Area Forecast Discussion
Issued by NWS Twin Cities, MN

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
000
FXUS63 KMPX 220858
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
358 AM CDT TUE APR 22 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM CDT TUE APR 22 2014

THINGS WILL BE FAIRLY QUIET THROUGH THE SHORT TERM... WITH THE
ONLY ITEM OF ANY CONCERN BEING CHANCES FOR SOME WARM ADVECTION
PCPN TO MOVE INTO THE WESTERN HALF OF THE AREA LATE TONIGHT.
CURRENT SURFACE ANALYSIS SHOWS HIGH PRESSURE CENTERED NEAR THE
MINNESOTA/DAKOTAS BORDER. THIS FEATURE WILL MOVE EAST THROUGH THE
DAY TODAY AS NORTHWEST UPPER FLOW PERSISTS... KEEPING THINGS
MOSTLY SUNNY AND DRY... ALTHOUGH MID-HIGH CLOUDS WILL START TO
WORK IN FROM THE WEST DURING THE AFTERNOON. THE UPPER TROUGH
CURRENTLY MOVING INTO THE WEST COAST WILL CONTINUE TO PUSH EAST
THROUGH TONIGHT... WORKING TO DRIVE THE UPPER RIDGE AXIS INTO OUR
AREA BY 12Z WEDNESDAY.MID-LEVEL WARM ADVECTION WILL QUICKLY
INCREASE LATE TONIGHT IN RESPONSE TO THE PROGRESSION OF THE UPPER
RIDGE... WITH SUFFICIENT SATURATION LIKELY TO OCCUR OVER THE WEST
AFTER THE 06-09Z FOR SOME PCPN. AT THIS POINT... THINK ANY PCPN
WILL STAY WEST OF I-35 THROUGH 12Z. WOULD BE A BIT MORE CONCERNED
ABOUT PCPN DEVELOPING FARTHER EAST THAN PROGGED BY THE MODELS...
SINCE THAT OFTEN OCCURS IN SIMILAR WARM ADVECTION SCENARIOS... BUT
THE LACK OF ANY APPARENT ELEVATED INSTABILITY THROUGH THE NIGHT
SHOULD KEEP THAT FROM OCCURRING. NEITHER MUCAPE... BEST LI...
SHOWALTER INDICES... NOR SIMPLE CONVECTIVE INSTABILITY VIA
850-500MB DIFFERENTIAL THETA-E INDICATE ANY INSTABILITY WORKING
INTO THE AREA TONIGHT... SO TIMING OF PCPN SHOULD REALLY REMAIN
TIED TO THE ISENTROPIC ASCENT AND SATURATION... WHICH LOOKS TO
ONLY IMPACT THE WESTERN THIRD-TO HALF OF THE AREA OVERNIGHT.
INCLUDED A CHANCE FOR SHRA OVER THE FAR WEST BY 06... THEN BROUGHT
IT TO JUST WEST OF I-35 BY 12Z. WE WILL SEE 850MB TEMPERATURES
WARM SLIGHTLY DURING THE DAY TODAY... AND FORECAST SOUNDINGS
SUGGEST WE SHOULD BE ABLE TO MIX THROUGH AROUND 825MB OR SO...
WHICH SHOULD ALLOW FOR HIGHS OF 60-65 OUT WEST... NEAR 60 IN THE
TWIN CITIES METRO... AND MID 50S IN WEST CENTRAL WISCONSIN.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 335 AM CDT TUE APR 22 2014

LONG TERM CONCERNS IS THE OVERALL DEVELOPMENT AND MOVEMENT OF THE
WESTERN CONUS TROUGH WEDNESDAY AND THURSDAY. IT APPEARS THERE IS A
GOOD LIKELIHOOD OF OF AT LEAST ONE HALF TO 1 INCH OF RAIN ACROSS
MUCH OF THE CENTRAL AND EASTERN PORTION OF THE CWA WEDNESDAY AND
THURSDAY. MUCH COOLER FOR THE REST OF THE PERIOD WITH A SMALL
THREAT OF RAIN AND SNOW CLIPPING MAINLY THE SOUTHERN CWA LATE IN
THE PERIOD.

MODELS ARE IN FAIR AGREEMENT IN THE TIMING AND MOVEMENT OF THE
TROUGH AND SURFACE FRONT DURING THE WED/THU TIME FRAME. LOOKS LIKE
SOME SOWERS DEVELOPING LATER TUESDAY NIGHT AND SPREADING EAST
DURING THE DAY ON WEDNESDAY. WILL RETAIN THE LIKELY POPS...WEST
EARLY...SPREADING INTO WESTERN WISCONSIN IN THE AFTERNOON. THERE
WILL LIKELY BE A LULL IN THE OVERALL ACTIVITY WEDNESDAY AFTERNOON.
THE STRONGER FORCING AND MOISTURE LIFT NORTHEAST ACROSS THE AREA
WEDNESDAY AND THURSDAY. THIS REMAINS THE BEST PERIOD TO CONTINUE
THE CATEGORICAL POPS OVER THE AREA. ABUNDANT CLOUD COVER ALONG
WITH THE RAIN WILL KEEP TEMPERATURES ON THE COOL SIDE OVER MUCH OF
THE AREA...STRUGGLING TO WARM TO 50 IN THE NORTHEAST CWA.
INSTABILITY IS MEAGER ACROSS THE AREA DURING THE PERIOD. THE STRONG
NATURE OF THE TROUGH COULD STILL INITIATE ISOLATED THUNDER OVER THE
AREA DURING THIS PERIOD.

IN THE WAKE OF THE SYSTEM...MUCH COLDER AIR IS DRIVEN SOUTH ACROSS
THE AREA. THE 00Z ECMWF IS EVEN COOLER THAN THE GFS THIS GO ROUND.
THE ECMWF ACTUALLY DRIVES BELOW ZERO H85 TEMPERATUREA OVER THE
NORTHEAST CWA...WITH THE POSSIBILITY OF RAIN/SNOW SCENARIO THERE
THURSDAY AFTERNOON INTO FRIDAY. WILL HAVE TO MONITOR THIS TREND
LATER TODAY.

FOR THE REMAINDER OF THE LONGER TERM...BELOW NORMAL TEMPERATURES
WILL REMAIN THROUGH THE WEEKEND INTO EARLY NEXT WEEK. MODELS ARE
INDICATING THE NEXT TROUGH COMING ASHORE OVER THE WEST COAST LATE
IN THE WEEK. BELIEVE THE 00Z GFS MAY BE A BIT FAST IN DRIVING THE
TROUGH EAST OVER THE WEEKEND. WILL KEEP SATURDAY DRY...AND SPREAD
SOME CHANCE POPS OVER MAINLY THE SOUTHWEST THIRD OF THE CWA INTO
SUNDAY. IT WILL BE TOUGH FOR THE TROUGH TO OVERCOME THE LARGE
CANADIAN HIGH THAT WILL PROVIDE A GENERALLY DRY EASTERLY FLOW
ACROSS THE AREA THROUGH MOST OF TH WEEKEND. ANY PRECIPITATION THAT
DOES MAKE IT INTO THE SOUTH WILL LIKELY BE MIXED RAIN/SNOW COMBO.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1106 PM CDT MON APR 21 2014

VFR THROUGHOUT THIS SET. WIND WILL REMAIN MAINLY NW WITH SPEEDS
5-10 KT OVERNIGHT INTO TMRW MRNG...THEN GRADUALLY SHIFT TO N AND
NE THRU THE DAY...CONTINUING TO VEER TO E AND SE THROUGH THE
EVENING. HIGH CLOUDS WILL START TO STREAM IN TMRW AFTN...BECOMING
A HIGH CEILING FOR THE MN SITES BY TMRW EVENING...BUT NO
SIGNIFICANT IMPACTS EXPECTED AND DRY WX THRU 23/06Z.

KMSP...VFR. WINDS REMAIN NW OVERNIGHT THRU DAYBREAK THEN BECOME
MORE NE BY MIDDAY TMRW...THEN CONTINUE TO VEER TO E AND SE LATE
TMRW AFTN THRU TMRW EVE. SPEEDS GENERALLY IN THE 5-10 KT RANGE. FEW-
SCT HIGH CLOUDS LATE DAY TMRW BECOME A HIGH CEILING TMRW EVENING.

/OUTLOOK FOR KMSP/
WED...MAINLY VFR. MVFR CONDS PSBL IN -RA. SE WIND 10-20 KT.
WED NGT...MVFR CONDS LIKELY IN -RA WITH IFR PSBL. SE WIND 15-20
KT.
THU...MVFR CONDS LIKELY EARLY WITH -RA. S WIND 10-20 KT SHIFTING
W.
THU NGT...VFR. W WIND 5-15 KT.
FRI...MAINLY VFR. MVFR CONDS PSBL WITH A CHC -RA. W WIND 5-15 KT
BCMG NW.


&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&

$$

SHORT TERM...TRH
LONG TERM...DWE
AVIATION...JPC






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