE WAKE OF A COOL FRONT. SOME CU POSSIBLE TOMORROW WITH
SOME HIGH CLOUDS RETURNING. NORTHWEST WINDS UP TO 10 KTS WILL BE
POSSIBLE...DIMINISHING TO LIGHT NORTHWEST AFTER 00Z.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
349 AM CDT TUE MAY 8 2012
.SHORT TERM...THROUGH THURSDAY NIGHT. WITH VERY LIMITED TO NO RISK
OF PRECIPITATION THROUGH THESE 72 HOURS...PRIMARY CHALLENGES BOIL
DOWN TO TEMPS/DEWPOINTS/WINDS...INCLUDING JUST HOW WARM THURSDAY
WILL ULTIMATELY GET.
STARTING OFF EARLY THIS MORNING...07Z OBJECTIVE SURFACE ANALYSIS
PLACES A BROAD HIGH PRESSURE AXIS CENTERED ALONG THE HIGH
PLAINS/FRONT RANGE FROM EASTERN MT THROUGH CENTRAL CO...WHILE A
WEAK LOW IS NOTED OVER FAR NORTHERN MN. WITH THE DOMINANT HIGH OFF
TO THE WEST...NEAR CALM TO LIGHT WESTERLY BREEZES DOMINATE THE
CWA. ALOFT...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA
INDICATE THE CENTRAL PLAINS ALONG THE SOUTHWESTERN FRINGES OF A
POSITIVELY TILTED TROUGH AXIS EXTENDING NORTHEASTWARD TO A CLOSED
500MB CIRCULATION SINKING SOUTHWARD INTO MN. MEANWHILE...ANOTHER
COMPACT CLOSED LOW IS EVIDENT ALONG THE AZ/SOUTHERN CALI
BORDER...WHILE A POSITIVELY TILTED RIDGE AXIS IS CENTERED FROM
CENTRAL CALI TO SOUTHWEST CANADA. ALONG THE SOUTHEASTERN PERIPHERY
OF THE GREAT LAKES REGION TROUGH AXIS...A MODEST 80+KT 300MB JET
STREAK IS CENTERED FROM CENTRAL NEB TO NORTH OF THE GREAT LAKES.
AS IS OH-SO COMMON IN THE ENTRANCE REGION OF SUCH A JET STREAK...A
NARROW BAND OF MID LEVEL FRONTOGENESIS EVIDENT NEAR THE 600MB
LEVEL IS FORCING A SNEAKY GENERALLY EAST-WEST BAND OF SPRINKLES
EXTENDING FROM EAST CENTRAL CO THROUGH AREAS ALONG AND MAINLY
SOUTH OF THE NEB-KS BORDER IN THE LOCAL AREA. WITH CLOUD CEILINGS
GENERALLY IN EXCESS OF 9K FEET...THIS WEAKLY FORCED PRECIPITATION
IS NOT EXPECTED TO MEASURE...BUT AS HINTED BY THE LATEST HRRR
RUNS...IT AT LEAST WARRANTS AN ISOLATED/SLIGHT CHANCE SPRINKLE
MENTION ACROSS PARTS OF THE SOUTHERN CWA DURING THE PRE-DAWN
HOURS. TURNING TO TEMPS...THE FAIRLY EXTENSIVE COVERAGE OF MID-
HIGH LEVEL CLOUDS SO FAR TONIGHT HAS HELD TEMPS WELL INTO THE
UPPER 40S/LOW 50S IN SOUTHERN ZONES...WITH NORTHERN AREAS JUST
NOW STARTING TO REALIZE SOME UPPER 30S/LOW 40S. LEANING ON THE 00Z
NAM 600MB RH FIELDS...THE THICKER BATCH OF MID CLOUDS/SPRINKLES
SHOULD GRADUALLY SINK SOUTHWARD THROUGH THE NEXT SEVERAL
HOURS...LIKELY ALLOWING A MORE PRONOUNCED TEMP DROP TOWARD
SUNRISE. THIS SHOULD ALLOW THE MAJORITY OF THE CWA TO AT LEAST
REALIZE LOW-MID 40S FOR LOWS...WITH SOME MID-UPPER 30S STILL
EXPECTED MAINLY WEST OF A GREELEY-LEXINGTON LINE. ALTHOUGH
CONFIDENCE IS LOW ON ANY AREAS TOUCHING THE 36-DEGREE RANGE LONG
ENOUGH TO FORM FROST...WITH NONETHELESS HANG ONTO SOME PATCHY
FROST WORDING EARLY THIS MORNING ONLY FOR PARTS OF DAWSON AND
NORTHWEST GOSPER COUNTIES...WITH MINIMAL IMPACT ANTICIPATED.
GETTING INTO THE DAYTIME HOURS POST-12Z...WILL CONTINUE TO FOLLOW
THE NAM 600MB RELATIVE HUMIDITY MAXIMUM FAIRLY CLOSELY TO
DELINEATE THE NORTHERN EDGE OF MORNING SPRINKLE POTENTIAL...AND
WILL LINGER THIS MENTION ONLY IN KS ZONES THROUGH 15Z...AND
HOPEFULLY THIS IS LONG ENOUGH AS LATEST HRRR TRIES SUGGESTING SOME
SPRINKLES COULD STICK AROUND EVEN THROUGH 17Z OR SO...BUT THIS
LOOKS A BIT OVERDONE AS LIFT IN THE ENTRANCE REGION OF THE UPPER
JET AND RESULTANT MID LEVEL SATURATION SINKS SOUTH OF THE AREA
WITH TIME. MAY HAVE TO DEBATE ADDING A SLIGHT MEASURABLE POP AS
WELL...BUT FEEL THAT MEASURABLE RAIN WILL BE THE EXCEPTION OUT OF
THIS ACTIVITY UNLESS RADAR TRENDS DICTATE OTHERWISE DURING NEXT
FEW HOURS. HAVE NO MENTION OF RAIN WHATSOEVER ANYWHERE IN THE CWA
BEYOND 15Z...AS THE MAIN GREAT LAKES REGION VORT MAX DROPS SOUTH
INTO NORTHERN IA BY 00Z. ALTHOUGH THE COLD POCKET ALOFT WITH THIS
WAVE WILL SURELY SPARK SCATTERED SHOWERS/MAYBE A FEW WEAK STORMS
THIS AFTERNOON AS CLOSE AS NORTHEAST NEB...WILL ASSUME FOR NOW
THAT THIS ACTIVITY WILL REMAIN OUTSIDE THE CWA. HOWEVER...PER THE
LATEST 00Z 4KM WRF-NMM REFLECTIVITY PROG...SOME OF THIS SHOWER
ACTIVITY COULD GET FAIRLY CLOSE TO BRUSHING THE FAR NORTHEAST CWA
IN THE NANCE/POLK COUNTY AREA AND NEXT SHIFTS WILL HAVE TO KEEP AN
EYE ON THIS ESPECIALLY BETWEEN 20Z-00Z. AS HAS ALREADY BEEN PROVEN
IN THE PAST 24 HOURS...SETUPS LIKE THIS CAN GO FROM LOOKING
COMPLETELY DRY 2 DAYS PRIOR...TO ULTIMATELY PRODUCING AT LEAST
NUISANCE SPRINKLES/LIGHT SHOWERS WITH LITTLE ADVANCE NOTICE.
TURNING TO OTHER FACETS OF TODAY/S FORECAST...DEEP MIXING TO NEAR
700MB PER NAM SOUNDINGS WILL PROMOTE ANOTHER BREEZY DAY...WITH
SUSTAINED SPEEDS EASILY 15-20 MPH WITH GUSTS TO AROUND 25 MPH
ESPECIALLY ACROSS THE NORTHEAST 1/2 OF THE CWA. TEMP-WISE...ALTHOUGH
COULD EASILY SEE A FAIR AMOUNT OF HIGH-BASED CUMULUS THIS
AFTERNOON...FORESEE NO WORSE THAN PARTLY CLOUDY SKIES OVERALL. AS
A RESULT...KEPT HIGHS SIMILAR TO PREVIOUS FORECAST...WITH MOST
AREAS IN THE UPPER 60S-LOW 70S. PER A NAM-BASED MIXING TOOL...DID
LOWER DEWPOINTS AT LEAST 5 DEGREES DURING THE DAY MOST AREAS.
ALTHOUGH THIS WOULD DROP SURFACE RH VALUES DOWN TO AROUND 20 PERCENT
OR SO...ANY FIRE WEATHER THREAT SHOULD BE QUITE MINIMAL GIVEN
RECENT RAINFALL AND CONTINUED GREEN-UP.
TONIGHT...SHORTWAVE RIDGING OVERTAKES THE CWA IN THE WAKE OF THE
DEPARTING TROUGH AXIS...WHICH WILL REACH ALONG A LINE FROM
SOUTHERN KS UP THROUGH THE EASTERN GREAT LAKES BY 12Z. ASSUMING
THAT NO SPRINKLES/LIGHT SHOWERS ARE AFFECTING THE NORTHEAST CWA
RIGHT AWAY IN THE EARLY EVENING...HAVE HIGH CONFIDENCE IN A DRY
OVERNIGHT PERIOD AS A ROUGHLY 1022MB SURFACE HIGH SETTLES
DIRECTLY OVER THE CWA. WITH MOSTLY CLEAR SKIES AND LIGHT/VARIABLE
BREEZES...SHOULD SEE A MORE EFFICIENT TEMP DROP TONIGHT...AND
NUDGED DOWN LOWS AT LEAST 2-3 DEGREES FROM PREVIOUS
FORECAST...PUTTING MOST OF THE CWA DOWN INTO THE 38-41 RANGE FOR
LOWS. AS FOR FROST POTENTIAL...ONLY HAVE FAR WESTERN AREAS SUCH AS
DAWSON AND GOSPER COUNTIES REACHING AS LOW AS 36...AND THUS
CONFINED PATCHY FROST MENTION TO ONLY THIS LIMITED AREA FOR
NOW...WITH NO FROST HEADLINE PLANNED.
WEDNESDAY...RIDGING CONTINUES TO DOMINATE THE CWA BOTH AT THE
SURFACE AND ALOFT...WITH HIGH CONFIDENCE IN A DRY DAY WITH AT
LEAST MOSTLY SUNNY SKIES. ALTHOUGH THE SURFACE RIDGE AXIS WILL
INHIBIT EFFICIENT MIXING MOST OF THE DAY...A GRADUAL RETURN TO
SOUTHERLY BREEZES WILL DEVELOP. CHANGED HIGHS LITTLE...WITH MOST
AREAS BETWEEN 71-74.
WEDNESDAY NIGHT...STEADY LIGHT SOUTHERLY BREEZES CONTINUE AS AN
EXPANSIVE MID/UPPER RIDGE RETAINS CONTROL AHEAD OF THE NEXT LARGE
SCALE SHORTWAVE TROUGH MOVING INTO THE PACIFIC NORTHWEST. THE
SOUTHERLY FLOW WILL HELP KEEP LOWS WARMER...AND STAYED CLOSE TO
GUIDANCE AND PREVIOUS FORECAST WITH UPPER 40S-NEAR 50 CWA-WIDE.
THURSDAY...THIS STILL LOOKS TO BE THE HANDS-DOWN WARMEST DAY OF
THE FORECAST PERIOD...AS HIGH PLAINS SURFACE PRESSURE FALLS AHEAD
OF THE INCOMING TROUGH INDUCES INCREASING SOUTHERLY BREEZES WITH
SUSTAINED SPEEDS EASILY 15-20 MPH. DEEPER MIXING...IN CONCERT WITH
WARMER TEMPS EVIDENT AT 850MB AND PLENTY OF SUNSHINE SHOULD REALLY
GIVE TEMPS A BOOST...AND RAISED HIGHS AT LEAST 2-3 DEGREES FROM
PREVIOUS FORECAST...NOW RANGING FROM LOW 80S EAST TO MID 80S WEST.
NUMERICAL MET/MAV GUIDANCE JUST LOOKS TO BE SEVERAL DEGREES TOO
COOL AT THIS TIME.
THURSDAY NIGHT...MAIN CHANGE WAS TO PULL THE TOKEN 20 PERCENT
CHANCE OF SHOWERS/STORMS THAT HAD BEEN ADVERTISED IN FAR NORTHWEST
COUNTIES THE PAST FEW FORECAST CYCLES. ALTHOUGH BOTH THE NAM/ECMWF
ARE IN GOOD AGREEMENT THAT A WELL-DEFINED COLD FRONT WILL ENTER
NORTHWEST PORTIONS OF THE CWA BETWEEN 06Z-12Z...WHAT MEAGER
ELEVATED INSTABILITY THERE IS SHOULD HANG BACK IN WEST CENTRAL/NORTH
CENTRAL NEB THROUGH THE ENTIRE NIGHT AS THE PARENT MID LEVEL
TROUGH AXIS MIGRATES ACROSS THE NORTHERN ROCKIES. WANT TO NOTE
THAT THE NAM/ECMWF ARE BOTH FASTER THAN THE GFS IN BRINGING THE
COLD FRONT AND INCREASING NORTHWEST WINDS INTO THE CWA...SO THERE
ARE STILL SOME TIMING ISSUE TO WORK OUT HERE.
.LONG TERM...FRIDAY THROUGH MONDAY. DURING THIS FORECAST PERIOD WE
START ANOTHER COOL DOWN WITH A COLD FRONTAL PASSAGE EARLY FRIDAY.
MOISTURE IS MEAGER ALONG THE BOUNDARY...BUT WE WILL NOTICE COOLING
TEMPERATURES BACK TO SEASONAL NUMBERS DURING THE DAY FRIDAY.
GLANCING BLOW OF UPPER LEVEL ENERGY AND TAIL END OF 250MB JET STREAK
COULD BE ENOUGH TO SPARK SOME SHOWERS...MAYBE A THUNDERSTORM OR TWO
BEHIND THE FRONT. ALL MODEL FORECAST HAVE THIS TREND. PRETTY STRONG
SURFACE HIGH PRESSURE SPREADS INTO THE REGION LATE FRIDAY AND
SATURDAY. EXPERIENCE WITH PRECIPITATION TRENDS AND BUILDING FRONT
RANGE SURFACE HIGH PRESSURES IN MODEL WORLD...IS THE MODELS TEND TO
OVERDO THE PRECIPITATION TOO FAR EAST AND WITH TOO MUCH OF IT. A
CONSERVATIVE APPROACH IS BEST AT THIS POINT...AS WE ARE LIABLE TO
SEE MORE CLOUDS THAN ANYTHING...ESPECIALLY THE FURTHER NORTH/EAST
YOU GO ACROSS OUR FORECAST AREA. THEREFORE...ONLY 20 TO 30 PERCENT
CHANCE FOR MEASURABLE PRECIPITATION AREA IN THE FORECAST. MID LEVEL
LAPSE RATES SUGGEST THUNDER RISK IF MARGINAL AT BEST AND ONLY AN
ISOLATED STORM IS EXPECTED. TEMPERATURES WILL DROP BACK INTO THE 60S
FOR A TIME...BUT START TO REBOUND LATE SUNDAY AND MONDAY. HARDLY A
RAINOUT BY ANY MEANS...BUT SOME SHOWERS WILL BE FLOATING AROUND ON
THIS MOTHERS DAY WEEKEND.
&&
.PREV DISCUSSION... /ISSUED 1036 PM CDT MON MAY 7 2012/
AVIATION...06Z TAF. VFR CONDITIONS ARE FORECAST THROUGH THE PERIOD
WITH NO VISIBILITY RESTRICTIONS AND ONLY OCCASIONAL MID LEVEL CLOUDS
BRUSHING BY THE AREA DURING THE DAY TUESDAY. WINDS WILL INCREASE
AGAIN AND GUST ABOVE 20KTS FOR MUCH OF THE DAY...BEFORE DROPPING
OFF EARLY IN THE EVENING AS HIGH PRESSURE MOVES INTO CENTRAL
NEBRASKA.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM/AVIATION...MORITZ
AREA FORECAST DISCUSSION
NWS PORTLAND OR
246 AM PDT TUE MAY 8 2012
.SYNOPSIS...AN UPPER LEVEL RIDGE THAT HAS BEEN OVER THE PACIFIC
NORTHWEST THE LAST COUPLE OF DAYS WILL CONTINUE TO MOVE EAST TODAY AS
AN UPPER LEVEL LOW NEAR THE GULF OF ALASKA APPROACHES WESTERN BRITISH
COLUMBIA. ONSHORE FLOW WILL INCREASE TODAY...WITH A WEAKENING COLD
FRONT MOVING ONSHORE THIS AFTERNOON AND THROUGH THE FORECAST AREA
THIS EVENING. A TRAILING UPPER TROUGH WILL MOVE THROUGH THE PACIFIC
NORTHWEST WEDNESDAY AND EARLY WEDNESDAY NIGHT FOR CONTINUED STRONG
ONSHORE FLOW...CLOUDS...AND MUCH COOLER TEMPERATURES...AND A CHANCE
OF SOME SPOTTY LIGHT PRECIPITATION. AN UPPER RIDGE WILL BEGIN
BUILDING AND MOVING INTO THE PACIFIC NORTHWEST THURSDAY AND CONTINUE
TO STRENGTHEN THROUGH THE WEEKEND. THIS WILL BRING DRY WEATHER AND
ABOVE NORMAL TEMPERATURES THAT MAY LAST WELL INTO NEXT WEEK.
&&
.SHORT TERM...AS THE UPPER RIDGE OF THE PAST COUPLE OF DAYS WAS
MOVING EAST EARLY TODAY...THIS HAS ALLOWED SOUTHWEST FLOW ALOFT TO
DEVELOP THAT IS HELPING TO DEVELOP MARINE CLOUDS ALONG THE COAST
EARLY THIS MORNING. THESE CLOUDS ARE PUSHING INTO THE COASTAL GAPS IN
OREGON...A FEW BRIEF LOW CLOUDS MAY REACH INTO THE WILLAMETTE VALLEY
THIS MORNING.
THE ONSHORE FLOW WILL CONTINUE TO INCREASE TODAY AS THE WEAKENING
COLD FRONT THAT HAS MOVED INSIDE 130W EARLY THIS MORNING APPROACHES
THE NORTH COAST LATE THIS MORNING...THEN PUSHES ONSHORE THIS
AFTERNOON. PRECIPITATION LOOKS TO BE SPOTTY AND LIGHT WITH THIS
FRONT...ESPECIALLY NEAR THE COAST AND OVER THE HIGHER TERRAIN IN THE
NORTHERN ZONES. THE BAND WILL MOVE THROUGH THE NORTHERN WILLAMETTE
VALLEY AND CLARK COUNTY DURING THE EVENING COMMUTE WITH MAINLY
CLOUDS...THOUGH A FEW SPRINKLES OR A LITTLE DRIZZLE IS NOT OUT OF
THE QUESTION. EXPECT CLOUDS BUT LITTLE OR NO PRECIPITATION FARTHER
SOUTH IN THE WILLAMETTE VALLEY THIS EVENING. THE BAND WILL PUSH EAST
OF THE CASCADES BY MIDNIGHT.
THE ONSHORE FLOW ASSOCIATED WITH THE FRONT WILL LIKELY GIVE SOME
BREEZY WEST WINDS MUCH OF OUR FORECAST AREA LATER TODAY AND THIS
EVENING...ESPECIALLY THROUGH THE COAST RANGE AND THE GORGE AND OVER
THE CASCADES...BUT SOME IN THE INTERIOR VALLEYS AS WELL.
DESPITE THE RATHER STRONG ONSHORE FLOW CONTINUING OVERNIGHT TONIGHT
AND ON WEDNESDAY...THE LOW LEVEL CLOUDS MAY BREAK UP SOME AT TIMES
ESPECIALLY AFTER THE FRONTAL BAND THIS EVENING AND ON WEDNESDAY. A
TRAILING UPPER TROUGH WILL PUSH THROUGH WEDNESDAY AFTERNOON AND
EVENING AND COULD PRODUCE A FEW SHOWERS ACROSS OUR NORTHERN ZONES AS
IT MOVES THROUGH...ESPECIALLY NEAR THE COAST AND OVER THE HIGHER
TERRAIN. EXPECTED BREEZY WEST WINDS TO CONTINUE. LOOK FOR TEMPS
WEDNESDAY TO FALL BELOW NORMAL...CLOSE TO 60 DEGREES INLAND.
THE UPPER TROUGH WILL MOVE EAST OF THE AREA BY THURSDAY MORNING WITH
PRECIPITATION GENERALLY ENDING. THERE WILL LIKELY BE AREAS OF LOW
CLOUDS AND PATCHY FOG THURSDAY MORNING...THEN CLEARING IN THE
AFTERNOON AS AN UPPER RIDGE BEGINS TO SPREAD ONSHORE. TEMPS WILL
BEGIN TO RECOVER BUT STILL BE A BIT BELOW NORMAL...IN THE LOWER TO
MID 60S. TOLLESON
.LONG TERM...THE UPPER RIDGE FROM THURSDAY IS FORECAST TO AMPLIFY
OVER THE PACIFIC NORTHWEST THROUGH THIS WEEKEND INTO EARLY NEXT
WEEK...GIVING SOUTHWEST WASHINGTON AND NORTHWEST OREGON ITS MOST
PROLONGED WARM AND DRY WEATHER OF THE SPRING SO FAR. WE COULD SEE
SOME 80S THIS WEEKEND INTO NEXT WEEK IN THE INLAND AREAS. THE NEXT
CHANCE OF ANY PRECIPITATION IS LOOKING TO BE THE MIDDLE OR LATTER
PART OF NEXT WEEK. TOLLESON
&&
.AVIATION...IFR/LOW MVFR CEILINGS ARE EXPANDING ALONG THE COAST AS A
WEAKENING COLD FRONT APPROACHES THE REGION. ONCE MORE EXPANSIVE
IFR/MVFR CIGS DO DEVELOP ALONG THE COAST TONIGHT...EXPECT THEM TO
LAST INTO TUESDAY MORNING BEFORE LIFTING AND DISSIPATING TUESDAY
EARLY TO MID AFTERNOON ALONG THE NORTH COAST...AND LATE AFTERNOON TO
EARLY EVENING ALONG THE CENTRAL COAST AS THE FRONT WILL TAKE LONGER
TO MOVE INLAND FARTHER SOUTH.
THE LOW STRATUS IS HAVING A HARD TIME GETTING THROUGH THE COASTAL
GAPS THIS MORNING. LATEST NAM IS STILL TRYING TO BRING LOW CLOUDS
INTO THE SOUTH AND CENTRAL VALLEY AND ALONG THE COLUMBIA RIVER TO
KELSO...WHEREAS THE LATEST HI RESOLUTION MODELS...NAMELY THE WRF/ARW
AND HRRR ARE KEEPING THINGS OUT...AS ARE ALL MOS GUIDANCE BULLETINS.
WE WILL MONITOR SATELLITE TRENDS DURING THE EARLY MORNING TO SEE IF
ANY LOW CLOUDS CAN MAKE IT THROUGH...THOUGH AT THIS TIME WE STILL
EXPECT INLAND TERMINALS SHOULD REMAIN VFR THROUGH THE PERIOD...
THOUGH THERE COULD BE A BRIEF PERIOD OF VERY LIGHT RAIN/DRIZZLE
DURING THE 00Z TO 06Z TIME FRAME WITH A WEAK FRONT MOVING THROUGH.
KMD
KPDX AND APPROACHES...VFR CONDITIONS GENERALLY EXPECTED. EXPECT
BREEZY NW WINDS IN THE 10-15 KT RANGE DURING THE AFTERNOON AND EARLY
EVENING. WE STILL EXPECT THAT BROKEN LOW CLOUDS WILL REMAIN AWAY FROM
THE TERMINAL THIS MORNING...THOUGH THERE IS A CHANCE THAT THEY MAY
MAKE TO KELSO AND A SMALL CHANCE OF GETTING FARTHER DOWN THE
COLUMBIA. KMD
&&
.MARINE...A WEAKENING COLD FRONT WILL BRUSH THE COASTAL WATERS LATE
TONIGHT INTO TUESDAY MORNING...FOLLOWED BY ENHANCED NORTHWEST
FLOW...AS HIGH PRESSURE BUILDS IN BEHIND THE FRONT TUESDAY. SMALL
CRAFT ADVISORY WINDS IN EXCESS OF 21 KT APPEAR LIKELY BY TUE
AFTERNOON. AFTER A BREAK TONIGHT...EXPECT SEVERAL PERIODS OF WIND
GUSTS GREATER IN THE 20 TO 25 KT RANGE IN THE AFTERNOON AND EVENING
PERIODS...ESPECIALLY FOR THE CENTRAL OREGON WATERS...BUT THE NORTH
OREGON WATERS MAY GET IN ON THE ACTION AS WELL. WEST SWELL ASSOCIATED
WITH THE PARENT LOW SHOULD ARRIVE EARLY WED...WILL SNEAK INTO THE LOW
TEENS...THEN QUICKLY DROP BACK BELOW 10 FT THU AFTERNOON.
DESPITE MINIMAL SWELL TODAY AND TUESDAY...THE STRONGEST EBBS OF THE
YEAR ARE STILL CAUSING ROUGH CONDITIONS FOR THE COLUMBIA RIVER
BAR...THUS A SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR
REMAINS FOR THE VERY STRONG EBB EXPECTED THIS MORNING. KMD
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS FROM NOON TODAY TO MIDNIGHT PDT
TONIGHT FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
CASCADE HEAD OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR WINDS FROM NOON TODAY THOUGH EARLY
WED MORNING FOR COASTAL WATERS FROM CASCADE HEAD TO FLORENCE
OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 5 AM TO
9 AM PDT THIS MORNING.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
1114 AM EDT TUE MAY 8 2012
.UPDATE...
ALTHOUGH SHOWERS NEAR COLUMBUS HAVE DISSIPATED FOR THE MOST
PART...STARTING TO SEE DEVELOPMENT OVER EAST CENTRAL GEORGIA.
ALTHOUGH SO ISOLATED SHOWERS WILL BE POSSIBLE THROUGH EARLY
AFTERNOON...THE BEST CHANCE OF THUNDERSTORMS WILL BE AFTER 2PM.
THIS IS ALSO INLINE WITH THE HRRR /ALTHOUGH THE RUN IS A LITTLE
OUTDATED/ THAT SUGGESTS INCREASED ACTIVITY AFTER 2PM. CLOUD
COVERAGE THIS MORNING IS LIMITING THE HEATING...ONLY A FEW BREAKS
IN THE CLOUDS...SO WILL TAKE A WHILE TO REACH HIGHER INSTABILITY
VALUES...THUS THINK BEST CHANCE OF SEVERE WILL BE LATE AFTERNOON
INTO THE EVENING WHICH ALSO BETTER CORRESPONDS WITH THE FRONT
MOVING INTO GA.
FORECAST DEW POINTS WERE A LITTLE ON THE LOW SIDE SO MINOR
ADJUSTMENTS TO THOSE GRIDS.
11
&&
.PREV DISCUSSION...
SHORT TERM /TODAY THROUGH WEDNESDAY/...
/ISSUED 359 AM EDT TUE MAY 8 2012/
CURRENTLY HAVE SCATTERED SHOWERS DEVELOPING OVER NORTH GEORGIA
ASSOCIATED WITH A WEAK SHORT WAVE SWEEPING PAST THE REGION.
COVERAGE SHOULD REMAIN SCATTERED THROUGH THE MORNING HOURS. UPPER
LEVEL FLOW TRANSITIONING TO SOUTHWESTERLY TODAY AHEAD OF A TROUGH
DIGGING INTO THE EASTERN U.S. GFS...NAM AND ECMWF ALL SHOW A COLD
FRONT ENTERING NORTHWEST GEORGIA BY THIS AFTERNOON WHICH SHOULD
HELP TO ENHANCE THUNDERSTORM ACTIVITY. CURRENT PACE AND TIMING OF
THE FRONT PUSHES BEST PRECIPITATION CHANCES INTO CENTRAL GEORGIA
FOR WEDNESDAY.
MODELS SHOW MUCAPE AROUND 1500 J/KG ACROSS THE MAJORITY OF THE
FORECAST AREA BY THIS AFTERNOON...SLIGHTLY HIGHER THAN YESTERDAY.
WITH EXTENSIVE CLOUD COVER THROUGH THE MAJORITY OF THE DAY WE WILL
HAVE A SLOW TIME REACHING THESE VALUES. THIS SHOULD KEEP THE CHANCES
FOR SEVERE THUNDERSTORMS AT A MINIMUM FOR TODAY...ALTHOUGH A FEW
ISOLATED SEVERE STORMS ARE NOT IMPOSSIBLE BY LATE AFTERNOON...
ESPECIALLY IF WE CAN GET SOME SUNSHINE ACROSS THE AREA. SIMILAR
NUMBERS ARE INDICATED AHEAD OF THE FRONT WEDNESDAY ACROSS CENTRAL
GEORGIA...HOWEVER THE AREA WILL BE UNDER THE INFLUENCE OF THE TAIL
END OF A SLIGHTLY STRONGER UPPER LEVEL WAVE WHICH MAY HELP TO
INCREASE THE CHANCES FOR ISOLATED SEVERE STORMS.
20
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
/ISSUED 359 AM EDT TUE MAY 8 2012/
MODELS SIMILAR WITH THE FRONTAL BOUNDARY PUSHING INTO SOUTH
GEORGIA WEDNESDAY EVENING...THEN OFF THE GEORGIA COAST BY EARLY
THURSDAY. HIGH PRESSURE BUILDS INTO THE SOUTHEAST U.S. BEHIND THE
FRONT AND REMAIN DOMINANT OVER NORTH AND CENTRAL GEORGIA INTO THE
WEEKEND. EXTENDED PROGS CONTINUE TO SHOW SOME DEEPER MOISTURE
SPREADING BACK INTO OUR AREA SUNDAY INTO MONDAY AS A WEAK BOUNDARY
DRIFTS SOUTHWARD FROM THE OHIO/TENNESSEE VALLEY...AND A LOW
PRESSURE SYSTEM LIFTS NORTHEAST FROM THE GULF. WILL KEEP POPS IN
THE SLIGHT CHANCE RANGE ON SUNDAY AND MONDAY FOR NOW UNTIL WE CAN
GET A BETTER HANDLE ON THESE FEATURES. OVERALL...NEAR NORMAL
TEMPERATURES EXPECTED DURING THE PERIOD.
49
AVIATION...
12Z UPDATE...
/ISSUED 730 AM EDT TUE MAY 8 2012/
MIXED MVFR/IFR CEILINGS AND VISIBILITIES CONTINUE ACROSS THE
MAJORITY OF NORTH AND CENTRAL GEORGIA AT THIS TIME...WILL BECOME
MAINLY MVFR BY 15Z AND VFR BY 18Z. ISOLATED TO SCATTERED SHOWERS AND
A FEW THUNDERSTORMS WILL CONTINUE TO BE POSSIBLE THROUGH 18Z...
BECOMING MORE WIDESPREAD BETWEEN 18Z AND 02Z. WINDS SOUTHEAST TO
SOUTHWEST 3-6KT WILL BECOME SOUTHWEST 6-10KT BY 15Z AND WEST TO
NORTHWEST BY 00Z.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM CONFIDENCE.
20
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 80 61 82 54 / 60 50 60 20
ATLANTA 81 64 80 56 / 60 50 60 10
BLAIRSVILLE 77 59 76 49 / 60 50 40 5
CARTERSVILLE 81 62 78 49 / 60 50 50 10
COLUMBUS 83 67 82 58 / 60 50 60 20
GAINESVILLE 79 61 79 54 / 60 50 50 10
MACON 83 65 84 56 / 60 50 60 30
ROME 81 60 77 50 / 60 50 40 5
PEACHTREE CITY 81 63 80 51 / 60 50 60 20
VIDALIA 84 67 86 62 / 60 50 70 60
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
722 AM CDT TUE MAY 8 2012
.UPDATE...JUST COMPLETED A QUICK UPDATE TO PURGE ISOLATED SPRINKLE
WORDING FROM KS ZONES...AS RADAR RETURNS EXITED STAGE SOUTH A BIT
FASTER THAN PREVIOUSLY EXPECTED WITHIN THE NARROW MID LEVEL
FRONTOGENETIC ZONE...AND AREN/T EXPECTED TO COME BACK. NEVER
ACTUALLY HAD CONFIRMED GROUND TRUTH THAT THIS LIGHT PRECIP REACHED
THE GROUND ANYWAY WITHIN THE CWA...BUT CHANCES ARE A FEW SPRINKLES
MANAGED TO. NO OTHER NOTABLE CHANGES MADE...OTHER THAN BRINGING
HOURLY TEMPS/DEWPOINTS/SKY COVER MORE IN LINE WITH LATEST OBS.
&&
.PREV DISCUSSION... /ISSUED 602 AM CDT TUE MAY 8 2012/
AVIATION...12Z TAF. VFR CONDITIONS ARE FORECAST FOR THE TAF
PERIOD. SOME LOW/MID CLOUDS WILL WRAP AROUND AN UPPER LOW INTO
THE AREA THIS AFTERNOON...ALONG WITH SOME CONVECTIVE CUMULUS
DEVELOPMENT. WINDS WILL PICK UP BY LATE MORNING AND GUST OVER
20KTS IN THE AFTERNOON. SKIES WILL CLEAR AND WIND DIMINISH
QUICKLY THIS EVENING.
PREV DISCUSSION... /ISSUED 349 AM CDT TUE MAY 8 2012/
SHORT TERM...THROUGH THURSDAY NIGHT. WITH VERY LIMITED TO NO RISK
OF PRECIPITATION THROUGH THESE 72 HOURS...PRIMARY CHALLENGES BOIL
DOWN TO TEMPS/DEWPOINTS/WINDS...INCLUDING JUST HOW WARM THURSDAY
WILL ULTIMATELY GET.
STARTING OFF EARLY THIS MORNING...07Z OBJECTIVE SURFACE ANALYSIS
PLACES A BROAD HIGH PRESSURE AXIS CENTERED ALONG THE HIGH
PLAINS/FRONT RANGE FROM EASTERN MT THROUGH CENTRAL CO...WHILE A
WEAK LOW IS NOTED OVER FAR NORTHERN MN. WITH THE DOMINANT HIGH OFF
TO THE WEST...NEAR CALM TO LIGHT WESTERLY BREEZES DOMINATE THE
CWA. ALOFT...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA
INDICATE THE CENTRAL PLAINS ALONG THE SOUTHWESTERN FRINGES OF A
POSITIVELY TILTED TROUGH AXIS EXTENDING NORTHEASTWARD TO A CLOSED
500MB CIRCULATION SINKING SOUTHWARD INTO MN. MEANWHILE...ANOTHER
COMPACT CLOSED LOW IS EVIDENT ALONG THE AZ/SOUTHERN CALI
BORDER...WHILE A POSITIVELY TILTED RIDGE AXIS IS CENTERED FROM
CENTRAL CALI TO SOUTHWEST CANADA. ALONG THE SOUTHEASTERN PERIPHERY
OF THE GREAT LAKES REGION TROUGH AXIS...A MODEST 80+KT 300MB JET
STREAK IS CENTERED FROM CENTRAL NEB TO NORTH OF THE GREAT LAKES.
AS IS OH-SO COMMON IN THE ENTRANCE REGION OF SUCH A JET STREAK...A
NARROW BAND OF MID LEVEL FRONTOGENESIS EVIDENT NEAR THE 600MB
LEVEL IS FORCING A SNEAKY GENERALLY EAST-WEST BAND OF SPRINKLES
EXTENDING FROM EAST CENTRAL CO THROUGH AREAS ALONG AND MAINLY
SOUTH OF THE NEB-KS BORDER IN THE LOCAL AREA. WITH CLOUD CEILINGS
GENERALLY IN EXCESS OF 9K FEET...THIS WEAKLY FORCED PRECIPITATION
IS NOT EXPECTED TO MEASURE...BUT AS HINTED BY THE LATEST HRRR
RUNS...IT AT LEAST WARRANTS AN ISOLATED/SLIGHT CHANCE SPRINKLE
MENTION ACROSS PARTS OF THE SOUTHERN CWA DURING THE PRE-DAWN
HOURS. TURNING TO TEMPS...THE FAIRLY EXTENSIVE COVERAGE OF MID-
HIGH LEVEL CLOUDS SO FAR TONIGHT HAS HELD TEMPS WELL INTO THE
UPPER 40S/LOW 50S IN SOUTHERN ZONES...WITH NORTHERN AREAS JUST
NOW STARTING TO REALIZE SOME UPPER 30S/LOW 40S. LEANING ON THE 00Z
NAM 600MB RH FIELDS...THE THICKER BATCH OF MID CLOUDS/SPRINKLES
SHOULD GRADUALLY SINK SOUTHWARD THROUGH THE NEXT SEVERAL
HOURS...LIKELY ALLOWING A MORE PRONOUNCED TEMP DROP TOWARD
SUNRISE. THIS SHOULD ALLOW THE MAJORITY OF THE CWA TO AT LEAST
REALIZE LOW-MID 40S FOR LOWS...WITH SOME MID-UPPER 30S STILL
EXPECTED MAINLY WEST OF A GREELEY-LEXINGTON LINE. ALTHOUGH
CONFIDENCE IS LOW ON ANY AREAS TOUCHING THE 36-DEGREE RANGE LONG
ENOUGH TO FORM FROST...WITH NONETHELESS HANG ONTO SOME PATCHY
FROST WORDING EARLY THIS MORNING ONLY FOR PARTS OF DAWSON AND
NORTHWEST GOSPER COUNTIES...WITH MINIMAL IMPACT ANTICIPATED.
GETTING INTO THE DAYTIME HOURS POST-12Z...WILL CONTINUE TO FOLLOW
THE NAM 600MB RELATIVE HUMIDITY MAXIMUM FAIRLY CLOSELY TO
DELINEATE THE NORTHERN EDGE OF MORNING SPRINKLE POTENTIAL...AND
WILL LINGER THIS MENTION ONLY IN KS ZONES THROUGH 15Z...AND
HOPEFULLY THIS IS LONG ENOUGH AS LATEST HRRR TRIES SUGGESTING SOME
SPRINKLES COULD STICK AROUND EVEN THROUGH 17Z OR SO...BUT THIS
LOOKS A BIT OVERDONE AS LIFT IN THE ENTRANCE REGION OF THE UPPER
JET AND RESULTANT MID LEVEL SATURATION SINKS SOUTH OF THE AREA
WITH TIME. MAY HAVE TO DEBATE ADDING A SLIGHT MEASURABLE POP AS
WELL...BUT FEEL THAT MEASURABLE RAIN WILL BE THE EXCEPTION OUT OF
THIS ACTIVITY UNLESS RADAR TRENDS DICTATE OTHERWISE DURING NEXT
FEW HOURS. HAVE NO MENTION OF RAIN WHATSOEVER ANYWHERE IN THE CWA
BEYOND 15Z...AS THE MAIN GREAT LAKES REGION VORT MAX DROPS SOUTH
INTO NORTHERN IA BY 00Z. ALTHOUGH THE COLD POCKET ALOFT WITH THIS
WAVE WILL SURELY SPARK SCATTERED SHOWERS/MAYBE A FEW WEAK STORMS
THIS AFTERNOON AS CLOSE AS NORTHEAST NEB...WILL ASSUME FOR NOW
THAT THIS ACTIVITY WILL REMAIN OUTSIDE THE CWA. HOWEVER...PER THE
LATEST 00Z 4KM WRF-NMM REFLECTIVITY PROG...SOME OF THIS SHOWER
ACTIVITY COULD GET FAIRLY CLOSE TO BRUSHING THE FAR NORTHEAST CWA
IN THE NANCE/POLK COUNTY AREA AND NEXT SHIFTS WILL HAVE TO KEEP AN
EYE ON THIS ESPECIALLY BETWEEN 20Z-00Z. AS HAS ALREADY BEEN PROVEN
IN THE PAST 24 HOURS...SETUPS LIKE THIS CAN GO FROM LOOKING
COMPLETELY DRY 2 DAYS PRIOR...TO ULTIMATELY PRODUCING AT LEAST
NUISANCE SPRINKLES/LIGHT SHOWERS WITH LITTLE ADVANCE NOTICE.
TURNING TO OTHER FACETS OF TODAY/S FORECAST...DEEP MIXING TO NEAR
700MB PER NAM SOUNDINGS WILL PROMOTE ANOTHER BREEZY DAY...WITH
SUSTAINED SPEEDS EASILY 15-20 MPH WITH GUSTS TO AROUND 25 MPH
ESPECIALLY ACROSS THE NORTHEAST 1/2 OF THE CWA. TEMP-WISE...ALTHOUGH
COULD EASILY SEE A FAIR AMOUNT OF HIGH-BASED CUMULUS THIS
AFTERNOON...FORESEE NO WORSE THAN PARTLY CLOUDY SKIES OVERALL. AS
A RESULT...KEPT HIGHS SIMILAR TO PREVIOUS FORECAST...WITH MOST
AREAS IN THE UPPER 60S-LOW 70S. PER A NAM-BASED MIXING TOOL...DID
LOWER DEWPOINTS AT LEAST 5 DEGREES DURING THE DAY MOST AREAS.
ALTHOUGH THIS WOULD DROP SURFACE RH VALUES DOWN TO AROUND 20 PERCENT
OR SO...ANY FIRE WEATHER THREAT SHOULD BE QUITE MINIMAL GIVEN
RECENT RAINFALL AND CONTINUED GREEN-UP.
TONIGHT...SHORTWAVE RIDGING OVERTAKES THE CWA IN THE WAKE OF THE
DEPARTING TROUGH AXIS...WHICH WILL REACH ALONG A LINE FROM
SOUTHERN KS UP THROUGH THE EASTERN GREAT LAKES BY 12Z. ASSUMING
THAT NO SPRINKLES/LIGHT SHOWERS ARE AFFECTING THE NORTHEAST CWA
RIGHT AWAY IN THE EARLY EVENING...HAVE HIGH CONFIDENCE IN A DRY
OVERNIGHT PERIOD AS A ROUGHLY 1022MB SURFACE HIGH SETTLES
DIRECTLY OVER THE CWA. WITH MOSTLY CLEAR SKIES AND LIGHT/VARIABLE
BREEZES...SHOULD SEE A MORE EFFICIENT TEMP DROP TONIGHT...AND
NUDGED DOWN LOWS AT LEAST 2-3 DEGREES FROM PREVIOUS
FORECAST...PUTTING MOST OF THE CWA DOWN INTO THE 38-41 RANGE FOR
LOWS. AS FOR FROST POTENTIAL...ONLY HAVE FAR WESTERN AREAS SUCH AS
DAWSON AND GOSPER COUNTIES REACHING AS LOW AS 36...AND THUS
CONFINED PATCHY FROST MENTION TO ONLY THIS LIMITED AREA FOR
NOW...WITH NO FROST HEADLINE PLANNED.
WEDNESDAY...RIDGING CONTINUES TO DOMINATE THE CWA BOTH AT THE
SURFACE AND ALOFT...WITH HIGH CONFIDENCE IN A DRY DAY WITH AT
LEAST MOSTLY SUNNY SKIES. ALTHOUGH THE SURFACE RIDGE AXIS WILL
INHIBIT EFFICIENT MIXING MOST OF THE DAY...A GRADUAL RETURN TO
SOUTHERLY BREEZES WILL DEVELOP. CHANGED HIGHS LITTLE...WITH MOST
AREAS BETWEEN 71-74.
WEDNESDAY NIGHT...STEADY LIGHT SOUTHERLY BREEZES CONTINUE AS AN
EXPANSIVE MID/UPPER RIDGE RETAINS CONTROL AHEAD OF THE NEXT LARGE
SCALE SHORTWAVE TROUGH MOVING INTO THE PACIFIC NORTHWEST. THE
SOUTHERLY FLOW WILL HELP KEEP LOWS WARMER...AND STAYED CLOSE TO
GUIDANCE AND PREVIOUS FORECAST WITH UPPER 40S-NEAR 50 CWA-WIDE.
THURSDAY...THIS STILL LOOKS TO BE THE HANDS-DOWN WARMEST DAY OF
THE FORECAST PERIOD...AS HIGH PLAINS SURFACE PRESSURE FALLS AHEAD
OF THE INCOMING TROUGH INDUCES INCREASING SOUTHERLY BREEZES WITH
SUSTAINED SPEEDS EASILY 15-20 MPH. DEEPER MIXING...IN CONCERT WITH
WARMER TEMPS EVIDENT AT 850MB AND PLENTY OF SUNSHINE SHOULD REALLY
GIVE TEMPS A BOOST...AND RAISED HIGHS AT LEAST 2-3 DEGREES FROM
PREVIOUS FORECAST...NOW RANGING FROM LOW 80S EAST TO MID 80S WEST.
NUMERICAL MET/MAV GUIDANCE JUST LOOKS TO BE SEVERAL DEGREES TOO
COOL AT THIS TIME.
THURSDAY NIGHT...MAIN CHANGE WAS TO PULL THE TOKEN 20 PERCENT
CHANCE OF SHOWERS/STORMS THAT HAD BEEN ADVERTISED IN FAR NORTHWEST
COUNTIES THE PAST FEW FORECAST CYCLES. ALTHOUGH BOTH THE NAM/ECMWF
ARE IN GOOD AGREEMENT THAT A WELL-DEFINED COLD FRONT WILL ENTER
NORTHWEST PORTIONS OF THE CWA BETWEEN 06Z-12Z...WHAT MEAGER
ELEVATED INSTABILITY THERE IS SHOULD HANG BACK IN WEST CENTRAL/NORTH
CENTRAL NEB THROUGH THE ENTIRE NIGHT AS THE PARENT MID LEVEL
TROUGH AXIS MIGRATES ACROSS THE NORTHERN ROCKIES. WANT TO NOTE
THAT THE NAM/ECMWF ARE BOTH FASTER THAN THE GFS IN BRINGING THE
COLD FRONT AND INCREASING NORTHWEST WINDS INTO THE CWA...SO THERE
ARE STILL SOME TIMING ISSUE TO WORK OUT HERE.
LONG TERM...FRIDAY THROUGH MONDAY. DURING THIS FORECAST PERIOD WE
START ANOTHER COOL DOWN WITH A COLD FRONTAL PASSAGE EARLY FRIDAY.
MOISTURE IS MEAGER ALONG THE BOUNDARY...BUT WE WILL NOTICE COOLING
TEMPERATURES BACK TO SEASONAL NUMBERS DURING THE DAY FRIDAY.
GLANCING BLOW OF UPPER LEVEL ENERGY AND TAIL END OF 250MB JET STREAK
COULD BE ENOUGH TO SPARK SOME SHOWERS...MAYBE A THUNDERSTORM OR TWO
BEHIND THE FRONT. ALL MODEL FORECAST HAVE THIS TREND. PRETTY STRONG
SURFACE HIGH PRESSURE SPREADS INTO THE REGION LATE FRIDAY AND
SATURDAY. EXPERIENCE WITH PRECIPITATION TRENDS AND BUILDING FRONT
RANGE SURFACE HIGH PRESSURES IN MODEL WORLD...IS THE MODELS TEND TO
OVERDO THE PRECIPITATION TOO FAR EAST AND WITH TOO MUCH OF IT. A
CONSERVATIVE APPROACH IS BEST AT THIS POINT...AS WE ARE LIABLE TO
SEE MORE CLOUDS THAN ANYTHING...ESPECIALLY THE FURTHER NORTH/EAST
YOU GO ACROSS OUR FORECAST AREA. THEREFORE...ONLY 20 TO 30 PERCENT
CHANCE FOR MEASURABLE PRECIPITATION AREA IN THE FORECAST. MID LEVEL
LAPSE RATES SUGGEST THUNDER RISK IF MARGINAL AT BEST AND ONLY AN
ISOLATED STORM IS EXPECTED. TEMPERATURES WILL DROP BACK INTO THE 60S
FOR A TIME...BUT START TO REBOUND LATE SUNDAY AND MONDAY. HARDLY A
RAINOUT BY ANY MEANS...BUT SOME SHOWERS WILL BE FLOATING AROUND ON
THIS MOTHERS DAY WEEKEND.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE/SHORT TERM...PFANNKUCH
LONG TERM/AVIATION...MORITZ
AREA FORECAST DISCUSSION
NWS HASTINGS NE
602 AM CDT TUE MAY 8 2012
.AVIATION...12Z TAF. VFR CONDITIONS ARE FORECAST FOR THE TAF
PERIOD. SOME LOW/MID CLOUDS WILL WRAP AROUND AN UPPER LOW INTO
THE AREA THIS AFTERNOON...ALONG WITH SOME CONVECTIVE CUMULUS
DEVELOPMENT. WINDS WILL PICK UP BY LATE MORNING AND GUST OVER
20KTS IN THE AFTERNOON. SKIES WILL CLEAR AND WIND DIMINISH
QUICKLY THIS EVENING.
&&
.PREV DISCUSSION... /ISSUED 349 AM CDT TUE MAY 8 2012/
SHORT TERM...THROUGH THURSDAY NIGHT. WITH VERY LIMITED TO NO RISK
OF PRECIPITATION THROUGH THESE 72 HOURS...PRIMARY CHALLENGES BOIL
DOWN TO TEMPS/DEWPOINTS/WINDS...INCLUDING JUST HOW WARM THURSDAY
WILL ULTIMATELY GET.
STARTING OFF EARLY THIS MORNING...07Z OBJECTIVE SURFACE ANALYSIS
PLACES A BROAD HIGH PRESSURE AXIS CENTERED ALONG THE HIGH
PLAINS/FRONT RANGE FROM EASTERN MT THROUGH CENTRAL CO...WHILE A
WEAK LOW IS NOTED OVER FAR NORTHERN MN. WITH THE DOMINANT HIGH OFF
TO THE WEST...NEAR CALM TO LIGHT WESTERLY BREEZES DOMINATE THE
CWA. ALOFT...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA
INDICATE THE CENTRAL PLAINS ALONG THE SOUTHWESTERN FRINGES OF A
POSITIVELY TILTED TROUGH AXIS EXTENDING NORTHEASTWARD TO A CLOSED
500MB CIRCULATION SINKING SOUTHWARD INTO MN. MEANWHILE...ANOTHER
COMPACT CLOSED LOW IS EVIDENT ALONG THE AZ/SOUTHERN CALI
BORDER...WHILE A POSITIVELY TILTED RIDGE AXIS IS CENTERED FROM
CENTRAL CALI TO SOUTHWEST CANADA. ALONG THE SOUTHEASTERN PERIPHERY
OF THE GREAT LAKES REGION TROUGH AXIS...A MODEST 80+KT 300MB JET
STREAK IS CENTERED FROM CENTRAL NEB TO NORTH OF THE GREAT LAKES.
AS IS OH-SO COMMON IN THE ENTRANCE REGION OF SUCH A JET STREAK...A
NARROW BAND OF MID LEVEL FRONTOGENESIS EVIDENT NEAR THE 600MB
LEVEL IS FORCING A SNEAKY GENERALLY EAST-WEST BAND OF SPRINKLES
EXTENDING FROM EAST CENTRAL CO THROUGH AREAS ALONG AND MAINLY
SOUTH OF THE NEB-KS BORDER IN THE LOCAL AREA. WITH CLOUD CEILINGS
GENERALLY IN EXCESS OF 9K FEET...THIS WEAKLY FORCED PRECIPITATION
IS NOT EXPECTED TO MEASURE...BUT AS HINTED BY THE LATEST HRRR
RUNS...IT AT LEAST WARRANTS AN ISOLATED/SLIGHT CHANCE SPRINKLE
MENTION ACROSS PARTS OF THE SOUTHERN CWA DURING THE PRE-DAWN
HOURS. TURNING TO TEMPS...THE FAIRLY EXTENSIVE COVERAGE OF MID-
HIGH LEVEL CLOUDS SO FAR TONIGHT HAS HELD TEMPS WELL INTO THE
UPPER 40S/LOW 50S IN SOUTHERN ZONES...WITH NORTHERN AREAS JUST
NOW STARTING TO REALIZE SOME UPPER 30S/LOW 40S. LEANING ON THE 00Z
NAM 600MB RH FIELDS...THE THICKER BATCH OF MID CLOUDS/SPRINKLES
SHOULD GRADUALLY SINK SOUTHWARD THROUGH THE NEXT SEVERAL
HOURS...LIKELY ALLOWING A MORE PRONOUNCED TEMP DROP TOWARD
SUNRISE. THIS SHOULD ALLOW THE MAJORITY OF THE CWA TO AT LEAST
REALIZE LOW-MID 40S FOR LOWS...WITH SOME MID-UPPER 30S STILL
EXPECTED MAINLY WEST OF A GREELEY-LEXINGTON LINE. ALTHOUGH
CONFIDENCE IS LOW ON ANY AREAS TOUCHING THE 36-DEGREE RANGE LONG
ENOUGH TO FORM FROST...WITH NONETHELESS HANG ONTO SOME PATCHY
FROST WORDING EARLY THIS MORNING ONLY FOR PARTS OF DAWSON AND
NORTHWEST GOSPER COUNTIES...WITH MINIMAL IMPACT ANTICIPATED.
GETTING INTO THE DAYTIME HOURS POST-12Z...WILL CONTINUE TO FOLLOW
THE NAM 600MB RELATIVE HUMIDITY MAXIMUM FAIRLY CLOSELY TO
DELINEATE THE NORTHERN EDGE OF MORNING SPRINKLE POTENTIAL...AND
WILL LINGER THIS MENTION ONLY IN KS ZONES THROUGH 15Z...AND
HOPEFULLY THIS IS LONG ENOUGH AS LATEST HRRR TRIES SUGGESTING SOME
SPRINKLES COULD STICK AROUND EVEN THROUGH 17Z OR SO...BUT THIS
LOOKS A BIT OVERDONE AS LIFT IN THE ENTRANCE REGION OF THE UPPER
JET AND RESULTANT MID LEVEL SATURATION SINKS SOUTH OF THE AREA
WITH TIME. MAY HAVE TO DEBATE ADDING A SLIGHT MEASURABLE POP AS
WELL...BUT FEEL THAT MEASURABLE RAIN WILL BE THE EXCEPTION OUT OF
THIS ACTIVITY UNLESS RADAR TRENDS DICTATE OTHERWISE DURING NEXT
FEW HOURS. HAVE NO MENTION OF RAIN WHATSOEVER ANYWHERE IN THE CWA
BEYOND 15Z...AS THE MAIN GREAT LAKES REGION VORT MAX DROPS SOUTH
INTO NORTHERN IA BY 00Z. ALTHOUGH THE COLD POCKET ALOFT WITH THIS
WAVE WILL SURELY SPARK SCATTERED SHOWERS/MAYBE A FEW WEAK STORMS
THIS AFTERNOON AS CLOSE AS NORTHEAST NEB...WILL ASSUME FOR NOW
THAT THIS ACTIVITY WILL REMAIN OUTSIDE THE CWA. HOWEVER...PER THE
LATEST 00Z 4KM WRF-NMM REFLECTIVITY PROG...SOME OF THIS SHOWER
ACTIVITY COULD GET FAIRLY CLOSE TO BRUSHING THE FAR NORTHEAST CWA
IN THE NANCE/POLK COUNTY AREA AND NEXT SHIFTS WILL HAVE TO KEEP AN
EYE ON THIS ESPECIALLY BETWEEN 20Z-00Z. AS HAS ALREADY BEEN PROVEN
IN THE PAST 24 HOURS...SETUPS LIKE THIS CAN GO FROM LOOKING
COMPLETELY DRY 2 DAYS PRIOR...TO ULTIMATELY PRODUCING AT LEAST
NUISANCE SPRINKLES/LIGHT SHOWERS WITH LITTLE ADVANCE NOTICE.
TURNING TO OTHER FACETS OF TODAY/S FORECAST...DEEP MIXING TO NEAR
700MB PER NAM SOUNDINGS WILL PROMOTE ANOTHER BREEZY DAY...WITH
SUSTAINED SPEEDS EASILY 15-20 MPH WITH GUSTS TO AROUND 25 MPH
ESPECIALLY ACROSS THE NORTHEAST 1/2 OF THE CWA. TEMP-WISE...ALTHOUGH
COULD EASILY SEE A FAIR AMOUNT OF HIGH-BASED CUMULUS THIS
AFTERNOON...FORESEE NO WORSE THAN PARTLY CLOUDY SKIES OVERALL. AS
A RESULT...KEPT HIGHS SIMILAR TO PREVIOUS FORECAST...WITH MOST
AREAS IN THE UPPER 60S-LOW 70S. PER A NAM-BASED MIXING TOOL...DID
LOWER DEWPOINTS AT LEAST 5 DEGREES DURING THE DAY MOST AREAS.
ALTHOUGH THIS WOULD DROP SURFACE RH VALUES DOWN TO AROUND 20 PERCENT
OR SO...ANY FIRE WEATHER THREAT SHOULD BE QUITE MINIMAL GIVEN
RECENT RAINFALL AND CONTINUED GREEN-UP.
TONIGHT...SHORTWAVE RIDGING OVERTAKES THE CWA IN THE WAKE OF THE
DEPARTING TROUGH AXIS...WHICH WILL REACH ALONG A LINE FROM
SOUTHERN KS UP THROUGH THE EASTERN GREAT LAKES BY 12Z. ASSUMING
THAT NO SPRINKLES/LIGHT SHOWERS ARE AFFECTING THE NORTHEAST CWA
RIGHT AWAY IN THE EARLY EVENING...HAVE HIGH CONFIDENCE IN A DRY
OVERNIGHT PERIOD AS A ROUGHLY 1022MB SURFACE HIGH SETTLES
DIRECTLY OVER THE CWA. WITH MOSTLY CLEAR SKIES AND LIGHT/VARIABLE
BREEZES...SHOULD SEE A MORE EFFICIENT TEMP DROP TONIGHT...AND
NUDGED DOWN LOWS AT LEAST 2-3 DEGREES FROM PREVIOUS
FORECAST...PUTTING MOST OF THE CWA DOWN INTO THE 38-41 RANGE FOR
LOWS. AS FOR FROST POTENTIAL...ONLY HAVE FAR WESTERN AREAS SUCH AS
DAWSON AND GOSPER COUNTIES REACHING AS LOW AS 36...AND THUS
CONFINED PATCHY FROST MENTION TO ONLY THIS LIMITED AREA FOR
NOW...WITH NO FROST HEADLINE PLANNED.
WEDNESDAY...RIDGING CONTINUES TO DOMINATE THE CWA BOTH AT THE
SURFACE AND ALOFT...WITH HIGH CONFIDENCE IN A DRY DAY WITH AT
LEAST MOSTLY SUNNY SKIES. ALTHOUGH THE SURFACE RIDGE AXIS WILL
INHIBIT EFFICIENT MIXING MOST OF THE DAY...A GRADUAL RETURN TO
SOUTHERLY BREEZES WILL DEVELOP. CHANGED HIGHS LITTLE...WITH MOST
AREAS BETWEEN 71-74.
WEDNESDAY NIGHT...STEADY LIGHT SOUTHERLY BREEZES CONTINUE AS AN
EXPANSIVE MID/UPPER RIDGE RETAINS CONTROL AHEAD OF THE NEXT LARGE
SCALE SHORTWAVE TROUGH MOVING INTO THE PACIFIC NORTHWEST. THE
SOUTHERLY FLOW WILL HELP KEEP LOWS WARMER...AND STAYED CLOSE TO
GUIDANCE AND PREVIOUS FORECAST WITH UPPER 40S-NEAR 50 CWA-WIDE.
THURSDAY...THIS STILL LOOKS TO BE THE HANDS-DOWN WARMEST DAY OF
THE FORECAST PERIOD...AS HIGH PLAINS SURFACE PRESSURE FALLS AHEAD
OF THE INCOMING TROUGH INDUCES INCREASING SOUTHERLY BREEZES WITH
SUSTAINED SPEEDS EASILY 15-20 MPH. DEEPER MIXING...IN CONCERT WITH
WARMER TEMPS EVIDENT AT 850MB AND PLENTY OF SUNSHINE SHOULD REALLY
GIVE TEMPS A BOOST...AND RAISED HIGHS AT LEAST 2-3 DEGREES FROM
PREVIOUS FORECAST...NOW RANGING FROM LOW 80S EAST TO MID 80S WEST.
NUMERICAL MET/MAV GUIDANCE JUST LOOKS TO BE SEVERAL DEGREES TOO
COOL AT THIS TIME.
THURSDAY NIGHT...MAIN CHANGE WAS TO PULL THE TOKEN 20 PERCENT
CHANCE OF SHOWERS/STORMS THAT HAD BEEN ADVERTISED IN FAR NORTHWEST
COUNTIES THE PAST FEW FORECAST CYCLES. ALTHOUGH BOTH THE NAM/ECMWF
ARE IN GOOD AGREEMENT THAT A WELL-DEFINED COLD FRONT WILL ENTER
NORTHWEST PORTIONS OF THE CWA BETWEEN 06Z-12Z...WHAT MEAGER
ELEVATED INSTABILITY THERE IS SHOULD HANG BACK IN WEST CENTRAL/NORTH
CENTRAL NEB THROUGH THE ENTIRE NIGHT AS THE PARENT MID LEVEL
TROUGH AXIS MIGRATES ACROSS THE NORTHERN ROCKIES. WANT TO NOTE
THAT THE NAM/ECMWF ARE BOTH FASTER THAN THE GFS IN BRINGING THE
COLD FRONT AND INCREASING NORTHWEST WINDS INTO THE CWA...SO THERE
ARE STILL SOME TIMING ISSUE TO WORK OUT HERE.
LONG TERM...FRIDAY THROUGH MONDAY. DURING THIS FORECAST PERIOD WE
START ANOTHER COOL DOWN WITH A COLD FRONTAL PASSAGE EARLY FRIDAY.
MOISTURE IS MEAGER ALONG THE BOUNDARY...BUT WE WILL NOTICE COOLING
TEMPERATURES BACK TO SEASONAL NUMBERS DURING THE DAY FRIDAY.
GLANCING BLOW OF UPPER LEVEL ENERGY AND TAIL END OF 250MB JET STREAK
COULD BE ENOUGH TO SPARK SOME SHOWERS...MAYBE A THUNDERSTORM OR TWO
BEHIND THE FRONT. ALL MODEL FORECAST HAVE THIS TREND. PRETTY STRONG
SURFACE HIGH PRESSURE SPREADS INTO THE REGION LATE FRIDAY AND
SATURDAY. EXPERIENCE WITH PRECIPITATION TRENDS AND BUILDING FRONT
RANGE SURFACE HIGH PRESSURES IN MODEL WORLD...IS THE MODELS TEND TO
OVERDO THE PRECIPITATION TOO FAR EAST AND WITH TOO MUCH OF IT. A
CONSERVATIVE APPROACH IS BEST AT THIS POINT...AS WE ARE LIABLE TO
SEE MORE CLOUDS THAN ANYTHING...ESPECIALLY THE FURTHER NORTH/EAST
YOU GO ACROSS OUR FORECAST AREA. THEREFORE...ONLY 20 TO 30 PERCENT
CHANCE FOR MEASURABLE PRECIPITATION AREA IN THE FORECAST. MID LEVEL
LAPSE RATES SUGGEST THUNDER RISK IF MARGINAL AT BEST AND ONLY AN
ISOLATED STORM IS EXPECTED. TEMPERATURES WILL DROP BACK INTO THE 60S
FOR A TIME...BUT START TO REBOUND LATE SUNDAY AND MONDAY. HARDLY A
RAINOUT BY ANY MEANS...BUT SOME SHOWERS WILL BE FLOATING AROUND ON
THIS MOTHERS DAY WEEKEND.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PORTLAND OR
845 AM PDT TUE MAY 8 2012
.SYNOPSIS...AN UPPER LEVEL RIDGE THAT HAS BEEN OVER THE PACIFIC
NORTHWEST THE LAST COUPLE OF DAYS WILL CONTINUE TO MOVE EAST TODAY AS
AN UPPER LEVEL LOW NEAR THE GULF OF ALASKA APPROACHES WESTERN BRITISH
COLUMBIA. ONSHORE FLOW WILL INCREASE TODAY...WITH A WEAKENING COLD
FRONT MOVING ONSHORE THIS AFTERNOON AND THROUGH THE FORECAST AREA
THIS EVENING. A TRAILING UPPER TROUGH WILL MOVE THROUGH THE PACIFIC
NORTHWEST WEDNESDAY AND EARLY WEDNESDAY NIGHT FOR CONTINUED STRONG
ONSHORE FLOW...CLOUDS...AND MUCH COOLER TEMPERATURES...AND A CHANCE
OF SOME SPOTTY LIGHT PRECIPITATION. AN UPPER RIDGE WILL BEGIN
BUILDING AND MOVING INTO THE PACIFIC NORTHWEST THURSDAY AND CONTINUE
TO STRENGTHEN THROUGH THE WEEKEND. THIS WILL BRING DRY WEATHER AND
ABOVE NORMAL TEMPERATURES THAT MAY LAST WELL INTO NEXT WEEK.
&&
.SHORT TERM...SATELLITE SHOWING WEAKENING FRONT FROM THE NORTH WA
COAST...SW TO ABOUT 80 MILES OFF THE CENTRAL OREGON COAST. THE FRONT
HAS BEEN WEAKENING THIS FEATURE OVER THE LAST SEVERAL HOURS BASED ON
SURFACE ANALYSIS. THE FRONT PUSHES ASHORE THIS AFTERNOON. PRECIPITATION
LOOKS TO BE SPOTTY AND LIGHT WITH THIS FRONT...ESPECIALLY NEAR THE
COAST AND OVER THE HIGHER TERRAIN IN THE NORTHERN ZONES. THE BAND
WILL MOVE THROUGH THE NORTHERN WILLAMETTE VALLEY AND CLARK COUNTY
DURING THE EVENING COMMUTE WITH MAINLY CLOUDS...THOUGH A FEW
SPRINKLES OR A LITTLE DRIZZLE IS NOT OUT OF THE QUESTION. EXPECT
CLOUDS BUT LITTLE OR NO PRECIPITATION FARTHER SOUTH IN THE
WILLAMETTE VALLEY THIS EVENING. THE BAND WILL PUSH EAST OF THE
CASCADES BY MIDNIGHT.
THE ONSHORE FLOW ASSOCIATED WITH THE FRONT WILL LIKELY GIVE SOME
BREEZY WEST WINDS MUCH OF OUR FORECAST AREA LATER TODAY AND THIS
EVENING...ESPECIALLY THROUGH THE COAST RANGE AND THE GORGE AND OVER
THE CASCADES...BUT SOME IN THE INTERIOR VALLEYS AS WELL.
DESPITE THE RATHER STRONG ONSHORE FLOW CONTINUING OVERNIGHT TONIGHT
AND ON WEDNESDAY...THE LOW LEVEL CLOUDS MAY BREAK UP SOME AT TIMES
ESPECIALLY AFTER THE FRONTAL BAND THIS EVENING AND ON WEDNESDAY. A
TRAILING UPPER TROUGH WILL PUSH THROUGH WEDNESDAY AFTERNOON AND
EVENING AND COULD PRODUCE A FEW SHOWERS ACROSS OUR NORTHERN ZONES AS
IT MOVES THROUGH...ESPECIALLY NEAR THE COAST AND OVER THE HIGHER
TERRAIN. EXPECTED BREEZY WEST WINDS TO CONTINUE. LOOK FOR TEMPS
WEDNESDAY TO FALL BELOW NORMAL...CLOSE TO 60 DEGREES INLAND.
THE UPPER TROUGH WILL MOVE EAST OF THE AREA BY THURSDAY MORNING WITH
PRECIPITATION GENERALLY ENDING. THERE WILL LIKELY BE AREAS OF LOW
CLOUDS AND PATCHY FOG THURSDAY MORNING...THEN CLEARING IN THE
AFTERNOON AS AN UPPER RIDGE BEGINS TO SPREAD ONSHORE. TEMPS WILL
BEGIN TO RECOVER BUT STILL BE A BIT BELOW NORMAL...IN THE LOWER TO
MID 60S. TOLLESON/MH
.LONG TERM...THE UPPER RIDGE FROM THURSDAY IS FORECAST TO AMPLIFY
OVER THE PACIFIC NORTHWEST THROUGH THIS WEEKEND INTO EARLY NEXT
WEEK...GIVING SOUTHWEST WASHINGTON AND NORTHWEST OREGON ITS MOST
PROLONGED WARM AND DRY WEATHER OF THE SPRING SO FAR. WE COULD SEE
SOME 80S THIS WEEKEND INTO NEXT WEEK IN THE INLAND AREAS. THE NEXT
CHANCE OF ANY PRECIPITATION IS LOOKING TO BE THE MIDDLE OR LATTER
PART OF NEXT WEEK. TOLLESON
&&
.AVIATION...MINIMAL CHANGES. PREVIOUS DISCUSSION FOLLOWS...IFR/LOW
MVFR CEILINGS ARE EXPANDING ALONG THE COAST AS A WEAKENING COLD
FRONT APPROACHES THE REGION. ONCE MORE EXPANSIVE IFR/MVFR CIGS DO
DEVELOP ALONG THE COAST TONIGHT...EXPECT THEM TO LAST INTO TUESDAY
MORNING BEFORE LIFTING AND DISSIPATING TUESDAY EARLY TO MID
AFTERNOON ALONG THE NORTH COAST...AND LATE AFTERNOON TO EARLY
EVENING ALONG THE CENTRAL COAST AS THE FRONT WILL TAKE LONGER TO
MOVE INLAND FARTHER SOUTH.
THE LOW STRATUS IS HAVING A HARD TIME GETTING THROUGH THE COASTAL
GAPS THIS MORNING. LATEST NAM IS STILL TRYING TO BRING LOW CLOUDS
INTO THE SOUTH AND CENTRAL VALLEY AND ALONG THE COLUMBIA RIVER TO
KELSO...WHEREAS THE LATEST HI RESOLUTION MODELS...NAMELY THE WRF/ARW
AND HRRR ARE KEEPING THINGS OUT...AS ARE ALL MOS GUIDANCE
BULLETINS. WE WILL MONITOR SATELLITE TRENDS DURING THE EARLY
MORNING TO SEE IF ANY LOW CLOUDS CAN MAKE IT THROUGH...THOUGH AT
THIS TIME WE STILL EXPECT INLAND TERMINALS SHOULD REMAIN VFR
THROUGH THE PERIOD...THOUGH THERE COULD BE A BRIEF PERIOD OF VERY
LIGHT RAIN/DRIZZLE DURING THE 0Z-6Z TIME FRAME WITH A WEAK FRONT
MOVING THROUGH. KMD
KPDX AND APPROACHES...VFR CONDITIONS GENERALLY EXPECTED. EXPECT
BREEZY NW WINDS IN THE 10-15 KT RANGE DURING THE AFTERNOON AND
EARLY EVENING. WE STILL EXPECT THAT BROKEN LOW CLOUDS WILL REMAIN
AWAY FROM THE TERMINAL THIS MORNING...THOUGH THERE IS A CHANCE
THAT THEY MAY MAKE TO KELSO AND A SMALL CHANCE OF GETTING FURTHER
DOWN THE COLUMBIA. KMD
&&
.MARINE...MINIMAL CHANGES. PREVIOUS DISCUSSION FOLLOWS...A
WEAKENING COLD FRONT WILL BRUSH THE COASTAL WATERS LATE TONIGHT
INTO TUESDAY MORNING...FOLLOWED BY ENHANCED NORTHWEST FLOW...AS
HIGH PRESSURE BUILDS IN BEHIND THE FRONT TUESDAY. SMALL CRAFT
ADVISORY WINDS IN EXCESS OF 21 KT APPEAR LIKELY BY TUE AFTERNOON.
AFTER A BREAK TONIGHT...EXPECT SEVERAL PERIODS OF WIND GUSTS
GREATER IN THE 20-25 KT RANGE IN THE AFTERNOON AND EVENING
PERIODS...ESPECIALLY FOR THE CENTRAL OREGON WATERS...BUT THE NORTH
OREGON WATERS MAY GET IN ON THE ACTION AS WELL. WEST SWELL
ASSOCIATED WITH THE PARENT LOW SHOULD ARRIVE EARLY WED...WILL
SNEAK INTO THE LOW TEENS...THEN QUICKLY DROP BACK BELOW 10 FT THU
AFTERNOON.
DESPITE MINIMAL SWELL TODAY AND TUESDAY...THE STRONGEST EBBS OF
THE YEAR ARE STILL CAUSING ROUGH CONDITIONS FOR THE COLUMBIA RIVER
BAR...THUS A SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR
REMAINS FOR THE VERY STRONG EBB EXPECTED THIS MORNING. KMD
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS FROM NOON TODAY TO MIDNIGHT PDT
TONIGHT FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
CASCADE HEAD OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR WINDS FROM NOON TODAY TO 5 AM PDT
WEDNESDAY FOR COASTAL WATERS FROM CASCADE HEAD OR TO
FLORENCE OR OUT 60 NM.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
214 PM EDT TUE MAY 8 2012
.PREV DISCUSSION...
UPDATE...
/ISSUED 1114 AM EDT TUE MAY 8 2012/
ALTHOUGH SHOWERS NEAR COLUMBUS HAVE DISSIPATED FOR THE MOST
PART...STARTING TO SEE DEVELOPMENT OVER EAST CENTRAL GEORGIA.
ALTHOUGH SO ISOLATED SHOWERS WILL BE POSSIBLE THROUGH EARLY
AFTERNOON...THE BEST CHANCE OF THUNDERSTORMS WILL BE AFTER 2PM.
THIS IS ALSO INLINE WITH THE HRRR /ALTHOUGH THE RUN IS A LITTLE
OUTDATED/ THAT SUGGESTS INCREASED ACTIVITY AFTER 2PM. CLOUD
COVERAGE THIS MORNING IS LIMITING THE HEATING...ONLY A FEW BREAKS
IN THE CLOUDS...SO WILL TAKE A WHILE TO REACH HIGHER INSTABILITY
VALUES...THUS THINK BEST CHANCE OF SEVERE WILL BE LATE AFTERNOON
INTO THE EVENING WHICH ALSO BETTER CORRESPONDS WITH THE FRONT
MOVING INTO GA.
FORECAST DEW POINTS WERE A LITTLE ON THE LOW SIDE SO MINOR
ADJUSTMENTS TO THOSE GRIDS.
11
SHORT TERM /TODAY THROUGH WEDNESDAY/...
/ISSUED 359 AM EDT TUE MAY 8 2012/
CURRENTLY HAVE SCATTERED SHOWERS DEVELOPING OVER NORTH GEORGIA
ASSOCIATED WITH A WEAK SHORT WAVE SWEEPING PAST THE REGION.
COVERAGE SHOULD REMAIN SCATTERED THROUGH THE MORNING HOURS. UPPER
LEVEL FLOW TRANSITIONING TO SOUTHWESTERLY TODAY AHEAD OF A TROUGH
DIGGING INTO THE EASTERN U.S. GFS...NAM AND ECMWF ALL SHOW A COLD
FRONT ENTERING NORTHWEST GEORGIA BY THIS AFTERNOON WHICH SHOULD
HELP TO ENHANCE THUNDERSTORM ACTIVITY. CURRENT PACE AND TIMING OF
THE FRONT PUSHES BEST PRECIPITATION CHANCES INTO CENTRAL GEORGIA
FOR WEDNESDAY.
MODELS SHOW MUCAPE AROUND 1500 J/KG ACROSS THE MAJORITY OF THE
FORECAST AREA BY THIS AFTERNOON...SLIGHTLY HIGHER THAN YESTERDAY.
WITH EXTENSIVE CLOUD COVER THROUGH THE MAJORITY OF THE DAY WE WILL
HAVE A SLOW TIME REACHING THESE VALUES. THIS SHOULD KEEP THE CHANCES
FOR SEVERE THUNDERSTORMS AT A MINIMUM FOR TODAY...ALTHOUGH A FEW
ISOLATED SEVERE STORMS ARE NOT IMPOSSIBLE BY LATE AFTERNOON...
ESPECIALLY IF WE CAN GET SOME SUNSHINE ACROSS THE AREA. SIMILAR
NUMBERS ARE INDICATED AHEAD OF THE FRONT WEDNESDAY ACROSS CENTRAL
GEORGIA...HOWEVER THE AREA WILL BE UNDER THE INFLUENCE OF THE TAIL
END OF A SLIGHTLY STRONGER UPPER LEVEL WAVE WHICH MAY HELP TO
INCREASE THE CHANCES FOR ISOLATED SEVERE STORMS.
20
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
/ISSUED 359 AM EDT TUE MAY 8 2012/
MODELS SIMILAR WITH THE FRONTAL BOUNDARY PUSHING INTO SOUTH
GEORGIA WEDNESDAY EVENING...THEN OFF THE GEORGIA COAST BY EARLY
THURSDAY. HIGH PRESSURE BUILDS INTO THE SOUTHEAST U.S. BEHIND THE
FRONT AND REMAIN DOMINANT OVER NORTH AND CENTRAL GEORGIA INTO THE
WEEKEND. EXTENDED PROGS CONTINUE TO SHOW SOME DEEPER MOISTURE
SPREADING BACK INTO OUR AREA SUNDAY INTO MONDAY AS A WEAK BOUNDARY
DRIFTS SOUTHWARD FROM THE OHIO/TENNESSEE VALLEY...AND A LOW
PRESSURE SYSTEM LIFTS NORTHEAST FROM THE GULF. WILL KEEP POPS IN
THE SLIGHT CHANCE RANGE ON SUNDAY AND MONDAY FOR NOW UNTIL WE CAN
GET A BETTER HANDLE ON THESE FEATURES. OVERALL...NEAR NORMAL
TEMPERATURES EXPECTED DURING THE PERIOD.
49
&&
.AVIATION...
18Z UPDATE...
SHOWERS HAVE ALREADY STARTED TO DEVELOP ACROSS THE AREA BUT THINK
BEST CHANCE OF CONVECTION AT THE TAF SITES WILL STILL BE LATER
THIS AFTERNOON /20-24Z/ THOUGH CHANCE OF THUNDER EXISTS THROUGH
02Z. ALTHOUGH PRECIP CHANCES WILL DECREASE OVERNIGHT...EXPECT AREA
OF SHRA TO SET UP OVER THE ATL AREA DURING THE LATE MORNING BUT
DECREASE FOR THE AFTERNOON AS THE FRONT MOVES INTO SOUTH GEORGIA.
CHANCE OF TSRA IN THE MORNING IS LOW. WINDS WILL BECOME MORE NW
AS THE FRONT MOVES THROUGH AND SHOULD STAY ON THE WEST SIDE
THROUGH THE TAF PERIOD. GUSTS WITH TSRA TODAY BUT BETTER CHANCE OF
STRONG PREDOMINATE WINDS ON WEDNESDAY.
//ATL CONFIDENCE...18Z UPDATE...
HIGH CONFIDENCE ON WINDS AND VSBYS. MEDIUM CONFIDENCE ON CIGS AND
MORNING VSBYS. HIGH CONFIDENCE ON OCCURRENCE OF TSRA AT THE
AIRPORT...BUT ONLY MEDIUM CONFIDENCE ON THE TIMING.
11
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 80 61 82 54 / 60 50 60 20
ATLANTA 81 64 80 56 / 60 50 60 10
BLAIRSVILLE 77 59 76 49 / 60 50 40 5
CARTERSVILLE 81 62 78 49 / 60 50 50 10
COLUMBUS 83 67 82 58 / 60 50 60 20
GAINESVILLE 79 61 79 54 / 60 50 50 10
MACON 83 65 84 56 / 60 50 60 30
ROME 81 60 77 50 / 60 50 40 5
PEACHTREE CITY 81 63 80 51 / 60 50 60 20
VIDALIA 84 67 86 62 / 60 50 70 60
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
314 PM EDT TUE MAY 8 2012
.SHORT TERM...
TONIGHT...WEDNESDAY...WEDNESDAY NIGHT...
WATER VAPOR IMAGERY AND LATEST RUC ANALYSIS CLEARLY DEPICTING THE
MAIN FEATURE OF CONCERN IN THE SHORT TERM...DEEP UPPER TROUGH OVER
MN THAT WILL BE DROPPING DOWN ACROSS THE GREAT LAKES REGION TONIGHT
AND WEDNESDAY. AHEAD OF THIS FEATURE WILL BE AN INCREASING SFC
GRADIENT ALONG WITH DRIER AIR IN THE BOUNDARY LAYER AND LOW LEVELS
WHICH SHOULD PRECLUDE ANY SIGNIFICANT FOG REDEVELOPMENT. 12Z RAOBS
SHOWING -25C COLD POOL TO ACCOMPANY TROUGH AND RESULT IN VERY STEEP
MID LEVEL LAPSE RATES BY THE LATE MORNING HOURS. EXPECT THE
DIURNALLY DRIVEN SHRA AND EVEN A FEW TSRA CURRENTLY SEEN OVER MN AND
WI WILL SPREAD OVER THE GREAT LAKES REGION AFTER MIDNIGHT TONIGHT
AND WEDNESDAY. WILL USE THE TRACK OF UPPER TROUGH AND COLD POOL IN
TIMING OF PRECIP CHANCES...BEGINNING IN THE NW CWA AFTER MIDNIGHT
TONIGHT AND CONTINUING IN THE EASTERN HALF THROUGH WEDNESDAY AFTN.
MAGNITUDE OF COLD POOL WILL ALSO FAVOR CONVECTIVE POTENTIAL BY THE
AFTERNOON HOURS...BUFKIT SOUNDINGS SHOWING TT GT 50...SO WILL ALSO
INCLUDE A MENTION OF THUNDER HERE. RESULTING TEMPS WILL BE
CONSIDERABLY COOLER IN THIS PATTERN...5-10F BELOW NORMAL BOTH
WEDNESDAY AND WEDNESDAY NIGHT.&&
.LONG TERM...
MEAN TROUGHING WILL REDVLP ACRS THE NE CONUS INTO THIS WEEKEND AS
WRN RIDGING AMPLIFIES. THUS W/PATTN REORIENTING TWD YET ANOTHER
PNA...XPC DRY WX TO CONT AS W/NW FLW ALOFT CONTS AND LL RIDGING
PERSISTS ACRS THE GOMEX W/LTL IN WAY OF SIG LL MSTR RTN UNTIL PSBLY
AT THE END OF THE PD ON DY8. TEMPS THROUGH THE PD GENERALLY NR
NORMAL.
&&
.AVIATION.../18Z TAFS/
LATEST VIS SAT SHOWING CU FIELD QUICKLY FILLING BACK IN OVER THE
KFWA AREA AND EXPECTED TO PERSIST REMAINDER OF THE AFTERNOON.
HOWEVER...KSBN IN LAKE SHADOW AREA ATTM WITH HIGHER BASED SCT CU
DECK MOVING ACROSS NE IL AND SOUTHERN LK MI...WILL HOLD&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...LOGSDON
LONG TERM...T
AVIATION...LOGSDON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
431 PM EDT TUE MAY 8 2012
.SYNOPSIS...
ISSUED AT 429 PM EDT TUE MAY 8 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH AXIS
FROM JAMES BAY THROUGH WRN LAKE SUPERIOR TO ERN MN. AT THE SFC...A
TROUGH EXTENDED FROM SE LAKE SUPERIOR THROUGH CNTRL UPPER MI INTO
WRN WI. THE COMBINATION OF DIURNAL HEATING...STEEP MID LEVEL LAPSE
RATES AND WEAK TO MODERATE QVECTOR CONV ASSOCIATED WITH THE MID
LEVEL TROUGH HAS SUPPORTED SCT/NMRS SHRA OVER MOST OF INLAND UPPER
MI. IN ADDITION...SOME ISOLD TSRA WITH SMALL HAIL HAVE ALSO
DEVELOPED. THE GREATEST SHRA COVERAGE AND HEAVIEST RAIN WAS OVER THE SE
CWA WHERE LOW LEVEL CONV WITH THE TROUGH AND LAKE BREEZE WAS MOST
PROMINENT.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 429 PM EDT TUE MAY 8 2012
AS THE MID LEVEL AND SFC TROUGH SHIFTS TO THE SOUTHEAST AND DIURNAL
HEATING SUBSIDES...EXPECT THE AREA OF SHOWERS TO DIMINISH AND SAG TO
THE SOUTH. SHOWERS MAY STILL BE NMRS/WIDESPREAD LATE THIS AFTERNOON
20Z-24Z BUT BY 00Z-03Z...THE REMAINING PCPN SHOULD BECOME SCT/ISOLD
AND END BY AROUND MIDNIGHT. HOWEVER...WITH ABUNDANT LOW LEVEL
MOISTURE REMAINING INCREASING CYCLONIC NE TO N FLOW (9505-850 MB N
WINDS OF 20-30 KT) INTO N CNTRL UPPER MI...HIGHER RES MODELS SUGGEST
LIGHT PCPN WILL DEVELOP IN LINE WITH PREVIOUS FCST.
MODELS SUGGEST THAT THE SHARP BACK EDGE OF THE LOW LEVEL
MOISTURE...PER VIS IMAGERY...WILL MOVE N-S THROUGH THE AREA BTWN
09Z-15Z. SO...ANY PCPN SHOULD END BY EARLY WED WITH PARTLY TO MOSTLY
SUNNY SKIES BY MIDDAY. SUNSHINE/MIXING SHOULD ALLOW INLAND TEMPS TO
CLIMB TO NEAR 60 BUT ONSHORE FLOW NORTH WILL KEEP READINGS IN THE
UPPER 40S TO LOWER 50S NEAR LAKE SUPERIOR.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 429 PM EDT TUE MAY 8 2012
A RIDGE OF HIGH PRESSURE...CENTERED FROM WY TO N MANITOBA WILL BE
PUSHING ACROSS THE UPPER GREAT LAKES WEDNESDAY NIGHT THROUGH FRIDAY
MORNING. WE CONTINUE TO LOOK INTO WEDNESDAY NIGHT/THURSDAY MORNING
AS BEING THE COLDEST TIME PERIOD...WITH LIGHT WINDS AND RELATIVELY
LOW PW VALUES. INCLUDED THE MENTION OF FREEZING TEMPS FOR THE
INTERIOR WEST IN THE HWO.
THE MAIN FEATURE OF INTEREST PRECIPITATION WISE WILL BE THE STACKED
LOW OVER N CENTRAL CANADA FOR THE LATTER HALF OF THE WORK WEEK. THE
LOW ITSELF WILL SLOWLY SHIFT ACROSS HUDSON BAY BY SATURDAY
NIGHT...WHERE IT WILL LIKELY LINGER THROUGH THE REMAINDER OF THE
PERIOD. WAVES ROTATING AROUND THE LOW SHOULD BRING THE INITIAL SFC
TROUGH/COLD FRONT TO FAR W LAKE SUPERIOR AT 18Z FRIDAY...CENTRAL
UPPER MI BY 00Z SATURDAY...AND EAST OF ALL UPPER MI BY 12Z SATURDAY.
TIMING DIFFERS BY 3-5HRS BETWEEN THE VARIOUS MODELS...WITH THE
08/00Z CANADIAN ON THE SLOW END...AND THE 08/00Z ECMWF AND 08/12Z
BEING ON THE QUICKER SOLUTIONS. THE 08/06Z GFS RUNS THE MIDDLE
GROUND BETWEEN THESE VARYING SOLUTIONS. ADDED THE MENTION OF
ISOLATED TS OVER THE WITH SB/MU CAPE VALUES OF 300 TO 600J/KG.
GIVEN THE STRENGTHENING SOUTHERLY WINDS AHEAD OF THE COLD FRONT
FRIDAY AFTERNOON WITH THE PEAK OF DAYTIME HEATING...FIRE WX CONCERNS
MAY INCREASE...PARTICULARLY OVER THE E HALF WHERE MORE LIMITED
HUMIDITY VALUES WILL LIKELY EXIST. WILL ALSO CONTINUE TO HIGHLIGHT
DOWNSLOPE AREAS FOR SOME OF THE WARMER TEMPS ACROSS THE CWA. SOME
GUIDANCE IS HINTING AT THE POTENTIAL OF 80 DEGREES OVER THE BARAGA
PLAINS FRIDAY.
EXPECT SHOWERS TO COME TO AN END SATURDAY MORNING...WITH DRY WEATHER
THEN TAKING HOLD THROUGH TUESDAY. GIVEN W TO NW FLOW ALOFT...THERE
COULD BE A SMALLER CHANCE OF SHOWERS...BUT WILL NOT INCLUDE AT THIS
TIME GIVEN THE LOW PROBABILITY...WITH HIGH PRESSURE SLIDING IN FROM
THE N/CENTRAL PLAINS. MODELS ARE NOT DOING THE BEST AT COMING
TOGETHER ON A SOLUTION FOR MONDAY...WITH THE POTENTIAL OF ANOTHER
COLD FRONT MOVING NW TO SE OVER THE CWA /LIKE THE 08/12Z ECMWF/.
THIS MAY BE ONE AREA OF THE FCST THAT CHANGES MORE THAN ANY OTHER
OVER THE NEXT SEVERAL DAYS. OTHERWISE...HIGHS IN THE 60S INLAND FROM
THE GREAT LAKES LOOK TO BE THE RULE FROM SUNDAY THROUGH NEXT TUESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 144 PM EDT TUE MAY 8 2012
AN UPPER LEVEL DISTURBANCE AND SFC TROUGH WILL RESULT IN SCT SHRA
OVER INLAND PORTIOS OF UPPER MI WITH THE BEST CHANCES WILL BE SOUTH
OF ALL OF THE TAF SITES. MVFR CIGS ARE POSSIBLE BY LATE AFTERNOON AT
KSAW AS INCREASING NORTH WINDS FAVOR UPSLOPE LOW CLOUDS.
SECONDARY SURGE OF MOISTURE ARRIVES THIS EVENING FOR ALL SITES AND
SHOULD LEAD TO ANOTHER PERIOD OF IFR OR LOWER CIGS. BEST CHANCE FOR
LOWER VSBYS WILL BE AT KSAW...WHERE UPSLOPE FLOW COULD LEAD TO
-DZ/FOG. THINK WINDS WILL BE STRONG ENOUGH FOR HIGHER VSBYS...BUT
IF CLOUDS ARE LOW ENOUGH COULD STILL SEE VSBYS FALLING TOWARDS ALT
LANDING MINS LIKE THE CIGS. DRIER AIR MOVING IN FROM THE NORTH WILL
LEAD TO QUICKLY IMPROVING CONDITIONS TO VFR BY MID WED MORNING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 429 PM EDT TUE MAY 8 2012
ABUNDANT LOW-LEVEL MOISTURE AND LIGHT CONVERGENT WIND FLOW HAS LEAD
TO AREAS OF FOG (DENSE AT TIMES) ACROSS LAKE SUPERIOR. THUS DENSE
FOG ADVY CONTINUES FOR MUCH OF THE LAKE. FOG WILL LIFT TONIGHT AS
DRIER AIR ARRIVES FROM THE N.
LACK OF SIGNIFICANT WEATHER FEATURES WILL RESULT IN WINDS MOSTLY
UNDER 20KT ACROSS LAKE SUPERIOR THRU THE END OF THE WEEK. THE
STRONGER WINDS THIS WEEK WILL OCCUR THIS EVENING INTO WED OVER
ERN LAKE SUPERIOR AS A LOW PRES TROF EXITS THE AREA...AND ALSO FRI
AS ANOTHER LOW PRES TROF MOVES ACROSS THE UPPER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LSZ249>251-
266-267.
DENSE FOG ADVISORY UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING FOR
LSZ162-248-263-265.
DENSE FOG ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR LSZ242>247-
264.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...KF
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS DULUTH MN
342 PM CDT TUE MAY 8 2012
SFC/MID LVL LOW COLLAPSING SOUTHWARD THIS AFTERNOON AS PROGRESSIVE
FLOW ALOFT CONTINUES. ELONGATED SFC TROUGH/CONVERGENCE ZONE HAS BEEN
A RESERVOIR OF LOW LVL INSTABILITY TODAY AS DEPICTED BY RUC13 THETAE
FIELDS IN LOWEST 3/4K FT. UPPER COLD POOL HAS PROVIDED OPPORTUNITY
FOR STEEP LAPSE RATES AND AREAS OF CONVECTION HAVE DEVELOPED. MOST
PERSISTENT PRECIP HAS BEEN LOCATED ALONG/NORTH OF DEEP SHEAR AXIS
ACROSS IRON RANGE...SLOWLY MOVING SOUTH. A FEW REPORTS OF SMALL HAIL
WERE RECEIVED ACROSS WISCONSIN ZONES EARLY THIS AFTERNOON.
TONIGHT...OTHER THAN EARLY EVENING CONVECTION POTENTIAL...CONDITIONS
SHOULD TREND TOWARDS LESS PRECIP AND DECREASING CLOUD COVER FROM
NORTH TO SOUTH. CONFIDENCE NOT HIGH ON BR/FG DEVELOPMENT SO HAVE
LEFT OUT OF GRIDS/ZFP FOR NOW. LOWEST TEMPS SHOULD OCCUR IN
ARROWHEAD WHERE CLEARING OCCURS FIRST.
TOMORROW/TOMORROW NIGHT...SFC/MID LVL RIDGING WILL DOMINATE
WEDNESDAY. EXPECT DECENT WARMING WITH MAX TEMPS NEAR/ABOVE CLIMO.
EXPECT AN AREA OF INCREASING HIGH CLOUDS TO PUSH ACROSS RIDGE AXIS INTO CWA
DURING THE AFTN/EVENING HOURS. TIMING IS A BIT OF A CHALLENGE AS
MDLS DIFFER ON EXTENT/SPEED OF HIGH LVL COND PRESS DEFICITS.
LONG TERM...THURSDAY THROUGH TUESDAY.
MAIN FORECAST CONCERN FOR THE EXTENDED FORECAST PERIOD IS A STRONG
COLD FRONT THAT IS PROGGED TO TRACK ACROSS THE UPPER MIDWEST
FRIDAY/FRIDAY NIGHT. AHEAD OF THE FRONT...A WARM-UP IS EXPECTED FOR
THURSDAY WITH HIGHS IN THE 70S. THE FRONT WILL TAP THIS WARMTH ALONG
WITH INCREASING MOISTURE TO PRODUCE A CHANCE OF SHOWERS AND STORMS
ACROSS THE NORTHLAND FRIDAY AND FRIDAY NIGHT. THE PRECIPITATION WILL
END BY SATURDAY...WITH MAINLY DRY CONDITIONS EXPECTED THROUGH EARLY
NEXT WEEK.
.AVIATION.../18Z TAF ISSUANCE/
STRATOCU WITH MVFR CIGS AND SCTD SHOWERS/ISOLD STORMS ASSOCTD
WITH AN UPPER LEVEL TROUGH MOVING ACROSS THE UPPER MIDWEST WILL
CONTINUE TO AFFECT MOST OF THE NORTHLAND THROUGH THE EARLY EVENING
HOURS. THE SHOWERS SHOULD QUICKLY END AROUND OR AFTER SUNSET AND
THE CLOUD COVER SHOULD SCTR OUT FOR MOST AREAS AFTER MIDNIGHT.
WITH LINGERING MOISTURE AND SOME NIGHTTIME COOLING...AREAS OF FOG
MAY DEVELOP TONIGHT.
.POINT TEMPS/POPS...
DLH 38 62 42 69 / 20 0 0 0
INL 34 65 41 73 / 10 0 10 0
BRD 40 65 43 75 / 10 0 10 0
HYR 36 64 38 72 / 30 0 0 0
ASX 36 63 39 71 / 20 0 0 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...CANNON
LONG TERM....BERDES
AREA FORECAST DISCUSSION
NWS HASTINGS NE
125 PM CDT TUE MAY 8 2012
.UPDATE...MORNING UPPER AIR ANALYSIS AND WATER VAPOR
IMAGERY INDICATES A MID LEVEL SHORT WAVE OVER THE NORTHERN PLAINS AND
UPPER MISSISSIPPI VALLEY...AS WELL AS A MID LEVEL LOW OVER THE
SOUTHWESTERN CONUS. LONG WAVE RIDGING EXISTS OVER THE EASTERN CONUS
AS WELL AS THE NORTHWESTERN CONUS. UPPER LEVEL JET ENERGY EXTENDS
FROM NEAR NEW MEXICO AND WEST-TEXAS...NORTHEASTWARD ACROSS THE
CENTRAL PLAINS AND ON INTO THE GREAT LAKES REGION...AND THEN
EASTWARD TOWARDS THE NORTHEASTERN CONUS. A ~110KT UPPER LEVEL JET
STREAK IS ALSO NOTED EXTENDING FROM THE GREAT LAKES REGION INTO
SOUTHERN ONTARIO AND SOUTHERN QUEBEC...AS WELL AS THE NORTHEASTERN
CONUS. VISIBLE SATELLITE IMAGERY SHOWS AN EXPANSIVE CU FIELD OVER
NORTHEASTERN NEBRASKA INCLUDING NORTHEASTERN PORTIONS OF OUR CWA...WITH
SUNNY SKIES NOTED ELSEWHERE ACROSS OUR CWA. AT THE SURFACE AN AREA OF
HIGH PRESSURE IS NOTED MOVING INTO THE CENTRAL PLAINS FROM THE
MIDDLE ROCKY MOUNTAIN RANGE...WITH THE LOW LEVEL WIND FIELD ACROSS
OUR AREA REMAINING FROM THE WEST/NORTHWEST FOR THE MOST PART.
INCREASING MID LEVEL LAPS RATES ALONG THE AXIS OF THE MID LEVEL
SHORT WAVE WILL CONTINUE PROMOTING AN EXPANSIVE BUT WEAK CU FIELD ACROSS
THE NORTHEASTERN HALF OF THE CWA THIS AFTERNOON. DESPITE THE
INCREASING CLOUD COVER...DRY CONDITIONS ARE EXPECTED THIS
AFTERNOON WITH UPDRAFT STRENGTH REMAINING WEAK AND FORECAST
PROXIMITY SOUNDINGS SUGGESTING THE TROPOSPHERE WILL REMAIN VERY
DRY BELOW 700MB. FORECAST PROXIMITY SOUNDINGS ALSO SUGGEST
AFTERNOON BOUNDARY LAYER MIXING WILL INCREASE TO NEAR 700MB THIS
AFTERNOON...THUS RESULTING IN A SIGNIFICANT DROP-OFF IN AFTERNOON
DEW POINTS. DEW POINTS HAVE ALREADY FALLEN INTO THE UPPER 20S AND
LOWER 30S AS OF 18Z...A TREND WHICH IS EXPECTED TO CONTINUE
THROUGH THE REMAINDER OF THE AFTERNOON. THESE LOW VALUES OF
HUMIDITY...ALONG WITH A STIFF NORTHWESTERLY WIND IN THE 15-20KT
RANGE ACROSS MUCH OF THE CWA...WOULD PRESENT A FIRE WEATHER
CONCERN TODAY BUT WITH FUEL STATUS REMAINING NEGATIVE FOR
EXPLOSIVE FIRE GROWTH ACROSS THE ENTIRE CWA...RFW ISSUANCE WILL NOT
BE REQUIRED TODAY.
&&
.PREV DISCUSSION... /ISSUED 1220 PM CDT TUE MAY 8 2012/
AVIATION...18Z KGRI TAF. VFR CONDITIONS EXPECTED THROUGH THE NEXT
24 HOURS. AFTERNOON CU NEAR 7000FT AGL WILL BE OBSERVED THROUGH
MUCH OF THE AFTERNOON...WITH CLEAR SKIES EXPECTED AFTER 01Z.
SURFACE WINDS WILL REMAIN FROM THE NORTHWEST AT AROUND
14KTS...GUSTING TO NEAR 23KTS...BEFORE BECOMING LIGHT AND VARIABLE
AFTER 01Z. VISIBILITY RESTRICTIONS ARE NOT EXPECTED THROUGH THE
NEXT 24 HOURS.
PREV DISCUSSION... /ISSUED 722 AM CDT TUE MAY 8 2012/
UPDATE...JUST COMPLETED A QUICK UPDATE TO PURGE ISOLATED SPRINKLE
WORDING FROM KS ZONES...AS RADAR RETURNS EXITED STAGE SOUTH A BIT
FASTER THAN PREVIOUSLY EXPECTED WITHIN THE NARROW MID LEVEL
FRONTOGENETIC ZONE...AND AREN/T EXPECTED TO COME BACK. NEVER
ACTUALLY HAD CONFIRMED GROUND TRUTH THAT THIS LIGHT PRECIP REACHED
THE GROUND ANYWAY WITHIN THE CWA...BUT CHANCES ARE A FEW SPRINKLES
MANAGED TO. NO OTHER NOTABLE CHANGES MADE...OTHER THAN BRINGING
HOURLY TEMPS/DEWPOINTS/SKY COVER MORE IN LINE WITH LATEST OBS.
PREV DISCUSSION... /ISSUED 349 AM CDT TUE MAY 8 2012/
SHORT TERM...THROUGH THURSDAY NIGHT. WITH VERY LIMITED TO NO RISK
OF PRECIPITATION THROUGH THESE 72 HOURS...PRIMARY CHALLENGES BOIL
DOWN TO TEMPS/DEWPOINTS/WINDS...INCLUDING JUST HOW WARM THURSDAY
WILL ULTIMATELY GET.
STARTING OFF EARLY THIS MORNING...07Z OBJECTIVE SURFACE ANALYSIS
PLACES A BROAD HIGH PRESSURE AXIS CENTERED ALONG THE HIGH
PLAINS/FRONT RANGE FROM EASTERN MT THROUGH CENTRAL CO...WHILE A
WEAK LOW IS NOTED OVER FAR NORTHERN MN. WITH THE DOMINANT HIGH OFF
TO THE WEST...NEAR CALM TO LIGHT WESTERLY BREEZES DOMINATE THE
CWA. ALOFT...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA
INDICATE THE CENTRAL PLAINS ALONG THE SOUTHWESTERN FRINGES OF A
POSITIVELY TILTED TROUGH AXIS EXTENDING NORTHEASTWARD TO A CLOSED
500MB CIRCULATION SINKING SOUTHWARD INTO MN. MEANWHILE...ANOTHER
COMPACT CLOSED LOW IS EVIDENT ALONG THE AZ/SOUTHERN CALI
BORDER...WHILE A POSITIVELY TILTED RIDGE AXIS IS CENTERED FROM
CENTRAL CALI TO SOUTHWEST CANADA. ALONG THE SOUTHEASTERN PERIPHERY
OF THE GREAT LAKES REGION TROUGH AXIS...A MODEST 80+KT 300MB JET
STREAK IS CENTERED FROM CENTRAL NEB TO NORTH OF THE GREAT LAKES.
AS IS OH-SO COMMON IN THE ENTRANCE REGION OF SUCH A JET STREAK...A
NARROW BAND OF MID LEVEL FRONTOGENESIS EVIDENT NEAR THE 600MB
LEVEL IS FORCING A SNEAKY GENERALLY EAST-WEST BAND OF SPRINKLES
EXTENDING FROM EAST CENTRAL CO THROUGH AREAS ALONG AND MAINLY
SOUTH OF THE NEB-KS BORDER IN THE LOCAL AREA. WITH CLOUD CEILINGS
GENERALLY IN EXCESS OF 9K FEET...THIS WEAKLY FORCED PRECIPITATION
IS NOT EXPECTED TO MEASURE...BUT AS HINTED BY THE LATEST HRRR
RUNS...IT AT LEAST WARRANTS AN ISOLATED/SLIGHT CHANCE SPRINKLE
MENTION ACROSS PARTS OF THE SOUTHERN CWA DURING THE PRE-DAWN
HOURS. TURNING TO TEMPS...THE FAIRLY EXTENSIVE COVERAGE OF MID-
HIGH LEVEL CLOUDS SO FAR TONIGHT HAS HELD TEMPS WELL INTO THE
UPPER 40S/LOW 50S IN SOUTHERN ZONES...WITH NORTHERN AREAS JUST
NOW STARTING TO REALIZE SOME UPPER 30S/LOW 40S. LEANING ON THE 00Z
NAM 600MB RH FIELDS...THE THICKER BATCH OF MID CLOUDS/SPRINKLES
SHOULD GRADUALLY SINK SOUTHWARD THROUGH THE NEXT SEVERAL
HOURS...LIKELY ALLOWING A MORE PRONOUNCED TEMP DROP TOWARD
SUNRISE. THIS SHOULD ALLOW THE MAJORITY OF THE CWA TO AT LEAST
REALIZE LOW-MID 40S FOR LOWS...WITH SOME MID-UPPER 30S STILL
EXPECTED MAINLY WEST OF A GREELEY-LEXINGTON LINE. ALTHOUGH
CONFIDENCE IS LOW ON ANY AREAS TOUCHING THE 36-DEGREE RANGE LONG
ENOUGH TO FORM FROST...WITH NONETHELESS HANG ONTO SOME PATCHY
FROST WORDING EARLY THIS MORNING ONLY FOR PARTS OF DAWSON AND
NORTHWEST GOSPER COUNTIES...WITH MINIMAL IMPACT ANTICIPATED.
GETTING INTO THE DAYTIME HOURS POST-12Z...WILL CONTINUE TO FOLLOW
THE NAM 600MB RELATIVE HUMIDITY MAXIMUM FAIRLY CLOSELY TO
DELINEATE THE NORTHERN EDGE OF MORNING SPRINKLE POTENTIAL...AND
WILL LINGER THIS MENTION ONLY IN KS ZONES THROUGH 15Z...AND
HOPEFULLY THIS IS LONG ENOUGH AS LATEST HRRR TRIES SUGGESTING SOME
SPRINKLES COULD STICK AROUND EVEN THROUGH 17Z OR SO...BUT THIS
LOOKS A BIT OVERDONE AS LIFT IN THE ENTRANCE REGION OF THE UPPER
JET AND RESULTANT MID LEVEL SATURATION SINKS SOUTH OF THE AREA
WITH TIME. MAY HAVE TO DEBATE ADDING A SLIGHT MEASURABLE POP AS
WELL...BUT FEEL THAT MEASURABLE RAIN WILL BE THE EXCEPTION OUT OF
THIS ACTIVITY UNLESS RADAR TRENDS DICTATE OTHERWISE DURING NEXT
FEW HOURS. HAVE NO MENTION OF RAIN WHATSOEVER ANYWHERE IN THE CWA
BEYOND 15Z...AS THE MAIN GREAT LAKES REGION VORT MAX DROPS SOUTH
INTO NORTHERN IA BY 00Z. ALTHOUGH THE COLD POCKET ALOFT WITH THIS
WAVE WILL SURELY SPARK SCATTERED SHOWERS/MAYBE A FEW WEAK STORMS
THIS AFTERNOON AS CLOSE AS NORTHEAST NEB...WILL ASSUME FOR NOW
THAT THIS ACTIVITY WILL REMAIN OUTSIDE THE CWA. HOWEVER...PER THE
LATEST 00Z 4KM WRF-NMM REFLECTIVITY PROG...SOME OF THIS SHOWER
ACTIVITY COULD GET FAIRLY CLOSE TO BRUSHING THE FAR NORTHEAST CWA
IN THE NANCE/POLK COUNTY AREA AND NEXT SHIFTS WILL HAVE TO KEEP AN
EYE ON THIS ESPECIALLY BETWEEN 20Z-00Z. AS HAS ALREADY BEEN PROVEN
IN THE PAST 24 HOURS...SETUPS LIKE THIS CAN GO FROM LOOKING
COMPLETELY DRY 2 DAYS PRIOR...TO ULTIMATELY PRODUCING AT LEAST
NUISANCE SPRINKLES/LIGHT SHOWERS WITH LITTLE ADVANCE NOTICE.
TURNING TO OTHER FACETS OF TODAY/S FORECAST...DEEP MIXING TO NEAR
700MB PER NAM SOUNDINGS WILL PROMOTE ANOTHER BREEZY DAY...WITH
SUSTAINED SPEEDS EASILY 15-20 MPH WITH GUSTS TO AROUND 25 MPH
ESPECIALLY ACROSS THE NORTHEAST 1/2 OF THE CWA. TEMP-WISE...ALTHOUGH
COULD EASILY SEE A FAIR AMOUNT OF HIGH-BASED CUMULUS THIS
AFTERNOON...FORESEE NO WORSE THAN PARTLY CLOUDY SKIES OVERALL. AS
A RESULT...KEPT HIGHS SIMILAR TO PREVIOUS FORECAST...WITH MOST
AREAS IN THE UPPER 60S-LOW 70S. PER A NAM-BASED MIXING TOOL...DID
LOWER DEWPOINTS AT LEAST 5 DEGREES DURING THE DAY MOST AREAS.
ALTHOUGH THIS WOULD DROP SURFACE RH VALUES DOWN TO AROUND 20 PERCENT
OR SO...ANY FIRE WEATHER THREAT SHOULD BE QUITE MINIMAL GIVEN
RECENT RAINFALL AND CONTINUED GREEN-UP.
TONIGHT...SHORTWAVE RIDGING OVERTAKES THE CWA IN THE WAKE OF THE
DEPARTING TROUGH AXIS...WHICH WILL REACH ALONG A LINE FROM
SOUTHERN KS UP THROUGH THE EASTERN GREAT LAKES BY 12Z. ASSUMING
THAT NO SPRINKLES/LIGHT SHOWERS ARE AFFECTING THE NORTHEAST CWA
RIGHT AWAY IN THE EARLY EVENING...HAVE HIGH CONFIDENCE IN A DRY
OVERNIGHT PERIOD AS A ROUGHLY 1022MB SURFACE HIGH SETTLES
DIRECTLY OVER THE CWA. WITH MOSTLY CLEAR SKIES AND LIGHT/VARIABLE
BREEZES...SHOULD SEE A MORE EFFICIENT TEMP DROP TONIGHT...AND
NUDGED DOWN LOWS AT LEAST 2-3 DEGREES FROM PREVIOUS
FORECAST...PUTTING MOST OF THE CWA DOWN INTO THE 38-41 RANGE FOR
LOWS. AS FOR FROST POTENTIAL...ONLY HAVE FAR WESTERN AREAS SUCH AS
DAWSON AND GOSPER COUNTIES REACHING AS LOW AS 36...AND THUS
CONFINED PATCHY FROST MENTION TO ONLY THIS LIMITED AREA FOR
NOW...WITH NO FROST HEADLINE PLANNED.
WEDNESDAY...RIDGING CONTINUES TO DOMINATE THE CWA BOTH AT THE
SURFACE AND ALOFT...WITH HIGH CONFIDENCE IN A DRY DAY WITH AT
LEAST MOSTLY SUNNY SKIES. ALTHOUGH THE SURFACE RIDGE AXIS WILL
INHIBIT EFFICIENT MIXING MOST OF THE DAY...A GRADUAL RETURN TO
SOUTHERLY BREEZES WILL DEVELOP. CHANGED HIGHS LITTLE...WITH MOST
AREAS BETWEEN 71-74.
WEDNESDAY NIGHT...STEADY LIGHT SOUTHERLY BREEZES CONTINUE AS AN
EXPANSIVE MID/UPPER RIDGE RETAINS CONTROL AHEAD OF THE NEXT LARGE
SCALE SHORTWAVE TROUGH MOVING INTO THE PACIFIC NORTHWEST. THE
SOUTHERLY FLOW WILL HELP KEEP LOWS WARMER...AND STAYED CLOSE TO
GUIDANCE AND PREVIOUS FORECAST WITH UPPER 40S-NEAR 50 CWA-WIDE.
THURSDAY...THIS STILL LOOKS TO BE THE HANDS-DOWN WARMEST DAY OF
THE FORECAST PERIOD...AS HIGH PLAINS SURFACE PRESSURE FALLS AHEAD
OF THE INCOMING TROUGH INDUCES INCREASING SOUTHERLY BREEZES WITH
SUSTAINED SPEEDS EASILY 15-20 MPH. DEEPER MIXING...IN CONCERT WITH
WARMER TEMPS EVIDENT AT 850MB AND PLENTY OF SUNSHINE SHOULD REALLY
GIVE TEMPS A BOOST...AND RAISED HIGHS AT LEAST 2-3 DEGREES FROM
PREVIOUS FORECAST...NOW RANGING FROM LOW 80S EAST TO MID 80S WEST.
NUMERICAL MET/MAV GUIDANCE JUST LOOKS TO BE SEVERAL DEGREES TOO
COOL AT THIS TIME.
THURSDAY NIGHT...MAIN CHANGE WAS TO PULL THE TOKEN 20 PERCENT
CHANCE OF SHOWERS/STORMS THAT HAD BEEN ADVERTISED IN FAR NORTHWEST
COUNTIES THE PAST FEW FORECAST CYCLES. ALTHOUGH BOTH THE NAM/ECMWF
ARE IN GOOD AGREEMENT THAT A WELL-DEFINED COLD FRONT WILL ENTER
NORTHWEST PORTIONS OF THE CWA BETWEEN 06Z-12Z...WHAT MEAGER
ELEVATED INSTABILITY THERE IS SHOULD HANG BACK IN WEST CENTRAL/NORTH
CENTRAL NEB THROUGH THE ENTIRE NIGHT AS THE PARENT MID LEVEL
TROUGH AXIS MIGRATES ACROSS THE NORTHERN ROCKIES. WANT TO NOTE
THAT THE NAM/ECMWF ARE BOTH FASTER THAN THE GFS IN BRINGING THE
COLD FRONT AND INCREASING NORTHWEST WINDS INTO THE CWA...SO THERE
ARE STILL SOME TIMING ISSUE TO WORK OUT HERE.
LONG TERM...FRIDAY THROUGH MONDAY. DURING THIS FORECAST PERIOD WE
START ANOTHER COOL DOWN WITH A COLD FRONTAL PASSAGE EARLY FRIDAY.
MOISTURE IS MEAGER ALONG THE BOUNDARY...BUT WE WILL NOTICE COOLING
TEMPERATURES BACK TO SEASONAL NUMBERS DURING THE DAY FRIDAY.
GLANCING BLOW OF UPPER LEVEL ENERGY AND TAIL END OF 250MB JET STREAK
COULD BE ENOUGH TO SPARK SOME SHOWERS...MAYBE A THUNDERSTORM OR TWO
BEHIND THE FRONT. ALL MODEL FORECAST HAVE THIS TREND. PRETTY STRONG
SURFACE HIGH PRESSURE SPREADS INTO THE REGION LATE FRIDAY AND
SATURDAY. EXPERIENCE WITH PRECIPITATION TRENDS AND BUILDING FRONT
RANGE SURFACE HIGH PRESSURES IN MODEL WORLD...IS THE MODELS TEND TO
OVERDO THE PRECIPITATION TOO FAR EAST AND WITH TOO MUCH OF IT. A
CONSERVATIVE APPROACH IS BEST AT THIS POINT...AS WE ARE LIABLE TO
SEE MORE CLOUDS THAN ANYTHING...ESPECIALLY THE FURTHER NORTH/EAST
YOU GO ACROSS OUR FORECAST AREA. THEREFORE...ONLY 20 TO 30 PERCENT
CHANCE FOR MEASURABLE PRECIPITATION AREA IN THE FORECAST. MID LEVEL
LAPSE RATES SUGGEST THUNDER RISK IF MARGINAL AT BEST AND ONLY AN
ISOLATED STORM IS EXPECTED. TEMPERATURES WILL DROP BACK INTO THE 60S
FOR A TIME...BUT START TO REBOUND LATE SUNDAY AND MONDAY. HARDLY A
RAINOUT BY ANY MEANS...BUT SOME SHOWERS WILL BE FLOATING AROUND ON
THIS MOTHERS DAY WEEKEND.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
1825Z UPDATE/AVIATION...BRYANT
1222Z UPDATE/SHORT TERM...PFANNKUCH
LONG TERM...MORITZ
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1220 PM CDT TUE MAY 8 2012
.AVIATION...18Z KGRI TAF. VFR CONDITIONS EXPECTED THROUGH THE NEXT
24 HOURS. AFTERNOON CU NEAR 7000FT AGL WILL BE OBSERVED THROUGH
MUCH OF THE AFTERNOON...WITH CLEAR SKIES EXPECTED AFTER 01Z.
SURFACE WINDS WILL REMAIN FROM THE NORTHWEST AT AROUND
14KTS...GUSTING TO NEAR 23KTS...BEFORE BECOMING LIGHT AND VARIABLE
AFTER 01Z. VISIBILITY RESTRICTIONS ARE NOT EXPECTED THROUGH THE
NEXT 24 HOURS.
&&
.PREV DISCUSSION... /ISSUED 722 AM CDT TUE MAY 8 2012/
UPDATE...JUST COMPLETED A QUICK UPDATE TO PURGE ISOLATED SPRINKLE
WORDING FROM KS ZONES...AS RADAR RETURNS EXITED STAGE SOUTH A BIT
FASTER THAN PREVIOUSLY EXPECTED WITHIN THE NARROW MID LEVEL
FRONTOGENETIC ZONE...AND AREN/T EXPECTED TO COME BACK. NEVER
ACTUALLY HAD CONFIRMED GROUND TRUTH THAT THIS LIGHT PRECIP REACHED
THE GROUND ANYWAY WITHIN THE CWA...BUT CHANCES ARE A FEW SPRINKLES
MANAGED TO. NO OTHER NOTABLE CHANGES MADE...OTHER THAN BRINGING
HOURLY TEMPS/DEWPOINTS/SKY COVER MORE IN LINE WITH LATEST OBS.
PREV DISCUSSION... /ISSUED 349 AM CDT TUE MAY 8 2012/
SHORT TERM...THROUGH THURSDAY NIGHT. WITH VERY LIMITED TO NO RISK
OF PRECIPITATION THROUGH THESE 72 HOURS...PRIMARY CHALLENGES BOIL
DOWN TO TEMPS/DEWPOINTS/WINDS...INCLUDING JUST HOW WARM THURSDAY
WILL ULTIMATELY GET.
STARTING OFF EARLY THIS MORNING...07Z OBJECTIVE SURFACE ANALYSIS
PLACES A BROAD HIGH PRESSURE AXIS CENTERED ALONG THE HIGH
PLAINS/FRONT RANGE FROM EASTERN MT THROUGH CENTRAL CO...WHILE A
WEAK LOW IS NOTED OVER FAR NORTHERN MN. WITH THE DOMINANT HIGH OFF
TO THE WEST...NEAR CALM TO LIGHT WESTERLY BREEZES DOMINATE THE
CWA. ALOFT...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA
INDICATE THE CENTRAL PLAINS ALONG THE SOUTHWESTERN FRINGES OF A
POSITIVELY TILTED TROUGH AXIS EXTENDING NORTHEASTWARD TO A CLOSED
500MB CIRCULATION SINKING SOUTHWARD INTO MN. MEANWHILE...ANOTHER
COMPACT CLOSED LOW IS EVIDENT ALONG THE AZ/SOUTHERN CALI
BORDER...WHILE A POSITIVELY TILTED RIDGE AXIS IS CENTERED FROM
CENTRAL CALI TO SOUTHWEST CANADA. ALONG THE SOUTHEASTERN PERIPHERY
OF THE GREAT LAKES REGION TROUGH AXIS...A MODEST 80+KT 300MB JET
STREAK IS CENTERED FROM CENTRAL NEB TO NORTH OF THE GREAT LAKES.
AS IS OH-SO COMMON IN THE ENTRANCE REGION OF SUCH A JET STREAK...A
NARROW BAND OF MID LEVEL FRONTOGENESIS EVIDENT NEAR THE 600MB
LEVEL IS FORCING A SNEAKY GENERALLY EAST-WEST BAND OF SPRINKLES
EXTENDING FROM EAST CENTRAL CO THROUGH AREAS ALONG AND MAINLY
SOUTH OF THE NEB-KS BORDER IN THE LOCAL AREA. WITH CLOUD CEILINGS
GENERALLY IN EXCESS OF 9K FEET...THIS WEAKLY FORCED PRECIPITATION
IS NOT EXPECTED TO MEASURE...BUT AS HINTED BY THE LATEST HRRR
RUNS...IT AT LEAST WARRANTS AN ISOLATED/SLIGHT CHANCE SPRINKLE
MENTION ACROSS PARTS OF THE SOUTHERN CWA DURING THE PRE-DAWN
HOURS. TURNING TO TEMPS...THE FAIRLY EXTENSIVE COVERAGE OF MID-
HIGH LEVEL CLOUDS SO FAR TONIGHT HAS HELD TEMPS WELL INTO THE
UPPER 40S/LOW 50S IN SOUTHERN ZONES...WITH NORTHERN AREAS JUST
NOW STARTING TO REALIZE SOME UPPER 30S/LOW 40S. LEANING ON THE 00Z
NAM 600MB RH FIELDS...THE THICKER BATCH OF MID CLOUDS/SPRINKLES
SHOULD GRADUALLY SINK SOUTHWARD THROUGH THE NEXT SEVERAL
HOURS...LIKELY ALLOWING A MORE PRONOUNCED TEMP DROP TOWARD
SUNRISE. THIS SHOULD ALLOW THE MAJORITY OF THE CWA TO AT LEAST
REALIZE LOW-MID 40S FOR LOWS...WITH SOME MID-UPPER 30S STILL
EXPECTED MAINLY WEST OF A GREELEY-LEXINGTON LINE. ALTHOUGH
CONFIDENCE IS LOW ON ANY AREAS TOUCHING THE 36-DEGREE RANGE LONG
ENOUGH TO FORM FROST...WITH NONETHELESS HANG ONTO SOME PATCHY
FROST WORDING EARLY THIS MORNING ONLY FOR PARTS OF DAWSON AND
NORTHWEST GOSPER COUNTIES...WITH MINIMAL IMPACT ANTICIPATED.
GETTING INTO THE DAYTIME HOURS POST-12Z...WILL CONTINUE TO FOLLOW
THE NAM 600MB RELATIVE HUMIDITY MAXIMUM FAIRLY CLOSELY TO
DELINEATE THE NORTHERN EDGE OF MORNING SPRINKLE POTENTIAL...AND
WILL LINGER THIS MENTION ONLY IN KS ZONES THROUGH 15Z...AND
HOPEFULLY THIS IS LONG ENOUGH AS LATEST HRRR TRIES SUGGESTING SOME
SPRINKLES COULD STICK AROUND EVEN THROUGH 17Z OR SO...BUT THIS
LOOKS A BIT OVERDONE AS LIFT IN THE ENTRANCE REGION OF THE UPPER
JET AND RESULTANT MID LEVEL SATURATION SINKS SOUTH OF THE AREA
WITH TIME. MAY HAVE TO DEBATE ADDING A SLIGHT MEASURABLE POP AS
WELL...BUT FEEL THAT MEASURABLE RAIN WILL BE THE EXCEPTION OUT OF
THIS ACTIVITY UNLESS RADAR TRENDS DICTATE OTHERWISE DURING NEXT
FEW HOURS. HAVE NO MENTION OF RAIN WHATSOEVER ANYWHERE IN THE CWA
BEYOND 15Z...AS THE MAIN GREAT LAKES REGION VORT MAX DROPS SOUTH
INTO NORTHERN IA BY 00Z. ALTHOUGH THE COLD POCKET ALOFT WITH THIS
WAVE WILL SURELY SPARK SCATTERED SHOWERS/MAYBE A FEW WEAK STORMS
THIS AFTERNOON AS CLOSE AS NORTHEAST NEB...WILL ASSUME FOR NOW
THAT THIS ACTIVITY WILL REMAIN OUTSIDE THE CWA. HOWEVER...PER THE
LATEST 00Z 4KM WRF-NMM REFLECTIVITY PROG...SOME OF THIS SHOWER
ACTIVITY COULD GET FAIRLY CLOSE TO BRUSHING THE FAR NORTHEAST CWA
IN THE NANCE/POLK COUNTY AREA AND NEXT SHIFTS WILL HAVE TO KEEP AN
EYE ON THIS ESPECIALLY BETWEEN 20Z-00Z. AS HAS ALREADY BEEN PROVEN
IN THE PAST 24 HOURS...SETUPS LIKE THIS CAN GO FROM LOOKING
COMPLETELY DRY 2 DAYS PRIOR...TO ULTIMATELY PRODUCING AT LEAST
NUISANCE SPRINKLES/LIGHT SHOWERS WITH LITTLE ADVANCE NOTICE.
TURNING TO OTHER FACETS OF TODAY/S FORECAST...DEEP MIXING TO NEAR
700MB PER NAM SOUNDINGS WILL PROMOTE ANOTHER BREEZY DAY...WITH
SUSTAINED SPEEDS EASILY 15-20 MPH WITH GUSTS TO AROUND 25 MPH
ESPECIALLY ACROSS THE NORTHEAST 1/2 OF THE CWA. TEMP-WISE...ALTHOUGH
COULD EASILY SEE A FAIR AMOUNT OF HIGH-BASED CUMULUS THIS
AFTERNOON...FORESEE NO WORSE THAN PARTLY CLOUDY SKIES OVERALL. AS
A RESULT...KEPT HIGHS SIMILAR TO PREVIOUS FORECAST...WITH MOST
AREAS IN THE UPPER 60S-LOW 70S. PER A NAM-BASED MIXING TOOL...DID
LOWER DEWPOINTS AT LEAST 5 DEGREES DURING THE DAY MOST AREAS.
ALTHOUGH THIS WOULD DROP SURFACE RH VALUES DOWN TO AROUND 20 PERCENT
OR SO...ANY FIRE WEATHER THREAT SHOULD BE QUITE MINIMAL GIVEN
RECENT RAINFALL AND CONTINUED GREEN-UP.
TONIGHT...SHORTWAVE RIDGING OVERTAKES THE CWA IN THE WAKE OF THE
DEPARTING TROUGH AXIS...WHICH WILL REACH ALONG A LINE FROM
SOUTHERN KS UP THROUGH THE EASTERN GREAT LAKES BY 12Z. ASSUMING
THAT NO SPRINKLES/LIGHT SHOWERS ARE AFFECTING THE NORTHEAST CWA
RIGHT AWAY IN THE EARLY EVENING...HAVE HIGH CONFIDENCE IN A DRY
OVERNIGHT PERIOD AS A ROUGHLY 1022MB SURFACE HIGH SETTLES
DIRECTLY OVER THE CWA. WITH MOSTLY CLEAR SKIES AND LIGHT/VARIABLE
BREEZES...SHOULD SEE A MORE EFFICIENT TEMP DROP TONIGHT...AND
NUDGED DOWN LOWS AT LEAST 2-3 DEGREES FROM PREVIOUS
FORECAST...PUTTING MOST OF THE CWA DOWN INTO THE 38-41 RANGE FOR
LOWS. AS FOR FROST POTENTIAL...ONLY HAVE FAR WESTERN AREAS SUCH AS
DAWSON AND GOSPER COUNTIES REACHING AS LOW AS 36...AND THUS
CONFINED PATCHY FROST MENTION TO ONLY THIS LIMITED AREA FOR
NOW...WITH NO FROST HEADLINE PLANNED.
WEDNESDAY...RIDGING CONTINUES TO DOMINATE THE CWA BOTH AT THE
SURFACE AND ALOFT...WITH HIGH CONFIDENCE IN A DRY DAY WITH AT
LEAST MOSTLY SUNNY SKIES. ALTHOUGH THE SURFACE RIDGE AXIS WILL
INHIBIT EFFICIENT MIXING MOST OF THE DAY...A GRADUAL RETURN TO
SOUTHERLY BREEZES WILL DEVELOP. CHANGED HIGHS LITTLE...WITH MOST
AREAS BETWEEN 71-74.
WEDNESDAY NIGHT...STEADY LIGHT SOUTHERLY BREEZES CONTINUE AS AN
EXPANSIVE MID/UPPER RIDGE RETAINS CONTROL AHEAD OF THE NEXT LARGE
SCALE SHORTWAVE TROUGH MOVING INTO THE PACIFIC NORTHWEST. THE
SOUTHERLY FLOW WILL HELP KEEP LOWS WARMER...AND STAYED CLOSE TO
GUIDANCE AND PREVIOUS FORECAST WITH UPPER 40S-NEAR 50 CWA-WIDE.
THURSDAY...THIS STILL LOOKS TO BE THE HANDS-DOWN WARMEST DAY OF
THE FORECAST PERIOD...AS HIGH PLAINS SURFACE PRESSURE FALLS AHEAD
OF THE INCOMING TROUGH INDUCES INCREASING SOUTHERLY BREEZES WITH
SUSTAINED SPEEDS EASILY 15-20 MPH. DEEPER MIXING...IN CONCERT WITH
WARMER TEMPS EVIDENT AT 850MB AND PLENTY OF SUNSHINE SHOULD REALLY
GIVE TEMPS A BOOST...AND RAISED HIGHS AT LEAST 2-3 DEGREES FROM
PREVIOUS FORECAST...NOW RANGING FROM LOW 80S EAST TO MID 80S WEST.
NUMERICAL MET/MAV GUIDANCE JUST LOOKS TO BE SEVERAL DEGREES TOO
COOL AT THIS TIME.
THURSDAY NIGHT...MAIN CHANGE WAS TO PULL THE TOKEN 20 PERCENT
CHANCE OF SHOWERS/STORMS THAT HAD BEEN ADVERTISED IN FAR NORTHWEST
COUNTIES THE PAST FEW FORECAST CYCLES. ALTHOUGH BOTH THE NAM/ECMWF
ARE IN GOOD AGREEMENT THAT A WELL-DEFINED COLD FRONT WILL ENTER
NORTHWEST PORTIONS OF THE CWA BETWEEN 06Z-12Z...WHAT MEAGER
ELEVATED INSTABILITY THERE IS SHOULD HANG BACK IN WEST CENTRAL/NORTH
CENTRAL NEB THROUGH THE ENTIRE NIGHT AS THE PARENT MID LEVEL
TROUGH AXIS MIGRATES ACROSS THE NORTHERN ROCKIES. WANT TO NOTE
THAT THE NAM/ECMWF ARE BOTH FASTER THAN THE GFS IN BRINGING THE
COLD FRONT AND INCREASING NORTHWEST WINDS INTO THE CWA...SO THERE
ARE STILL SOME TIMING ISSUE TO WORK OUT HERE.
LONG TERM...FRIDAY THROUGH MONDAY. DURING THIS FORECAST PERIOD WE
START ANOTHER COOL DOWN WITH A COLD FRONTAL PASSAGE EARLY FRIDAY.
MOISTURE IS MEAGER ALONG THE BOUNDARY...BUT WE WILL NOTICE COOLING
TEMPERATURES BACK TO SEASONAL NUMBERS DURING THE DAY FRIDAY.
GLANCING BLOW OF UPPER LEVEL ENERGY AND TAIL END OF 250MB JET STREAK
COULD BE ENOUGH TO SPARK SOME SHOWERS...MAYBE A THUNDERSTORM OR TWO
BEHIND THE FRONT. ALL MODEL FORECAST HAVE THIS TREND. PRETTY STRONG
SURFACE HIGH PRESSURE SPREADS INTO THE REGION LATE FRIDAY AND
SATURDAY. EXPERIENCE WITH PRECIPITATION TRENDS AND BUILDING FRONT
RANGE SURFACE HIGH PRESSURES IN MODEL WORLD...IS THE MODELS TEND TO
OVERDO THE PRECIPITATION TOO FAR EAST AND WITH TOO MUCH OF IT. A
CONSERVATIVE APPROACH IS BEST AT THIS POINT...AS WE ARE LIABLE TO
SEE MORE CLOUDS THAN ANYTHING...ESPECIALLY THE FURTHER NORTH/EAST
YOU GO ACROSS OUR FORECAST AREA. THEREFORE...ONLY 20 TO 30 PERCENT
CHANCE FOR MEASURABLE PRECIPITATION AREA IN THE FORECAST. MID LEVEL
LAPSE RATES SUGGEST THUNDER RISK IF MARGINAL AT BEST AND ONLY AN
ISOLATED STORM IS EXPECTED. TEMPERATURES WILL DROP BACK INTO THE 60S
FOR A TIME...BUT START TO REBOUND LATE SUNDAY AND MONDAY. HARDLY A
RAINOUT BY ANY MEANS...BUT SOME SHOWERS WILL BE FLOATING AROUND ON
THIS MOTHERS DAY WEEKEND.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AVIATION...BRYANT
UPDATE/SHORT TERM...PFANNKUCH
LONG TERM...MORITZ
AREA FORECAST DISCUSSION...CORRECTED
NWS RALEIGH NC
335 PM EDT TUE MAY 8 2012
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE WEST TONIGHT...THEN SLOWLY
PROGRESS EAST THROUGH THE CAROLINAS WEDNESDAY AND WEDNESDAY NIGHT.
HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT ON THURSDAY AND
FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 315 PM TUESDAY...
LATEST SFC ANALYSIS SHOWS A COLD FRONT EXTENDING SOUTHWESTERLY
ACROSS THE OH AND TN VALLEYS. MULTIPLE WEAK SFC TROUGHS WERE NOTED
ACROSS THE SOUTHERN APPALACHIANS AND GA/SC. LATEST SPC MESOANALYSIS
INDICATES A WEAKLY UNSTABLE AIRMASS ACROSS FAR WESTERN NC AND SC
WITH MLCAPE VALUES OF AROUND 250-500 J/KG IN A REGION OF ENHANCED
SFC DEW POINTS IN THE LOW/MID 60S. FURTHER EAST ACROSS THE PIEDMONT
AND COASTAL PLAIN THE AIR MASS IS MORE STABLE WITH LITTLE OR NO
SBCAPE/MLCAPE IN A REGION OF DEW POINTS IN THE MID 50S TO AROUND 60.
SCT SHOWERS CONTINUE TO MOVE NORTHEAST AT AROUND 20KTS. MUCH OF
CENTRAL NC UNDER A BKN CLOUD DECK WITH CIGS RANGING FROM 3-5KFT.
RECENT SIMULATIONS FROM THE WRF HIRESW AND HRRR SUGGEST THAT THE SCT
CONVECTION WILL PERSIST INTO THE EVENING HOURS AND CONTINUE TO SHIFT
EASTWARD. IN FACT SOME SIMULATION SUGGEST THAT THE CONVECTION ACROSS
THE FOOTHILLS WILL INTENSIFY A BIT AND GROW INTO A BROKEN LINE AND
MOVE ACROSS THE WESTERN PIEDMONT INTO THE EASTERN PIEDMONT BUT
LIKELY WEAKEN OR HOLD WEST OF THE COASTAL PLAIN. THREAT OF SEVERE
CONVECTION THIS AFTN/EVE IS LIMITED WITH A WEAKLY UNSTABLE AIRMASS
THIS AFTN CHARACTERIZED BY MLCAPE VALUES LESS THAN 500 J/KG...MODEST
0-6KM BULK SHEAR OF 15 KTS OR LESS AND WEAK MID LEVEL LAPSE RATES.
GIVEN AN INCREASE IN PW VALUES NOW APPROACHING 1.7 INCHES IN THE
SOUTHERN PIEDMONT...SOME LOCATIONS COULD SEE HEAVY RAIN THIS
EVENING. THREAT OF PRECIPITATION OVERNIGHT DECREASES SOMEWHAT WITH
LIMITED FORCING FOR ASCENT BUT WILL MAINTAIN AT LEAST A SLIGHT CHC
POP OVERNIGHT. GIVEN WIDESPREAD CLOUDINESS...A LIGHT SOUTHERLY WIND
TRANSPORTING SLIGHTLY HIGHER DEW POINTS INTO THE REGION...HAVE EDGED
TOWARD THE WARMER END OF THE GUIDANCE ENVELOPE WITH LOWS IN THE
62-66 RANGE. -BLAES
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 315 PM TUESDAY...
THE NORTHERN STREAM SHORTWAVE WILL DIVE INTO THE OH VALLEY TOWARD
DAYBREAK ON WED. BOTH THE NAM/GFS HAVE TRENDED A LITTLE SHARPER WITH
THIS FEATURE AS IT PIVOTS EAST AND BECOMES NEUTRAL OR EVEN BRIEFLY
NEGATIVELY TILTED WEDNESDAY NIGHT. THE BEST FORCING FOR ASCENT WITH
THE WAVE WILL REMAIN IN WV/VA NORTHWARD. THE POLAR JET STRENGTHENS
ACROSS PA/NY AND EXTEND SOUTHWEST TO THE OH VALLEY WED AFTERNOON BUT
WILL LIKELY ONLY PROVIDE LIMITED FORCING FOR ASCENT OVER NC. WHILE
THE BEST FORCING WILL REMAIN NORTH OF NC...SFC DEW POINTS RECOVER
INTO THE LOWER TO MID 60S WHICH MAY BE SUFFICIENT FOR PERHAPS A
MODERATELY UNSTABLE AIRMASS WITH MLCAPE VALUES CLIMBING TO AROUND
1000 J/KG IN THE COASTAL PLAIN WITH REDUCED MLCAPE VALUES IN THE
PIEDMONT GIVEN A SHALLOWER BOUNDARY LAYER. NAM/GFS FORECAST
SOUNDINGS BOTH DEPICT A MOIST ENVIRONMENT WITH THIN CAPE AND LIMITED
DRY AIR ALOFT. BULK SHEAR VALUES INCREASE DURING THE AFTERNOON AND
REACH THE 25-30KT RANGE IN THE EAST AND AROUND 35KTS ACROSS THE
WEST. WHILE THE SHEAR IS SUFFICIENT TO SUPPORT SOME
ORGANIZATION...THE MOIST PROFILES SUGGEST THE SEVERE WEATHER THREAT
MAY BE SOMEWHAT LIMITED. WITH A GENERALLY LINEAR WIND PROFILE AND
THE MEAN WIND PARALLEL TO THE APPROACHING COLD FRONT...THE
CONVECTION WILL LIKELY TAKE ON A MORE LINEAR ORIENTATION. ANY
DISCRETE STORM WILL HAVE AN INCREASED SEVERE WEATHER THREAT GIVEN
THE MARGINAL POTENTIAL FOR SUPERCELLS AND SEMI STRAIGHT HODOGRAPHS
WHICH SUGGEST POSSIBLE SPLITTING SUPERCELLS. PW VALUES CLIMB TO
AROUND 1.75 INCHES AND THE CONVECTION WILL LIKELY BECOME ORIENTED
PARALLEL TO THE THE NORTHEAST MOTION...SUGGESTING THAT STORMS WILL
HAVE THE POTENTIAL TO DUMP HEAVY RAIN OVER A GIVEN LOCATION FOR A
PROLONGED PERIOD OF TIME. GIVEN THIS...THE PRIMARY SEVERE THREAT ON
WEDNESDAY AND WEDNESDAY EVENING WILL BE FLOODING AND WET DOWNBURSTS.
WILL RAMP UP POPS INTO THE LIKELY RANGE ON WEDNESDAY AFTERNOON AND
EARLY EVENING AND THEN QUICKLY DIMINISH POPS FROM WEST TO EAST AFTER
MIDNIGHT. HIGH TEMPERATURES ON WEDNESDAY WILL RANGE IN THE MID 70S
WEST TO THE UPPER 70S TO AROUND 80 EAST. WILL KEEP LOWS ON WEDNESDAY
NIGHT TOWARD THE HIGHER END OF THE GUIDANCE RANGE GIVEN THE CLOUD
COVER AND TENDENCY FOR OVERNIGHT LOWS TO REMAIN ELEVATED WITH COLD
FRONTAL PASSAGES LATE AT NIGHT. LOWS IN THE MID 50S NORTHWEST TO
AROUND 60 SOUTHEAST. -BLAES
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS OF 300 PM TUESDAY...
THURSDAY THROUGH FRIDAY...THE UPPER TROUGH AXIS PUSHES EAST OF
CENTRAL NORTH CAROLINA QUICKLY DURING THE MORNING...WITH THE JET
ALOFT ALSO MOVING EAST. GOOD SUBSIDENCE TAKES PLACE AS HIGH PRESSURE
BUILDS IN...WITH BUFR SOUNDINGS AT 12Z STABLE TO DEEP CONVECTION
THROUGHOUT CENTRAL NORTH CAROLINA ON BOTH THE NAM AND THE GFS.
PRECIPITABLE WATER VALUES THAT FALL TO AROUND 0.75 INCH AROUND 12Z
THURSDAY FALL FURTHER TO AROUND 0.5 INCH BY 18Z THURSDAY...WHERE
THEY REMAIN THROUGH THE DAY ON FRIDAY. EXCEPT FOR VERY EARLY
THURSDAY...K INDICES ARE NEGATIVE...WELL NEGATIVE FOR FRIDAY.
WHILE IT WILL BE CLOSE TO THE INTERSTATE 95 CORRIDOR...EXPECT
PRECIPITATION TO BE JUST EAST OF CENTRAL NORTH CAROLINA BY 12Z
THURSDAY. FROM THERE...SKIES SHOULD CLEAR...BUT A RELATIVE MAXIMUM
OF 850MB THETA-E IN THE COASTAL PLAIN COULD YIELD SOME SHALLOW
AFTERNOON CU. IN ADDITION...A FEW CLOUDS COULD DRIFT FROM THE
MOUNTAINS...WHERE COOL AIR ALOFT WILL MAKE CONDITIONS THERE
RELATIVELY UNSTABLE...TOWARD THE TRIAD...BUT THE AIR SHOULD BE SO
STABLE THAT ONLY FEW SHOULD MAKE IT TO NEAR KINT AND KGSO. THE
SURFACE GRADIENT BEHIND THE FRONT WILL BE TIGHT TO START THE DAY...
RESULTING IN WIND GUSTS WITH MIXING AS HIGH AS THE LOWER 20S MPH
BEFORE 925MB WINDS FALL TO AROUND 15KT IN THE AFTERNOON...LESSENING
THE WIND GUSTS. UNDER OVERALL 850MB THETA-E TROUGHINESS FRIDAY...AND
AMPLE SUBSIDENCE AND DRY AIR...UNDER A SLACK GRADIENT AS WELL...
EXPECT PLENTY OF SUNSHINE AND CALM CONDITIONS FOR THE DAY...POSSIBLY
A BRIEF NOTICEABLE WIND GUST TO AROUND 10KT WITH MIXING EARLY.
BASED ON A COMBINATION OF 1000-850MB THICKNESSES...MOS GUIDANCE...
AND EXPECTED MIXING BASED ON BUFR SOUNDINGS...FORECAST HIGHS NEAR
THE HIGHER MAV MOS ON THURSDAY. WITH A FORECAST NEARER THE COOLER
GUIDANCE THURSDAY NIGHT UNDER A CLEAR SKY AND DIMINISHING WIND...
TEMPERATURES IN CENTRAL NORTH CAROLINA FRIDAY SHOULD BE SIMILAR TO
THURSDAY WITH A THICKNESS DIFFERENCE OF ONLY ABOUT 5M. FOR
NOW...WENT ABOUT A DEGREE COOLER FRIDAY COMPARED TO THURSDAY DUE TO
THE LIGHT...GENERALLY NORTHERLY LOW-LEVEL FLOW.
HEIGHTS ALOFT RISE NOTICEABLY FRIDAY NIGHT INTO SATURDAY...BEFORE
HEIGHTS START TO FALL AGAIN AS A WEAKENING UPPER-LEVEL LOW THAT
MOVES FROM THE SOUTHWEST STATES INTO THE SOUTH PLAINS SLOWLY PUSHES
FARTHER EAST. THE SOUTHEAST CONUS FALLS ON THE DOWNSTREAM SIDE OF
THE UPPER REMNANT TROUGH BY THE END OF THE WEEKEND...AND WHILE A
MID-LEVEL SHORTWAVE OF SOME STRENGTH SHOULD REACH CENTRAL NORTH
CAROLINA BY LATE SUNDAY...THE UPPER FLOW IS INITIALLY CONFLUENT AND
THE SURFACE RIDGE AXIS REMAINS OVERHEAD. DRY CONDITIONS SHOULD EXIST
FRIDAY NIGHT THROUGH SATURDAY IN HIGH PRESSURE SURFACE AND
ALOFT...AND WILL CONTINUE A DRY FORECAST FOR NOW THROUGH SUNDAY DUE
TO THE PRESENCE OF SURFACE HIGH PRESSURE AND THE CONFLUENT FLOW
ALOFT. LATE SUNDAY AND SUNDAY NIGHT...IT IS POSSIBLE THAT THE
SURFACE RIDGE AXIS STARTS TO MOVE NORTH OF THE AREA RESULTING IN
INCREASING ATLANTIC MOISTURE...AND WHILE AN ISOLATED SHOWER OR
THUNDERSTORM IS POSSIBLE...WILL LEAVE IT OUT OF THE FORECAST FOR NOW
THAT FAR OUT IN TIME. MOST OF THE GUIDANCE IS DRY OR TRENDING DRIER
FOR SUNDAY.
WHILE THE EVOLUTION OF SURFACE AND UPPER-LEVEL FEATURES ARE IN
QUESTION EARLY NEXT WEEK...CURRENTLY THE PREPONDERANCE OF THE
EVIDENCE SUGGESTS A MOISTENING AIR MASS WITH INCREASING LIFT. AT A
MINIMUM...ATLANTIC MOISTURE SHOULD BE ABLE TO SPREAD INTO CENTRAL
NORTH CAROLINA...AND THE UPPER-LEVEL FLOW...PERSISTENTLY
SOUTHWEST...BECOMES LESS CONFLUENT. AT LEAST SLIGHT CHANCES FOR
SHOWERS AND THUNDERSTORMS WILL BE FORECAST MONDAY...WITH SLIGHTLY
HIGHER CHANCES IN THAT CATEGORY OVER THE WESTERN PIEDMONT DUE TO
GREATER INSTABILITY AND CONVERGENCE EXPECTED TOWARD THE MOUNTAINS...
ALONG WITH A MORE FAVORABLE UPSLOPE FLOW FOR DEEPER CONVECTION WHICH
MAY THEN MOVE INTO THE TRIAD AND AREAS NEAR THE YADKIN RIVER ON THE
WESTERLY THERMAL WIND AS CURRENTLY FORECAST. BY TUESDAY...MOISTENING
CONTINUES...AND WITH A SLIGHTLY MORE DIFFLUENT FLOW ALOFT UNDER A
SERIES OF MID-LEVEL WAVES MOVING THROUGH ON THE SOUTHWEST FLOW...
AT LEAST CHANCES FOR SHOWERS AND THUNDERSTORMS ARE EXPECTED. GFSX
MOS ENSEMBLE GUIDANCE POPS ARE VIRTUALLY ALL ABOVE CLIMATOLOGY
MONDAY AND TUESDAY...AND IT IS POSSIBLE OVER TIME THAT CHANCES FOR
PRECIPITATION WILL INCREASE DURING PART OR ALL OF THOSE TWO DAYS...
WITH THAT INCREASE SEEMINGLY MORE LIKELY FOR TUESDAY.
1000-850MB THICKNESSES SUPPORT TEMPERATURES EACH DAY FROM THE MID
70S TO NEAR 80 DEGREES...BASICALLY AROUND NORMAL. HIGHEST
THICKNESSES ARE SATURDAY...BUT THE DAY TO DAY VARIATION IS ON THE
ORDER OF 5 TO 10M ON BOTH THE GFS AND ECMWF. LEANED TOWARD COOLER
VALUES TUESDAY DUE TO THE INCREASING POTENTIAL FOR CLOUDS AND
PRECIPITATION...BUT STILL SLIGHTLY ABOVE THE HPC GUIDANCE VALUES FOR
NOW BASED ON EXPECTED WARMER OVERNIGHT LOWS AS A RESULT OF CLOUD
COVER...AND SOME WARMING POTENTIAL ANTICIPATED DUE TO THE TIME OF
YEAR.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
AS OF 205 PM TUESDAY...
GOOD CONFIDENCE OF VFR/MVFR CIGS AND VSBY THIS AFTN/EVE...IFR/LIFR
CIGS EXPECTED LATE TONIGHT WITH STRATUS...PERIODS OF MVFR/IFR
CONDITIONS LIKELY AT TIMES WED WITH SCT THUNDERSTORMS.
STRATUS AND WIDELY SCT SHOWERS SHOULD CONTINUE NEAR KINT/KGSO
THROUGH THE LATE AFTN WITH PERIODS OF MVFR CONDITIONS WHILE
KRDU/KRWI/KFAY WILL LARGELY EXPERIENCE VFR CONDITIONS THROUGH LATE
AFTN. SCT SHOWERS AND POSSIBLY A THUNDERSTORM ACROSS THE WESTERN
PIEDMONT WILL MOVE EAST AND WEAKEN THIS EVENING PERHAPS PRODUCING A
BRIEF PERIOD OF MVFR CONDITIONS. FORECAST SOUNDINGS INDICATED LOW
STRATUS AND POSSIBLY SOME FOG WILL DEVELOP DURING THE PREDAWN HOURS.
NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP AHEAD OF
A COLD FRONT DURING THE LATE MORNING AND EARLY AFTERNOON WED AND
THEN MOVE EASTWARD. THE BEST CHANCE WILL OCCUR AFTER THE CURRENT TAF
PERIOD AND HAVE OMITTED THE MENTION OF THUNDER FOR NOW. SOUTHERLY
SURFACE WINDS WITH A FEW GUSTS TO AROUND 15KT THIS AFTERNOON WILL
DIMINISH TO LIGHT SOUTHERLY TONIGHT AND THEN SOUTHWEST AT AROUND
10KTS ON WEDNESDAY.
LOOKING FURTHER AHEAD...THE COLD FRONT WILL MOVE OFFSHORE AROUND
MIDNIGHT THURSDAY WITH LINGERING SHOWERS AND LOW CIGS DISSIPATING BY
DAYBREAK THURSDAY. HIGH PRESSURE BUILDS INTO THE REGION ON THURSDAY
AND PERSISTS WITH FAIR WEATHER FROM FRIDAY THROUGH SUNDAY. -BLAES
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLAES
NEAR TERM...BLAES
SHORT TERM...BLAES
LONG TERM...DJF
AVIATION...BLAES
AREA FORECAST DISCUSSION
NWS RALEIGH NC
318 PM EDT TUE MAY 8 2012
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE WEST TONIGHT...THEN SLOWLY
PROGRESS EAST THROUGH THE CAROLINAS WEDNESDAY AND WEDNESDAY NIGHT.
HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT ON THURSDAY AND
FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 315 PM TUESDAY...
LATEST SFC ANALYSIS SHOWS A COLD FRONT EXTENDING SOUTHWESTERLY
ACROSS THE OH AND TN VALLEYS. MULTIPLE WEAK SFC TROUGHS WERE NOTED
ACROSS THE SOUTHERN APPALACHIANS AND GA/SC. LATEST SPC MESOANALYSIS
INDICATES A WEAKLY UNSTABLE AIRMASS ACROSS FAR WESTERN NC AND SC
WITH MLCAPE VALUES OF AROUND 250-500 J/KG IN A REGION OF ENHANCED
SFC DEW POINTS IN THE LOW/MID 60S. FURTHER EAST ACROSS THE PIEDMONT
AND COASTAL PLAIN THE AIRMASS IS MORE STABLE WITH LITTLE OR NO
SBCAPE/MLCAPE IN A REGION OF DEW POINTS IN THE MID 50S TO AROUND 60.
SCT SHOWERS CONTINUE TO MOVE NORTHEAST AT AROUND 20KTS. MUCH OF
CENTRAL NC UNDER A BKN CLOUD DECK WITH CIGS RANGING FROM 3-5KFT.
RECENT SIMULATIONS FROM THE WRF HIRESW AND HRRR SUGGEST THAT THE SCT
CONVECTION WILL PERSIST INTO THE EVENING HOURS AND CONTINUE TO SHIFT
EASTWARD. IN FACT SOME SIMULATION SUGGEST THAT THE CONVECTION ACROSS
THE FOOTHILLS WILL INTENSIFY A BIT AND GROW INTO A BROKEN LINE AND
MOVE ACROSS THE WESTERN PIEDMONT INTO THE EASTERN PIEDMONT BUT
LIKELY WEAKEN OR HOLD WEST OF THE COASTAL PLAIN. THREAT OF SEVERE
CONVECTION THIS AFTN/EVE IS LIMITED WITH A WEAKLY UNSTABLE AIRMASS
THIS AFTN CHARACTERIZED BY MLCAPE VALUES LESS THAN 500 J/KG...MODEST
0-6KM BULK SHEAR OF 15 KTS OR LESS AND WEAK MID LEVEL LAPSE RATES.
GIVEN AN INCREASE IN PW VALUES NOW APPROACHING 1.7 INCHES IN THE
SOUTHERN PIEDMONT...SOME LOCATIONS COULD SEE HEAVY RAIN THIS
EVENING. THREAT OF PRECIPITATION OVERNIGHT DECREASES SOMEWHAT WITH
LIMITED FORCING FOR ASCENT BUT WILL MAINTAIN AT LEAST A SLIGHT CHC
POP OVERNIGHT. GIVEN WIDESPREAD CLOUDINESS...A LIGHT SOUTHERLY WIND
TRANSPORTING SLIGHTLY HIGHER DEW POINTS INTO THE REGION...HAVE EDGED
TOWARD THE WARMER END OF THE GUIDANCE ENVELOPE WITH LOWS IN THE
62-66 RANGE. -BLAES
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 315 PM TUESDAY...
NORTHERN STREAM SHORTWAVE WILL DIVE INTO THE OH VALLEY TOWARD
DAYBREAK ON WED. BOTH THE NAM/GFS HAVE TRENDED A LITTLE SHARPER WITH
THIS FEATURE AS IT PIVOTS EAST AND BECOMES NEUTRAL OR EVEN BRIEFLY
NEGATIVELY TILTED WEDNESDAY NIGHT. THE BEST FORCING FOR ASCENT WITH
THE WAVE WILL REMAIN IN WV/VA NORTHWARD. THE POLAR JET STRENGTHENS
ACROSS PA/NY AND EXTEND SOUTHWEST TO THE OH VALLEY WED AFTERNOON
WILL LIKELY ONLY PROVIDE LIMITED FORCING FOR ASCENT OVER NC. WHILE
THE BEST FORCING WILL REMAIN NORTH OF NC...SFC DEW POINTS RECOVER
INTO THE LOWER TO MID 60S WHICH MAY BE SUFFICIENT FOR A MARGINALLY
UNSTABLE AIRMASS WITH MLCAPE VALUES CLIMBING TO AROUND 1000 J/KG IN
THE COASTAL PLAIN WITH SLIGHTLY REDUCED MLCAPE VALUES IN THE
PIEDMONT. NAM/GFS FORECAST SOUNDINGS BOTH DEPICT A MOIST ENVIRONMENT
WITH THIN CAPE AND LIMITED DRY AIR ALOFT. BULK SHEAR VALUES INCREASE
DURING THE AFTERNOON AND REACH THE 25-30KT RANGE IN THE EAST AND
AROUND 35KTS ACROSS THE WEST. WHILE THE SHEAR IS SUFFICIENT TO
SUPPORT SOME ORGANIZATION THE MOST PROFILES SUGGEST THE SEVERE
WEATHER THREAT MAY BE SOMEWHAT LIMITED. WITH THE MEAN WIND PARALLEL
TO THE APPROACHING COLD FRONT...THE CONVECTION WILL LIKELY TAKE ON A
MORE LINEAR ORIENTATION BUT ANY DISCRETE STORM WILL HAVE AN
INCREASED SEVERE WEATHER THREAT. PW VALUES CLIMB TO AROUND 1.75
INCHES
AND THE CONVECTION WILL LIKELY BECOME ORIENTED PARALLEL TO THE
THE NORTHEAST MOTION...SUGGESTING THAT STORMS WILL HAVE THE
POTENTIAL TO DUMP HEAVY RAIN OVER A GIVEN LOCATION FOR A PROLONGED
PERIOD OF TIME. GIVEN THIS...THE PRIMARY SEVERE THREAT ON WEDNESDAY
AND WEDNESDAY EVENING WILL BE FLOODING AND WET DOWNBURSTS. WILL RAMP
UP POPS INTO THE LIKELY RANGE ON WEDNESDAY AFTERNOON AND EARLY
EVENING AND THEN QUICKLY DIMINISH POPS FROM WEST TO EAST AFTER
MIDNIGHT. HIGH TEMPERATURES ON WEDNESDAY WILL RANGE IN THE MID 70S
WEST TO THE UPPER 70S TO AROUND 80 EAST. WILL KEEP LOWS ON WEDNESDAY
NIGHT TOWARD THE HIGHER END OF THE GUIDANCE RANGE GIVEN THE CLOUD
COVER AND TENDENCY FOR OVERNIGHT LOWS TO REMAIN ELEVATED WITH COLD
FRONTAL PASSAGES LATE AT NIGHT. LOWS IN THE MID 50S NORTHWEST TO
AROUND 60 SOUTHEAST. -BLAES
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS OF 300 PM TUESDAY...
THURSDAY THROUGH FRIDAY...THE UPPER TROUGH AXIS PUSHES EAST OF
CENTRAL NORTH CAROLINA QUICKLY DURING THE MORNING...WITH THE JET
ALOFT ALSO MOVING EAST. GOOD SUBSIDENCE TAKES PLACE AS HIGH PRESSURE
BUILDS IN...WITH BUFR SOUNDINGS AT 12Z STABLE TO DEEP CONVECTION
THROUGHOUT CENTRAL NORTH CAROLINA ON BOTH THE NAM AND THE GFS.
PRECIPITABLE WATER VALUES THAT FALL TO AROUND 0.75 INCH AROUND 12Z
THURSDAY FALL FURTHER TO AROUND 0.5 INCH BY 18Z THURSDAY...WHERE
THEY REMAIN THROUGH THE DAY ON FRIDAY. EXCEPT FOR VERY EARLY
THURSDAY...K INDICES ARE NEGATIVE...WELL NEGATIVE FOR FRIDAY.
WHILE IT WILL BE CLOSE TO THE INTERSTATE 95 CORRIDOR...EXPECT
PRECIPITATION TO BE JUST EAST OF CENTRAL NORTH CAROLINA BY 12Z
THURSDAY. FROM THERE...SKIES SHOULD CLEAR...BUT A RELATIVE MAXIMUM
OF 850MB THETA-E IN THE COASTAL PLAIN COULD YIELD SOME SHALLOW
AFTERNOON CU. IN ADDITION...A FEW CLOUDS COULD DRIFT FROM THE
MOUNTAINS...WHERE COOL AIR ALOFT WILL MAKE CONDITIONS THERE
RELATIVELY UNSTABLE...TOWARD THE TRIAD...BUT THE AIR SHOULD BE SO
STABLE THAT ONLY FEW SHOULD MAKE IT TO NEAR KINT AND KGSO. THE
SURFACE GRADIENT BEHIND THE FRONT WILL BE TIGHT TO START THE DAY...
RESULTING IN WIND GUSTS WITH MIXING AS HIGH AS THE LOWER 20S MPH
BEFORE 925MB WINDS FALL TO AROUND 15KT IN THE AFTERNOON...LESSENING
THE WIND GUSTS. UNDER OVERALL 850MB THETA-E TROUGHINESS FRIDAY...AND
AMPLE SUBSIDENCE AND DRY AIR...UNDER A SLACK GRADIENT AS WELL...
EXPECT PLENTY OF SUNSHINE AND CALM CONDITIONS FOR THE DAY...POSSIBLY
A BRIEF NOTICEABLE WIND GUST TO AROUND 10KT WITH MIXING EARLY.
BASED ON A COMBINATION OF 1000-850MB THICKNESSES...MOS GUIDANCE...
AND EXPECTED MIXING BASED ON BUFR SOUNDINGS...FORECAST HIGHS NEAR
THE HIGHER MAV MOS ON THURSDAY. WITH A FORECAST NEARER THE COOLER
GUIDANCE THURSDAY NIGHT UNDER A CLEAR SKY AND DIMINISHING WIND...
TEMPERATURES IN CENTRAL NORTH CAROLINA FRIDAY SHOULD BE SIMILAR TO
THURSDAY WITH A THICKNESS DIFFERENCE OF ONLY ABOUT 5M. FOR
NOW...WENT ABOUT A DEGREE COOLER FRIDAY COMPARED TO THURSDAY DUE TO
THE LIGHT...GENERALLY NORTHERLY LOW-LEVEL FLOW.
HEIGHTS ALOFT RISE NOTICEABLY FRIDAY NIGHT INTO SATURDAY...BEFORE
HEIGHTS START TO FALL AGAIN AS A WEAKENING UPPER-LEVEL LOW THAT
MOVES FROM THE SOUTHWEST STATES INTO THE SOUTH PLAINS SLOWLY PUSHES
FARTHER EAST. THE SOUTHEAST CONUS FALLS ON THE DOWNSTREAM SIDE OF
THE UPPER REMNANT TROUGH BY THE END OF THE WEEKEND...AND WHILE A
MID-LEVEL SHORTWAVE OF SOME STRENGTH SHOULD REACH CENTRAL NORTH
CAROLINA BY LATE SUNDAY...THE UPPER FLOW IS INITIALLY CONFLUENT AND
THE SURFACE RIDGE AXIS REMAINS OVERHEAD. DRY CONDITIONS SHOULD EXIST
FRIDAY NIGHT THROUGH SATURDAY IN HIGH PRESSURE SURFACE AND
ALOFT...AND WILL CONTINUE A DRY FORECAST FOR NOW THROUGH SUNDAY DUE
TO THE PRESENCE OF SURFACE HIGH PRESSURE AND THE CONFLUENT FLOW
ALOFT. LATE SUNDAY AND SUNDAY NIGHT...IT IS POSSIBLE THAT THE
SURFACE RIDGE AXIS STARTS TO MOVE NORTH OF THE AREA RESULTING IN
INCREASING ATLANTIC MOISTURE...AND WHILE AN ISOLATED SHOWER OR
THUNDERSTORM IS POSSIBLE...WILL LEAVE IT OUT OF THE FORECAST FOR NOW
THAT FAR OUT IN TIME. MOST OF THE GUIDANCE IS DRY OR TRENDING DRIER
FOR SUNDAY.
WHILE THE EVOLUTION OF SURFACE AND UPPER-LEVEL FEATURES ARE IN
QUESTION EARLY NEXT WEEK...CURRENTLY THE PREPONDERANCE OF THE
EVIDENCE SUGGESTS A MOISTENING AIR MASS WITH INCREASING LIFT. AT A
MINIMUM...ATLANTIC MOISTURE SHOULD BE ABLE TO SPREAD INTO CENTRAL
NORTH CAROLINA...AND THE UPPER-LEVEL FLOW...PERSISTENTLY
SOUTHWEST...BECOMES LESS CONFLUENT. AT LEAST SLIGHT CHANCES FOR
SHOWERS AND THUNDERSTORMS WILL BE FORECAST MONDAY...WITH SLIGHTLY
HIGHER CHANCES IN THAT CATEGORY OVER THE WESTERN PIEDMONT DUE TO
GREATER INSTABILITY AND CONVERGENCE EXPECTED TOWARD THE MOUNTAINS...
ALONG WITH A MORE FAVORABLE UPSLOPE FLOW FOR DEEPER CONVECTION WHICH
MAY THEN MOVE INTO THE TRIAD AND AREAS NEAR THE YADKIN RIVER ON THE
WESTERLY THERMAL WIND AS CURRENTLY FORECAST. BY TUESDAY...MOISTENING
CONTINUES...AND WITH A SLIGHTLY MORE DIFFLUENT FLOW ALOFT UNDER A
SERIES OF MID-LEVEL WAVES MOVING THROUGH ON THE SOUTHWEST FLOW...
AT LEAST CHANCES FOR SHOWERS AND THUNDERSTORMS ARE EXPECTED. GFSX
MOS ENSEMBLE GUIDANCE POPS ARE VIRTUALLY ALL ABOVE CLIMATOLOGY
MONDAY AND TUESDAY...AND IT IS POSSIBLE OVER TIME THAT CHANCES FOR
PRECIPITATION WILL INCREASE DURING PART OR ALL OF THOSE TWO DAYS...
WITH THAT INCREASE SEEMINGLY MORE LIKELY FOR TUESDAY.
1000-850MB THICKNESSES SUPPORT TEMPERATURES EACH DAY FROM THE MID
70S TO NEAR 80 DEGREES...BASICALLY AROUND NORMAL. HIGHEST
THICKNESSES ARE SATURDAY...BUT THE DAY TO DAY VARIATION IS ON THE
ORDER OF 5 TO 10M ON BOTH THE GFS AND ECMWF. LEANED TOWARD COOLER
VALUES TUESDAY DUE TO THE INCREASING POTENTIAL FOR CLOUDS AND
PRECIPITATION...BUT STILL SLIGHTLY ABOVE THE HPC GUIDANCE VALUES FOR
NOW BASED ON EXPECTED WARMER OVERNIGHT LOWS AS A RESULT OF CLOUD
COVER...AND SOME WARMING POTENTIAL ANTICIPATED DUE TO THE TIME OF
YEAR.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
AS OF 205 PM TUESDAY...
GOOD CONFIDENCE OF VFR/MVFR CIGS AND VSBY THIS AFTN/EVE...IFR/LIFR
CIGS EXPECTED LATE TONIGHT WITH STRATUS...PERIODS OF MVFR/IFR
CONDITIONS LIKELY AT TIMES WED WITH SCT THUNDERSTORMS.
STRATUS AND WIDELY SCT SHOWERS SHOULD CONTINUE NEAR KINT/KGSO
THROUGH THE LATE AFTN WITH PERIODS OF MVFR CONDITIONS WHILE
KRDU/KRWI/KFAY WILL LARGELY EXPERIENCE VFR CONDITIONS THROUGH LATE
AFTN. SCT SHOWERS AND POSSIBLY A THUNDERSTORM ACROSS THE WESTERN
PIEDMONT WILL MOVE EAST AND WEAKEN THIS EVENING PERHAPS PRODUCING A
BRIEF PERIOD OF MVFR CONDITIONS. FORECAST SOUNDINGS INDICATED LOW
STRATUS AND POSSIBLY SOME FOG WILL DEVELOP DURING THE PREDAWN HOURS.
NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP AHEAD OF
A COLD FRONT DURING THE LATE MORNING AND EARLY AFTERNOON WED AND
THEN MOVE EASTWARD. THE BEST CHANCE WILL OCCUR AFTER THE CURRENT TAF
PERIOD AND HAVE OMITTED THE MENTION OF THUNDER FOR NOW. SOUTHERLY
SURFACE WINDS WITH A FEW GUSTS TO AROUND 15KT THIS AFTERNOON WILL
DIMINISH TO LIGHT SOUTHERLY TONIGHT AND THEN SOUTHWEST AT AROUND
10KTS ON WEDNESDAY.
LOOKING FURTHER AHEAD...THE COLD FRONT WILL MOVE OFFSHORE AROUND
MIDNIGHT THURSDAY WITH LINGERING SHOWERS AND LOW CIGS DISSIPATING BY
DAYBREAK THURSDAY. HIGH PRESSURE BUILDS INTO THE REGION ON THURSDAY
AND PERSISTS WITH FAIR WEATHER FROM FRIDAY THROUGH SUNDAY. -BLAES
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLAES
NEAR TERM...BLAES
SHORT TERM...BLAES
LONG TERM...DJF
AVIATION...BLAES
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
251 PM EDT TUE MAY 8 2012
.SYNOPSIS...
A STRONG COLD FRONT WILL APPROACH FROM THE WEST TONIGHT AND BRING
SHOWERS AND THUNDERSTORMS TO THE AREA WEDNESDAY AND WEDNESDAY NIGHT.
COOL AND DRY HIGH PRESSURE WILL BUILD INTO THE AREA THURSDAY AND
PERSIST THROUGH THE WEEKEND. THE HIGH WILL SLIP OFF THE COAST BY
LATE SUNDAY MOVING FARTHER OFFSHORE AS NEXT FRONT APPROACHES LATE
MONDAY INTO TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 245 PM TUESDAY...LARGE SCALE GUIDANCE AS WELL AS LOCAL
MESOSCALE WRF/HRRR SHOW LINE OF CONVECTION DEVELOPING BY 20Z A FEW
COUNTIES WEST OF THE CWA BUT LARGELY FIZZLING OUT DUE TO LOSS OF
HEATING BEFORE REACHING OUR WESTERN ZONES. THIS SEEMS PLAUSIBLE AS
CU FIELD HAS NOT SHOWN SIGNIFICANT AGITATION/VERTICAL DEVELOPMENT
OVER ANY OF THE ILM COUNTIES AND RUC ANALYSIS SHOWS VIRTUALLY NO
CAPE OVER THE REGION. HAVE TRIMMED POPS ONCE AGAIN FOR THE REST OF
THE AFTERNOON AND EVENING TO BE CAPPED AT SLIGHT CHANCE AND CONFINED
EVEN FURTHER WEST THAN THE PREVIOUS/MID MORNING TRIMMING. SUSPECT
THAT THE OVERNIGHT HOURS REMAIN LARGELY RAIN-FREE AS WELL BUT IN
VERY WEAK WAA THE SLIGHT CHANCE POPS FROM CONTINUITY ARE HARD TO
ARGUE WITH AS OVERALL MOISTURE GROWS DEEPER.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 245 PM TUESDAY...MAIN FORECAST CHALLENGE IS THE POTENTIAL FOR
SEVERE WEATHER WITH A COLD FRONT MOVING THROUGH THE AREA WEDNESDAY
AND WEDNESDAY NIGHT. AMPLE CLOUD COVER AHEAD OF THE FRONT WILL
IMPACT THE INSTABILITY...HOWEVER RRQ OF AN H3 JET WILL ADD LIFT TO
THE REGION RESULTING IN DECENT CONVECTIVE COVERAGE. IN THE END...MAY
NEED TO DEAL WITH A FEW SEVERE TSTMS WITH DAMAGING WINDS AS THE
PRIMARY THREAT. SPC CONTINUES TO HIGHLIGHT NEARLY THE ENTIRE ILM
FORECAST AREA IN A SLIGHT RISK.
ONCE THE FRONT MOVES THROUGH MUCH DRIER CONDITIONS WILL PREVAIL WITH
NEAR SEASONABLE TEMPERATURES ON TAP. PRECIPITABLE WATER VALUES OF
1.7 INCHES WEDNESDAY AFTERNOON/EVE WILL DROP BELOW 0.75 INCHES
THURSDAY. TIME HEIGHT CROSS SECTIONS INDICATE A VERY DRY COLUMN
ABOVE H8 WHICH WILL LEAD TO MOSTLY SUNNY SKIES BY THURSDAY MORNING.
HIGHS ON THURSDAY WILL BE AROUND 80 MOST LOCATIONS AND LOWS WILL BE
A COUPLE CATEGORIES BELOW NORMAL THURSDAY NIGHT (LOWER 50S PEE DEE
AND LBT AREAS TO THE MID 50S INLAND COASTAL AREAS). LASTLY...UNTIL
THE LOW-LEVEL WIND FIELD WEAKENS COULD SEE 20-25 MPH GUSTS IN
NORTHWEST FLOW THURSDAY MORNING.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 245 PM TUESDAY...PERIOD STARTS OFF DRY WITH TEMPERATURES NEAR
TO SLIGHTLY CLIMO AS 5H TROUGH AXIS MOVES OFF THE COAST AND SURFACE
HIGH SETTLES IN FROM THE NORTH. COMBINATION OF SURFACE HIGH AND WEAK
5H RIDGE AXIS OVER THE WEEKEND SHOULD KEEP THE AREA DRY FOR MUCH OF
THE WEEKEND. LATE SUN AFTERNOON RETURN FLOW AROUND EXITING HIGH AND
DEEPER SOUTHWEST FLOW ON THE WEST SIDE OF EXITING RIDGE ALOFT MAY
LEAD TO SOME CONVECTION ACROSS WESTERN AREAS. WILL CARRY SILENT POP
FOR SUN AFTERNOON AT THIS POINT. PRECIP CHANCES INCREASE DURING THE
MON/TUE TIMEFRAME. MEDIUM RANGE GUIDANCE IS SHOWING BROAD 5H TROUGH
DEVELOPING OVER THE EASTERN US NEXT WEEK...THOUGH MANY OF THE
PARTICULARS REMAIN IN QUESTION. IT DOES APPEAR THERE WILL BE PLENTY
OF MOISTURE IN THE AREA...GIVEN THE DEEP SOUTHWEST FLOW. SETUP MON
LOOK FAVORABLE AS FAR AS DIURNAL CONVECTION IS CONCERNED. TUE LOOKS
A LITTLE MORE SYNOPTIC WITH A WEAK COASTAL TROUGH OR WARM FRONT IN
THE VICINITY AND LOW PRESSURE MOVING UP THE COAST. AT THIS POINT
WILL CONTINUE WITH SLIGHT CHANCE MON/MON NIGHT INCREASING TO LOW
CHANCE FOR TUE/TUE NIGHT. TEMPERATURES WILL REMAIN NEAR TO SLIGHTLY
BELOW CLIMO THROUGH THE PERIOD.
&&
.AVIATION /18Z TUESDAY THROUGH SATURDAY/...
AS OF 18Z...VISIBLE SATELLITE IMAGES AND SURFACE OBSERVATIONS THIS
AFTERNOON DEPICT WIDESPREAD SCATTERED TO BROKEN LOW CLOUDS FROM 3-5K
JUST INLAND OF THE COAST. NO PRECIPITATION IS CURRENTLY OCCURRING.
BERMUDA HIGH PRESSURE WILL CONTINUE TO ADVECT LOW LEVEL MOISTURE
INLAND THIS TAF VALID PERIOD ON SOUTHEAST TO SOUTH WINDS. CONFIDENCE
THAT PERIODS OF MVFR CEILINGS WILL OCCUR THIS TAF VALID PERIOD IS
HIGH...BUT CONFIDENCE IN THE EXACT TIMING IS LOW. IN GENERAL...MVFR
CEILINGS AND/OR MVFR VISIBILITIES WILL BE POSSIBLE LATE THIS
AFTERNOON INTO THE EARLY EVENING AT FLO AS SHOWERS AND POSSIBLY AN
ISOLATED THUNDERSTORM MAINLY WEST OF THE TERMINAL SPREAD EAST. SOME
OF THIS PRECIPITATION WILL REACH THE LBT TERMINAL BUT EXPECT VFR TO
CONTINUE AT THAT TERMINAL. MVFR CEILINGS WILL BECOME MORE LIKELY
AFTER 07-10Z.
MVFR CEILINGS WILL CONTINUE AFTER SUNRISE THROUGH THE MORNING HOURS
AS PRECIPITATION CHANCES INCREASE AHEAD OF AN APPROACHING COLD
FRONT. WINDS WILL BE SOUTH TO SOUTHWEST 5 TO 10 KNOTS.
EXTENDED OUTLOOK...MODERATE CONFIDENCE FOR SCATTERED TO POSSIBLE
NUMEROUS SHOWERS AND THUNDERSTORMS WEDNESDAY AFTERNOON THROUGH
WEDNESDAY NIGHT...WITH INTERMITTENT IFR POSSIBLE. BECOMING VFR
THURSDAY AND CONTINUING THROUGH SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 245 PM TUESDAY...S TO SE WINDS OVERNIGHT NO HIGHER THAN IN THE
10 TO 15 KT RANGE AND EVEN THIS MAY BE A LITTLE PESSIMISTIC AS HIGH
PRESSURE REMAINS WELL DISPLACED OFF THE NE AND MID ATLANTIC COAST.
LOCAL SWAN INITIALIZED ABOUT 0.5 FT TOO HIGH BUT OTHERWISE SHOWED
DECENT GRADIENTS AND WAS FOLLOWED CLOSELY WITH AFOREMENTIONED VALUE
SUBTRACTED FROM BASE VALUES. AS SUCH SEAS WILL GENERALLY BE IN THE 2
T 3 FT RANGE AND COMPRISED MOSTLY OF 7 SECOND WIND CHOP AND
DIMINISHING 10-11 SECOND SWELL.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 245 PM TUESDAY...SOUTHERLY WINDS WEDNESDAY AHEAD OF THE COLD
FRONT WILL VEER TO A WEST-NORTHWEST DIRECTION IN ITS WAKE WEDNESDAY
NIGHT. ADDITIONAL VEERING TO A NORTHERLY DIRECTION EXPECTED THURSDAY
AS HIGH PRESSURE BUILDS ACROSS THE WATERS. SPEEDS WILL INCREASE
10-15 KTS AHEAD OF THE FRONT THEN PEAK AROUND 15 KNOTS IN ITS WAKE.
COULD SEE A MINOR SURGE ARRIVE OVER THE WATERS LATE THURSDAY WITH
SPEEDS PICKING UP OVER THE WATERS AWAY FROM THE COAST. SEAS WILL
RANGE FROM 2-3 FT ACROSS LONG BAY AND 2-4 FT ACROSS ONSLOW BAY
WEDNESDAY...THEN NEARLY A SOLID 4 FT OFF CAPE FEAR AND 3 FT OVER
LONG BAY WED NIGHT. SEAS WILL BE AROUND 3 FT THURSDAY THEN SLIGHTLY
INCREASE AWAY FROM THE COAST LATE THURSDAY NIGHT WITH THE
AFOREMENTIONED MINOR SURGE. OTHERWISE...SCATTERED TO NUMEROUS
SHOWERS AND TSTMS WILL LOCALLY ENHANCE WINDS...ESPECIALLY WEDNESDAY
NIGHT.
LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 245 PM TUESDAY...NORTHERLY FLOW AT THE START OF THE PERIOD
WILL BE DECREASING AND VEER TO NORTHEAST THROUGHOUT THE DAY AS
SURFACE HIGH SETTLES SOUTH. RELAXED GRADIENT WILL SEE SPEEDS DROP TO
10 KT OR LESS BY AFTERNOON. WEAK SEA BREEZE DEVELOPS IN THE
AFTERNOON...BUT COOLER NORTHEAST FLOW WILL HELP LIMIT THE STRENGTH
OF THE NEAR SHORE CIRCULATION. LIGHT NORTHEAST FLOW CONTINUE TO VEER
FRI NIGHT INTO SAT AS CENTER OF THE HIGH MOVES OFF THE COAST JUST
NORTH OF THE WATERS. EAST TO SOUTHEAST FLOW AROUND 10 KT SAT BECOMES
SOUTHEAST SAT NIGHT AND SUN. SPEEDS START TO PICK UP SUN INTO SUN
NIGHT AS GRADIENT BECOMES A LITTLE MORE DEFINED. WINDS UNDER 15 KT
THROUGH THE PERIOD WILL KEEP SEAS 2 TO 3 FT.
&&
.TIDES/COASTAL FLOODING...
AS OF 245 PM TUESDAY...DESPITE SOME OF THE APPRECIABLE DEVIATIONS OF
RECENT HIGH TIDES THE WANING MOON IS HAVING LESS OF AN EFFECT NOW
WITH EACH CYCLE. AFTER MONITORING THIS EARLY AFTERNOON`S HIGH TIDE
(THE LOWER OF THE TWO) THE ET SURGE MODEL APPEARED TO DO QUITE WELL.
SAID MODEL STILL BRINGS EAST FACING BEACHES AND CAPE FEAR RIVER TO
THE VERY CUSP OF MINOR FLOOD...WHICH IS QUITE TYPICAL/QUITE COMMON.
HAVE MADE NO CHANGES TO THE CURRENT ADVISORY. A LITTLE LESS CERTAIN
ABOUT BRUNSWICK COUNTY BEACHES WITH TIDE GAGE NOT WORKING BUT THERE
WERE SEVERAL REPORTS TODAY OF FLOODING OCEAN ISLE BEACH...WOULD
PREFER TO LEAVE ADVISORY UNCHANGED THERE AS WELL AT THIS TIME.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...COASTAL FLOOD ADVISORY FROM 8 PM THIS EVENING TO MIDNIGHT EDT
TONIGHT FOR NCZ106-108-110.
COASTAL FLOOD ADVISORY FROM 11 PM THIS EVENING TO 3 AM EDT
WEDNESDAY FOR NCZ107.
MARINE...NONE.
&&
$$
NEAR TERM...MBB
SHORT TERM...SRP
LONG TERM...III
AVIATION...MRR
TIDES/COASTAL FLOODING...MBB
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
318 PM CDT TUE MAY 8 2012
.TONIGHT AND WEDNESDAY...FORECAST CONFIDENCE...MEDIUM TO HIGH
500MB SHORTWAVE TROUGH CONTINUES TO SLIDE SOUTHEAST ACROSS MINNESOTA
AND NORTHWEST WISCONSIN. THIS FEATURE HAS 500MB TEMPERATURES OF 24
TO 27 BELOW ZERO CELSIUS PER RUC ANALYSIS IN ITS CORE FROM SOUTHWEST
MINNESOTA TO NORTHERN WISCONSIN. IN ADDITION...STEEP LOW TO MID
LEVEL LAPSE RATES WITH LOW LEVEL MLCAPES OF A HUNDRED OR SO J/KG
SEEN ACROSS THIS AREA. THESE FEATURES HELPING GENERATE SCATTERED TO
NUMEROUS SHOWERS...WHICH ARE ENTERING THE WESTERN AND NORTHWESTERN
COUNTIES.
THESE SHOULD CONTINUE TO SPREAD EAST SOUTHEAST ACROSS THE FORECAST
AREA LATE THIS AFTERNOON AND EARLY THIS EVENING...WITH PASSAGE OF
SHORTWAVE TROUGH. ISOLATED THUNDER POSSIBLE AS WELL...WITH A FEW
LIGHTNING STRIKES SEEN TO THE NORTHWEST OF THE AREA EARLIER TODAY.
LOW FREEZING LEVELS MAY ALLOW FOR SOME GRAUPEL OR SMALL HAIL TO FALL
WITH A STORM. MAIN SURFACE TROUGH DOES NOT SHIFT SOUTH THROUGH THE
AREA UNTIL LATER TONIGHT...SO NOT CONCERNED ABOUT COLD AIR FUNNELS.
AFTER SHORTWAVE TROUGH SWINGS THROUGH BY 06Z WEDNESDAY...ANOTHER
VORTICITY MAXIMUM SLIDES SOUTH THROUGH THE AREA LATE TONIGHT AND
EARLY WEDNESDAY MORNING. ALTHOUGH LOW CLOUDS ARE EXPECTED TO MOVE
INTO THE AREA LATER TONIGHT AND INTO WEDNESDAY MORNING IN THE
EAST...NOT SEEING MUCH MOISTURE ABOVE THIS LAYER TO WARRANT ANYTHING
MORE THAN ISOLATED SHOWERS AFTER MIDNIGHT...WITH WEDNESDAY MORNING
DRY.
CLOUDS GRADUALLY LIFT AND SCATTER OUT BY THE AFTERNOON FROM WEST TO
EAST ACROSS THE AREA...WITH HIGH PRESSURE BRINGING QUIET WEATHER.
PRESSURE GRADIENT WEAKENS ENOUGH FOR WINDS TO VEER NORTHEAST NEAR
THE LAKE IN THE AFTERNOON. HIGHS SHOULD RISE INTO THE UPPER 50S
LAKESIDE...TO THE LOWER TO MID 60S INLAND PER 925MB TEMPERATURES.
.WEDNESDAY NIGHT THROUGH FRIDAY...FORECAST CONFIDENCE...MEDIUM TO HIGH
HIGH PRESSURE CENTERED OVER ILLINOIS WEDNESDAY NIGHT WILL SLOWLY
DRIFT EASTWARD TO THE OHIO RIVER VALLEY BY FRIDAY EVENING. THIS WILL
BRING FAIR WEATHER TO SOUTHERN WISCONSIN THROUGH THIS PERIOD...WITH
ONLY A FEW MID AND HIGH LEVEL CLOUDS PASSING THROUGH AT TIMES.
925 MB TEMPS ANTICIPATED TO INCREASE TO AROUND 14-15C BY THU
AFTERNOON...THEN TO UP TO 18C BY FRI AFTERNOON. WITH A GOOD AMOUNT
OF SUNSHINE EXPECTED...SHOULD BE A NICE COUPLE OF DAYS WITH HIGH
TEMPS RISING TO A FEW DEGREES ABOVE NORMAL BY FRIDAY. LIGHT WINDS
THURSDAY SHOULD ALLOW A LAKE BREEZE TO PUSH INLAND...KEEPING THINGS
COOLER NEAR THE LAKE. AN APPROACHING TROUGH OF LOW PRESSURE FRIDAY
MAY INCREASE SOUTHWEST WINDS ENOUGH TO KEEP THE LAKE BREEZE OFF
SHORE. TEMPS WERE THUS BUMPED UP A BIT NEAR THE LAKE.
.FRIDAY NIGHT AND SATURDAY...FORECAST CONFIDENCE...MEDIUM
WEAK SFC TROUGH AND COLD FRONT TO SLIDE THOUGH FRIDAY NIGHT AND INTO
SATURDAY. LIFT NOT THAT GREAT OVERALL...BUT GFS PRECIPITABLE WATER
VALUES DO GET UP OVER AN INCH...SO KEPT SOME LOW POPS GOING. A
LITTLE BIT OF ELEVATED CAPE IN THE GFS SOUNDINGS...SO LEFT A SLIGHT
CHANCE OF THUNDER IN THE FORECAST AS WELL. TEMPS SHOULD BE COOLER ON
SATURDAY BEHIND THE FRONT...ESPECIALLY IF CLOUDS AND SHOWERS LINGER
THROUGH THE MORNING HOURS.
.SUNDAY THROUGH TUESDAY...FORECAST CONFIDENCE...MEDIUM TO HIGH
HIGH PRESSURE GENERALLY EXPECTED FOR SUNDAY THROUGH TUESDAY...WITH
MOSTLY SUNNY TO PARTLY CLOUDY SKIES AND NEAR NORMAL TEMPERATURES.
LOOKS LIKE A PRETTY NICE START TO NEXT WEEK.
&&
.AVIATION/00Z TAFS/...
SCATTERED TO NUMEROUS RAIN SHOWERS WILL DEVELOP BY 00Z WEDNESDAY
ACROSS TAF SITES...AND LINGER TO AROUND 03Z TO 04Z WEDNESDAY...AS
UPPER LEVEL DISTURBANCE PASSES THROUGH AREA. BROKEN TO NEARLY
OVERCAST VFR CEILINGS ARE EXPECTED LATE THIS AFTERNOON AND EVENING
AS WELL. GUSTY WEST WINDS LATE THIS AFTERNOON WILL WEAKEN BY EARLY
THIS EVENING...AND VEER NORTHWEST TO NORTH LATER TONIGHT WITH
PASSAGE OF SURFACE WIND SHIFT.
CEILINGS WILL LOWER TO MVFR BY 08Z TO 09Z WEDNESDAY ACROSS TAF
SITES...AND SHOULD LINGER UNTIL AROUND 15Z WEDNESDAY BEFORE MIXING
UP TO VFR LEVELS. BROKEN VFR DIURNAL CUMULUS SHOULD THEN LINGER
THROUGH THE REST OF THE DAY. NORTH WINDS AROUND 10 KNOTS ARE
EXPECTED THROUGH THE REST OF WEDNESDAY...VEERING NORTHEAST TO EAST
IN THE AFTERNOON AT MILWAUKEE AND KENOSHA.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TONIGHT/WEDNESDAY AND AVIATION...WOOD
WEDNESDAY NIGHT THROUGH TUESDAY...DDV