Area Forecast Discussion
Issued by NWS Twin Cities, MN

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 KMPX 020840
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
340 AM CDT SAT AUG 2 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CDT SAT AUG 2 2014

EXTENT OF CONVECTION DURING THE DAY AND TONIGHT THE MAIN FOCUS OF
THE SHORT TERM.

AREAS OF FOG DEVELOPED AFTER MIDNIGHT ACROSS MUCH OF THE AREA.  WILL
CONTINUE THIS UNTIL 13Z.  EXTENT OF THUNDER THREAT IS THE MAIN
PROBLEM.  INITIALLY HAVE A BAND OF ISOLATED THUNDER ASSOCIATED WITH
A SHORT WAVE MOVING ACROSS THE EASTERN DAKOTAS.  MOST MODELS
INDICATE THIS FEATURE MOVING INTO WESTERN MN THIS MORNING AND THEN
SOUTHEAST DURING THE AFTERNOON.  THE GFS IS MOST AGGRESSIVE WITH THE
WAVE COMING THROUGH.  IT FOCUSES THE MAIN FORCING/THUNDER THREAT
OVER THE EASTERN PORTION OF THE AREA.  VARIOUS HIRES MODELS AND THE
HOPWRF INDICATE WIDELY SCATTERED CONVECTION DEVELOPING INTO WESTERN
MN BY 18Z.  THEY THE MOVE IT SLOWLY EAST TOWARD THE WEST METRO
THROUGH 00Z SUN.  WE WILL STILL HAVE MLCAPE IN EXCESS OF 1500 J/KG
OVER MOST OF THE AREA INTO THE AFTERNOON...WITH TEMPERATURES WARMING
THROUGH THE MID 80S. SEVERE PARAMETERS LACKING ONCE AGAIN...BUT
ISOLATED/WIDELY SCATTERED MULTICELL STORMS POSSIBLE ONCE AGAIN.

A WEAK FRONT STILL PROGGED TO DROP INTO CENTRAL MN OVERNIGHT. MODELS
DIVERGE ON OVERALL PRECIPITATION POTENTIAL OVERNIGHT.  THE GFS TAKES
THE INITIAL WAVE/FORCING SOUTHEAST OF THE AREA AND LIMITS ANY REAL
DEVELOPMENT OVER THE AREA.  THE NAM NOT SO MUCH.  WILL CONTINUE THE
TREND OF SOME CHANCE POPS ACROSS MOST OF THE AREA FOR THE FOR THIS
THREAT ALONG THE FRONT.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 340 AM CDT SAT AUG 2 2014

A WEAK BOUNDARY WILL SAG SOUTH ACROSS NORTHERN WISCONSIN AND
CENTRAL MINNESOTA SUNDAY. IT WILL BE THE FOCUS FOR MORE DIURNALLY-
DRIVEN SHOWERS AND THUNDERSTORMS. LIKE THE LAST SEVERAL
DAYS...THEY WILL BE SCATTERED AND NOT PERSIST IN ANY ONE LOCATION
FOR TOO LONG. NAM IS MOST WIDESPREAD IN COVERAGE WHEREAS THE GFS
DOESN/T SHOW MUCH EXCEPT OVER WI. THE REMAINING MODELS ARE
SOMEWHERE IN BETWEEN BUT ALL AGREE THE BEST CHANCES WILL BE ACROSS
ERN MN AND WRN WI. THIS IS WHERE THE 40-50 POPS ARE MAINTAINED...
WITH SLIGHT CHANCES FURTHER WEST.

HIGH PRESSURE WILL BUILD IN ENOUGH TO ALLOW FOR COMPLETE REMOVAL
OF POPS IN MOST PLACES SUNDAY NIGHT THROUGH MONDAY NIGHT. IT MAY
BE A RATHER CHILLY NIGHT MONDAY NIGHT WITH THE HIGH CENTERED OVER
WESTERN LAKE SUPERIOR AND DRIER AIR ADVECTING IN FROM THE
NORTHEAST. COULD SEE LOWS IN THE LOWER 50S OVER NORTHWEST WI.

MODELS HAVE REVERTED BACK SOMEWHAT FOR MIDWEEK WITH A WEAKER
TROUGH OVER NEW ENGLAND AND A BUILDING RIDGE INTO THE CENTRAL
PLAINS. THIS HAS ESSENTIALLY BROUGHT THE BETTER CHANCES FOR RAIN
BACK INTO SRN MN TUESDAY NIGHT AND WEDNESDAY MORNING PER ECMWF.
THE GEM IS EVEN FURTHER NORTH...WITH THE BRUNT OF IT IMPACTING
CENTRAL MN AND NORTHERN WI. THE GFS MAINTAINS A SURFACE
ANTICYCLONE OVER THE GREAT LAKES INTO WEDNESDAY MORNING WITH THE
FEATURE NOT ARRIVING UNTIL WEDNESDAY NIGHT...A FULL 24 HOURS LATER
THAN THE ECMWF AND GEM. THERE DOES NOT SEEM TO BE TOO MANY GOOD
OPTIONS HERE...BUT DECIDED TO LEAN TOWARD THE ECMWF SOLUTION WHICH
IS SOMEWHAT OF A SPLIT AMONGST THE MODELS...AND INCREASE POPS
MODESTLY FOR THIS PERIOD WITH THE HIGHEST NUMBERS SOUTH OF I-94.

FOLLOWING WEDNESDAY...THE EC SHOVES THE FRONT WELL SOUTH AND IS
DRY FOR THE REST OF THE WEEK. THE GEM GENERATES A MID LEVEL CUT
OFF LOW AND THUS THE SHOWERY PATTERN CONTINUES. GFS IS MAINLY DRY
AFTER THE 24 HOUR DELAY IN GETTING THE MCS GENERATING SYSTEM
THROUGH. WAS NOT CONFIDENT ENOUGH TO REMOVE POPS COMPLETELY GIVEN
THE ROUGH GO OF IT WITH THE MODELS LATELY...SO MAINTAINED THE LOW
CHANCE INHERITED FOR NOW.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1113 PM CDT FRI AUG 1 2014

WITH CLEAR SKIES AND LIGHT WINDS...FOG WILL AGAIN BE A
POSSIBILITY AT THE TYPICAL FOG-PRONE LOCATIONS. CONDITIONS TODAY
WERE VERY SIMILAR TO YESTERDAY AND NONE OF THE TAF SITES SAW ANY
APPRECIABLE RAINFALL FROM THE ISOLATED THUNDERSTORMS THIS
AFTERNOON. WITH THAT IN MIND...THE FORECAST FOR TOMORROW MORNING
IS SIMILAR WITH WHAT OCCURRED THIS MORNING...PATCHY FOG IN PRONE
AREAS. LIFR FOG IS STILL POSSIBLE...BUT AT THIS POINT I BELIEVE IT
WILL BE VERY ISOLATED IF IT EXISTS AT ALL SO CONFIDENCE WASNT
THERE FOR ADDING IT TO THE TAF FOR NOW.

KMSP...VFR EXPECTED WITH FOG REMAINING IN OUTLYING AREAS AWAY
FROM THE AIRPORT GROUNDS. WE KEPT THE TAF DRY THIS AFTERNOON...BUT
AS WAS THE CASE ON FRIDAY...THE AFTERNOON COULD FUEL ISOLATED
SHOWERS AND WEAK STORMS. CONFIDENCE IN RAIN AT THE AIRPORT IS TOO
LOW TO INCLUDE IN THE TAF AT THIS POINT.

/OUTLOOK FOR KMSP/

SUN...VFR. SLIGHT CHANCE TSRA. WINDS SW 5-10 KTS.
MON...VFR. CHANCE TSRA. WINDS ESE 5-10 KTS.
TUE...VFR. CHANCE MVFR IN TSRA. WINDS EAST 5-7KTS.


&&

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

$$

SHORT TERM...DWE
LONG TERM...BORGHOFF
AVIATION...CLF






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