Area Forecast Discussion
Issued by NWS Des Moines, IA

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FXUS63 KDMX 021749
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1249 PM CDT MON MAY 2 2016

.SHORT TERM.../TODAY/
ISSUED AT 405 AM CDT MON MAY 2 2016

FORECAST ISSUE FOR TODAY WILL BE A SHORTWAVE THAT WILL PASS ACROSS
THE STATE AND THE PRECIP POTENTIAL ASSOCIATED WITH ITS PASSING.
INITIALLY THOUGH WE WILL BE DEALING WITH THE LAST OF THE MVFR
STRATUS GRADUALLY LIFTING/ROTATING OUT OF SOUTHERN IOWA.  ACROSS THE
NORTH WHERE SKIES HAVE CLEARED THERE WILL BE THE POTENTIAL FOR
STRATUS/FOG THROUGH 8 OR 9 AM BUT AS OF FORECAST ISSUANCE THIS HAS
NOT GOTTEN OUT OF HAND.  I SUSPECT THE 5 AM TO 9 AM TIMEFRAME MAY BE
WHEN WE SEE VISIBILITIES DROP.

THEN AS WE GET TOWARDS PEAK HEATING WITH THAT SHORTWAVE DROPPING
DOWN WE SHOULD SEE AN INCREASE IN CLOUD COVER AGAIN DURING THE LATE
MORNING THROUGH EARLY AFTERNOON.  FORECAST SOUNDINGS SHOW SOME STEEP
LOW TO MID LEVEL LAPSE RATES AND MOISTURE BETWEEN 850MB AND 700MB
BUT THE MOISTURE IS SPOTTY AT BEST AND MOISTURE IN THE LOWEST LEVELS
IS PRETTY SPARSE.  BEST SCENARIO HERE IS DIURNALLY DRIVEN HIT OR
MISS VERY LIGHT SHOWERS OR SPRINKLES DURING THE LATE MORNING INTO
MID AFTERNOON HOURS AND MAINLY OVER THE SOUTHEAST TWO THIRDS OF THE
FORECAST AREA.

.LONG TERM.../TONIGHT THROUGH SUNDAY/
ISSUED AT 405 AM CDT MON MAY 2 2016

DRIER AIR WILL BE MOVING INTO THE AREA OVERNIGHT AND SHOULD BRING
AN END TO THE SHOWER ACTIVITY BY 00Z. WARM ADVECTION WILL ARRIVE
ON TUESDAY AHEAD OF THE NEXT SYSTEM THAT WILL ARRIVE LATE IN THE
DAY. HIGH TEMPERATURES WILL BE IN THE UPPER 60S TO LOWER 70S. A
STRONG SHORT WAVE WILL DROP SOUTH FROM NEAR THE ONTARIO/MINNESOTA
BORDER AT 12Z TUE TO SRN MINNESOTA BY 00Z WITH QG FORCING
SPREADING INTO NORTHEAST IOWA BY LATE AFTERNOON. CONTINUE TO HAVE
POPS ACROSS NORTHERN AND EASTERN PORTIONS OF THE FORECAST AREA.
HOWEVER...MOISTURE ASSOCIATED WITH THE SYSTEM WILL BE SHALLOW AND
FOCUSED NEAR 750 MB AND DRIER AIR ABOVE AND BELOW THIS LEVEL. ANY
LINE OF PRECIPITATION LOOKS TO BE SCATTERED AT BEST. IN
ADDITION...THE WINDOW OF OPPORTUNITY FOR PRECIPITATION WILL BE
NARROW THEREFORE HAVE KEPT POPS IN THE LOW CHANCE CATEGORY OVER
THESE REGIONS AND DRY ELSEWHERE.

THIS SYSTEM WILL DRAG COOLER AIR BACK SOUTH AND WILL LEAD TO
TEMPERATURES FALLING BACK INTO THE LOW TO MID 60S FOR WEDNESDAY. A
MESSY SYNOPTIC OVERVIEW FOR MID TO LATE WEEK WITH UPPER LOWS
GALORE WITH UP TO 5 FEATURES FROM ALASKA THROUGH CANADA AND THE
CONUS. THE POSITIONING OF THE EASTERN CONUS UPPER LOW AND THE
DESERT SOUTHWEST LOW WILL CREATE RIDGING THROUGH THE NATIONS MID
SECTION AND BRING MUCH WARMER AIR TO THE STATE. THE RESULT WILL BE
WARMER...DRY AND AN ABUNDANCE OF SUN MID TO LATE WEEK. HIGH
TEMPERATURES BY FRIDAY AND SATURDAY MAY REACH 80 IN SOME
LOCATIONS. THE SOUTHWEST UPPER LOW WILL BEGIN TO MOVE EAST BY THE
WEEKEND AND PUSH THE RIDGE EAST AND TRANSITION THE UPPER FLOW TO
THE SOUTHWEST. THIS WILL BRING A MORE ACTIVE PATTERN SATURDAY
NIGHT INTO SUNDAY WITH MOISTURE STREAMING NORTH AND A BOUNDARY
APPROACHING FROM THE NORTH. THIS WILL BRING THUNDERSTORM CHANCES
BACK TO THE STATE.

&&

.AVIATION.../FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON/
ISSUED AT 1249 PM CDT MON MAY 2 2016

SOME LOWER TO MID LEVEL VFR CU THIS AFTERNOON...MAY LEAD TO AN
ISOLATED SHOWER. IN SITES WITH THE BEST CHANCE TO SEE A LIGHT
SHOWER HAVE HIGHLIGHTED WITH VCSH. OTHERWISE WINDS TO BE LIGHT
AND VARIABLE BEFORE SHIFTING AROUND TO THE WEST TONIGHT...AND
PICKING UP SOME INTO TUESDAY.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...FAB
LONG TERM...DONAVON
AVIATION...BEERENDS



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