FXUS63 KOAX 010822
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
322 AM CDT WED JUN 1 2011
.DISCUSSION...
HEAT AND MOISTURE RETURN TO THE AREA TODAY...SPARKING POTENTIAL FOR
SHOWERS AND THUNDERSTORMS POSSIBLY THIS AFTERNOON AND MORE LIKELY
TONIGHT. SUBJECTIVE 00Z UPPER AIR ANALYSIS INDICATES UPPER LOW
CENTERED IN NORTHERN MN/SOUTHERN MB...WITH 500MB HEIGHT FALLS UP
TO 180M AHEAD OF IT AND RISES OF UP TO 150M BEHIND IT. NEXT UPPER
LOW WAS JUST OFF THE PACIFIC NORTHWEST COAST...WITH ZONAL TO
SOUTHWESTERLY FLOW ACROSS THE CENTRAL US. MOISTURE AT 850MB WAS
SHUNTED AHEAD OF THE LOW...WITH 8C+ DEWPOINTS EAST OF A LINE FROM
MI/IL/MO TO THE OK/TX PANHANDLES. SURFACE HIGH AT 08Z WAS CENTERED
IN NORTHEAST NEB/SOUTHEAST SD...WITH LOW DEVELOPING IN NORTHEAST
CO.
CONVECTIVE POTENTIAL REMAINS UNCERTAIN THROUGH THIS EVENING...WITH
BETTER CERTAINTY TONIGHT IN THE EASTERN CWA. AS 850MB WINDS RETURN
TO SOUTHERLY INTO THE PLAINS...MOISTURE TRANSPORT WILL FEED INTO KS
AND EVENTUALLY NEB/IA THROUGH THE DAY. RESULT WILL BE A
DESTABILIZING AIRMASS ACROSS THE AREA. HOWEVER...500MB HEIGHTS
WILL BE STEADY OR SLIGHTLY RISING TODAY...AND THERE IS LITTLE IF ANY
MECHANISM TO TRIGGER OR FOCUS CONVECTION IN EASTERN NEB IN THE
AFTERNOON. KEPT SLIGHT CHANCE TO CHANCE POPS IN THE LATE
AFTERNOON...BUT HAVE VERY LOW CONFIDENCE IN ANY DEVELOPMENT IN THE
AREA BEFORE MIDNIGHT...WITH SCANT AT BEST SUPPORT FROM THE SREF AND
WITH MOST OPERATIONAL MODELS REMAINING DRY IN THE AREA DURING THE
DAY. SHOULD STORMS DEVELOP...ADEQUATE 0-6KM BULK SHEAR WOULD
SUPPORT SUPERCELLS...AND IF THE STORMS COULD PERSIST LONG ENOUGH TO
BECOME ORGANIZED...WOULD SEE A POTENTIAL FOR ISOLATED SEVERE
HAIL/WINDS AT LEAST AND POSSIBLY AN ISOLATED TORNADO GIVEN FAVORABLE
0-1KM SHEAR AND HELICITY PROFILES.
AFTER MIDNIGHT TONIGHT...INCREASING LOW-LEVEL JET VEERS SLIGHTLY
INTO WESTERN IOWA...AND CONSENSUS IS MUCH BETTER WITH THE LATEST
RUNS IN INITIATING AN AREA OF CONVECTION IN WESTERN IOWA ALONG AN
AXIS OF 850MB MOISTURE CONVERGENCE. HAVE INCREASED POPS AFTER
06Z...WITH A CONTINUED THUNDER MENTION AS ELEVATED INSTABILITY
PERSISTS THROUGH THE NIGHT. SEVERE POTENTIAL IS LESS CERTAIN...BUT
GIVEN FORECAST ELEVATED INSTABILITY AND DEEP-LAYER BULK
SHEAR...WOULD NOT BE SURPRISED BY ELEVATED SEVERE HAILERS. CARRIED
A SMALL POP INTO THURSDAY MORNING AS WELL...TO CAPTURE THE POTENTIAL
FOR CONVECTION LINGERING IN THE AREA. FOR THE REST OF THE
CWA...HAVE BUMPED UP TEMPS A BIT ON THURSDAY AS EVEN 850MB MIX-DOWN
TEMPS ARE WELL INTO THE 90S...THOUGH DID HOLD EASTERNMOST CWA INTO
THE UPPER 80S WITH MORNING CLOUDY START.
KEPT CWA DRY THURSDAY AFTERNOON THROUGH FRIDAY. UPPER LOW WILL MAKE
EASTWARD PROGRESS...DRAGGING A SURFACE FRONT INTO THE CWA BY FRIDAY
AFTERNOON. SHOULD SEE STRONG HEATING AHEAD OF THE FRONT AGAIN ON
FRIDAY...AND NUDGED TEMPS UP THERE...WITH SLIGHTLY COOLER TEMPS
BEHIND THE FRONT IN THE NORTHWEST CWA. GFS KEEPS CWA CAPPED DURING
THE DAY ON FRIDAY...AND NEITHER GFS NOR ECMWF DEVELOP PRECIP IN THE
AREA BEFORE 00Z SATURDAY. DID KEEP SLIGHT CHANCE TO CHANCE POPS ON
FRIDAY NIGHT THOUGH...WITH THE POTENTIAL FOR NOCTURNAL
CONVECTION...AND WITH THE HIGHEST CHANCES AFTER MIDNIGHT.
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
06Z TAFS
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. WITH LIGHT
WINDS...CLEAR SKIES AND COOL TEMPERATURES...WE MAY SEE SOME VERY
LIGHT MVFR VISBY THIS MORNING AT OMA/LNK...BUT NOTHING SIGNIFICANT.
OTHERWISE SOUTHERLY FLOW WILL BE ON THE INCREASE AT ALL TAF SITES
TODAY WITH MID AND HIGH LEVEL CLOUDS INCREASING BY MID TO LATE
MORNING. DESPITE THE RETURN IN MOISTURE...THERE IS LITTLE TO TRIGGER
PRECIPITATION THROUGH THE DAY...AND THUS WILL LEAVE THE TAF SITES
DRY. A LITTLE BETTER SHOT AT PRECIPITATION DEVELOPS
TONIGHT...ESPECIALLY AT KOMA AFTER 05Z. ATTM WILL LEAVE THE TAFS DRY
TONIGHT DUE TO UNCERTAINLY IN TIMING OF THE POTENTIAL SCT ACTIVITY.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
MAYES/BOUSTEAD