Area Forecast Discussion
Issued by NWS Indianapolis, IN

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 48 49 50
459
FXUS63 KIND 090935
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
535 AM EDT Sun Jun 9 2024

.KEY MESSAGES...

- Breezy Today.

- Dry with near to below average temps through Wednesday.

- Warming trend beginning Thursday.

&&

.SHORT TERM (Today and tonight)...
Issued at 300 AM EDT Sun Jun 9 2024

Today...

Radar and obs data were showing a fine line with diminishing very
light returns from near a Muncie to Indianapolis to Sullivan line at
2 AM. Th fine line was coincident with a cold front that will move
into Kentucky before daybreak. In the mean time, Goes-16 IR loop and
obs were indicating there was a thick stratus deck spreading in from
east central Illinois, in the wake of the front. These clouds will
general sink southeast with the cold front this morning and leave
behind plenty of afternoon sunshine. Would not completely rule out a
shower or two over far south central Indiana, this morning. This
area will be closer to the departed cold front and impulses in fast
northwest flow that was located around the base of a southeastern
Canadian upper low. Otherwise, Hi-Res soundings were showing the low
levels drying as surface high pressure gradually builds in from the
Plains, providing subsidence. This should lead to increasing
afternoon sunshine and allow temperatures to climb back to the upper
70s to around 80 degrees. Last but certainly not least, Hi-Res
soundings are showing the potential for 25 knot northwest winds to
be mixed down from 5K feet, this afternoon. In addition, model winds
look way too low, so raised them. It will once again be a breezy
afternoon as has been the case the past few days.

Tonight...

The upper trough on the back side of the southeastern Canada and
northern New England upper low, will pivot south to the lower Great
Lakes tonight. This will send a surface trough across central
Indiana as well. Hi-Res soundings are showing an increase in sfc-5K
moisture tonight. However, they also were showing dry air aloft.
With forcing weak and only limited low level moisture, skies should
be mostly clear. The gusty winds will quickly die off near sunset as
the diurnal mixing is lost. With northwest winds in place and upper
50s and lower 50s dew points, overnight lows will bottom out well
into the 50s with good confidence.

&&

.LONG TERM (Monday through Saturday)...
Issued at 300 AM EDT Sun Jun 9 2024

A synoptic pattern characterized by flow with a predominantly
northerly component will keep our weather quiet through the long
range. Nevertheless, there are still a few things to talk about.

First, a secondary shot of cold air looks to arrive Monday morning
followed by surface high pressure. Some cloud cover may coincide
with this frontal passage, but the overall dry nature of the
continental air mass in place should limit this. The air flowing
southward behind the front is quite cold. Temperatures at 850mb look
to be between 0 and 5C, which corresponds to surface highs near 70
Monday afternoon. Additionally, as high pressure builds southward
winds should diminish leading to ideal radiational cooling potential
Monday night. Low temperatures by Tuesday morning may dip well into
the 40s outside of urban areas.

Second, a pattern change appears likely towards the end of the week.
While flow aloft retains a northwesterly component, low-level flow
takes on a more southerly component as surface high pressure shifts
southeastward. Modest warm air advection should lead to a gradual
increase in temperatures through Thursday. It is possible that highs
climb into the upper 80s or even near 90 by Friday. However, there
remains some uncertainty regarding this. Some members of guidance
are insistent on bringing a cold front through the region Thursday
night or early Friday. This would act to stunt any significant warm
up, at least for a few days. Some precipitation may accompany the
front depending on how quickly moisture can flow northward Wed and
Thur.

By the weekend, ensemble guidance continues to show substantial
ridge-building over the eastern CONUS. NAEFS/ECMWF situational
tables depict anomalous 250mb heights by Saturday/Sunday (ECMWF
showing 99th percentile heights). In this scenario the polar jet is
displaced well to the north across Canada, with weak flow through
the column across the Midwest. Such a pattern supports above-normal
temperatures with below-average precipitation. However, guidance is
picking up on a plume of tropical moisture developing far to our
south towards the end of the coming week. Should this lift northward
into the ridge, then we may see a few more opportunities for
rainfall than one would expect with such limited synoptic forcing.
CPC`s official outlook echoes this, with above-average temperatures
favored with near-average precipitation.

&&

.AVIATION (12Z TAF Issuance)...
Issued at 535 AM EDT Sun Jun 9 2024

Impacts:

- Small chance of MVFR ceilings and or visibilities
  through 12z or so

- Winds 300-330 degrees with gusts to 20+ knots
  from 19z-24z

Discussion:

The cold front has moved southeast of the terminals allowing winds
to shift to the north and northwest less than 10 knots. There is
also a small chance for MVFR flying conditions this morning.
Otherwise, high confidence in VFR flying conditions through the
TAF period.

Wind gusts to 20+ knots are also possible late this afternoon and
early evening associated with diurnal mixing.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

SHORT TERM...MK
LONG TERM...Eckhoff
AVIATION...MK