000
FXUS63 KARX 131725
AFDARX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
1225 PM CDT MON MAY 13 2013

.UPDATE...
ISSUED AT 711 AM CDT MON MAY 13 2013

HAVE LET THE FREEZE WARNINGS AND FROST ADVISORIES EXPIRE ON
SCHEDULE. WITH MOSTLY SUNNY SKIES FOR THE NEXT FEW
HOURS...TEMPERATURES WILL CLIMB QUICKLY. BOTH MEDFORD WI AND
ROCHESTER MN ALREADY ROSE 5-6F BETWEEN 11-12Z.

THE LIGHT SHOWERS ARE STILL ON TRACK TO IMPACT THE FORECAST AREA
BEGINNING NEAR NOON...THEN PROGRESSING EAST THROUGH THE AFTERNOON
AND EVENING.

&&

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 344 AM CDT MON MAY 13 2013

SURFACE MAP THIS MORNING FEATURES A RIDGE OF HIGH PRESSURE EXTENDING
FROM ONTARIO CANADA...ACROSS WI...AND INTO THE MID-MISSISSIPPI RIVER
VALLEY REGION. UNDER THIS RIDGE/MOSTLY CLEAR SKIES WERE SEEN WITH
TEMPERATURES AS LOW AS THE MIDDLE/UPPER 20S ACROSS THE CRANBERRY
COUNTRY OF CENTRAL WI. CURRENT FROST/FREEZE HEADLINES LOOK GOOD IN
LIGHT OF THIS. MEANWHILE...A WARM FRONT WAS WORKING ITS WAY EAST
ACROSS MT INTO THE WESTERN DAKOTAS. IR/WATER VAPOR IMAGERY  SHOWING
A PRETTY DECENT PACIFIC MOISTURE TAP AND COPIOUS CIRRUS/AC SHIELD
AHEAD OF THE WARM FRONT HEADING INTO WESTERN MN/IA AND TOWARD THE
FORECAST AREA.

13.00Z MODELS SHOWING GOOD AGREEMENT THROUGH THE SHORT TERM.

FOR TODAY...WILL BE WATCHING THAT WARM FRONT OVER THE DAKOTAS
PROGRESS EASTWARD INTO MN. GOOD AMOUNT OF 850-700MB MOISTURE
TRANSPORT/ISENTROPIC LIFT NOTED AHEAD OF THE FRONT FOR
ACCAS/SCATTERED SHOWER PRODUCTION MAINLY ALONG/NORTH OF THE I-90/94
CORRIDORS LATE THIS MORNING THROUGH THE AFTERNOON HOURS.

LOOK FOR THE WARM FRONT TO CONTINUE PROGRESSING EASTWARD TO
BASICALLY ALONG THE MISSISSIPPI RIVER BY 12Z TUESDAY. THIS PUSHES
MAINLY AREA OF LIFT/RAIN CHANCES EAST OF THE AREA AFTER MIDNIGHT.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 344 AM CDT MON MAY 13 2013

LOOK FOR THE WARM FRONT TO PUSH EASTWARD THROUGH THE REST OF THE
AREA BY TUESDAY AFTERNOON. THIS WILL OPEN THE DOOR TO NEAR RECORD
WARMTH FOR PORTIONS OF THE AREA AS SOUTHWEST WINDS DRAW
WARMED/DOWNSLOPED PLAINS AIR INTO THE REGION. SEE THE CLIMATE
SECTION BELOW FOR REFERENCE TO RECORD HIGHS. LOOK FOR HIGHS TO TOP
OFF IN THE LOWER TO MIDDLE 80S ACROSS CENTRAL WI...TO THE
MIDDLE/UPPER 80S/AROUND 90 ALONG AND WEST OF THE MISSISSIPPI RIVER.
BY LATE TUESDAY AFTERNOON/EVENING...INTRODUCED A SLIGHT CHANCE OF
SHOWERS/THUNDERSTORMS INTO THE FORECAST AS A COLD FRONT DROPS
SOUTHEAST OUT OF THE DAKOTAS INTO THE REGION AND 850MB CAP WEAKENS.
MOISTURE/INSTABILITY CONFINED TO LEVELS ABOVE APPROXIMATELY 8KFT
CONNECTED TO ELEVATED MOISTURE TAP FROM THE PACIFIC. ASSUMING
CONVECTIVE INITIATION...MAY HAVE TO KEEP AN EYE ON WIND/SMALL HAIL
THREAT GIVEN INVERTED-V TYPE SOUNDING. OTHERWISE...RECORD HEAT/LOWER
SURFACE RH/BREEZY SOUTHWEST WINDS ACROSS PORTIONS OF SOUTHEAST
MN/NORTHEAST IA RAISE A CONCERN FOR FIRE WEATHER. THIS IS COVERED
BELOW IN THE FIRE WEATHER SECTION.

FOR WEDNESDAY THROUGH THURSDAY...LOOKS LIKE DRY CONDITIONS WITH
TEMPERATURES NEAR NORMAL IN THE MIDDLE/UPPER 70S AS SURFACE-MID
LEVEL RIDGING WORKS INTO THE AREA.

FOR THURSDAY NIGHT AND INTO THE WEEKEND...GFS AND ECMWF ARE AT ODDS
WITH TIMING OF LOW PRESSURE THAT MOVES OUT OF THE PLAINS TOWARD OUR
AREA. THE GFS IS DEFINITELY THE MORE PROGRESSIVE OF THE TWO...MOVING
THE LOW INTO WI BY MON 00Z. THE ECMWF...WHICH HAS A BIT MORE
RUN-TO-RUN CONSISTENCY...KEEPS THE LOW WEST OF THE AREA OVER WITH A
WARM FRONT SOUTHWEST-SOUTH OF THE AREA. THIS WOULD KEEP THE AREA IN
COOLER/SHOWERY ISOLD THUNDER SCENARIO. WILL MAINTAIN A BLEND OF THE
TWO WITH LOW-END SHRA/THUNDER CHANCES FROM THURSDAY THROUGH
FRIDAY...AND GRADUALLY INCREASING CHANCES INTO THE WEEKEND. OUTCOME
HIGH TEMPERATURES FROM THE BLEND YIELDS UPPER 60S/MID 70S ON
FRIDAY...LOWERING INTO THE LOWER 60S TO LOWER 70S BY SUNDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1225 PM CDT MON MAY 13 2013

MID LEVEL MOISTURE AND LIFT SPREADING EAST ACROSS THE UPPER MIDWEST
WERE PRODUCING AN LINE OF WEAK -SHRA/SPRINKLES ACROSS CENTRAL MN.
THESE WILL SPREAD EAST/SOUTHEAST ACROSS THE KRST AREA 18-21Z AND
KLSE IN THE 20-23Z WINDOW. WITH PLENTY OF LOWER LEVEL DRY AIR...
CONDITIONS EXPECTED TO REMAIN VFR AS THIS LINE OF -SHRA PASSES.
WINDS WILL INCREASE AS THE GRADIENT TIGHTENS THIS AFTERNOON...THEN
DECREASE AS THE GRADIENT RELAXES TONIGHT. SOME LLWS EXPECTED DURING
THE LATE EVENING AND OVER NIGHT AT DECOUPLED/VALLEY SITES LIKE
KLSE...WITH BOUNDARY LAYER WINDS LIGHT SOUTH-SOUTHEAST AND WINDS AT
1.5K FT IN THE 35-40KT RANGE FROM THE SOUTHWEST. THE 1.5K FT WINDS
DECREASE BY 12Z TUE WITH QUICK PASSAGE OF THE 925-850MB TROUGH.
ANOTHER TROUGH/WARM FRONT APPROACHES/PASSES TUE WITH WINDS AGAIN
INCREASING FOR THE LATER MORNING/AFTERNOON. AIRMASS IS QUITE DRY
WITH THE WARM FRONT FOR TUE...WITH CIGS/VSBYS REMAINING VFR THRU TUE.

&&

.FIRE WEATHER...TUESDAY
ISSUED AT 344 AM CDT MON MAY 13 2013

WINDY CONDITIONS OVER THE WEEKEND HAVE DRIED SOME FINE FUELS/OLD
LEAF LITTER ACROSS SOUTHEAST MINNESOTA AND NORTHEAST IOWA. WITH THIS
IN MIND AND NEAR RECORD WARMTH/LOWER RH LEVELS/BREEZY SOUTHWEST
WINDS EXPECTED TUESDAY...THE CONCERN FOR AN ELEVATED FIRE RISK
REMAINS. IT APPEARS AREAS WEST OF A DODGE CENTER/AUSTIN MN TO
CHARLES CITY IA LINE WOULD BE MOST UNDER THE GUN WHERE RH LEVELS MAY
DIP AS LOW AS 24-25 PERCENT. HOWEVER...SUSTAINED WINDS LOOK TO
REMAIN BELOW RED FLAG CRITERIA AND THERE IS THE ISSUE OF INCREASING
CLOUD COVER AND A SLIGHT CHANCE OF SHOWERS/THUNDERSTORMS LATE IN THE
AFTERNOON. WITH THIS IN MIND...WILL HOLD OFF ON A FIRE WEATHER WATCH
FOR NOW AND PASS TO THE DAYSHIFT FOR FURTHER ASSESSMENT.

&&

.CLIMATE...TUESDAY
ISSUED AT 344 AM CDT MON MAY 13 2013

RECORD HIGHS FOR REFERENCE FOR TUESDAY...MAY 14TH...GIVEN THE
UNSEASONABLE WARMTH FORECAST:

IOWA...

CHARLES CITY      93 IN 1932
DECORAH           94 IN 1940
FAYETTE           93 IN 1932

MINNESOTA...

ROCHESTER         94 IN 2007
AUSTIN            91 IN 2001
CALEDONIA         87 IN 1894
PRESTON           86 IN 1991

WISCONSIN...

LA CROSSE         92 IN 2007
PRAIRIE DU CHIEN  92 IN 1932
SPARTA            88 IN 1991
MEDFORD           87 IN 1991
RICHLAND CENTER   89 IN 1932
VIROQUA           90 IN 1932

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&

$$

UPDATE.........AJ
SHORT TERM.....DAS
LONG TERM......DAS
AVIATION.......RRS
FIRE WEATHER...DAS
CLIMATE........AJ