000
FXUS63 KMPX 111050
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
550 AM CDT SAT OCT 11 2008
.AVIATION.../12Z TAF ISSUANCE/
AVIATION FORECAST CONCERNS CONTINUE TO REVOLVE AROUND TROUGH
AXIS/WARM FRONT WHICH EXTENDS FROM SOUTHWEST MINNESOTA NORTHEAST
TOWARD THE BOUNDARY WATERS AREA. THE BULK OF THE AREA WILL REMAIN
ON THE WARM SIDE OF THIS BOUNDARY THROUGH THE PERIOD... ALTHOUGH
KAXN WILL BE CLOSEST AND COULD FEEL SOME OF THE IMPACTS FROM IT.
THE MAIN ISSUE WILL BE THE LOWER CEILINGS AND VISIBILITIES WHICH
WILL BE FOUND ALONG AND TOWARD THE WESTERN/COOL SIDE OF THE
BOUNDARY. THE NAM AND GFS... AS WELL AS THE OTHER SHORT RANGE
MODELS... CONTINUE TO KEEP THE TROUGH AXIS IN ROUGHLY THE SAME
AREA THROUGH TONIGHT... POSSIBLY SHIFTING IT SLIGHTLY WEST WITH
TIME TONIGHT. WILL GENERALLY CARRY VFR CONDITIONS FOR ALL SITES...
BUT WILL INCLUDE SOME MVFR VISIBILITIES IN TEMPO GROUPS FOR KAXN
AND KSTC... WHILE KEEPING CEILINGS VFR THROUGH THE PERIOD.
CONVECTIVE POTENTIAL IS STILL THERE... OWING TO SOME ELEVATED
CAPE... BUT LOW CONFIDENCE IN TIMING AND LOCATION OF ANY
CONVECTIVE ELEMENTS PRECLUDES MENTIONING ANYTHING MORE THAN A CB
IN THE CLOUD GROUPS AT THIS POINT. WINDS LOOK TO STAY LIGHT
THROUGH THE PERIOD AND GENERALLY EAST-SOUTHEAST VEERING MORE
SOUTHEAST WITH TIME.
&&
.PREV DISCUSSION...
/ISSUED 342 AM CDT SAT OCT 11 2008/
FORECAST CONCERN NEAR TERM...POTENTIAL FOR SHRA/TSRA MAINLY ACROSS
NORTHWEST CWA...AND TEMPERATURE TRENDS. RATHER POTENT FRONT ACROSS
FAR WESTERN CWA THIS MORNING. GOOD TEMPERATURE CONTRAST INDICATED
THIS MORNING. MODELS INDICATE THAT THIS BOUNDARY WILL REMAIN
NEARLY STATIONARY TODAY. THIS WILL LIKELY GENERATE HIGH BUST
POTENTIAL IN MAX TEMPERATURES IN THE VCNTY OF THIS BOUNDARY. FEW
-SHRA LIFTING NORTH ACROSS MAINLY NORTHERN PORTION OF THE CWA AND
SATELLITE SHOWING SOME HIGH CLOUD ENHANCEMENT OVER EASTERN SOUTH
DAKOTA INTO NORTHWEST MN ASSOCIATED WITH SHORT WAVE MOVING ACROSS
EASTERN SOUTH DAKOTA THIS MORNING. THIS MAY YET GENERATE SOME
SHOWERS INTO MAINLY NORTHWEST CWA THIS MORNING. WILL MAINTAIN SOME
LOW POPS FOR THIS. OVERNIGHT...MODELS MOVE ANOTHER SHORT WAVE
NORTHEAST OVER MAINLY NORTHWEST CWA OVERNIGHT. AS THIS MOVES
THROUGH...RIDGING ALOFT DEVELOPS AGAIN IN RESPONSE TO ITS PASSAGE
AND DEEPENING TROF OVER THE WESTERN CONUS. THE SFC BNDRY REDEVELOPS
BACK WEST INTO THE WESTERN DAKOTAS OVERNIGHT. THIS WILL DRAW IN
SOME WARMER AIR TO MOST OF THE CWA TONIGHT...KEEPING LOWS MAINLY
IN THE 50S.
MODELS THEN TREND JET ENERGY LIFTING NORTHEAST AS THE UPPER LOW
BEGINS TO LIFT NORTHEAST ACROSS THE DAKOTAS. THE SFC CDFNT MOVES
INTO WESTERN MN BY LATE SUNDAY AFTERNOON. ENOUGH DYNAMIC FORCING
MOVES ACROSS THE WESTERN AREAS TO GENERATE LIKELY POPS AGAIN DURING
THE AFTERNOON. IT DOES APPEAR MODEL FORECAST PRECIPITABLE WATER
VALUES A BIT HIGH INITIALLY. MORE MOISTURE WILL BE LIFTED
NORTHEAST ACROSS THE PLAINS AND ALONG THE COLD FRONT SUNDAY NIGHT
AND MONDAY HOWEVER. MODELS INDICATE SOME SUBTROPICAL MOISTURE
SHOULD LIFT NORTHEAST AS NORBERT REMNANTS MOVE INTO NEW MEXICO
REGION LATER SUNDAY. SFC CDNFT THEN MOVES SLOWLY EAST SUNDAY NIGHT
AND MONDAY. WILL CONTINUE WITH HIGH POPS AS THIS MOVES EAST.
MARGINAL INSTABILITY ASSCOAITED WITH THE FNT MOVING THROUGH...WITH
LOW-MID K INDEX VALUES AND H85 LI SLIGTLY NEGATIVE. SHOULD BE
ENOUGH FOR SOME WIDELY SCT TSRA ALONG FNT INTO SUNDAY NIGHT AND
MONDAY. MUCH COLDER AIR FOLLOWS THE FRONT...AND SHOULD DRY OUT
WESTERN POTION OF THE CWA BY MONDAY EVENING.
MODELS ARE TRENDING SLOWER FRONTAL MOVEMENT ACROSS WESTERN
WISCONSIN MONDAY NIGHT INTO TUESDAY. GFS IS DEEPER AND THEREFORE
SLOWER WITH THE TROUGH LIFTING NORTH AND EAST ACROSS THE AREA.
WILL HOLD ONTO SOME LOW END POPS IN CASE THIS FEATURE SLOWS
FURTHER. 21Z SREF AND 00Z GFS ENSEMBLES WERE HOLDING ONTO SOME
POPS INTO EARLY TUESDAY AS WELL.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
TRH/DWE
