Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI

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 KMKX 250359
AFDMKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
959 PM CST TUE FEB 24 2015

.UPDATE...THE COLD ADVECTION HAS BEEN SLOW THIS EVENING BUT AS THE
WINDS WEAKEN LATE TNT...RADIATIONAL COOLING WILL DOMINATE. TEMPS
WILL STILL LIKELY FALL INTO THE SINGLE DIGITS BY SUNRISE. THE NRN
FRINGES OF LIGHT SNOW FROM LOW PRESSURE TRACKING SOUTH ALONG THE
MO RIVER VALLEY WILL THEN DEVELOP ACROSS THE SRN HALF OF THE CWA
FOR WED AFT AND EVE. NELY BOUNDARY LAYER WINDS WILL ALSO
CONTRIBUTE TO A PERIOD OF LAKE EFFECT SNOW SHOWERS WED NT FROM
MILWAUKEE SOUTH TO THE IL BORDER. MINOR SNOW ACCUMS ARE EXPECTED
WITH PERHAPS AN INCH OR TWO OVER FAR SE WI.

&&

.AVIATION/06Z TAFS/...VFR CONDITIONS TO PREVAIL FOR MUCH OF WED
UNTIL THE LGT SNOW DEVELOPS BY LATE AFTERNOON OR EVENING. AREAS OF
MVFR CIGS AND VSBYS ARE EXPECTED WITH VSBYS POSSIBLY FALLING TO
1SM AT TIMES OVER FAR SE WI DUE TO LAKE EFFECT SNOW SHOWERS.

&&

.PREV DISCUSSION... /ISSUED 248 PM CST TUE FEB 24 2015/

SHORT TERM...

REST OF THIS AFTERNOON AND TONIGHT - CONFIDENCE...MEDIUM

LOW PRESSURE CONTINUES TO SHIFT EAST OF LAKE SUPERIOR AND DRAG
ARCTIC FRONT THROUGH CNTRL/SRN WI. MAIN STORY WILL BE COLD
ADVECTION. AFTERNOON SCT SHSN WILL DIMINISH WITH RAPID CLEARING
TAKING HOLD. WITH 925 TEMPS DROPPING WELL INTO THE NEGATIVE TEENS
CELSIUS WE SHOULD SEE PLENTY OF SINGLE DIGIT LOW TEMPS.

WEDNESDAY - CONFIDENCE...MEDIUM

AFTER A MAINLY CLEAR AND COLD START WITH INFLUENCE OF ARCTIC HIGH...
WILL BE WATCHING FOR AN INCREASE IN CLOUDS DUE TO NEXT SHORTWAVE
APPROACHING. MODELS SHOW VARIOUS SOLUTIONS WITH RESPECT TO ANY
SNOW SPREADING IN DURING THE LATER AFTERNOON HOURS. IN THE LOW
LEVELS COLD ADVECTION CONTINUES WITH THE NORTHERLY FLOW. 280-290K
ISENTROPIC PLOTS SHOWS LIMITED LIFT. HOWEVER THERE IS AN
IMPRESSIVE MOISTURE SURGE ON THE ISENTROPIC PLOTS BETWEEN 18-00Z
WITH CONDENSATION PRESSURE DEFICITS DROPPING MARKEDLY. SOME
REFLECTION OF A LEADING SHORTWAVE DEVELOPING ACROSS NE IA INTO SRN
WI DURG THE AFTN...WITH PRIMARY SHORTWAVE WELL WEST OF THE AREA.
THE GFS IS A COMPROMISE SOLUTION BETWEEN THE MORE AGRESSIVE
ECMWF/GEM AND LESS ROBUST NAM. FOR NOW WILL KEEP POPS CONFINED TO
SW OF KMSN FOR THE AFTERNOON HOURS...FOLLOWING A CONSENSUS OF MOS
WHICH FAVORS A SOMEWHAT DRIER SCENARIO THAN THE ECMWF/GEM...BUT
MORE SO THAN THE NAM.

WEDNESDAY NIGHT AND THURSDAY...FORECAST CONFIDENCE HIGH.

THE SPLIT FLOW BREAKS DOWN AS THE NORTHERN TROUGH BUILDS BACK
TOWARD THE SOUTHWEST WITH THE 500 MB TROUGH AXIS ACROSS WISCONSIN
TOWARDS NEBRASKA.

THE COLD SURFACE HIGH SAGS ACROSS THE PLAINS AND INTO THE UPPER
MISSISSIPPI VALLEY INTO WISCONSIN. AS THE HIGH MOVES ACROSS...
BELOW NORMAL TEMPERATURES WILL HAVE A FIRM GRIP ON THE REGION.
WITH LIGHT WINDS LOW TEMPERATURES WILL BE VERY COLD WELL INLAND IF
SKIES ARE MOSTLY CLEAR. WINDS CHILLS WILL NOT BE MUCH OF A
FACTOR. THE LOW LEVEL FLOW BECOME NORTHEAST ON THURSDAY. HOWEVER
THE INVERSION LEVEL IS LOW...AROUND 3 THSD FT. SOME FLURRY
POTENTIAL MAY DEVELOP OFF THE LAKE. WITH THE LIGHT NORTHEAST FLOW
TEMPERATURES NEAR LAKE MICHIGAN WILL NOT BE AS COLD.

THURSDAY NIGHT AND FRIDAY...FORECAST CONFIDENCE HIGH.

500 MB POSITIVE VORTICITY ADVECTION TRANSLATES INTO THE REGION FROM
THE NORTHWEST ALONG WITH A 500 MB SHORTWAVE TROUGH THURSDAY
NIGHT. SOME 700 MB ISENTROPIC OMEGA EXISTS SOUTHWEST OF SOUTHERN
WISCONSIN...WITH SOME OF THE LIFT SWINGING INTO THE FORECAST AREA.
THIS 700 MB LIFT WILL BE SHORT-LIVED HOWEVER...AS IT MOVES OFF TO
OUR SOUTH BY FRIDAY MORNING.

COLD SFC TEMPERATURES WILL CONTINUE FRIDAY AS A 1004 MB HIGH
PRESSURE SYSTEM MOVES INTO THE MID MISSISSIPPI REGION. WEAK SURFACE
WINDS WILL BE IN PLACE DURING THE DAY...SO WIND CHILLS SHOULD NOT BE
NEAR WIND CHILL ADVISORY CRITERIA.

LONG TERM...

SATURDAY THROUGH TUESDAY...FORECAST CONFIDENCE MEDIUM.

A POSITIVELY TILTED WESTERN SHORTWAVE TROUGH TRANSLATES TO THE
SOUTHWEST U.S...EJECTING POSITIVE VORTICITY ENERGY INTO WISCONSIN.
THE GFS AND ECMWF MODELS ARE SHOWING PRETTY GOOD AGREEMENT IN THE
PLACEMENT OF THE MAIN WESTERN SHORTWAVE. THE ECMWF PROGS A POTENT
POSITIVE VORTICITY MAXIMA TO DEVELOP MONDAY MORNING...WHEREAS THE
GFS DOES NOT.

THE ECMWF KEEPS THIS VORTICITY MAXIMA TRANSLATING INTO
WISCONSIN...WHICH IS FASTER THAN WHAT THE GFS IS PROGGING. THE GFS
IS BEHIND THE ECMWF ON WHEN THIS SHORTWAVE ENERGY WILL REACH
WISCONSIN. ECMWF HAS THE SHORTWAVE AXIS REACHING WISCONSIN 12Z
TUESDAY MORNING...WHILE THE GFS HAS THE SHORTWAVE AXIS REACHING
WISCONSIN BY 00Z WEDNESDAY.

THE ECMWF HAS MORE QPF AMOUNTS PROGGED FOR OUR FORECAST AREA THAN
THE GFS AS WELL FOR SUNDAY. BY TUESDAY...ADDITIONAL ENERGY WILL
BRING MORE CHANCES OF SNOW BY TUESDAY. AGAIN...THE ECMWF IS
BRINGING IN MORE QPF AMOUNTS THAN THE GFS. THE GFS IS WANTING TO
KEEP PRECIPITATION INTO WEDNESDAY...WHILE THE ECMWF HAS THE SNOW
MOVING OFF TO THE EAST BY TUESDAY AFTERNOON.

AVIATION/00Z TAFS/...

ONE LAST LINE OF SNOW SHOWERS TO EXIT THE SOUTHEAST
LATE THIS AFTERNOON...THEN RAPID CLEARING TAKES SHAPE. WEAK RIDGING TAKES
HOLD INTO WEDNESDAY MORNING. NEXT SHORTWAVE WILL INCREASE MID DECK ON
WEDNESDAY THOUGH WILL KEEP ANY AFTERNOON SNOW CHANCES SW OF KMSN. SURFACE
LOW PRESSURE TRACKS FROM THE DAKOTAS TO NORTHERN MO BY END OF PERIOD.

MARINE...GUSTY WINDS ASSOCIATED WITH ARCTIC FRONT WILL PERSIST INTO
THE EVENING HOURS...THUS SMALL CRAFT ADVISORY REMAINS IN EFFECT.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR LMZ643>646.

&&

$$

UPDATE...GEHRING
TONIGHT/WEDNESDAY AND AVIATION/MARINE...COLLAR
WEDNESDAY NIGHT THROUGH TUESDAY...HENTZ


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