FXUS63 KOAX 040804
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
304 AM CDT MON APR 4 2011
.DISCUSSION...
GUSTY WINDS CONTINUE ACROSS THE REGION TONIGHT. SUBJECTIVE 00Z UPPER
AIR ANALYSIS INDICATES NEGATIVELY TILTED UPPER-LEVEL TROUGH
EXTENDING FROM MB THROUGH ND/WY/UT...WITH 500MB HEIGHT FALLS UP TO
110M AHEAD OF IT. 850MB FRONT AT 00Z EXTENDED FROM LOW CENTERED
NEAR KDLH...THROUGH WESTERN IA/NORTHEASTERN KS/OK PANHANDLE...WITH
CWA IN THE COLD AIR ADVECTION BEHIND THE FRONT. BY 06Z...SURFACE
LOW WAS CENTERED IN SOUTHEASTERN WI...WITH FRONT EXTENDING THROUGH
IL/MO/EASTERN OK AND WITH THUNDERSTORMS ALONG AND JUST BEHIND THE
FRONT. SURFACE PRESSURE GRADIENT REMAINS TIGHT ACROSS THE
PLAINS...AND 3 HR PRESSURE RISES OF 3-4MB WERE MOVING INTO CENTRAL
NEB/EASTERN SD.
MAIN FORECAST CONCERN IS WINDS TODAY...THEN TEMPERATURE SWINGS
THROUGH MID-WEEK. WINDS HAVE TEMPORARILY LULLED IN EASTERN
NEB/WESTERN IA AS INITIAL FRONTAL SURGE HAS MOVED TO THE SOUTH...BUT
PEAK ISALLOBARIC FORCING IS JUST MOVING INTO THE AREA. EXPECT WINDS
TO INCREASE FROM WEST TO EAST THROUGH THE EARLY MORNING HOURS...AND
ALREADY AM SEEING WIND SPEEDS INCREASE AT WESTERN/NORTHWESTERN
SITES. WINDS WILL INCREASE AGAIN BY MID-MORNING AS DIURNAL MIXING
TAPS 40-45KT WINDS AT 800-900MB /AND EVEN UP TO 750MB MIXING
POTENTIAL/...WITH SPEEDS TAPERING FROM WEST TO EAST BY MID TO LATE
AFTERNOON AS PRESSURE GRADIENT FINALLY DECREASES. HAVE EXTENDED
WIND ADVISORY FOR ALL AREAS THROUGH 20Z...THOUGH EXPECT THAT WESTERN
SITES MAY BE ABLE TO CANCEL EARLY AND EASTERN SITES COULD NEED AN
EXTENSION. HAVE SHAVED A DEGREE OR TWO OFF THE MAX TEMP FORECAST
TODAY IN THE NORTHERN AND WESTERN CWA...AS EVEN MIXING TO 750MB WITH
SOME SUN YIELDS TEMPS ONLY IN THE MID TO UPPER 40S.
TEMPERATURES THEN BECOME THE FOCUS THROUGH MID-WEEK. WARM AIR
ADVECTION DEVELOPS ON TUESDAY WITH WEST TO SOUTHWEST LOW-LEVEL
FLOW...WITH 850MB TEMPS REBOUNDING ABOVE 10C BY 00Z WEDNESDAY. KEPT
MILD FORECAST UNDER FAVORABLE MIXING TO AROUND 800MB AND FAIRLY DRY
BOUNDARY LAYER. TUESDAY EVENING/NIGHT...A WEAK COLD FRONT IS
PROGGED TO MOVE ACROSS THE CWA. MOISTURE WILL BE TOO MEAGER TO
SUPPORT PRECIP GIVEN WEAK FORCING...BUT TEMPS WILL COOL A BIT ON
WEDNESDAY...AND HAVE TAPERED TEMPS IN THE NORTH DOWNWARD IN
PARTICULAR. PACE OF RECOVERY FOR THURSDAY BECOMES MUCH MORE
QUESTIONABLE AS A SURFACE LOW DEVELOPS IN WESTERN KS...WITH A WARM
FRONT LIFTING THROUGH KS AND POSSIBLY INTO SOUTHERN NEB THROUGH THE
DAY. NORTH OF THE FRONT...LIKELY WILL SEE COOLER TEMPS AND
DRIZZLY/RAINY WEATHER...WHILE THE SOUTH MAY SEE TEMPS POP UP AS THE
WARM SECTOR ENCROACHES. GFS SOLUTION IS FARTHER SOUTH THAN
ECMWF...BUT BOTH SOLUTIONS KEEP THE NORTHERN CWA IN THE COOL
SECTOR...AND HAVE TWEAKED TEMPS DOWNWARD. SOUTH AND PARTICULARLY
CENTRAL CWA IS MUCH LESS CERTAIN...AND TEMPS ARE LOW CONFIDENCE
THERE. DID LIMIT THUNDER MENTION TO ONLY THE AFTERNOON AND ONLY THE
SOUTHERN CWA AS INSTABILITY LOOKS LIMITED IN THE NORTH.
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
06Z TAFS
MVFR CIGS AND STRAY LIGHT SHOWERS WILL AFFECT EASTERN NEBRASKA TAF
SITES THROUGH 16Z MONDAY. STRONG NORTHWEST WINDS OF 25 TO 35 KTS
WILL ALSO CONTINUE THROUGH MUCH OF THE DAY...21Z TO 23Z TIME
FRAME...BEFORE HIGH PRESSURE BEGINS TO SETTLE INTO THE REGION. SOME
GUSTS TO 40KTS ARE POSSIBLE. OTHERWISE VFR CONDITIONS WILL RULE
AFTER MVFR CIGS LIFT/MOVE OUT. LIGHT SOUTH WINDS WILL RETURN AFTER
06Z TUESDAY...AND SOME MID LEVEL CIGS ARE POSSIBLE TUESDAY MORNING.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY UNTIL 3 PM CDT THIS AFTERNOON FOR NEZ011-012-
015>018-030>034-042>045-050>053-065>068-078-088>093.
IA...WIND ADVISORY UNTIL 3 PM CDT THIS AFTERNOON FOR IAZ043-055-056-
069-079-080-090-091.
&&
$$
MAYES/DERGAN