Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
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 KDVN 071201
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
601 AM CST SUN FEB 7 2016

...AVIATION UPDATE...

.SYNOPSIS...
ISSUED AT 330 AM CST SUN FEB 7 2016

MSAS ANALYSIS HAD A 996 MB LOW ANALYZED NEAR LAKE OF THE WOODS
ALONG THE ONTARIO/MINNESOTA BORDER. SFC TEMPS FOR E
IOWA/ILLINOIS/NE MISSOURI WERE VERY MILD..IN THE MID TO UPPER
30S...FOR 3 AM IN EARLY FEBRUARY. SOUTHWESTERLY WINDS WERE
BETWEEN 15-20 MPH. OTHERWISE...DRY CONDITIONS HAVE PREVAILED INTO
THIS OVERNIGHT PERIOD.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 330 AM CST SUN FEB 7 2016

TODAY AND TONIGHT...MILD TEMPS TO START THE DAY THANKS TO STEADY
SW WINDS WRAPPING INTO A SFC LOW TRACKING ACROSS LAKE SUPERIOR.
HIGH TEMPS WILL BE ABOUT 10 DEGREES ABOVE AVG BY EARLY FEBRUARY
STANDARDS... UPPER 30S FAR NORTH...MID 40S ALONG I-80...AND UPPER
40S FAR SOUTH.

SFC WINDS WILL VEER TO THE WEST DURING THE LATE MORNING INTO THE
AFTN. HOWEVER...THIS CHANGE IN WIND DIRECTION WILL ONLY ACT TO
SLIGHTLY LOWER SFC TEMPS BECAUSE THE TIGHTER TEMP GRADIENT WILL
STILL BE LOCATED IN THE DAKOTAS AND MINNESOTA. EXPECT SFC TEMPS TO
FALL FASTER NEAR OR AFTER MIDNIGHT MONDAY WHEN WINDS TO SHIFT TO
THE NW BEHIND A SECONDARY COLD FRONT.

WIND GUSTS...WINDS WILL INCREASE BEHIND THE SECONDARY FEATURE AS
THE PRESSURE GRADIENT INCREASES AND ISENTROPIC DOWNGLIDE/CAA
PROVIDES A SUFFICIENTLY DEEP AND WELL-MIXED BOUNDARY LAYER UP TO
850 MB. FORECAST SOUNDINGS HAVE PEAK WINDS IN THE MIXED LAYER
BETWEEN 35-40 KTS...EASILY SUPPORTING GUSTS BETWEEN 30-40 MPH
LATE SUNDAY NIGHT AND MONDAY.

PRECIPITATION...NUMEROUS SNOW SHOWERS ARE FORECAST TONIGHT INTO
MONDAY MORNING...SOME POSSIBLY CONVECTIVE IN NATURE GIVEN
800-700MB LAPSE RATES DURING THE ONSET AND PRESENCE OF SBCAPE UP
TO 25-50 J/KG. 0-1 KM CONVERGENCE IS ENHANCED BETWEEN MIDNIGHT TO
6 AM MONDAY...AIDING SNOW SHOWER FORMATION...THEN WEAKENS LATER
MONDAY MORNING.

SYNOPTIC LIFT IS THERE AS WELL...A 500MB VORTICITY LOBE WILL
ROTATE AROUND THE 500MB LOWER CENTER SPREADING DCVA ACROSS E
IOWA/W ILLINOIS/NE MISSOURI OVER NIGHT SUNDAY NIGHT INTO MONDAY
MORNING. ALSO NOTICED THE FORECAST DEPTH OF THE DENDRITIC SNOW
GROWTH IS LARGE NEAR 200 MB...FAVORING POWDERY SNOW WITH
15:1-20:1 SLRS. SNOW AMOUNTS THROUGH 6 AM MONDAY WILL BE A HALF
INCH OR LESS FOR MOST LOCATIONS.

POTENTIAL IMPACTS...GREATEST CONCERN IS THE COMBINATION OF WIND
GUSTS BETWEEN 30-40 MPH AND SNOW SHOWERS PRODUCING POWDERY SNOW...
SOME POSSIBLY WITH BRIEF MODERATE INTENSITY...TOGETHER RESULTING
IN PERIODS OF LOCALIZED LOW VISIBILITIES TO LESS THAN A HALF MILE.

THINKING MID TO UPPER 30S AIR TEMPS OVER THE EXISTING SNOW-COVER
WILL RESULT IN COMPACTION...DRASTICALLY REDUCING THE POTENTIAL FOR
BLOWING OF THE SNOW THAT IS CURRENTLY ON THE GROUND ACROSS THE
NORTHERN SECTION OF THE DVN CWA. NONETHELESS...A WINTER WEATHER
ADVISORY MAY BE NECESSARY FOR PARTS OF THE AREA BUT IS CONTINGENT
ON WHERE THE MOST ORGANIZED/PERSISTENT SNOW SHOWERS/NARROW BANDS
SET UP AND MAY NOT BE NEEDED FOR THE ENTIRE CWA. UTTECH

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 330 AM CST SUN FEB 7 2016

MONDAY MORNING...HAVE BUMPED POPS UP INTO THE LIKELY TO
CATEGORICAL RANGE WITH CONTINUED PERIODS OF SNOW SHOWERS AND BRIEF
BURSTS OF HIGHER INTENSITY SNOW EXPECTED. CONFIDENCE IS LOW IN
SPECIFIC AREAS THAT WOULD BE MORE FAVORED FOR MODEST SNOWFALL
ENHANCEMENTS...SO HAVE STAYED WITH THE BLENDED QPF WHICH YIELDS AN
ADDITIONAL DUSTING TO HALF INCH ACROSS THE FORECAST AREA. THE
LATEST RUNS OF THE WRF ARE HIGHLIGHTING A COUPLE OF HIGHER SWATHS
IN THE CENTRAL AND SOUTH. HAVE ALSO EXPANDED AREAS OF BLOWING SNOW
ALONG AND WEST OF THE MISSISSIPPI RIVER...COINCIDENT WITH THE
HIGHEST WIND GUSTS AROUND 40 MPH. THE MONDAY MORNING COMMUTE COULD
BE CHALLENGING...WITH PERIODS OF NO SIGNIFICANT WEATHER...QUICKLY
CHANGING TO SNOW SHOWERS...BLOWING SNOW AND SHARPLY REDUCED
VISIBILITIES...AND SHALLOW DRIFTING ACROSS ROADS. LONG TERM LOW
VISIBILITIES ARE NOT EXPECTED...SO THAT TAKES A BLIZZARD WARNING
OUT OF PLAY. HOWEVER...AN ADVISORY MAY EVENTUALLY BE NEEDED FOR AT
LEAST PARTS OF THE FORECAST AREA DURING THIS PERIOD.

MONDAY AFTERNOON...WINDS WILL REMAIN STRONG...ESPECIALLY IN EASTERN
IOWA...BUT THE OVERALL COVERAGE OF SNOW SHOWERS IS EXPECTED TO
DIMINISH SO HAVE GONE WITH PATCHY BLOWING SNOW RATHER THAN AREAS.
AFTERNOON HIGHS SHOULD ONLY REACH THE 20S.

MONDAY NIGHT INTO TUESDAY...EXPECT LINGERING LIGHT SNOW...MAINLY
ALONG/EAST OF THE MISSISSIPPI. WINDS ARE EXPECTED TO DIMINISH
SOMEWHAT SO THAT SIGNIFICANT BLOWING SNOW SHOULD NOT BE AN ISSUE.
HOWEVER...SHALLOW DRIFTING AND SLICK ROADS WILL LIKELY PERSIST.
STRONG COLD AIR ADVECTION WILL DROP TEMPS INTO THE SINGLE DIGITS
NORTHWEST MONDAY NIGHT...WITH WIND CHILL VALUES IN THE 5 TO 15 BELOW
RANGE. THE WIND IS EXPECTED TO REMAIN UP THROUGH TUESDAY NIGHT...AND
WIND CHILLS COULD APPROACH THE 20 BELOW ADVISORY CRITERIA ALONG THE
HIGHWAY 20 CORRIDOR.

WEDNESDAY THROUGH SATURDAY...HAVE MAINTAINED DRY FORECAST...ALTHOUGH
SOME BRIEF PERIODS OF SCATTERED LIGHT SNOW CANNOT BE RULED OUT WITH
WEAK IMPULSES EMBEDDED IN THE NORTHWEST FLOW. EXPECT GRADUALLY
MODERATING TEMPS INTO THE 20S TO LOW 30S...ABOUT 5 TO 10 DEGREES
BELOW NORMAL FOR THE PERIOD.&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1140 PM CST SAT FEB 6 2016

VFR CONDITIONS TO DOMINATE THE NEXT 24 HOURS. HIGH CLOUDS WILL INCREASE
OVERNIGHT WITH A STRENGTHENING SOUTHWEST WIND OF 5 TO 10 KTS WITH OCCASIONAL
GUSTS OF 15-20 KTS. BKN-OVC CLOUDS WITH ANY CIGS AOA 5K AGL ON SUNDAY
WITH WINDS INCREASING FROM THE WEST AT 15 TO 25+ KTS BY AFTERNOON. SUNDAY
EVENING FLURRIES AND LIGHT SNOW WILL APPROACH THE TERMINALS WITH POSSIBLE
MVFR CONDITIONS WHICH ARE HANDLED AS A PROB30 GROUP THIS FAR OUT.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 544 AM CST SUN FEB 7 2016

VFR TO CONTINUE THROUGH THIS AFTN.

A COLD FRONT IS SET TO BRING BOUTS OF SNOW SHOWERS TO THE
TERMINALS...ESPECIALLY AFTER 9 PM TONIGHT...CONTINUING INTO MONDAY
MORNING. CIGS WILL LOWER TO MVFR WITH THE POTENTIAL FOR A PERIOD
OF IFR...MOSTLY LIKELY UNDER THE STEADIER SHSN. WNW WINDS WILL
GUST BETWEEN 25-30 KTS AND WHEN COUPLED WITH FALLING SNOW COULD
CAUSE VSBYS TO BRIEFLY DROP TO LIFR OR NEAR/BELOW A HALF MILE.
UTTECH

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&

$$

SYNOPSIS...UTTECH
SHORT TERM...UTTECH
LONG TERM...RP KINNEY
AVIATION...UTTECH


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