Forecast Discussions mentioning any of
"ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 04/07/23
Area Forecast Discussion
National Weather Service Indianapolis IN
959 PM EDT Thu Apr 6 2023
.Forecast Update...
Issued at 959 PM EDT Thu Apr 6 2023
Fair weather will continue overnight as surface high pressure
continues to build into the region while the ridge`s center slides
west to east across the Great Lakes...continuing to provide dry
low/mid levels and light northerly winds. A broad 150-175 kt upper-
level jet will continue to flow from the Upper Midwest and across
the Great Lakes...with central Indiana`s proximity near the jet`s
right-entrance region continuing to promote upper level cloudiness.
Upper clouds will decrease towards dawn as the jet both weakens and
slowly slides east. Back at the surface, light northerly flow will
hold the slightly below normal temperature regime over the
region...although upper clouds should prevent more than a 15-20
degree drop from Thursday`s max to dawn Friday. Lows tonight will
range from the mid 30s across the northern tier to upper 30s south
of the I-70 corridor.
&&
.Short Term...(This evening through Friday)
Issued at 247 PM EDT Thu Apr 6 2023
* Dry and tranquil conditions through the end of the week
* Warming trend begins tomorrow
An extended stretch of warmer and quiet weather is on the way for
much of Indiana tomorrow through next week. Different story this
afternoon though as the main cold front which pushed through
yesterday is well south of the region and satellite imagery reveals
high clouds still streaming in overhead from the southwest. Just
north of the region, a strong 170 kt jet streak still persists with
Indiana in the right entrance region of it. Strong upper level
moisture advection within the baroclinic zone has kept higher clouds
around much of the day with the thickest cloud cover across southern
portions of Indiana. In the lower levels, high pressure is centered
over the Central Plains resulting in light northerly flow across
Indiana. Latest IND ACARS soundings shows the saturated layer
between 200mb and 400mb where the high cloud deck is located. Closer
to the surface, soundings reveal much drier air through the low and
mid levels due to subsidence under the high pressure system. Cold
air advection behind the front and increased cloud cover have lead
to below average temperatures across the state today with many
locations struggling to reach the 50 degree mark. Lowered highs this
afternoon accordingly as temperatures have been slow to rise. Expect
the increase in cloud cover to keep temperatures slightly elevated
tonight, so kept tonight`s lows above NBM guidance in the mid to
upper 30s for most places. Best chance at clearing skies is across
North Central Indiana where lows may approach freezing in some spots.
The warming trend begins tomorrow as high pressure shifts
northeastward towards the Great Lakes region. Upper level winds and
moisture advection weaken through the day tomorrow, so expect upper
level clouds to thin out and begin to clear out from north to south.
Low and mid level winds shift from northerly to easterly with 850 mb
temps steady around 0-2C. With an increase in sunshine tomorrow and
lack of cold air advection, expect high temperatures to reach the
upper 50s to low 60s. Latest RAP forecast soundings show deep mixing
tomorrow afternoon up to 7 kft agl with steep low level lapse rates
and the possibility of drier air mixing to the surface. Lowered
afternoon dew points to NBM 10th percentile from 14z to 23z
tomorrow, which brings Min RH values down into the 20s. With little
to no pressure gradient and weak winds aloft, do not expect winds to
increase much over 10 kts during the afternoon hours. Despite low RH
values, do not think there will be an elevated fire threat.
&&
.Long Term...(Friday night through Thursday)
Issued at 247 PM EDT Thu Apr 6 2023
Quiet weather is expected throughout the long term, with high
pressure in control through most of the period.
A weak upper trough will move through around Monday, but this
feature will not have any deep moisture to work it. Also, there now
looks to be little if any surface reflection. Thus, have removed the
small chances for rain that had been in Monday and Monday night.
Temperatures will gradually moderate early in the long term. Friday
night will have lows in the mid to upper 30s. For areas in the
southern forecast area where the frost/freeze season has started,
clouds and winds should keep frost at bay there Friday night. Will
keep an eye on it.
As high pressure settles in to the southeast of central Indiana
later in the period, southwest flow will bring in well above normal
temperatures. Highs from Tuesday through Thursday look to be in the
70s, with perhaps near 80 degree readings by Thursday.
&&
.Aviation...(00Z TAF Issuance)
Issued at 719 PM EDT Thu Apr 6 2023
Impacts:
* None
Discussion:
VFR conditions will be the rule across central Indiana as all
terminals remain amid a broad mid/low-level dry conveyor through
Friday. Seasonably strong surface high pressure presently centered
along the Upper Mississippi Valley will promote north-northwesterly
winds sustained at/under 7 kts this evening.
The surface ridge will slowly slide to the eastern Great Lakes by
the end of the TAF period...with winds correspondingly veering to
east-northeasterly after dawn Friday...sustained around 7-9 knots
after 14z. High clouds over the region are expected to decrease
through AM hours FridaFair weather will continue overnight as surface high pressure
continues to build into the region while the ridge`s center slides
west to east across the Great Lakes...continuing to provide dry
low/mid levels and light northerly winds. A broad 150-175 kt upper-
level jet will continue to flow from the Upper Midwest and across
the Great Lakes...with central Indiana`s proximity near the jet`s
right-entrance region continuing to promote upper level cloudiness.
Upper clouds will decrease towards dawn as the jet both weakens and
slowly slides east. Back at the surface, light northerly flow will
hold the slightly below normal temperature regime over the
region...although upper clouds should prevent more than a 15-20
degree drop from Thursday`s max to dawn Friday. Lows tonight will
range from the mid 30s across the northern tier to upper 30s south
of the I-70 corridor. y.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Update...AGM
Short Term...CM
Long Term...50
Aviation...AGM