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 251505
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
1105 AM EDT Sun Jun 25 2017

.SYNOPSIS...
Issued at 1058 AM EDT Sun Jun 25 2017

An isolated shower or storm is possible through tonight over
mainly far southern Lower Michigan. A low level disturbance
will bring a chance of showers and thunderstorms Monday. Dry
weather is then expected to return later Monday evening into
Tuesday. High temperatures today will range from 70 to 75 with low
temperatures tonight dropping into the low to mid 50s. High
temperatures on Monday will be limited to the upper 60s to around
70.

&&

.SHORT TERM...(Today through Monday Night)
Issued at 345 AM EDT Sun Jun 25 2017

Previous forecast remains in good shape with focus of the remainder
of the weekend into Monday on the below normal temperatures and
isolated shower/storm potential.

A strong but moisture-starved upper vort max across the western
Great Lakes will be accompanied by a few showers across extreme
northern Indiana/southern Lower Michigan over the next few hours.
Forcing with this wave will eventually shift eastward after
daybreak. Looking upstream, no immediate significant short wave is
evident this morning that will impact the local area today, with
just a sheared vorticity maximum shifting eastward across the
southern Great Lakes this afternoon. With a dry air low level air
mass in place and relatively weak mid level lapse rates, shower
potential still looks quite limited given lack of substantial
upper forcing. Have opted to hold onto the 15 to 20 PoPs across
northern third of the area later this afternoon during peak
heating/weak surface based instability. As was the case last
evening, stronger upper forcing with next upstream wave dropping
out of southern Manitoba should reach the southern Great Lakes
later tonight with a few showers possible. Passage of secondary
cold front this morning will take another few degrees off high
temperatures today, generally in the lower 70s. Steep low level
lapse rates will allow for gusty west winds again today into the
20 to 25 mph range.

Mid/upper levels will continue to cool for Monday with next upper
level short wave of interest dropping southeast out of the
Northern/Central Plains Monday afternoon. Strongest upper level
Q-vector convg signal with this wave starting to look more
favorable across southwest/southern portions of the forecast area
late Monday afternoon into early Monday evening where broad low
level confluence zone should also set up. Steeper mid level lapse
rates Monday should compensate for still meager moisture to
provide some uptick in sfc based instability, and have not made
much change to low chance rain/slight chance thunder PoPs Monday
afternoon. Given recent guidance trends in timing this wave, did
accept model consensus idea of prolonging low PoPs into the early
evening Monday. Coolest temps of the period expected Monday when
highs across the north will likely be limited to the mid-upper 60s
to around 70 south. Record low maximum temperatures for Monday
will likely not be threatened however (65 at KSBN in 1970, and 61
at KFWA in 1928).

&&

.LONG TERM...(Tuesday through Saturday)
Issued at 345 AM EDT Sun Jun 25 2017

Tuesday/Tuesday night will be dry as mid/upper height rises
spread eastward. Low level thermal troughing will linger across
the region however as another Hudson Bay vort should allow for
only slow low level thermal moderation Tuesday. Thermal/moisture
advection becomes stronger for the Wed/Wed night period with
eventual deamplification of central CONUS upper ridge in response
to a series of Pacific short waves. While details will need to be
sorted out/refined in terms of timing and strength of individual
short waves, the Wed night-Fri period is still shaping up as an
active one with increasing deep moisture and a couple of frontal
waves likely impacting the region due to active Pacific short wave
pattern. While timing is still of low confidence, may need to
watch a few periods of strong storm and heavy rain potential Thu-
Fri. Continued temperature moderation is expected for Wed-Thu with
highs back into the lower to mid 80s by Thursday. Some
indications in medium range model consensus that frontal boundary
may be driven far enough south by next weekend to lessen precip
coverage for the holiday weekend, with temps near or slightly
below normal before heat builds back in closer to the 4th of July.

&&

.AVIATION...(For the 12Z TAFS through 12Z Monday Morning)
Issued at 1049 AM EDT Sun Jun 25 2017

(For the 12Z TAFS through 12Z Monday Morning)
Issued at 614 AM EDT Sun Jun 25 2017

Gusty winds will continue today as west to northwest winds persist
as a low pressure trof moves southeast out of Michigan. Kept
showers & storms out of the TAFs for now due to the isolated
nature of the expected showers. VFR conditions should continue.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...Beach Hazards Statement through Monday evening for INZ003.

MI...Beach Hazards Statement through Monday evening for MIZ077.

OH...NONE.
LM...Small Craft Advisory until 8 PM EDT Monday for LMZ043-046.

&&

$$

SYNOPSIS...Skipper
SHORT TERM...Marsili
LONG TERM...Marsili
AVIATION...Skipper


Visit us at www.weather.gov/iwx

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.