FXUS63 KOAX 200855
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
355 AM CDT WED APR 20 2011
.DISCUSSION...
FORECAST CONCERNS FOR THE REST OF THE WEEK WILL BE TIMING OF
SHOWERS AND THUNDERSTORMS AS UNSETTLED WEATHER PATTERN CONTINUES.
THE STORM SYSTEM THAT BROUGHT A SOAKING RAIN TO THE MIDLANDS
TUESDAY MORNING AND 2 TO 4 INCHES OF SNOW TO NORTHEAST NEBRASKA
HAS SHIFTED INTO THE OHIO AND TENNESSEE VALLEYS. AT 08Z SURFACE
HIGH PRESSURE WAS CENTERED FROM THE WESTERN DAKOTAS INTO SOUTHEAST
NEBRASKA...HOWEVER A BLANKET OF CLOUDS STILL COVERED THE MISSOURI
RIVER VALLEY. A SHORTWAVE TROF WAS MOVING ACROSS THE DAKOTAS INTO
MINNESOTA WITH THE BULK OF THE PRECIPITATION IN SOUTH DAKOTA. THE
WAVE WILL BRING THROUGH SOME SUBTLE COOLING ALOFT. SOME PATCHY FOG
AND DRIZZLE EARLY THIS MORNING. NORTHWESTERLY FLOW ALOFT SHOULD
HELP SCOUR OUT THE CLOUDS AND MIXING SHOULD ALLOW TEMPERATURES TO
TOP OUT IN THE UPR 40S NORTH TO THE MID AND A FEW UPR 50S SOUTH.
A SUBTLE SHORTWAVE TROF WILL TRACK ACROSS THE ROCKIES WEDNESDAY
NIGHT AND INTO THE PLAINS THURSDAY. CLOUDS WILL BE ON THE INCREASE
OVERNIGHT WITH SHOWERS WORKING INTO THE WRN PORTIONS OF THE
FORECAST AREA BY THURSDAY MORNING. THERE IS STRONG MID LEVEL WARM
AIR ADVECTION AND EXPECT SHOWERS TO CONTINUE ACROSS THE AREA
THURSDAY. CLOUDS AND PRECIP TO HOLD TEMPERATURES DOWN THURSDAY
WITH HIGH IN THE 40S TO LOWER 50S. THETA-E ADVECTION INCREASES
ACROSS THE SOUTH AND MORE SHORTWAVE TROUGH ENERGY MOVES INTO THE
PLAINS. WITH THE SFC BOUNDARY IN KANSAS...THIS LIFT SHOULD BE
ENOUGH FOR MORE SHOWERS AND THUNDERSTORMS OVERNIGHT INTO FRIDAY.
FRIDAY...THE MID TROPOSPHERIC LOW TRACKS ACROSS SOUTH
DAKOTA. THERE IS A SFC LOW OVER SOUTH DAKOTA POSSIBLY INTO EASTERN
NEBRASKA ...WITH A SECOND AREA OF LOW PRESSURE OVER OKAHOMA INTO
KANSAS. THIS PATTERN WOULD LIMIT THE NORTHWARD PROGRESS OF THE
DEEPER MOISTURE WITH MORE DRYING DURING THE AFTERNOON. THERE ARE
STILL SOME SIGNIFICANT DIFFERENCES IN HOW WARM TEMPERATURES WILL
GET...BUT DO HAVE HIGHS IN THE 60S. MAINTAINED THE CHANCE FOR
SHOWERS AND THUNDERSTORMS FRIDAY MORNING...HOWEVER DID DRY THINGS
OUT MORE IN THE AFTERNOON AND INTO FRIDAY NIGHT.
THE WEEKEND FORECAST IS STILL QUESTIONABLE FOR SUNDAY AS THE 00Z
ECMWF HAS THE SFC FRONT AROUND KANSAS CITY...WHILE THE GFS IS
FARTHER SOUTH. HOPEFULLY THERE WILL BE MORE AGREEMENT TODAY...BUT
STILL LOOKS STORMY FOR PARTS OF THE MIDWEST FROM THE WEEKEND INTO
EARLY NEXT WEEK.
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
06Z TAFS
MVFR AND IFR CIGS BETWEEN FL007 AND FL015 WILL PERSIST ACROSS
EASTERN NEBRASKA TAF SITES THROUGH ABOUT 18Z BEFORE LIFTING TO VFR
NEAR FL040. CIGS WILL SCATTER TO SKC CONDITIONS BY 00Z. HOWEVER MID
LEVEL CIGS WILL ONCE AGAIN INVADE THE AREA FROM THE SOUTHWEST BY 06Z
THURSDAY. SCATTERED SHRA/TSRA COULD DEVELOP BETWEEN 06Z AND 12Z
THURSDAY WITH ATTENDANT MVFR/IFR CONDITIONS.
DERGAN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
ZAPOTOCNY/DERGAN