Area Forecast Discussion
Issued by NWS Northern Indiana

Home | Current Version | Previous Version | Graphics & Text | 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 KIWX 180542
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
142 AM EDT SAT OCT 18 2014

.SYNOPSIS...
ISSUED AT 820 PM EDT FRI OCT 17 2014

A LOW PRESSURE SYSTEM WILL CONTINUE TO INFLUENCE THE REGION INTO
TOMORROW. THE NORTHERN HALF HAS A CHANCE FOR RAIN TONIGHT WITH THE
NORTHERN AND EASTERN PORTIONS HAVING THE CHANCE FOR RAIN TOMORROW.
THE WIND WILL ALSO BE BREEZY OUT OF THE NORTHWEST. LOWS TONIGHT
WILL RANGE FROM THE LOWER 40S IN SOUTHERN MICHIGAN TO AROUND 50
ALONG THE OHIO RIVER. HIGHS TOMORROW WILL RANGE FROM THE UPPER 40S
IN SOUTHERN MICHIGAN TO THE LOWER 50S NEAR THE OHIO RIVER. HIGH
PRESSURE WILL THEN SPREAD OVER THE REGION TOMORROW NIGHT INTO
SUNDAY PROVIDING DRY COOL WEATHER.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 333 PM EDT FRI OCT 17 2014

SUCCINCT POTENT SHORTWAVE ENERGY CROSSING THROUGH NORTHERN LAKE
MICHIGAN THIS AFTERNOON. ASSOCIATED SURFACE FRONTAL BOUNDARY
EXTENDS SOUTHWARD FROM LOW CENTER JUST SOUTH OF JAMES
BAY...ENHANCED BY LAKE ENVIRONMENT THROUGH FAR WESTERN MICHIGAN
INTO FAR NWRN IN. SATURATION WELL LAGGED WELL UPSTREAM OF FRONTAL
BOUNDARY WITH NARROW POST FRONTAL DRY SLOT WHICH EVENTUALLY
PINCHES OFF LATE EVENING THROUGH SERN CWA ALLOWING RAPID INCREASE
IN CLOUD COVERAGE. UPTICK IN LAKE INDUCED INSTABILITY BY LATE
NIGHT/06-12 UTC TIMEFRAME AS LAKE INDUCED CAPE RISES TO 200-250
J/KG...AND EVEN FURTHER EARLY SATURDAY TO NEAR 300 J/KG WITH LK
EQL RISING TO 9-10KFT. LESSER PVU ANOMALY /CURRENTLY ENTERING FAR
WRN SD/ TO BEGIN TO PHASE INTO LONGWAVE TROF AXIS WELL EAST OF
CWA...AFFORDING NEWD ACCELERATION OF GONZALO REMNANTS INTO
NORTHERN ATL. GIVEN MODEST DEGREE OF LAKE INDUCED INSTABILITY
ALONG WITH CYCLONIC SFC-8H FLOW AND DOMINANT/SUFFICIENTLY DEEP
CAA CONTINUING INTO MIDDAY WILL OPT FOR COVERAGE TYPE WORDING
DOWNSTREAM OF LAKE MI FOR POPS GTE 30 PERCENT LATE TONIGHT INTO
MIDDAY SAT...TIERED TO LOW CHANCE WORDING FARTHER INLAND. QUICK
EASTWARD SHIFT OF HEIGHT FALL CENTROID THROUGH LOWER GREAT LAKES
SHOULD KEEP OVERALL SYSTEM RATHER LACKLUSTER/VOID OF
COHESIVENESS. RELAXATION OF LOW LEVEL FLOW INTO SAT AFTERNOON/
EVENING ALONG WITH APPROACH OF STRONG 80-100M/12HR MOVING INTO
WESTERN GREAT LAKES/NRN WI BY 00 UTC SUN...AFFORDING START OF
WITH AT LEAST PARTIAL CLEARING COMMENCING OUTSIDE OF LAKE
INFLUENCE REGION. THICK STRATOCU COVERAGE AND RAINFALL
NORTHWEST/NORTHERN CWA ALONG WITH PRESENCE OF COLD UPSTREAM TROF
NORTH OF CWA ELONGATED E-W TO STYMIE DIURNAL RISE ON
SAT...LOWERING A SKOSH ESPECIALLY NWRN/NRN INTO CENTRAL INTERIOR
CWA.

&&

.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 333 PM EDT FRI OCT 17 2014

LONG TERM PERIOD GENERALLY QUIET WITH SEASONABLE TEMPERATURES AS
ONE SYSTEM EXITS THE REGION AT THE START OF THE PERIOD AND
ANOTHER CLIPPER TYPE SYSTEM IMPACTS THE AREA SUNDAY NIGHT INTO
TUESDAY MORNING.

INITIAL SYSTEM WILL BE EXITING THE WESTERN GREAT LAKES REGION
SATURDAY NIGHT WITH HIGH PRESSURE BUILDING IN. GRADUAL CLEARING
AND DRYING EXPECTED WITH EXCEPTION IMMEDIATELY DOWNWIND OF LAKE
MICHIGAN. DELTA T VALUES NOT THAT GREAT BUT LIKELY LARGE ENOUGH
TO AID IN CLOUD DEVELOPMENT OFF THE WARM LAKE. THIS IS RATHER
IMPORTANT WITH RESPECT TO FROST AND FREEZE POTENTIAL BY EARLY
SUNDAY MORNING. THOSE LOCATIONS WHICH CLEAR EARLY WILL LIKELY DIP
INTO THE LOWER 30S OR EVEN UPPER 20S IN RURAL LOCATIONS WHILE
AREAS REMAINING UNDER ANY LAKE CLOUDS WILL SEE READINGS REMAIN IN
THE MID TO EVEN UPPER 30S CLOSER TO THE LAKE. HAVE KEPT WITH
PREVIOUS IDEA OF COLDEST TEMPERATURES FAR NORTHEAST AND WARMEST
ACROSS THE WEST. TIMING OF THESE FREEZING TEMPERATURES VERY CLOSE
TO CLIMATOLOGICAL NORMAL AND TYPICAL END OF OUR FROST AND FREEZE
HEADLINES IS USUALLY AROUND OCTOBER 20TH.

NEXT CLIPPER SYSTEM QUICKLY APPROACHES WITH WARM AIR ADVECTION
AND MODEST THETA E INCREASE SUNDAY NIGHT. WITH ATMOSPHERE
INITIALLY DRY AND MOISTURE ADVECTION NOT CONSIDERABLE OPTED TO
KEEP THE 00-06Z TIME PERIOD DRY AND INTRODUCE POPS AFTER 06Z.
THESE CHANCES CONTINUE INTO MONDAY NIGHT AS SHORT WAVE AND
ASSOCIATED COLD FRONT TRAVERSE THE AREA. LINGERING CYCLONIC FLOW
AND NUMEROUS SUBTLE SHORT WAVES WARRANT LOW POPS MONDAY NIGHT
WITH HIGHEST VALUES IN THE EAST. DID INCLUDE A LOW POP TO RIDE
OVER EASTERN HALF OF AREA TUESDAY WITH LATEST GUIDANCE SUGGESTING
PHASING OF UPPER LOW OVER EASTERN GREAT LAKES MAY SLOW ITS EXIT.
REMAINDER OF LONG TERM LOOKS TO BE PCPN FREE AS HIGH PRESSURE
BUILDS IN AND AFOREMENTIONED UPPER LOW ONLY SLOWLY DRIFTS
EAST...STACKING UP THE PATTERN.

OVERALL TEMPERATURES WILL BE NEAR OR SLIGHTLY BELOW NORMAL BUT NO
STRONG COLD AIR INTRUSION IS EXPECTED. HIGHS IN THE LOW TO MID
50S BUT TRENDING TOWARD UPPER 50S AND EVEN LOWER 60S BY END OF
THE PERIOD. A FEW NIGHTS INTO THE 30S UNDER HIGH PRESSURE BUT
MODERATING TO 40S.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 137 AM EDT SAT OCT 18 2014

MVFR CONDITIONS EXPECTED TO CONTINUE THROUGH MUCH OF THE PERIOD AS
LAKE EFFECT CLOUDS/LIGHT SHOWERS AND GUSTY WINDS EXPAND OVER THE
NEXT COUPLE OF HOURS AND PERSIST INTO AT LEAST MID AFTERNOON.
IMPACTS WILL REMAIN LONGEST AT KSBN WITH VFR CIGS EVENTUALLY
TAKING SHAPE AT KFWA AS DRIER AIR BEGINS TO FILTER IN.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SUNDAY FOR LMZ043-046.

&&

$$

SYNOPSIS...LOTHAMER
SHORT TERM...MURPHY
LONG TERM...LASHLEY
AVIATION...FISHER


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

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
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.