Area Forecast Discussion
Issued by NWS Northern Indiana

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
000
FXUS63 KIWX 250643
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
243 AM EDT FRI APR 25 2014

.SYNOPSIS...
ISSUED AT 210 AM EDT FRI APR 25 2014

A LOW PRESSURE SYSTEM WILL RACE NORTHEAST ACROSS THE REGION TODAY.
SHOWERS ASSOCIATED WITH THE LOW WILL END FROM WEST TO EAST TODAY
AS THE LOW MOVES NORTHEAST. HIGHS TODAY WILL RANGE FROM THE UPPER
50S OVER LOWER MICHIGAN AND NORTHERN OHIO TO THE LOWER 70S OVER
NORTHEAST ILLINOIS. SOME ADDITIONAL LIGHT SHOWERS ARE POSSIBLE
TONIGHT WITH A WEAK UPPER LEVEL SYSTEM. LOWS SHOULD BE IN THE 40S.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 352 PM EDT THU APR 24 2014

PRIMARY FOCUS ON APPROACH OF VIGOROUS UPSTREAM SHORTWAVE TROF
EMBEDDED WITHIN OVERALL NEGATIVE TILTED LONGWAVE PATTERN.
ATTENDANT WESTERN MO SURFACE LOW TO TRACK ENEWD INTO CNTRL IN BY
12 UTC FRI AND INTO NRN OH AT 18 UTC. STRONG MOISTURE FLUX
CONVERGENCE GIVEN ADVECTION OF 5 PLUS G/KG 8-5H LYR AS MID
TROPOSPHERIC FLOW OF 40-50KTS ACRS SRN MO MOVES UP OHIO RIVER
VALLEY BASIN. HAVE RELEGATED SLIGHT TSRA MENTION TO FAR SRN/SERN
CWA MAXIMIZED HODO WITH DEEP LAYER FORCED PARCEL ASCENT AMPLIFIED
BY ARRIVAL OF 80-100M/12HR ALONG WITH NORTHERN EXTENT OF MUCAPE
PLUME/APEX AOB 200 J/KG TOWARD DAYBREAK. SOME SLIGHT SLOWING OF
FRONTAL SYSTEM AFFORDED GIVEN NEG TILT/MATURATION TO OCCLUSION.
MAINTAIN WARM TEMPS ON FRI AS POST FNTL THERMAL TROF RATHER
NARROW... LACK OF STRONG UPSTREAM SFC RIDGE AND POTENTIAL STRONG
AFTERNOON INSOLATION.

&&

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 352 PM EDT THU APR 24 2014

FRONTAL BOUNDARY SHOULD BE CLEAR OF THE AREA AT THE START OF THE
PERIOD WITH A DRY START TO FRI EVENING. A HANDFUL OF MODELS STILL
BRING A WEAK DISTURBANCE ACROSS THE CWA WITH LIGHT QPF. NOT OVERLY
IMPRESSED BUT GIVEN LOCATION OF FRONT JUST SOUTH OF THE AREA CAN`T
DISCOUNT ENTIRELY. HAVE WENT WITH SLGT CHC POPS ONLY LATE FRI NGT.

OTHERWISE FOCUS WILL SHIFT TO LARGE UPPER LOW THAT WILL SLOWLY MAKE
ITS PRESENCE KNOWN ACROSS THE REGION TOWARDS MID WEEK. A MASSIVE
STRUGGLE SHOULD TAKE PLACE IN MSTR RETURN WITH LIMITED FLOW FROM THE
GULF UNTIL THE LOW DRAWS CLOSER. ECMWF CLOSEST TO THIS THOUGHT
PROCESS WITH OTHER MED RANGE MODELS TRYING TO BRING PRECIP IN
FASTER. AS A RESULT HAVE INCREASED POPS FAR SW STARTING SUN NGT AND
SLOWLY EXPANDING NE THROUGH MONDAY NIGHT AND TUESDAY WHEN UPPER LOW
BEGINS TO MOVE OVERHEAD. FROM THIS POINT FORWARDS IS WHERE IT
BECOMES SOMEWHAT MORE INTERESTING. AS NOTED ABOVE...MSTR FROM THE
GULF WILL BEGIN TO COME NORTH AND GET WRAPPED ON THE EAST SIDE OF
THE LOW. HINTS OF DEWPTS INTO THE 50S EXIST WITH GUIDANCE NUMBERS
POINTING TOWARD POTENTIAL HIGHS IN THE 60S TO MAYBE NEAR 70. TO
COMPLICATE FURTHER...AS IS TYPICAL WITH THESE SPRING CUT OFF
LOWS...POOL OF COLD 500 MB TEMPS WILL BE APPROACHING...POSSIBLY
PUSHING -20 C DEPENDING ON MODEL OF CHOICE. IF POCKET OF LIMITED
CLEARING CAN OCCUR...VERY STEEP LAPSE RATES WOULD ENSURE WITH
POTENTIAL FOR LOW TOPPED CONVECTION. SINCE THIS IS SEVERAL DAYS OFF
AND NO REAL AGREEMENT IN MODELS WILL KEEP TEMPS CONSERVATIVE FOR
HIGHS AND HOLD OFF ON ANY THUNDER MENTION. LOW WILL TAKE ITS OWN
SWEET TIME LEAVING THE AREA STILL GIVING LINGERING EFFECTS OUTSIDE
THE CURRENT PERIOD.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY MORNING) ISSUED AT
230 AM EDT FRI APR 25 2014

A MESO VORT ASSOC WITH AN UPPER LEVEL SYSTEM WILL RACE EAST EARLY
THIS MORNING ACROSS CENTRAL INDIANA INTO OHIO. GIVEN THE TRACK OF
THIS SYSTEM AND DEEPER CONVECTION FARTHER SOUTH ALONG THE OHIO
RIVER...REALLY PESSIMISTIC ABOUT NUMEROUS SHOWERS AND LOW CLOUDS OVER
NRN INDIANA...ESPECIALLY GIVEN OVERNIGHT DEW POINTS JUST RECOVERING
OUT OF THE 20S AND UPPER AIR OBS AND ACFT SOUNDING STILL SHOWING A
VERY DRY BOUNDARY LAYER. HAVE REMOVED MVFR CONDITIONS AT SBN AND
FWA. ALTHOUGH A VERY BRIEF MVFR CIG IS POSSIBLE...ONGOING OBS ARE
NEARLY 100 PERCENT VFR WITH HIGH BASED CIGS. KEPT A WIND SHIFT
EARLY THIS MORNING...FOLLOWED BY SOME MIXING THE NEXT SEVERAL
HOURS WILL ALLOW GUSTS BETWEEN 25 AND 30 KTS. WINDS SHOULD
DECOUPLE BY EARLY EVENING.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

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


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA






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