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 43 44 45 46 47 48 49 50
000
FXUS63 KMPX 111903
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
203 PM CDT FRI JUL 11 2014

.UPDATE...
ISSUED AT 156 PM CDT FRI JUL 11 2014

UPDATED TO INCLUDE 18Z AVIATION DISCUSSION BELOW.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 313 AM CDT FRI JUL 11 2014

THE MORNING CONVECTION WILL CONTINUE FOR SEVERAL MORE HOURS...BUT
GRADUALLY WEAKEN WITH TIME AS THE LLJ SUBSIDES AND SLIDES TO THE
EAST. WE EXPECT AT LEAST PARTLY CLOUDY SKIES BY THE AFTERNOON AND
WARM TEMPERATURES...ESPECIALLY IN WESTERN MN WHERE MID TO UPPER
80S ARE EXPECTED UNDER THE NORTHWARD EXTENSION OF THE THERMAL
RIDGE.

SURFACE BOUNDARIES ARE NOTICEABLY LACKING ACROSS THE FORECAST AREA
WITH THE SURFACE LOW AND COLD FRONT HANGING BACK ACROSS THE
DAKOTAS. HOWEVER...THERE REMAINS A FAIRLY EXTENSIVE AREA OF
SHOWERS AND STORMS STRETCHING FROM SOUTHWEST NE TO LAKE SUPERIOR
THIS MORNING. THIS FOLLOWS A NICE CORRIDOR OF 925-850MB MOISTURE
TRANSPORT IN RESPONSE TO A 35-45KT LLJ JET. THE MERRIMAN PROFILER
AROUND MIDNIGHT SHOWED 45KTS AT 850MB. THIS SAME CORRIDOR OF
MOISTURE ADVECTION IS ALSO COLLOCATED WITH AN AXIS OF PWATS
BETWEEN 1.6"-1.9". THE MOST VIGOROUS CONVECTION LOCALLY IS BEING
DRIVEN BY A SHORTWAVE THAT MADE IT`S WAY OUT OF THE DAKOTAS LAST
NIGHT. RAINFALL OF 1-4" HAS FALLEN ACROSS MUCH OF DOUGLAS...TODD
AND MORRISON THIS MORNING DUE TO THE CONTINUAL REDEVELOPMENT OF
CONVECTION NEAR OR JUST AHEAD OF THE 850-300MB THICKNESS RIDGE.
THIS RIDGE DOES TRANSVERSE THE ENTIRE FORECAST AREA TODAY...BUT
WITH THE LLJ DECREASING AND THE CONVECTION OUT-RUNNING THE BEST
MUCAPE...CHANCE POPS ARE PROBABLY THE BEST FIT AFTER 12Z THIS
MORNING AT A VAST MAJORITY OF LOCATIONS. A WEAK SURFACE REMAINS
SOUTHWEST TONIGHT AND THE FLOW TURNS QUITE BAGGY OVERNIGHT. THIS
COULD SET THE STAGE FOR FOG EARLY SATURDAY MORNING.

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 313 AM CDT FRI JUL 11 2014

A WEAK CDFNT WILL DROP THRU THE REGION DURG THE DAY ON
SAT...LEADING TO THE HIGHEST ADVERTISED POPS IN THE EXTENDED
PERIOD. PERIODS OF SHWRS/TSTMS...PARTICULARLY OVER SRN MN INTO
SWRN WI...CAN BE EXPECTED FOR SAT AFTN-EVE BEFORE THE WX SETTLES
DOWN GOING INTO SAT NIGHT AND SUN AS THE CDFNT DEPARTS. THIS COLD
FROPA WILL ALSO BE THE START OF THE SWD MOVEMENT OF A VERY DEEP
UPR LVL LOW PRES CENTER FROM CENTRAL CANADA. A MORE POTENT CDFNT
WILL DROP THRU THE REGION LATE SUN INTO MON...AND IT IS THIS CDFNT
IN CONJUNCTION WITH THE DEEP COLD POOL OF AIR PLUNGING INTO THE
UPR MISS RIVER VALLEY AND GREAT LAKES REGIONS THAT WILL MAKE THE
MOST SIGNIFICANT CHANGE IN THE WX. A FEW SHWRS MAY LINGER SUN INTO
MON WITH THE STRONG COLD FROPA AND THE UPR LOW OVHD. IN FACT... ON
MON...WITH THE CLOSE PROXIMITY OF THE UPR LOW AND SEVERAL SHTWV
DISTURBANCE ROTATING ARND THE WRN FRINGES OF THIS UPR LOW AND ACRS
THE MPX CWFA...SOME SHWRS WITH GRAUPEL CANNOT BE RULED OUT DUE TO
THE AMPLE COLD AIR ALOFT. REGARDLESS OF THIS POTENTIAL...THE MAIN
STORY WITH THIS FROPA AND COLD UPR LVL LOW WILL BE THE VERY
NOTICEABLE DROP IN TEMPS FOR THE START OF NEXT WEEK. H85 TEMPS
WILL DROP TO BETWEEN 4 AND 6 DEG C...WHICH WHEN TRANSLATED TO THE
SFC...SPELL HIGHS ONLY IN THE 60S ON MON AND TUE. GRADUAL
MODERATION IS EXPECTED THRU THE MIDDLE OF NEXT WEEK BUT THIS WILL
ONLY PUSH HIGH TEMPS INTO THE LOW 70S ON WED THEN TO THE MID 70S
ON THU. HOWEVER...IN CONJUNCTION WITH THIS COOLDOWN WILL BE AN
EXPANSIVE AND FAIRLY PERSISTENT HIGH PRES DOME ACRS THE AREA WHICH
WILL PREVENT ANY PRECIP FROM DEVELOPING FOR LATE TUE ON THROUGH
THE REST OF THE WEEK.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 156 PM CDT FRI JUL 11 2014

WILL HAVE VARIOUS ISSUES THROUGH THE PERIOD. LINGERING CEILINGS
ACROSS THE AREA SHOULD GENERALLY IMPROVE THROUGH THE AFTERNOON...
WHILE REMAINING MOST FOCUS NEAR AND DOWNSTREAM OF THE FRONT/TROUGH
WHERE SOME MVFR REMAINS. THERE IS A CHANCE FOR A FEW SHRA/TSRA
FROM 21Z THROUGH 03Z AT MOST SITES... BUT COVERAGE IS EXPECTED TO
BE LOW IF THINGS OCCUR... SO LEFT ANY MENTION OUT OF THE FORECAST
FOR NOW. LATER TONIGHT WE COULD SEE SOME FOG AT MOST SITES... AND
IT COULD BE WORSE THAN FORECAST IF WINDS DIE AND WE HAVE LESS IN
THE WAY OF MID-HIGH CLOUDS THAN EXPECTED. HINTED AT SOME LOWER
VISIBILITIES... BUT DID NOT GO AS LOW AS WHAT IS POSSIBLE GIVEN
THE UNCERTAINTY. SHRA/TSRA WILL BE POSSIBLE AGAIN ON SATURDAY...
BUT THERE REMAINS UNCERTAINTY ON HOW FAR NORTH ACROSS THE AREA IT
WILL EXTEND... SO PLAYED THINGS OPTIMISTIC FOR NOW AND DID NOT
INCLUDE TOO MUCH OF A MENTION.

KMSP...CONFIDENCE IN FORECAST SPECIFICS IS LOW GIVEN SLOWLY MOVING
FRONT/TROUGH AND LINGERING BAROCLINIC ZONE WITHOUT ANY SIGNIFICANT
FORCING FEATURE OVER THE AREA. FOG ISSUES AND PERHAPS SOME STRATUS
COULD BE WORSE THAN INDICATED LATER TONIGHT... AND PCPN COULD BE
MORE WIDESPREAD INTO THE AREA LATER TONIGHT.

/OUTLOOK FOR KMSP/
SATURDAY NIGHT...VFR. WEST WIND LESS THAN 10 KT BECOMING NORTH.
SUNDAY...VFR. NORTHWEST WIND 5 TO 15 KT.
SUNDAY NIGHT. MVFR POSSIBLE WITH A CHANCE OF SHRA/TSRA. NORTHWEST WIND 5 TO
15 KT.
MONDAY...MVFR POSSIBLE WITH A CHANCE OF SHRA/TSRA. NORTHWEST WIND
10 TO 20 KT.
MONDAY NIGHT...MVFR POSSIBLE. NORTHWEST WIND 5 TO 10 KT.
TUESDAY...VFR. NORTHWEST WIND LESS THAN 10 KT.

&&

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

$$

UPDATE...
SHORT TERM...CLF
LONG TERM...JPC
AVIATION...





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