Issued by NWS Northern Indiana
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
000 FXUS63 KIWX 220831 AFDIWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTHERN INDIANA 431 AM EDT MON SEP 22 2008 .SHORT TERM... TODAY THROUGH WEDNESDAY MORNING. LITTLE IN WAY OF ISSUES WRT SHORT TERM FCST. MID LVL RIDGE BUILDS OFF OF MARFA/EDWARDS PLATEAU. RIDGE STRENGTHENS AS IT BUILDS NWD THROUGH THE SHORT TERM PD EXTNDG FROM DESERT SW INTO SRN GRTLKS RGN BY WED AM. AS RIDGE BUILDS WEAK 5H CIRC ARCS ERN KY TO CONT SLOW EWD DISPLACEMENT TO NC OUTER BANKS BY TUE AM...TO AID IN CARIBBEAN TROPICAL DEPRESSION/STORM DEVELOPMENT/STRENGTHENING. 1034MB SFC HIGH S OF JAMES BAY TO ANCHOR FM NEW ENGLAND WITH STRONG RIDGE EXTNDG SWWRD INTO SRN GRTLKS...WITH ERLY 1000-850MB FLOW TO BRING MUCH DRIER AIR INTO CWA FM SWRN ONT. SHALLOW MOISTURE REMAINS THIS AM BLO STRONG SFC BASED INVERSION WITH WIDESPREAD BR/POCKETS OF ST TO AID IN SOME SCT CU DEVELOPMENT BY LATE AM. PWAT FALLS TO BLO 0.75 INCHES BY TUE AFTN WITH LITTLE MORE THAN HIGH THIN CI EXPECTED FROM CONVECTION ASSOCD WITH SERIES OF SHORTWAVES SLIDING THROUGH MEAN PAC NW/NRN ROCKIES TROF...WITH 110 KT UL JET MAX/STRONG TROP FOLD OFF BC COAST YET TO ENTER. SYSTEMS TO REMAIN OFF TO NORTHWEST OF CWA AS TROF BROADENS ACRS NRN PLAINS TO PAC NW BY 12 UTC WED. && .LONG TERM... WEDNESDAY THROUGH SUNDAY...A BLOCKING PATTERN WILL PERSIST ACROSS THE SOUTHERN CONUS...WITH AN UPPER LEVEL LOW BECOMING CUT OFF OVER THE SOUTHEAST CONUS PER 00Z GFS/GFS ENSEMBLE AND ECMWF. A TROPICAL SYSTEM WILL MOVE NORTH OR NORTHWEST OUT OF THE CARIBBEAN LATE IN THE WEEK. THE GFS KEEPS THE TRACK OF THIS SYSTEM FARTHER EAST...AWAY FROM THE ATLANTIC COAST...WHEREAS THE ECMWF BRINGS THIS SYSTEM ONSHORE. THE INTERACTION OF THE TROPICAL SYSTEM AND THE CUT OFF LOW IS NOT LIKELY TO BE HANDLED WELL BY THE MODELS GIVEN THE POTENTIAL OF THE FUJIWHARA EFFECT. THE MAJORITY OF THE CANADIAN ENSEMBLE MEMBERS SUPPORT THE LATTER SOLUTION...WITH A DEEP LOW TRACKING EITHER INLAND OR NEAR THE COAST. THIS WOULD MEAN THE POTENTIAL FOR MODIFIED ATLANTIC AIR ADVECTING INTO THE FORECAST AREA ABOUT FRIDAY...WITH A BETTER CHANCE FOR CLOUDS. FOR THIS PACKAGE GIVEN UNCERTAINTIES...HAVE LEFT TEMPERATURES UNCHANGED...BUT RAISED CLOUD COVER SOME LATE IN THE WEEK. OTHERWISE...THE STAGNANT PATTERN WILL CONTINUE. DIURNAL RANGES SHOULD APPROACH OR EXCEED 30 DEGREES AS THE GROUND CONDITIONS CONTINUE TO DRY OUT...ESPECIALLY OVER EAST AREAS INCLUDING NW OHIO. && .AVIATION... GRDLY WEAKENING SFC PRESS GRADIENT WL ALLOW FURTHER RADIATIONAL COOLING/WIDESPREAD MVFR BR FORMATION ACRS NRN IN A FEW HOURS. MOISTER GROUND/SMALLER DEWPOINT DEPRESSION INVOF KSBN SHOULD ALLOW FOR BRIEF PD OF IFR VSBYS BEFORE QUICKLY MIXING OUT BY LATE AM. AT KFWA CONT WITH MVFR RESTRICTION ONLY...WHICH SHOULD HOLD. MOISTURE IN 925-850MB LYR WITH SIG DRIER AIR ABOVE TO SUPPORT LITTLE MORE THAN SCT DIURNAL CU LATE AM/AFTN. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SHORT TERM...MURPHY LONG TERM...SKIPPER AVIATION...MURPHY
