Area Forecast Discussion
Issued by NWS Twin Cities, MN

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 KMPX 260803
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
303 AM CDT SUN OCT 26 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 244 AM CDT SUN OCT 26 2014

SFC ANALYSIS THIS MORNING SHOWS LARGE SFC HIGH PRES CENTERED OVER
THE CENTRAL GREAT LAKES...MAINTAINING ITS WRN FRINGES OVER THE UPR
MISS RIVER VALLEY...WHILE A COMPLEX AREA OF LOW PRES BECOMES MORE
ORGANIZED OVER SRN ALBERTA. THIS SFC LOW IS DEVELOPING IN ADVANCE
OF A LONGWAVE TROF MOVING ACROSS THE NRN ROCKIES AND GREAT
BASIN...AND THIS TROF TRAILS A RIDGE AXIS ALOFT THAT WILL SHIFT
ACRS MN AND WI TDA. AS THE RIDGE EXITS TO THE E...CLOUDS WILL
STEADILY INCREASE THROUGHOUT THE DAY TDA...PARTICULARLY AS A WMFNT
APPROACHES FROM THE W TDA. AN ARGUMENT CAN BE MADE THAT THE FRONT
WILL BE MORE OF AN OCCLUSION SINCE THE MAIN LOW...A NRN STREAM
LOW...WILL REMAIN WOUND UP AND N OF THE AREA WHILE A SECONDARY SRN
STREAM LOW FROM THE ROCKIES STAYS TO THE S AND KEEPS THE MORE BONA
FIDE WARM AIR TO THE S. REGARDLESS...THE EFFECTS WILL BE AN INCRS
IN CLOUD COVER BUT NOT NECESSARILY MOISTURE. 1000-500MB COLUMNS
LOOK TO REMAIN FAIRLY SHALLOW ACRS THE ENTIRE CWFA DURG THE
DAYLIGHT HRS TDA. SO DESPITE THE INCRS IN FRONTAL LIFT WITH THE
INCOMING SYSTEM...PRECIP GENERATION LOOKS MEAGER AT BEST SO HAVE
OPTED TO MAINTAIN A DRY FCST...EVEN FOR WRN WI WHERE FRONTAL LIFT
AND MOST INSTABILITY LOOK TO BE COINCIDENT. THE APPROACHING UPPER
TROUGH LOOKS TO BECOME SHARPER AND DIG DEEPER INTO THE NRN-CENTRAL
PLAINS OVERNIGHT INTO MON MRNG WHICH WILL ENHANCE LIFT WHILE
PIVOTING THE SFC LOW MOVING INTO SRN MANITOBA. MOISTURE DOES BEGIN
TO POOL TNGT OVER ERN PORTIONS OF THE CWFA...SO THIS LENDS TO
BETTER AGREEMENT OF SEEING SCATTERED SHOWERS OVER MAINLY FAR ERN
MN INTO WRN WI OVERNIGHT TNGT THRU MON MRNG. IN
ADDITION...NAM/SREF/HRRR DO DEPICT SOME MODEL INSTABILITY TO THE
TUNE OF NEARLY 1000 J/KG MUCAPE...SO HAVE MAINTAINED SLGT CHC TSTM
MENTION IN THE FCST. NOT LOOKING FOR A LOT OF COVERAGE AT
ALL...BUT THE PROSPECTS OF THUNDER CANNOT BE IGNORED SO HAVE GIVEN
IT ITS DUE DILIGENCE. AS FOR TEMPS...THE CLEAR SKIES AND LIGHT
WINDS THIS MRNG HAVE ALLOWED TEMPS TO BOTTOM OUT IN THE 30S FOR
THE ENTIRE CWFA. AMPLE SUNSHINE AND SE WINDS THRU THE FIRST HALF
OF TDA WILL ALLOW TEMPS TO REBOUND NICELY INTO THE 60-70 DEGREE
RANGE...WITH THE HIGHEST TEMPS IN WRN MN. CLOUDS TNGT AND STRONG
SLY FLOW ASSOCIATED WITH THE WARM FROPA WILL PRODUCE MUCH MORE
MILD TEMPS TNGT INTO MON MRNG. WILL LOOK FOR LOWS TO ONLY DROP TO
THE UPR 40S TO LWR 50S.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 244 AM CDT SUN OCT 26 2014

MODELS HAVE BEEN TRENDING FOR A MORE POTENT SHRTWV/UPPER LOW TO
FORM/MOVE ACROSS THE UPPER MIDWEST LATE MONDAY/TUESDAY WHICH
CORRESPONDS TO A BETTER CHC OF SHRA...ESPECIALLY TUE AS THE CORE
OF THE COLDEST AIR MOVES ACROSS THE REGION. THE ONLY CONCERN IS
THE AMT OF DEEP MOISTURE AVAILABLE DUE TO THE MAIN FRONT WELL SOUTH
OF OUR REGION. IN ADDITION...THE PHASING OF THE SOUTHERN/NORTHERN
JET REMAINS QUESTIONABLE...ESPECIALLY EARLY IN THE PERIOD...WITH A
BETTER CHC OF THE SOUTHERN STREAM HAVING MORE INFLUENCE ON
DEEPER MOISTURE/CONVECTION. THERE REMAINS ENOUGH CONFIDENCE FOR
SCATTERED/ISOLD SHRA FOR MONDAY...ESPECIALLY DURING THE AFTN...AND
AGAIN TUESDAY AFTN AS THE UPPER LOW MOVES NEAR THE REGION.

PAST TUESDAY...PRECIPITATION CHC/S REMAIN LOW CONSIDERING THE MUCH
DRIER AIR MASS REPLACING TUESDAY/S SYSTEM AND THE HIGH AMPLITUDE
OF UPPER RIDGE FORECAST TO BUILD ACROSS THE ROCKIES LATE IN THE
WEEK. IN OUR REGION...THIS AMPLIFIED PATTERN WILL LEAD TO A SHARP
CONTRAST FROM THE GREAT LAKES/OHIO VALLEY TO THE HIGH PLAINS AND
THE ROCKIES BY NEXT WEEKEND. IT IS LIKELY THAT THE COLDEST AIR OF
THE SEASON WILL SURGE SOUTHWARD THU/FRI AS THIS AMPLIFIED PATTERN
DEVELOPS. DEPENDING UPON THE STRENGTH OF THE LONG WAVE TROUGH IN
THE EASTERN U.S. AND HOW IT BECOMES BLOCKED IN THE OVERALL
PATTERN...WILL DETERMINE WHEN THE WARMER AIR REBOUNDS ACROSS THE
UPPER MIDWEST THE FIRST WEEK OF NOVEMBER.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1106 PM CDT SAT OCT 25 2014

HIGH CONFIDENCE IN VFR TONIGHT AND TOMORROW. WINDS WILL REMAIN
LIGHT OR CALM TONIGHT BEFORE INCREASING OUT OF THE SOUTHEAST IN
THE LATE MORNING. BY THE END OF THE TAF PERIOD...00Z-
MONDAY...LIGHT SHOWERS ARE POSSIBLE IN EASTERN MN AND WESTERN WI.
IT IS ALSO ENTIRELY POSSIBLE MOST OF THE LIGHT RAIN WILL PASS TO
THE EAST.

KMSP...

LITTLE TO NO WEATHER IMPACTS THROUGH THE TAF PERIOD. WIND DIRECTION
WILL BE TOUGH TO PIN DOWN LATE TONIGHT WITH HIGH PRESSURE MOVING
RIGHT OVERHEAD. WE DO THINK THE WINDS WILL FINALLY ESTABLISH A
SOUTHEAST DIRECTION BY 14Z. RAIN IS NOT IMPOSSIBLE BY THE END OF
THE TAF PERIOD...BUT THE CHANCES DON`T LOOK GREAT EITHER - MAYBE
SOME SPRINKLES OUT OF A MID DECK OF CLOUDS. THUNDER IS NOT OUT OF
THE QUESTION EITHER SOMEWHERE IN SOUTHEAST MN OR WESTERN WI
TOMORROW EVENING.

/OUTLOOK FOR KMSP/
MON...MVFR CIGS LIKELY EARLY. CHC SHRA. WINDS BCMG WNW 5-10 KTS.
TUE...CHC MVFR/SHRA. WINDS WNW 15G25 KTS.

&&

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

$$

SHORT TERM...JPC
LONG TERM...JLT
AVIATION...CLF




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