Area Forecast Discussion
Issued by NWS Northern Indiana

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000
FXUS63 KIWX 151201
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
701 AM EST MON DEC 15 2014

.SYNOPSIS...
ISSUED AT 435 AM EST MON DEC 15 2014

A RIDGE OF HIGH PRESSURE ACROSS THE OHIO VALLEY WILL TRACK INTO
THE MID ATLANTIC STATES BY THIS EVENING AND ALLOW SOUTHERLY WINDS
TO CONTINUE ACROSS THE REGION WITH ABOVE NORMAL TEMPERATURES. AN
UPPER LEVEL DISTURBANCE TRACKING OUT OF THE CENTRAL PLAINS WILL
BRING A LIKELIHOOD OF RAIN FROM THIS AFTERNOON INTO TUESDAY
MORNING. HOWEVER...COLDER AIR WILL FILTER BACK INTO THE REGION
BEHIND THIS SYSTEM FOR THE MIDDLE OF THE WEEK. HIGHS TODAY WILL
REACH INTO THE UPPER 40S AND LOWER 50S. LOWS TONIGHT WILL RANGE
FROM 40 TO 45.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 438 AM EST MON DEC 15 2014

AN EXPANDING AREA OF CLEARING WAS ALONG AND SOUTHEAST OF A LINE FROM
PORTLAND TO LIMA. THIS AREA SHOULD FILL BACK IN LATER TODAY AS A
NEGATIVELY TILTED TROF NORTHEAST OVER THE FORECAST AREA. SOME
PATCHY DENSE FOG IS POSSIBLE EARLY IN THE VICINITY OF THE CLEARING.
HAVE BEEN HANDLING THE PATCHY DENSE FOG OVERNIGHT IN A SPECIAL
WEATHER STATEMENT DUE TO THE LOCAL AND BRIEF NATURE OF THE FOG. MADE
SOME MINOR ADJUSTMENTS IN THE TIMING OF THE ONSET OF RAIN LATER
TODAY IN FAVOR A SLOWER SOLUTION IN THE LIGHT OF THE LATEST 12KM NAM
WHICH HAS BEEN VERIFYING THIS SYSTEM REASONABLY WELL WITH THE
ISENTROPIC LIFT ON THE 300K SFC. TEMPERATURES SHOULD BE MILD AGAIN
TONIGHT WITH TEMPERATURES REMAINING WELL ABOVE FREEZING.

&&

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 438 AM EST MON DEC 15 2014

UPSTREAM VORTEX CRNTLY ACRS SRN KS EARLY THIS AM TO TRACK ENEWD
THROUGH CWA/SRN GRTLKS TUE. CENTROID SHOULD BE ACRS SERN LWR MI/NWRN
OH BY 18 UTC TUE IN NEARLY STACKED/MATURE FASHION. MEANWHILE AN
INTENSE SCNTL CANADA SHORTWAVE TO DIVE SSEWD INTO BACK EDGE OF
DEPARTING SYSTEM LENDING E-W ELONGATED TROF AXIS...KEEPING COLDEST
LOW LEVEL CAA PUSH NW-N OF REGION. RETURN TO MORE SEASONABLE SFC
TEMPS BY MIDWEEK IN WAKE OF SYSTEM...HOWEVER ONLY EXPECT MODEST AT
BEST LES RESPONSE...AS FAR SRN LK MI DELTA T IN THE LWR TEENS
FURTHER MITIGATED BY LACK OF/OR SHALLOW AT BEST DGZ WITHIN SHALLOW
SATURATED ZONE THICKNESS. NRN PLAINS SFC RIDGE TO ENVELOP WRN GRTLKS
DY3-5. SUBSIDENCE INVERSION STRENGTH AND NOTABLE VAST ST/STRATOCU
DECK NERN MT/ND/SCNTL CANADA MAY PORTEND TO RISK OF DIRTY RIDGE
DIFFICULTIES YET AGAIN. FOR NOW OPT TO INCRS CLOUD COVER NOMINALLY
OVER BLENDED APPROACH AND EMPLOY WATCHFUL WAITING. DIURNAL RANGES TO
LIKELY BECOME EVEN MORE SUBDUED THAN PRESENT SHOULD WIDESPREAD CLOUD
COVERAGE PRESENT...PRIMARILY WITH WARMER LOW TEMPS. CONTINUED LARGE
RANGE OF POTENTIAL SOLUTIONS EXHIBITED IN MODEL SPREAD REGARDING
PHASING OF ENERGY CRNTLY OFF CA COAST FOLLOWED BY REDIG OF PAIRED
ALEUTIAN/NRN PAC BASED SHORTWAVES. SYSTEM TO LIKELY CUTOFF ACRS SRN
INTMTN RGN ON THU THEN PUSH EWD INTO MIS VLY BY SAT AM. ECMWF
TRENDING SIG FARTHER SWD/RIGHT TRACKED WITH SYSTEM AND NOW FAVORING
RIGHT OF APPALACHIAN SPINE CYCLOGENESIS INTO SAT...OVR GFS NRLY OHIO
VALLEY SFC LOW TRACK. MANY GEFS ENSEMBLE MEMBERS TRENDING TOWARD
ECMWF SIGNALS...CONTINUING TO SUGGEST ONLY TOKEN SN POPS WARRANTED
FRI NIGHT/SAT...HIEST FAR SRN/SERN CWA.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 647 AM EST MON DEC 15 2014

AN UPPER TROF WILL BRING RAIN TO NORTHERN INDIANA THIS AFTERNOON.
SBN AND FWA WILL IMPROVE LATER TODAY FROM LOW IFR AND IFR
CONDITIONS RESPECTIVELY AS RAIN OVERSPREADS THE TERMINALS THIS
AFTERNOON. A LARGE AREA OF CLEARING WAS EXPANDING OVER EAST
CENTRAL INDIANA AND WEST CENTRAL OHIO. IT IS POSSIBLE FWA MAY
SCATTER OUT THIS MORNING FOR A WHILE. CONDITIONS ARE EXPECTED TO
DETERIORATE AGAIN LATE IN THE TAF PERIOD TO IFR OR NEAR IFR
CONDITIONS.


&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...DENSE FOG ADVISORY UNTIL 7 PM EST THIS EVENING FOR LMZ043-046.

&&

$$

SYNOPSIS...SKIPPER
SHORT TERM...SKIPPER
LONG TERM...MURPHY
AVIATION...SKIPPER


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