Hello everyone!
We’re heading back to the 50’s today for highs but this time we will be seeing more clouds as our next storm approaches. All in all, not a perfect day but not a bad one either.
Rain and wind arrive for the coast tomorrow but it won’t be that big a deal. I will likely not have enough time for an evening update with several school functions to attend tonight but the full rain/wind forecast will be up tomorrow morning.
-Jack
Hello everyone!
A quick update this evening to keep everyone up to speed on the next chance for inclement weather heading into the middle/later part of this week.
The 18Z GFS shows us some of the main players in Wednesday’s storm. While the 18Z GFS usually isn’t that reliable and while I hate to use the GFS in the short term, it offers the most reasonable solution (as well as the Euro which I can’t post). Most other models have a stronger storm which I still have doubts about given the lack of upper level support. Not too complex a storm here, we’re looking at steady moderate rain for a few hours Wednesday morning into early afternoon along the coast with inland showers around the same time inland. Winds will be breezy with gusts in the 20-30 mph range most likely along the coast, lesser but still active winds inland. Rain wraps up by evening as the storm moves offshore.
More rain arrives late in the day Thursday in association with a front moving in from the west.
Updates will stay on the twice a day schedule until the weather returns to its state of calm we’ve grown so accustomed to recently.
-Jack
Hello everyone!
We continue our remarkable streak of lovely weather today with sunny skies and highs ranging through the 50’s. Enjoy it while it lasts though because we do have a few wetter days ahead.
-Jack
Hello everyone!
I’m going to start up evening updates on an as-needed basis this week as we have two shots at some rain in the next 5 days.
A low pressure system will develop offshore Tuesday and move NE up the coast but before it reaches Cape Cod, it looks to turn east and away from the coast. The upper level pattern is very conducive to this motion and the energy sparking this storm is very weak so it does not look to be a big storm. What is big though is the high pressure center up in northern Quebec/Labrador. A piece of this sprawling high will likely extend down into Maine which will help to create a respectable but certainly not impressive pressure gradient Wednesday which will lead to some gustier than normal winds. For northern areas, expect slightly breezier conditions and mainly cloudy skies but little/no precip. Coastal areas look to see breezy conditions with drizzle/showers likely. All in all, nothing intense but a dreary day nonetheless.
A new storm will be developing at the same time over the Central US and will drag a cold front towards the region for Thursday evening into Friday. While the current timing is not conducive to any mixed precip, should the storm arrive a little earlier closer to Thursday morning or a little later more towards early Friday morning, the mountains would have to watch for some light icing at the onset. As of now this does not appear to be an issue but it is something to keep an eye on.
This wouldn’t be a bad time to check up on your salt/sand supply as even if this icing event does not materialize, there will be more down the road and now is the perfect time to make sure you’re ready for the winter weather that lies ahead.
Should the current forecast remain unchanged, the rain would occur mainly during the overnight hours Thursday before clearing up Friday morning.
A shot of colder air lurks behind this system for next weekend.
I’ll have another update on tomorrow’s weather tomorrow morning and another update on these rain events this time tomorrow evening.
-Jack
Hello everyone!
A typical upslope/downslope pattern is set up across the region with west/northwest winds which leads to mountain clouds and shower chances and inland/coastal sun and warmth. Highs will top out near 60 today at the coast with upper 40’s/low 50’s up north. Skies south will be sunny and up north clouds will hang around most of the day.
For more info on the upslope/downslope pattern, check out yesterday’s neat weather tidbit which explains that frequently seen pattern.
-Jack
Hello everyone!
Last night between 8 and 9 PM, something really cool happened all across southern Maine. Several hours after dark and following the passage of a cold front, temps spiked between 4 and 6 degrees in less than an hour going against all logic that temps should fall after dark especially without any large scale weather system to draw warm air north. Let’s see what happened.
At 8:00 last night, a cold front was crossing the area from west to east with SW winds ahead of it and W winds behind it. Temps were already pretty warm, in the 60’s, as southerly winds ahead of the front brought warm air into the region. Colder air lurked behind the front and temps in the 30’s were being reported in the upper Great Lakes with west winds bringing those temps right to us. So what happened? Shouldn’t temps have dropped after the passage of a cold front with an actual cold airmass behind it?
The answer lies in downsloping. This is a term I’ve used a lot but really want to explain here. Winds after the cold front were
westerly/northwesterly and thus the air over southern Maine came from New York/Quebec and then up and over the Appalachian Mountains. When the air rose up the west side of the Appalachians, it cooled but not a lot of the moisture was rung out as shown by the lack of precip at the time.
Because the air was still pretty saturated at the time, the sinking air on the east side of the mountains warmed at the saturated adiabatic lapse rate of roughly 5.5F for every thousand feet. The 5.5 degrees per 1,000 feet figure is for fully saturated air with relative humidity of 100%. The relative humidity in Portland at the time was 73% so the air could be expected to warm at 73% of the moist (partially saturated) adiabatic lapse rate. 73% of 5.5 degrees is 4.015 degrees, very close to the 4 degree rise measured at PWM.
At Augusta, the same calculation works. The temperature rose 5 degrees from 59 degrees at 9 PM to 64 degrees at 11PM. With a relative humidity at 9PM of 90%, that works out to a moist adiabatic lapse rate of 4.95 degrees, again, darn close to the 5 degrees observed in actuality.
Another contributing factor to the suddenness of the spike in temps was warm air aloft suddenly being mixed down to the surface. The 7PM sounding up in Gray showed warm air just above the surface which promptly mixed down with the turbulence caused by the passage of the front.
The air just above the surface was being downsloped to just the right temperature with westerly winds just above the surface and when the surface front came through, the turbulence broke the inversion and sent those warm temps crashing to the ground.
I’ll be back in the morning with tomorrow’s weather. A sneak peek reveals cooler but still not chilly temps in the 50’s with mainly sunny skies.
-Jack
Hello everyone!
More nice weather is lined up for today with gusty NW winds bringing in ever so slightly cooler air. Highs will range from near 50 up north to near 60 down south. With a NW wind flow set up, expect the typical upslope/downslope pattern to take place today with clouds and sprinkles up north and clear skies downwind of the mountains.
I’ll be back with a neat weather tidbit I noticed last night later on this afternoon.
-Jack
Hello everyone!
Today will feature more of the lovely warm weather we’ve been enjoying but with a few more clouds as a cold front approaches. Expect highs in the low to mid 50’s north and low to mid 60’s south. More clouds will be in the cards for all but the greatest cloud cover will be up north where some sprinkles/showers are possible as well.
-Jack
Hello everyone!
Today will feature a split between east and west with the west seeing September like conditions with warm temps in the 60’s and mainly sunny skies while eastern areas (Portland to Lewiston and east) see more clouds, some drizzle/fog, and cooler temps in the 50’s to low 60’s. Low clouds and fog should move out early in the afternoon leaving at least partly sunny skies for most.
-Jack
Forecasterjack 