Area Forecast Discussion
Issued by NWS Des Moines, IA

Home | Current Version | Previous Version | Graphics & Text | 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
206
FXUS63 KDMX 040541
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1141 PM CST WED FEB 3 2016

.SHORT TERM /TONIGHT/...
ISSUED AT 308 PM CST WED FEB 3 2016

THE WIND WILL CONTINUE TO DIMINISH THROUGH SUNSET AND WILL DROP OFF
EVEN FURTHER AFTER SUNSET.  CLOUDS ARE RAPIDLY DIMINISHING FOR THE
TIME BEING AS WELL SO THE EXPECTATION IS FOR TEMPERATURES TO DROP
FAIRLY QUICKLY THIS EVENING.  SATELLITE SHOWING SOME CLOUD STREETS
MOVING ACROSS THE SOUTHWEST AND THERE ARE FLURRIES BEING REPORTED IN
OBSERVATION SITES UNDER THESE CLOUDS.  THIS SHOULD BE DONE IN AN
HOUR OR SO AND CERTAINLY WITH SUNSET.

LATER TONIGHT THROUGH THURSDAY IOWA WILL GET HIT WITH A ONE/TWO
PUNCH OF SHORTWAVES...NEITHER OF WHICH WILL BE CAPABLE OF PRODUCING
MEASURABLE SNOW FOR THE FORECAST AREA AND WHILE A FEW FLURRIES ARE
POSSIBLE VERY LATE TONIGHT...CONFIDENCE WASN`T EVEN HIGH ENOUGH TO
INCLUDE IN THE FORECAST.  CLOUDS ASSOCIATED WITH THE FIRST WAVE
THOUGH ARE VISIBLE ON SATELLITE AND WILL MAKE THEIR WAY INTO THE
NORTHWEST BY 06Z THEN SPREAD ACROSS THE NORTHERN HALF OF THE STATE
OVERNIGHT.  TEMPERATURES WILL BE OF SOME CONCERN...ESPECIALLY OVER
THE NORTHWEST WHERE CLOUD COVER MOVES IN EARLIEST.  LOWS WILL LIKELY
OCCUR ACROSS THE NORTH BEFORE MIDNIGHT THEN SLOWLY RISE AFTER 09Z.
ACROSS THE SOUTH...WHERE CLOUDS WILL EITHER BE ABSENT OR LATE IN
COMING...TEMPS WILL CONTINUE TO FALL THROUGH 12Z AND PROBABLY BOTTOM
OUT BETWEEN 10 AND 15 DEGREES.  AS THE SURFACE HIGH SHIFTS SOUTHEAST
OVERNIGHT THE WIND WILL BECOME MORE WEST THEN WEST SOUTHWEST WHICH
MAY ALSO HAMPER HOW FAR TEMPS FALL TONIGHT..ESPECIALLY IF THE WINDS
SHIFT A BIT SOONER THAN EXPECTED. IOWA WILL GET HIT WITH A
ONE/TWO PUNCH OF SHORTWAVES...NEITHER OF WHICH WILL BE CAPABLE OF
PRODUCING MEASURABLE SNOW FOR THE FORECAST AREA AND WHILE A FEW
FLURRIES ARE POSSIBLE VERY LATE TONIGHT...CONFIDENCE WASN`T EVEN
HIGH ENOUGH TO INCLUDE IN THE FORECAST. CLOUDS ASSOCIATED WITH THE
FIRST WAVE THOUGH ARE VISIBLE ON SATELLITE AND WILL MAKE THEIR WAY
INTO THE NORTHWEST BY 06Z THEN SPREAD ACROSS THE NORTHERN HALF OF
THE STATE OVERNIGHT. TEMPERATURES WILL BE OF SOME
CONCERN...ESPECIALLY OVER THE NORTHWEST WHERE CLOUD COVER MOVES IN
EARLIEST. LOWS WILL LIKELY OCCUR ACROSS THE NORTH BEFORE MIDNIGHT
THEN SLOWLY RISE AFTER 09Z. ACROSS THE SOUTH...WHERE CLOUDS WILL
EITHER BE ABSENT OR LATE IN COMING...TEMPS WILL CONTINUE TO FALL
THROUGH 12Z AND PROBABLY BOTTOM OUT BETWEEN 10 AND 15 DEGREES. AS
THE SURFACE HIGH SHIFTS SOUTHEAST OVERNIGHT THE WIND WILL BECOME
MORE WEST THEN WEST SOUTHWEST WHICH MAY ALSO HAMPER HOW FAR TEMPS
FALL TONIGHT..ESPECIALLY IF THE WINDS SHIFT A BIT SOONER THAN
EXPECTED.

.LONG TERM /THURSDAY THROUGH WEDNESDAY/...
ISSUED AT 308 PM CST WED FEB 3 2016

CHALLENGES FOR THE EARLY PORTION OF THE EXTENDED PERIOD INCLUDE SOME
MINOR DISTURBANCES WITH POTENTIAL FOR SOME SNOWFALL/WIND.
TEMPERATURES WILL ALSO BE A CHALLENGE THROUGH THE PERIOD. BY LATE
WEEKEND INTO NEXT WEEK...MODELS NOW COMING INTO BETTER AGREEMENT
REGARDING ARCTIC INTRUSION ACROSS THE REGION... ACCOMPANIED BY
STRONG WINDS POTENTIALLY LEADING TO VERY COLD WIND CHILLS.

OVER THE NEXT FEW DAYS THE PATTERN WILL OSCILLATE BETWEEN SOUTHWEST
TO NORTHWEST FLOW ALOFT AS RELATIVELY WEAK WAVES FORMING ALONG THE
LEE OF THE ROCKIES OR DROPPING SOUTHEAST OUT OF CANADA PROGRESS EAST
THROUGH/NEAR THE REGION. THE FIRST WAVE WILL PASS NORTH OF THE AREA
TOMORROW. THIS WILL RESULT IN THE PASSAGE OF A TROUGH WITH SOME
LIGHT SNOW/FLURRIES ACROSS THE NORTHEAST THURSDAY AFTERNOON. NO
ACCUMULATIONS ARE ANTICIPATED. ANOTHER GENERALLY MOISTURE STARVED
WAVE WILL PROGRESS ACROSS MINNESOTA FRIDAY AND FRIDAY NIGHT BRINGING
ANOTHER CHANCE OF LIGHT SNOW TO THE NORTH.

THE WAVE IS ACCOMPANIED BY A STRONGER VORT MAX AND A PERIOD OF WARM
AIR ADVECTION. A PERIOD OF LIGHT SNOW WILL OCCUR FROM LATE FRIDAY
AFTERNOON THROUGH FRIDAY NIGHT WITH SOME LINGERING FLURRIES INTO
EARLY SATURDAY MORNING. MINOR ACCUMULATIONS ARE ANTICIPATED MAINLY
NORTH CENTRAL AND NORTHEAST. THERE ARE STILL SOME DIFFERENCES
WITH THE HANDLING OF THE SFC WAVE AND FORCING...WITH THE GFS
FARTHER SOUTH THAN THE EURO MODEL AT THIS TIME. NONE THE LESS SOME
LIGHT ACCUMULATIONS ARE POSSIBLE WITH THE WAVE AS IT PASSES SOUTHEAST.
DURING THE PERIOD TEMPERATURES WILL BE WARMER OVER THE SOUTH WHERE
LESS SNOW COVER REMAINS. OVER THE WEEKEND A STRONGER WAVE WILL
TRACK ALONG THE US CANADIAN BORDER WITH H850 TEMPERATURES RISING
TO 0C OVER CENTRAL IOWA AND NEAR 2C IN THE WEST BY 00Z SUNDAY.
ALONG WITH BRISK WESTERLY WINDS AND BREAKS IN THE CLOUD COVER AREA
TEMPERATURES SHOULD WARM NICELY SATURDAY AFTERNOON AND THEN REMAIN
MILD OVERNIGHT SATURDAY NIGHT. ON SUNDAY THEY WILL QUICKLY RECOVER
INTO THE 30S TO LOWER 40S BY AFTERNOON BEFORE FALLING OVERNIGHT
SUNDAY NIGHT.

A PACIFIC COLD FRONT WILL ACCOMPANY THE CLIPPER SYSTEM SUNDAY
MORNING FOLLOWED BY AN ARCTIC FRONT DROPPING SOUTHEAST SUNDAY NIGHT
OR MONDAY. THERE REMAIN SOME UNCERTAINTIES WITH THE MODEL TIMING
OF THE MAIN ARCTIC SURGE. THE EUROPEAN MODEL IS FASTER THAN THE
GFS...THOUGH THEY ARE WITHIN 12 HOURS OF EACH OTHER OUT 5 DAYS.
EARLY NEXT WEEK...TEMPERATURES WILL BECOME MUCH COLDER THROUGHOUT
THE REGION. TODAYS MEDIUM RANGE MODELS ARE IN BETTER AGREEMENT
WITH THE MAGNITUDE OF THE COLD AIRMASS...WITH H850 TEMPERATURES
QUICKLY FALLING TO 15 TO 20 BELOW BY 00Z TUESDAY. CURRENT FORECAST
GUIDANCE MEAN TEMPERATURES MAY BE TOO WARM GIVEN THE SPREAD OF
VALUES OVER THE REGION MONDAY NIGHT INTO TUESDAY...BUT WILL GO
WITH HAVE TO STICK WITH THE MEAN VALUES FOR NOW GIVEN SOME RECENT
UNCERTAINTY IN AGREEMENT BETWEEN VARIOUS MODELS. REALISTICALLY WE
WILL PROBABLY SEE TEMPS COME DOWN ANOTHER 10 DEGREES LOWER IN
SUCCEEDING PACKAGES IF THE CURRENT TRENDS ARE MAINTAINED. OUR
RECENT SNOW COVER...EVEN WITH SOME MELTING/COMPACTION THIS
WEEKEND WILL AID IN MAINTAINING THE COLD AIR AS IT MOVES
SOUTHEAST. WIND WITH THE ADVANCING COLD AIR BECOMING RELATIVELY
STRONG ALOFT AND WITH STRONG MIXING ANTICIPATED...THERE WILL BE A
GOOD PROBABILITY FOR SHEAR DRIVEN SNOW SHOWERS BOTH MONDAY AND
TUESDAY AS THE COLD AIR REMAINS ACROSS THE REGION AND WINDS REMAIN
STRONG THROUGH THE BOUNDARY LAYER. THOUGH OUR SNOW PACK WILL HAVE
SETTLED OVER THE WEEKEND WITH THE MILDER TEMPERATURES...ANY NEW
LIGHT SNOW WILL BE EASILY BLOWN AROUND AND MIGHT RESULT IN SOME
GROUND VISIBILITY ISSUES MONDAY. ALSO...WITH A GOOD POSSIBILITY
THAT HIGHS/LOWS WILL BE COLDER THAN THE MEANS NOW FORECAST...WILL
NEED TO MONITOR TRENDS FOR APPARENT TEMPERATURES/WIND CHILL FROM
MONDAY THROUGH AT LEAST TUESDAY WHEN SFC WINDS ARE EXPECTED TO BE
THE STRONGEST.

&&

.AVIATION...04/06Z
ISSUED AT 1141 PM CST WED FEB 3 2016

VFR CONDITIONS WILL PREVAIL THROUGH TONIGHT WITH LIGHT SOUTHWEST
WINDS. ON THURSDAY AFTERNOON AND EVENING THERE IS A POSSIBILITY
THAT MVFR OR EVEN IFR CIGS WILL MOVE DOWN FROM MINNESOTA AND
AFFECT THE NORTHERN TERMINALS...BUT AT THIS RANGE CONFIDENCE IS
TOO LOW TO ADVERTISE EXCEPT AT MCW.

&&

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

&&

$$

SHORT TERM...FAB
LONG TERM...REV
AVIATION...LEE



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