The computer weather models are struggling with the January outlook

The day-to-day runs are all over the place. The GFS has a tornado outbreak on January 3rd and then back to a cold and snowy pattern.



The Canadian model has the same except the the tornado outbreak to our west; Iowa and Illinois.



The European model shows it being warm and rainy with one small cold front.




Here is what the National Weather Service thinks:

.Long Term...(Friday night through Thursday)
Issued at 247 PM EST Thu Dec 29 2022

* Periods of rain Friday night. Limited Flood Risk
* Potential for moderate-heavy rainfall, embedded thunder Mon night
* Breezy and Warm Tuesday

Friday night into Saturday...

As an upper trough approaches central Indiana from the southwest, a
surface low will develop and move along the front in the area Friday
night.

Plentiful moisture will remain in place from the low level
jet from during the day Friday. Some moisture transport will
continue Friday night as well, but not as strong as previously.
Precipitable water values will be around an inch in the southeast
Friday night.

The broad forcing with the upper trough/surface low combined with
the plentiful moisture will continue rain across central Indiana, so
will go with likely category or higher PoPs all areas, with the
highest PoPs southeast closer to the front.

Rain amounts may be enough for some minor flooding, mainly southwest
where higher amounts are expected. Shallow ground temperatures are
warming thanks to the warm air temperatures, so some of the rain
will able to soak in.

As the system exits on Saturday, some rain will linger in the
morning, mainly east. Most areas will be dry Saturday afternoon.

Temperatures will vary from cooler northwest to warmer southeast
with the front in the area, but readings will remain above normal.

Saturday night through Sunday night...

Quiet weather will rule during this period with quasi-zonal flow
aloft in between systems. Surface high pressure will briefly build
in, but a warm front will approach the area from the southwest
Sunday night. Forcing from this will be weak enough at this time to
continue a dry forecast.

Above normal temperatures will continue with the colder air bottled
up to the north.

Monday through Tuesday...

A large upper trough across the western half of the country will
develop a strong surface low that will move into the upper
Mississippi Valley. There are some uncertainties on the track of
this low, but central Indiana will remain on the warm side of the
system.

A 60kt low level jet will pump in moisture straight from the Gulf of
Mexico into the area (this is near the 99th climatological
percentile). Ensemble guidance indicates that precipitable water
values will be near climatological maximum by Monday night as well.

Strong forcing will accompany an initial upper wave that will
move through on Monday night. Will have chance PoPs Monday as the
the system approaches, and then categorical PoPs Monday night as the
it moves through. PoPs will diminish on Tuesday as the initial upper
energy exits.

Rainfall amounts could cause some localized flooding issues. Will
continue to monitor.

Enough instability will work north to mention thunder Monday night.
Potential for severe weather looks to remain south of the area.

Gradient winds will increase as the surface low deepens and the
surface front approaches. 40mph gusts are possible Monday night and
Tuesday.

Above normal temperatures will continue, with highs in the 60s
ahead of the cold front on Tuesday.

Tuesday night onward...

Some low PoPs will linger into Wednesday as the surface front moves
through and perhaps a surface trough will rotate in behind the low
pressure system. The upper trough will linger on Thursday, but
forcing may be weak enough to go with a dry forecast then.

Temperatures will cool to closer to normal by Thursday as the upper
trough moves in.


No comments:

Post a Comment