FXUS63 KOAX 060936
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
436 AM CDT WED JUL 6 2011
.DISCUSSION...
FORECAST CONCERNS FOR THE REST OF THE WEEK WILL BE THE PLACEMENT
OF BEST CHANCE OF THUNDERSTORMS WITH MORE SUBTLE FEATURES IN THE
WEATHER PATTERN.
SEVERAL CONVECTIVE COMPLEXES AFFECTED THE REGION TODAY AND THE
LATEST WSR-88D MOSAIC HAS A COUPLE OF COMPLEXES OVER SOUTH CENTRAL
NEBRASKA INTO KANSAS. THE LATEST IR SATELLITE HIGHLIGHTS THIS...IN
ADDITION TO NEW CONVECTION OVER SOUTHEAST MONTANA. WATER VAPOR
SATELLITE IMAGERY CONTINUES TO SHOW THE TROPICAL FETCH OF MOISTURE
THAT IS BEING DRAWN ACROSS ARIZONA AND CA INTO NV/UT/CO/WY/NEB/KS.
THE 00Z PRECIPITABLE WATER CHART HAD OAX AT 158% OF NORMAL AND
NORTH PLATTE WAS 174% OF NORMAL.
THIS MORNING...THE FORECAST AREA IS UNDER THE INFLUENCE OF
NORTHWEST FLOW ALOFT AND THE SUBTLE SHORTWAVES MOVING FROM
SOUTHEAST WYOMING AND NORTHEAST COLORADO INTO NEBRASKAA/KANSAS AND
MISSOURI. THE MAIN AREA OF CONVECTION SHOULD HOLD TO OUR
SOUTHWEST...HOWEVER AREAS WEST OF LINCOLN AND TOWARD FAIRBURY MAY
SEE SOME STORMS WITH CONTINUED MID LEVEL WARM ADVECTION AND UPWARD
VERTICAL MOTION IN A VERY MOIST ENVIRONMENT. WILL INCLUDE SOME
PATCHY FOG EARLY THIS MORNING WITH THE HIGH HUMIDITY AND WHERE
THERE IS LESS CONVECTIVE DEBRIS AND LIGHT SOUTHEAST WINDS.
THIS AFTERNOON THE SURFACE LOW IS OVER SOUTHWEST KANSAS WITH THE MAIN
SURFACE HEATING TAKING PLACE OVER OKLAHOMA INTO KANSAS...MEANWHILE...A
NORTHERN PLAINS WARM FRONT IS TAKING SHAPE AS SOUTH FLOW INCREASES
OVER THE WESTERN DAKOTAS INTO WESTERN NEBRASKA. DO NOT HAVE
CONFIDENCE IN THE 06Z NAM PRECIP AS IT IS MISSING THE CURRENT COMPLEX.
THE GFS CONTINUES SOME TSRA ACTIVITY THRU THE MORNING ACROSS THE
WESTERN PLAINS/ERN ROCKIES INTO NEBRASKA AND KANSAS DURING THE
DAY. HAVE HIGHEST POPS IN THE SOUTHWEST ZONES...THEN ONLY ISOLATED
MENTION FARTHER NORTHEAST DUE TO LESS SUPPORT.
ALTHOUGH THE LOCATIONS VARY BY THE MODEL...LATE THIS
AFTERNOON AND TONIGHT THERE IS GOOD AGREEMENT THAT THUNDERSTORMS
WILL RE- DEVELOP. TENDED TOWARD THE GFS AS THIS FIT THE LOCATION
OF THE BEST AFTERNOON HEATING ACROSS KANSAS AND THE UPSLOPE DEVELOPMENT
IN WESTERN HIGH PLAINS. THE ECWMF WAS FARTHER NORTH WITH THE HEAVY
PRECIPITATION AND THIS WILL NEED TO BE WATCHED. FOR NOW...HAVE
HIGHEST POPS IN THE SOUTHWEST ZONES AND LOWEST IN THE NORTHEAST
PART OF THE FORECAST AREA IN WESTERN IOWA. MEANWHILE...THERE WILL
BE STORMS EVEN FARTHER NORTH IN THE DAKOTAS. HEAVY RAIN POSSIBLE
MAINLY FOR KANSAS...BUT ALSO COULD OCCUR IN WESTERN/SRN NEBRASKA.
VERY HIGH PRECIPITABLE WATER...THETA-E ADVECTION...WARM CLD LAYER
OVER 4KM...THICKNESS DIFFLUENCE INDICATING BACKBUILDING AND UPPER
LEVEL DIFFLUENCE. THE MODELS TEND TO SPREAD THE HEAVY RAIN EAST TO
EASTERN KANSAS AS THE UPPER LEVEL SUPPORT SHIFTS EAST. IN REGARD
TO SEVERE STORMS...THE MORE ORGANIZED SEVERE WEATHER SHOULD BE
CLOSER TO THE FRONT IN KANSAS AND WITH STORMS FROM WESTERN
NEBRASKA THAT MOVE INTO SOUTHERN NEBRASKA.
THURSDAY...THE NORTHWEST FLOW ALOFT PERSISTS WITH SHORTWAVE TROFS
EMBEDDED IN THIS FLOW. WHILE THERE IS A BETTER CHANCE FOR STORMS
NEAR THE BOUNDARY IN THE DAKOTAS...COULD ALSO SEE SOME AFTERNOON
STORMS IN OUR AREA. OVERNIGHT...THE NORTHERN PLAINS FRONT WILL
MOVE TOWARD SOUTHERN MINNESOTA TOWARD NORTHEAST NEBRASKA AND COULD
SEE SOME STORMS ROLL IN FROM THE NORTH.
FRIDAY...THE WEAK NORTHERN BOUNDARY APPEARS TO LIFT NORTH AS MID
LEVEL RIDGING BUILDS. THUNDERSTORMS SHOULD AGAIN BE MORE ORGANIZED
TO THE WEST OF THE AREA. FRIDAY NIGHT THERE IS A SHORTWAVE THAT IS
ROTATING AROUND THE CLOSED MID TROPOSPHERIC IN SOUTHERN CANADA
WHICH HAS A COLD FRONT PROGRESSING INTO THE NORTHERN AND CENTRAL
PLAINS. THUNDERSTORMS SHOULD FIRE ALONG THIS FRONT WITH THE BEST
COVERAGE IN THE DAKOTAS.
UNSETTLED WEATHER WILL CONTINUE INTO EARLY NEXT WEEK. THE PATTERN
TRANSITIONS TO MORE OF A MID LEVEL TROF IN THE PACIFIC NORTHWEST
AND RIDGING FOR THE CNTRL U.S. MONSOONAL MOISTURE WILL BE DRAWN
NORTHWARD INTO THE ROCKIES AND PLAINS SATURDAY THRU TUESDAY. THE
LOCAL AREA SHOULD SEE MORE 90S...BUT ALSO PERIODS OF TSRA.
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
06Z TAFS
CHALLENGING AVIATION FORECASTS DUE TO THE POTENTIAL FOR CONVECTION
AS WELL AS THE POTENTIAL FOR IFR CONDITIONS GIVEN THE HIGH HUMIDITY
AND THE FRONT THAT IS IN THE REGION. HOWEVER...DESPITE THESE
POTENTIALS THE MAJORITY OF THE TAF PERIOD SHOULD BE VFR WITH FAIRLY
LIGHT WINDS. THUNDERSTORM COMPLEX OVER SOUTHERN NEBRASKA AND
NORTHERN KANSAS SHOULD REMAIN WELL SOUTH OF THE TAF SITES DURING THE
EARLY MORNING HOURS WITH ONLY LIGHT FOG FORMING OVER EASTERN
NEBRASKA. DURING THE DAYTIME...ANY FOG SHOULD DISSIPATE BUT
SCATTERED THUNDERSTORMS MAY DEVELOP ESPECIALLY OVER SOUTHERN
NEBRASKA.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
ZAPOTOCNY/NIETFELD