Christopher Duvall
Meteorologist, Rutgers University
3/15/2000 Message of the Day

Precipitation:

Howdy!  The one thing all of us weather weenies seem to agree on is 
that the weather pattern will be changing significantly between Tuesday 
evening and Wednesday evening.  Other than that, a lot of the areas 
forecast to receive precipitation are very localized and "iffy"- the 
Chicago and Southeastern Texas areas, for example.  As of Tuesday 
evening, the weather pattern was something called "zonal", where 
there aren't any big, strong Highs or Lows around, just regular ol' 
straight winds from West to East.  

So why is everything so tough to figure out ahead of time for today 
(Wed.)?  Well, there is a lot of cold air getting ready to flow south 
from the northern Plains across to the Great Lakes/Michigan area 
through Wednesday and into Thursday.  However, there isn't a strong 
Low associated with this cold air as the air advances south (as a 
cold front) that would help to create an unstable atmosphere for lots 
of storms.  As of Tue. evening, there was a weak Low around North 
Dakota, that's it.  You should see Highs and Lows on the weather map 
for Thursday into Friday, but there won't be any strong, large-scale, 
or "synoptic-scale" Highs and Lows around to rile up the weather for 
Wednesday.  By Wed. evening, we should see a pattern of Highs and Lows 
begin to emerge.

So when the large-scale weather patterns don't help us to figure out 
what's going to happen, meteorologists look to smaller-scale, or 
"mesoscale" patterns.  Mesoscale patterns are roughly the size of a 
county or two.  Wednesday will primarily be a "mesoscale" weather day.  
The weather from state to state will be relatively calm, but some 
areas the size of a few counties may see more active weather, i.e. 
rain or even some light snow around the Great Lakes and Rockies.  
Southeast Texas will be the best bet for the most significant rain 
throughout the day- otherwise there shouldn't be any large areas of 
precipitation in the U.S..  Remember, when the large-scale weather 
patterns are weak but favorable for active weather, the small-scale, 
or mesoscale, patterns will have the opportunity to take over. 

So what I *can* tell you is, there should not be any record-breaking 
of any kind in the U.S. for Wednesday, but the weather will likely get 
active in small areas or perhaps a Low will form along the cold front 
and help to lift the air to produce clouds and rain.

Temperatures:

Most coastal areas of the U.S. have a chance to see some patchy fog in 
the morning that should clear up by lunchtime, allowing the temperatures 
to be in at least a normal, springtime range by mid-afternoon.  The 
Texas/Louisiana area may stay a little cooler if enough clouds and rain 
continue to form in the area Wednesday morning.  As of Tuesday evening, 
there was a bunch of storms off the entire coast of Texas that had a lot 
of clouds spreading out from it, so you may see the remnants of this 
system in the morning around the Gulf Coast area, keeping sunlight out 
and the temperatures down.

I will be available off and on during the day if you have any questions, 
or you're welcome to look me up By Author to read some general 
explanations of key features of the weather.  Good luck hunting for 
"mesoscale" weather today!

- C.D.   3/15/2000