000
FXUS63 KARX 141222 CCA
AFDARX

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE LA CROSSE WI
634 AM CDT TUE MAY 14 2013

CORRECTED CLIMATE SECTION FOR RECORD FOR LA CROSSE.

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 330 AM CDT TUE MAY 14 2013

WATER VAPOR IMAGERY/RAP 500MB ANALYSIS SHOWS A BROAD RIDGE OF HIGH
PRESSURE ACROSS THE CENTRAL CONUS. A MID-LEVEL SHORTWAVE TROUGH
MOVING ACROSS NORTHERN MT WAS SPARKING AN MCS OVER SOUTHEAST
SASKATCHEWAN AND NORTHERN ND. AT THE SURFACE...A WARM FRONT WAS
POSITIONED FROM JUST EAST OF THE MISSISSIPPI WITH TEMPERATURES AT 3
AM ACROSS THE AREA RANGING FROM THE UPPER 40S/LOWER 50S ACROSS NORTH
CENTRAL WI...TO THE MID 50S/NEAR 60 ACROSS THE REST OF THE AREA.

FOR TODAY...WILL SEE THAT WARM FRONT JUST EAST OF THE MISSISSIPPI
RIVER PUSH EAST ACROSS THE REST OF THE AREA BY LATER THIS MORNING.
WILL HAVE TO WATCH THAT MCS UPSTREAM THIS MORNING...BUT FAIRLY
CONFIDENT IT WILL STAY NORTH OF THE AREA OVER NORTHERN MN/UPPER
MICHIGAN GIVEN THE MOISTURE TRANSPORT/CORFIDI VECTORS.

MEANWHILE...A DRY LINE OF SORTS PUSHES EAST INTO NORTHEAST
IA/SOUTHEAST MN BY MID-AFTERNOON WITH INCREASING HEAT AND LOWERING
SURFACE DEW POINTS. IN ADDITION...HIGHER BASED 850-700MB MOISTURE
TRANSPORT AHEAD OF AN APPROACHING COLD FRONT BEHIND THE DRY LINE
WILL PRODUCE ACCAS AND ISOLATED TO SCATTERED SHRA/TS BY LATE THIS
AFTERNOON. NAM/EC DEPICTING 850-500MB MUCAPE IN THE 1000-1800J/KG
WHICH MAY LEAD TO SOME VIGOROUS HIGH-BASED CONVECTION WITH CLOUD
BASES AT OR ABOVE 700MB. THIS CONVECTION WILL THEN HAVE THE
POTENTIAL TO PRODUCE BRIEF ERRATIC WIND GUSTS AROUND 40
MPH...AND...WITH MOST PRECIPITATION EVAPORATING BEFORE REACHING THE
GROUND...SOME DRY LIGHTNING AS WELL. THE COMBINATION OF VERY LOW
RELATIVE HUMIDITY AND THIS CONVECTION HAVE AN IMPACT ON FIRE WEATHER
WHICH IS FURTHER DISCUSSED IN THE FIRE WEATHER SECTION BELOW.
OTHERWISE...LOOK FOR NEAR RECORD HIGHS TODAY ACROSS THE AREA WITH
READINGS RANGING FROM THE LOWER/MIDDLE 80S ACROSS CENTRAL
WISCONSIN...TO THE LOWER 90S ACROSS NORTHEAST IA/SOUTHEAST MN.

LOOK FOR THAT COLD FRONT AND SCATTERED SHOWER/TS ACTIVITY TO PUSH
SOUTHEAST ACROSS THE AREA THIS EVENING...AND THEN CLEARING OUT OF
THE AREA AFTER MIDNIGHT. PLAN ON LOWS OVERNIGHT IN THE 50S.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 330 AM CDT TUE MAY 14 2013

A WEAK RIDGE OF HIGH PRESSURE WILL DRIFT ACROSS THE REGION WEDNESDAY
THROUGH THURSDAY FOR DRY CONDITIONS. THE NAM DOES HINT AT A WEAK
MID-LEVEL TROUGH PROPAGATING EAST THROUGH THE RIDGE AND DOES PRODUCE
SOME MID-LEVEL MOISTURE AND LIGHT QPF FOR WEDNESDAY AFTN/EVE.
HOWEVER...IT IS THE ONLY MODEL DOING THIS...SO DISCOUNTED FOR NOW
BUT WILL HAVE TO BE WATCHED WITH 12Z MODEL RUN.

THEN FOR THURSDAY NIGHT INTO FRIDAY...WILL SEE AN INCREASE AGAIN IN
850-700MB MOISTURE TRANSPORT AND ISENTROPIC LIFT INTO THE REGION
AHEAD OF LOW PRESSURE MOVING OUT OF THE ROCKIES INTO THE HIGH PLAINS.
THIS WILL YIELD A CHANCE OF SHOWERS AND THUNDERSTORMS. HIGHS
EXPECTED TO TOP OFF IN THE MID/UPPER 70S ON THURSDAY...THEN COOLING
A FEW DEGREES ON FRIDAY WITH INCREASED CLOUD COVER/SCATTERED
PRECIPITATION.

FOR THE WEEKEND...GFS/ECMWF SHOW A DEEPENING MID-LEVEL TROUGH OVER THE
WEST WITH SURFACE LOW PRESSURE DEVELOPING OVER THE PLAINS AND
APPROACHING THE UPPER MISSISSIPPI RIVER VALLEY REGION. CONTINUED
MOISTURE TRANSPORT AHEAD OF THE TROUGH/LOW WILL PRODUCE AN EXTENDED
PERIOD FOR A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS. HIGH
TEMPERATURES LOOK TO REMAIN RIGHT AROUND NORMAL IN THE 70S.
THUNDERSTORM CHANCES CONTINUE INTO MONDAY WITH COLD FROPA. WILL HAVE
TO WATCH THIS WEEKEND CLOSELY AS EXACT DETAILS ON WHERE BEST
DYNAMICS SET UP ARE NOT CLEAR. THIS WOULD DETERMINE WHERE ANY SEVERE
THREAT WOULD ARISE. STAY TUNED.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 634 AM CDT TUE MAY 14 2013

A COLD FRONT OVER CENTRAL SOUTH DAKOTA WILL MOVE THROUGH THE TAF
SITES BETWEEN 00-03Z THIS EVENING. BOTH AHEAD AND BEHIND THE
FRONT...PLENTIFUL DRY AIR IN THE LOWER LEVELS OF THE ATMOSPHERE IS
EXPECTED TO MAINTAIN VFR CONDITIONS. HOWEVER...THERE IS A CONCERN
OF A FEW THUNDERSTORMS WITH LITTLE RAINFALL OCCURRING WITH THE
COLD FRONT BETWEEN 22-02Z. THE AREAL COVERAGE EXPECTED WITH THESE
IS TOO SMALL TO MENTION THUNDERSTORMS AT EITHER TAF SITES...THOUGH
ENOUGH CERTAINTY IS PRESENT TO MENTION AT LEAST A VCSH AT KRST.
SHOULD A THUNDERSTORM IMPACT A TAF SITE...THE POTENTIAL IS THERE
FOR SOME ERRATIC WIND GUSTS UP TO 40 KT ALONG WITH SMALL HAIL.

REGARDING WINDS...THE PRESSURE GRADIENT IS FORECAST TO TIGHTEN
BACK UP THIS AFTERNOON AHEAD OF THE FRONT...CAUSING WINDS TO
INCREASE TO 10-20 KT WITH GUSTS OF 20-30 KT. HIGHEST WINDS ARE
EXPECTED AT KRST WITH DEEPER MIXING. WINDS WILL DIMINISH THIS
EVENING WITH LOSS OF HEATING...AND TURN NORTHWESTERLY WITH THE
PASSAGE OF THE COLD FRONT.

&&

.FIRE WEATHER...TODAY
ISSUED AT 330 AM CDT TUE MAY 14 2013

VERY WARM PUSH OF AIR TODAY WITH VERY LOW SURFACE RELATIVE
HUMIDITIES BY THIS AFTERNOON ACROSS PORTIONS OF SOUTHEAST
MN/NORTHEAST IA. LOOKING FOR HIGHS ACROSS THAT AREA IN THE LOWER 90S
WITH RELATIVE HUMIDITY DIPPING INTO THE LOWER 20 PERCENT RANGE. ADD
IN GUSTY SOUTHWEST WINDS AND SOME FUELS NOT GREENED UP YET AND
WILDFIRE THREAT IS THE RESULT. IN ADDITION...SOME DRY THUNDERSTORMS
MAY BE SEEN LATER IN THE AFTERNOON AHEAD OF AN APPROACHING COLD
FRONT. THIS MAY RESULT IN ERRATIC WIND GUSTS AROUND 40 MPH AND DRY
LIGHTNING FOR PERHAPS SOME FIRE STARTS IF FUELS ARE RECEPTIVE
ENOUGH. FOR THIS REASON...WENT AHEAD AND ISSUED A RED FLAG WARNING
FROM NOON TODAY UNTIL 8 PM THIS EVENING FOR DODGE/MOWER COUNTIES IN
SOUTHEAST MN...AND MITCHELL/FLOYD COUNTIES IN NORTHEAST IA.

&&

.CLIMATE...TODAY
ISSUED AT 330 AM CDT TUE MAY 14 2013

RECORD HIGHS FOR REFERENCE FOR TODAY...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         93 IN 1932
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...RED FLAG WARNING FROM NOON TODAY TO 8 PM CDT THIS EVENING FOR
     MNZ086-094.

IA...RED FLAG WARNING FROM NOON TODAY TO 8 PM CDT THIS EVENING FOR
     IAZ008-018.

&&

$$

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