000
FXUS63 KDMX 140908
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
408 AM CDT TUE MAY 14 2013

.SHORT TERM.../TODAY /...
ISSUED AT 407 AM CDT TUE MAY 14 2013

FORECAST CHALLENGE TODAY IS WITH RECORD OR
NEAR RECORD HIGH MAX TEMPS...DEW POINTS AND WINDS. MODELS STILL
INITIALIZING TOO MOIST WITH THE RAP CONTINUING TO BE THE DRY
SOLUTION TODAY. RAP ALSO HAS THE BETTER HANDLE ON THE TEMPS
TODAY...SO LEANED CLOSER TO THE RAP SOLUTION.

WINDS WILL INCREASE LATE THIS MORNING AND CONTINUE TO MIX DURING THE
AFTERNOON WITH RAP SHOWING THE BEST DRY ADIABATIC SOUNDING. MIXING
TO 850MB SHOULD TAP INTO THE +25C TEMPERATURES ADVECTING INTO
WESTERN TO NORTHERN IOWA BY THIS AFTERNOON. NAM/GFS/ECMWF SOUNDINGS
ARE NOT AS AGGRESSIVE WITH THE MIXING TODAY...AND POSSIBLY ONE
REASON THESE MODELS OVERDOING THE DEW POINTS. TEMPS OVERNIGHT
REMAINING IN THE UPPER 50S/LOWER 60S ACROSS MUCH OF THE FORECAST
AREA...AND WITH THE NORTHWEST FORECAST AREA RISING 2-4 DEGREES
WARMER MONDAY THAN ANTICIPATED...CONFIDENT ENOUGH TO TWEAK MAX TEMPS
UP SLIGHTLY OVER THE WEST AND NORTH. WENT ROUGHLY 3 TO 5 DEGREES
ABOVE THE WARMEST GUIDANCE TODAY. WITH THE DRIER DEW POINTS AND RH
VALUES COMBINED WITH THE GUSTY SOUTHWEST WINDS...DECIDED TO UPGRADE
TO A RED FLAG WARNING. SEE FIRE WEATHER DISCUSSION FOR FURTHER
DETAILS.

.LONG TERM.../TONIGHT THROUGH MONDAY/...
ISSUED AT 400 AM CDT TUE MAY 14 2013

THE FRONTAL BOUNDARY WILL DROP SLOWLY SOUTH THROUGH THE STATE
OVERNIGHT BEFORE STALLING IN THE ZONAL FLOW JUST SOUTH INTO
MISSOURI ON WEDNESDAY. MOISTURE REMAINS QUITE LIMITED WITH THE
SYSTEM. ANY SHOWERS AND THUNDERSTORMS THAT DO FORM WILL BE
EXTREMELY HIGH BASED AND ABOVE THE PRIMARY AREA OF FORCING. THIS
COMBINED WITH THE LACK OF ASSOCIATED MOISTURE WILL KEEP ANY
ACTIVITY QUITE SPARSE. BROAD AREA OF LOW PRESSURE WILL BECOME
REFOCUSED OVER WYOMING AND THE WESTERN DAKOTAS THURSDAY INTO
FRIDAY. THIS WILL HELP DRIVE THE FRONTAL BOUNDARY BACK NORTH AS A
WARM FRONT. PRECIPITATION CHANCES WILL CONTINUE MAINLY OVER THE
SOUTH WEDNESDAY BEFORE SPREADING BACK NORTH WITH THE FRONTAL
PASSAGE THROUGH THE END OF THE WEEK.

HAVE MAINTAINED THUNDERSTORM CHANCES ON SATURDAY THOUGH THE SIGNS
BEGINNING TO POINT TO THE STATE BEING IN THE WARM SECTOR WITH THE
WARM FRONT MOVING NORTH OF THE STATE. WARM AIR ALOFT WOULD LEAVE A
FAIR AMOUNT OF CONVECTIVE INHIBITION TO OVERCOME ON SATURDAY.
BETTER CHANCE FOR THUNDERSTORMS AND POSSIBLY SEVERE WEATHER WOULD
BE SUNDAY AS A THE UPPER LEVEL RIDGE BEGINS TO BE SHOVED EAST BY
AN UPPER LEVEL SYSTEM ENTERING THE NORTHWESTERN CONUS. THIS WILL
INCREASE THE SOUTHWEST FLOW INTO THE STATE EARLY SUNDAY WITH A
COLD FRONT ARRIVING LATER IN THE DAY. CERTAINLY A FAVORABLE SETUP
FOR SURFACE BASED CONVECTION WITH THE PRIMARY THREATS OF WIND AND
HAIL WITH THE TRIPLE POINT WELL TO THE NORTH...BUT IT IS STILL
SEVERAL DAYS AWAY.

TEMPERATURES THROUGH THE PERIOD WILL BE SEASONAL TO ABOVE NORMAL.
POSSIBLY CLOUD COVER ON WEDNESDAY AND THURSDAY WILL HAVE AN IMPACT
ON TEMPERATURES. THURSDAY ESPECIALLY WILL BE COOLER THAN THE NORTH
DUE TO PRECIPITATION AND CLOUDS. LIKELY A RETURN TO THE 80S ON
SATURDAY WITH DEWPOINTS POSSIBLY RISING INTO THE 60S.

&&

.AVIATION...14/06Z
ISSUED AT 1145 PM CDT MON MAY 13 2013

VFR CONDITIONS THROUGH THE TAF PERIOD...WITH SOUTHERLY WINDS
INCREASING THROUGH THE DAY TUESDAY. WINDS TO BECOME MORE
SOUTHWESTERLY TO WESTERLY AS A FRONTAL BOUNDARY APPROACHES TUESDAY
EVENING. SCT-BKN150 HIGH CLOUDS POSSIBLE THROUGH THE PERIOD.

&&

.FIRE WEATHER...
STRONGEST WIND GUSTS AND LOWEST RELATIVE HUMIDITY VALUES ARE
EXPECTED BETWEEN NOON AND 7PM TODAY OVER WESTERN AND NORTHERN
PORTIONS OF THE FORECAST AREA. RH VALUES RANGING FROM 17 TO 22
PERCENT AND SUSTAINED WINDS AROUND 25 MPH OR SLIGHTLY HIGHER ARE
LIKELY DURING THE AFTERNOON. GFDI VALUES RANGES IN THE MODERATE TO
HIGH CATEGORY PAST NOON TODAY AND MAY BARELY BUMP INTO THE EXTREME
CATEGORY FOR A FEW HOURS BETWEEN 2PM AND 5PM THIS AFTERNOON.
MIXING HEIGHT LOOKS TO BE IN THE 3000 TO 3500 FEET LATE THIS
MORNING AND INTO THE AFTERNOON...WITH A SHORT STINT OF MIXING
HIGHER. REPLACED THE FIRE WEATHER WATCH WITH A RED FLAG WARNING
DUE TO THE VERY LOW RH VALUES...STRONG WINDS...AND FUELS NOT
ENTIRELY GREEN YET.


&&

.DMX WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM NOON TODAY TO 8 PM CDT THIS EVENING FOR
ADAIR-ADAMS-AUDUBON-BOONE-CALHOUN-CARROLL-CASS-CERRO GORDO-
CRAWFORD-DALLAS-EMMET-FRANKLIN-GREENE-GUTHRIE-HAMILTON-HANCOCK-
HUMBOLDT-KOSSUTH-PALO ALTO-POCAHONTAS-SAC-WEBSTER-WINNEBAGO-
WORTH-WRIGHT.

&&

$$

SHORT TERM...PODRAZIK
LONG TERM...DONAVON
AVIATION...BEERENDS
FIRE WEATHER...PODRAZIK