FXUS63 KOAX 250817
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
317 AM CDT MON APR 25 2011
.DISCUSSION...
NOT MUCH CHANGE IN SURFACE PATTERN THIS MORNING. RIDGE AXIS
STRETCHES FROM THE GREAT LAKES REGION INTO THE CENTRAL PLAINS
WHILE QUASI-STATIONARY FRONT EXTENDS FROM LOW PRESSURE OVER
NORTHERN TEXAS ACROSS SOUTHERN PARTS OF MISSOURI AND ILLINOIS.
THIS BOUNDARY HAS BEEN THE MAIN FOCUS FOR CONVECTION PAST FEW DAYS.
MID LEVEL TROUGH OVER THE CENTRAL ROCKIES IS EXPECTED TO MOVE INTO
THE CENTRAL PLAINS TODAY SPREADING ANOTHER ROUND OF RAIN ACROSS THE
FORECAST AREA INTO TUESDAY. RADAR ALREADY SHOWING AN AREA OF RAIN
FROM WESTERN NEBRASKA INTO SOUTH CENTRAL KANSAS SPREADING
NORTHEAST IN ADVANCE OF SHORT WAVE OVER EASTERN COLORADO.
FORECAST SOUNDINGS SUGGEST LITTLE CAPE AVAILABLE AND EXPECT
CHANCE OF THUNDER TO STAY SOUTH OF THE AREA TODAY. ISENTROPIC LIFT
ASSOCIATED WITH WARM ADVECTION ACTS AS MAIN FORCING MECHANISM
ALONG WITH THE MID LEVEL WAVE. BOTH GFS AND NAM SHOWING THE WAVE
CLOSING OFF VICINITY OF SOUTHERN MINNESOTA ON TUESDAY THEN STALL
IT OUT IN THIS GENERAL AREA THROUGH WEDNESDAY. FOR NOW HAVE WENT
WITH A DRY FORECAST TUESDAY NIGHT INTO WEDNESDAY BUT SOME LIGHT
SHOWERS MAY BE POSSIBLE IN THE CYCLONIC CIRCULATION THAT DEVELOPS
ACROSS THE AREA AND LATER FORECASTS WILL HAVE TO EVALUATE THIS
POTENTIAL.
WITH THE UPPER CIRCULATION SETTING UP TO THE NORTHEAST OF THE AREA
TEMPERATURES ALSO EXPECTED TO BE ON THE COOL SIDE. HAVE COOLED
HIGHS BACK SOME ON TUESDAY ESPECIALLY NORTH WHERE RAIN AND CLOUDS
EXPECTED TO LIMIT HEATING. LOW LEVEL NORTHWEST FLOW CONTINUES
INTO WEDNESDAY WITH EXTENT OF CLOUDS AND POSSIBLE SHOWERS MAIN
CONCERNS AT THAT TIME. CLOSED LOW THEN TAKES A GRADUAL SHIFT
EASTWARD WEDNESDAY NIGHT INTO THURSDAY WITH UPPER RIDGING MOVING
INTO THE PLAINS LATE THURSDAY.
LITTLE CHANGE TO THE EXTENDED PORTION OF THE FORECAST AT THIS TIME
BUT 00Z GFS AND ECMWF LOOK TO BRING MORE WET AND COOL WEATHER TO
THE AREA THIS WEEKEND...ALTHOUGH THEY DIFFER ON UPPER FEATURES WITH
GFS CLOSING OFF AN UPPER LOW EARLIER THAN THE ECMWF.
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
06Z TAFS
VFR CONDITIONS SHOULD PREVAIL WITH CEILINGS ABOVE 5000 FEET UNTIL
MID OR LATE MORNING...THEN EXPECT CEILINGS AND VISIBILITIES TO DROP
INTO THE MVFR CATEGORY WITH SHOWERS. INSTABILITY IS MARGINAL...SO
DID NOT INCLUDE MENTION OF THUNDER AT THIS TIME. CONDITIONS AT KOFK
SHOULD DECREASE INTO THE MVFR CATEGORY BY EARLY OR MID AFTERNOON.
IFR CONDITIONS ARE POSSIBLE AT ALL THREE SITES...MAINLY AFTER 00Z.
INITIALLY WINDS WILL BE LIGHT...UNDER 8 KNOTS...BUT INCREASE FROM
THE NORTHEAST AT 10 TO 15 KTS AND THEN GRADUALLY SHIFT TO NORTH.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
FOBERT/MILLER