Area Forecast Discussion
Issued by NWS La Crosse, WI

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 KARX 192336
AFDARX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
636 PM CDT SUN APR 19 2015

.SHORT TERM...(TONIGHT THROUGH TUESDAY NIGHT)
ISSUED AT 245 PM CDT SUN APR 19 2015

SCATTERED SHOWERS RANGE FROM NORTHERN WI INTO NORTHEAST IA...WITH
LARGER AREA OF SHOWERS AND A FEW STORMS OVER SOUTHWEST IA.
ANOTHER AREA OF RAIN WAS MOVING NORTH ACROSS CENTRAL ILL.

COLD FRONT TRACKING EAST ACROSS THE REGION TONIGHT...WITH GOOD
FRONTOGENETIC FORCING ASSOCIATED WITH IT. QG FORCING INCREASES IN
THE 850-500 MB LAYER THIS EVENING...ALONG THE FRONT AND JUST AHEAD
OF AN APPROACHING UPPER LEVEL TROUGH. TO THE SOUTH...A SHORT WAVE
TROUGH/SFC LOW ARE GOING TO STAY SOUTH...SLIDING ACROSS IL INTO
MICH. TRACK WILL SERVE TO BRING SOME MOISTURE NORTHWARD INTO WI
THOUGH...HELPING TO FUEL SHOWER CHANCES. ALL THE FORCING SHOULD
RESULT IN A BLOSSOMING AREA OF PCPN THIS EVENING...WITH MODEL
CONSENSUS FAVORING MISSISSIPPI RIVER-WEST THIS EVENING...GRADUALLY
EASING EAST OVERNIGHT. THE RAIN WILL THEN CONTINUE TO LIFT EAST
NORTHEAST THROUGH THE REST OF MON MORNING.

CYCLONIC FLOW A LOFT AND COLD AIR ADVECTION MON/TUE SETS THE STAGE
FOR SOME SHOWER POTENTIAL. GOOD LOW/MID LEVEL LAPSE RATES ALONG WITH
A 100-200 MB LAYER OF WEAK INSTABILITY ABOVE 800 MB MON/TUE
AFTERNOONS...PER BUFKIT SOUNDINGS. BITS OF UPPER LEVEL ENERGY
PROGGED TO SPIRAL AROUND THE 500 MB LOW...WITH MODEL CONSENSUS ON
DRIVING A PIECE ACROSS THE FORECAST AREA TUE AFTERNOON. RH FIELDS
KEEP THE DEEPEST SATURATION ACROSS THE NORTH...BUT ENOUGH SHOULD BE
AROUND TO FUEL THE INSTABILITY SHOWER THREAT. TUE LOOKING LIKE
THE HIGHER PROBABILITY DAY WITH THE ADDITION OF THE RIPPLE IN THE
UPPER LEVEL FLOW.

.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 245 PM CDT SUN APR 19 2015

MODELS IN GOOD AGREEMENT WITH A PATTERN SHIFT FOR THE UPCOMING WEEK.
THE UPPER LEVEL TROUGH WILL HOLD FAST ACROSS SOUTHEAST CANADA...WITH
THE RESULTING NORTHWEST FLOW PROVIDING A CONTINUOUS FETCH OF
UNSEASONABLY COLD AIR. 850 MB TEMPS FALL FROM AROUND 8 C TODAY...TO
-8 C BY TUE. EXPECTING HIGHS 10 TO 15 DEGREES BELOW NORMAL INTO NEXT
WEEKEND. ASIDE FROM THE START OF THE NEW WORK WEEK...THE PATTERN
FAVORS DRY CONDITIONS FOR THE LOCAL AREA.

MODELS START TO STRAY FROM EACH OTHER TOWARD FRIDAY WITH THE EC/GEM
FAVORING SOME UPPER LEVEL RIDGE BUILDING WHILE THE GFS PREFERS TO
HOLD ONTO THE TROUGH TROUGH THE WEEKEND. OBVIOUS IMPACTS ON TEMPS
//COOL WOULD CONTINUE WITH GFS - RETURN TO NORMAL WITH GEM/EC // BUT
SCENARIOS STILL LEAN ON THE DRY SIDE. NOT SOLD WE/LL BREAK OUT OF
THE COOL PATTERN...BUT GOING TO LEAN ON THE CONSENSUS SOLUTION FOR
THE DETAILS.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 636 PM CDT SUN APR 19 2015

LOW PRESSURE LIFTING NORTH OUT OF IL INTO THE GREAT LAKES REGION
OVERNIGHT INTO MONDAY WILL CONTINUE TO PRODUCE WIDESPREAD SHOWERS
ACROSS THE AREA. SOME OF THESE SHOWERS COULD BE LOCALLY HEAVY AT
TIMES THIS EVENING...REDUCING VISIBILITY DOWN TO 1SM. AS THIS LOW
CONTINUES TO DEEPEN AS IT MOVES NORTHWARD...LOOK FOR WINDS TO
INCREASE OUT OF THE NORTHWEST BECOMING QUITE GUSTY AT BOTH
KRST/KLSE TAF SITES. LOOKING FOR SHRA ACTIVITY TO SLOLWY COME TO
AN END FROM WEST TO EAST...PRETTY MUCH OUT OF THE KRST TAF SITE BY
12Z AND OUT OF KLSE AROUND 17Z. OTHERWISE...LOOK FOR MVFR
CONDITIONS THROUGH 17Z...THEN IMPROVING INTO VFR RANGE AFTER 17Z.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&

$$

SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION...DAS



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