Area Forecast Discussion
Issued by NWS Des Moines, IA

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS63 KDMX 281159
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
659 AM CDT TUE APR 28 2015

...UPDATED AVIATION DISCUSSION...

.SHORT TERM /TODAY/...
ISSUED AT 305 AM CDT TUE APR 28 2015

WEAK COLD FRONT ENTERS NORTHWEST IOWA THIS AFTERNOON AND BRINGS
SOME MID-LEVEL THETA-E ADVECTION AND VERY WEAK FRONTOGENETICAL
FORCING (AND THAT IS DEPENDENT ON WHICH MODEL)...BUT MIGHT BE
SUFFICIENT ENOUGH TO SUPPORT A FEW SPRINKLES OVER NORTHERN IOWA.
MORE CONFIDENT IN VIRGA ACROSS THE NORTH AS ANYTHING THAT DOES
DEVELOP WILL BE ABOVE 7000 FEET AS BELOW THIS LEVEL REMAINS VERY
DRY TO THE SURFACE. PLUS...WITH THE LACK OF SIGNIFICANT FORCING AS
WELL AS DEEP MOISTURE...SATURATION ONLY FROM ABOUT 750-550MB...LOW
CONFIDENCE WITH ANY MEASURABLE PRECIPITATION. HENCE...LEFT OUT
POPS ATTM AND ONLY HAVE SPRINKLES MENTIONED ACROSS THE NORTH PAST
20Z. CLOUD COVER MAY HINDER HIGHS SLIGHTLY COOLER THAN FORECAST
BUT WITH THE WARMER START (THAN MONDAY MORNING) AND LIKELY ENOUGH
SUNSHINE PRIOR TO THE COLD FROPA...KEPT LOW 70S GOING IN NORTHERN
IOWA. FURTHER SOUTH...TWEAKED UP MAX TEMPS 2-3 DEGREES PER WARMER
START AND WITH THE DRY AIR MASS IN PLACE AND ENOUGH
MIXING...THINKING MAX TEMPERATURES SHOULD WARM CLOSER TO THE MAV
MOS GUIDANCE FOR HIGHS.

.LONG TERM /TONIGHT THROUGH MONDAY/...
ISSUED AT 305 AM CDT TUE APR 28 2015

THE MAJORITY OF THE EXTENDED SHOULD BE RATHER QUIET...WITH A RETURN
OF MORE ACTIVE WEATHER OVER THE WEEKEND INTO EARLY NEXT WEEK.
TONIGHTS PATTERN SHOWS A LARGE BOCKING RIDGE OF HIGH PRESSURE
OVER THE NORTHERN ROCKIES AND EASTERN GREAT LAKES. ACROSS THE EAST
A LARGE LOW CONTINUES TO KEEP NEW ENGLAND COOL AND THIS FEATURE IS
ALSO SLOWING THE EASTWARD PROGRESSION OF ANY WAVES ACROSS THE
NORTHERN PLAINS. THROUGH WEDNESDAY A WEAK BOUNDARY WILL MOVE
INTO THE AREA BY LATE THIS EVENING AND WEAKEN AS IT CROSSES THE
FORECAST AREA. THIS WILL RESULT IN A FEW CLOUDS BUT WITH MOISTURE
AND FORCING LACKING...THERE WILL BE LITTLE CHANCE FOR ANY
PRECIPITATION. ALREADY BY LATE WEDNESDAY AND INTO THURSDAY...SOME
UNCERTAINTY IS INTRODUCED INTO THE FORECAST. BOTH THE GEM/EURO/NAM
ARE HINTING AT A BACK DOOR SYSTEM TRACKING SOUTH INTO THE WESTERN
GREAT LAKES... PUNCHING A COLD FRONT ACROSS WI AND MN INTO IOWA
WED NIGHT INTO THURSDAY MORNING...FOLLOWED BY A COOL CANADIAN HIGH
PRESSURE SYSTEM FOR THURSDAY. THE GFS HAS YET TO LATCH ONTO THIS
FEATURE... AND THUS IS MUCH WARMER FOR THURSDAY AFTERNOON. WILL BE
MODIFYING THE FORECAST TO ACCOUNT FOR THE FRONT AND COOL CANADIAN
HIGH FOR THURSDAY. WILL BE LOWERING HIGHS INTO THE LOWER TO MID
60S OVER MUCH OF THE AREA. BY FRIDAY A NORTHERN STREAM WAVE DROPS
SOUTHEAST WITH ASSOCIATED LIFT RESULTING IN SCT COVERAGE OF
SHOWERS AND ISO THUNDER. UPSTREAM ADIABATIC WARMING WILL ADVANCE
INTO THE AREA FOR SATURDAY AND SUNDAY AS A MORE VIGOROUS TROUGH
BEGINS TO AFFECT THE REGION SATURDAY NIGHT...SUNDAY INTO MONDAY.
BOTH SATURDAY AND SUNDAY LOOK WARM AND MORE HUMID WITH SCATTERED
STORMS...ESPECIALLY SOUTH SATURDAY NIGHT...NORTH SUNDAY MORNING
AND OVER THE ENTIRE AREA SUNDAY NIGHT INTO EARLY MONDAY MORNING AS
THE SYSTEM PASSES TO THE EAST. WITH THIS PACKAGE...INSTABILITY
LOOKS STRONG ENOUGH FOR POSSIBLE VERY LIMITED SVR STORMS AS WIND
FIELDS NOT OVERLY IMPRESSIVE OR FAVORABLE FOR SUSTAINED ORGANIZED
STORMS. WILL LEAN TOWARD THE EURO FROM FRIDAY THROUGH MONDAY WITH
WARMEST DAY LOOKING TO BE SUNDAY...70S SAT TO NEAR 80 SUNDAY THEN
IN THE 60S TO LOWER 70S MONDAY AS FRONT SLIDES SOUTHEAST. RAINFALL
THROUGH THE PERIOD LOOKS TO BE LIGHT TO MODERATE WITH TOTALS
GENERALLY UNDER AN INCH BASED ON TONIGHTS MODEL DATA.

&&

.AVIATION...28/12Z
ISSUED AT 659 AM CDT TUE APR 28 2015

VFR CONDITIONS WILL PREVAIL THROUGH ENTIRE TAF PERIOD WITH ONLY
SOME MID-LEVEL CLOUDS MOVING IN LATE THIS AFTERNOON AND EARLY
EVENING.

&&

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

&&

$$

SHORT TERM...PODRAZIK
LONG TERM...REV
AVIATION...PODRAZIK


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.