Monday, December 9, 2019

Rainy Days and Mondays ... Come to Think of It, Neither Really Get Me Down**

**With sincere apologies to the great Karen Carpenter.

Rainy, gloomy afternoon, at the corner of U and 13th Streets NW, Washington, D.C., 1:05 p.m. December 9, 2019

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This is just a brief late afternoon update. I realize I didn't post a follow-up entry on Sunday. I also didn't make it to the gym this weekend. My intention is to go tonight.

Today, the second Monday this December, has been a very rainy, misty, low-overcast, gloomy day.

Rainfall totals today were in the 1/2" to 3/4" range to include the following through 4 p.m. EST:

KDCA: 0.73"
KBWI: 0.76"
KIAD: 0.50"
KDMH: 0.62"

Today's total pushes KDCA over the current 30-year annual average of 39.74" and over the 40-inch mark for the year (as of 4 p.m., the year-to-date is 40.31").

So, this means KDCA ends up with a "wetter than normal" year even if no more precipitation fell this month -- although no where near last year's 66.28" yearly record.

KBWI is at 36.00" -- which is 3.57" below the normal year-to-date and last year's 71.82" yearly record is quite safe. KIAD is at 38.80" -- or 0.76" below normal. Last year's 66.74" yearly record is also quite safe.

The KDMH annual total is just under 40 inches at 39.70" through 4 p.m. today.

Remember that this ASOS station is going offline starting on Dec 18th -- and will be offline until at least March … if it ever comes back online since it is located in the disastrous mess of Baltimore City with all that this implies …

Anyway, what this means is that as of now, KDCA is actually the highest for precipitation amount for the four main climate stations in the immediate Metro D.C. and Baltimore areas -- and that is due to that 3.44-inch gully-washer back on July 8th.

Afternoon highs today were fairly uniformly in the 46F to 48F range. However, temps are expected to rise tonight as a stronger southerly flow sets up ahead of tomorrow's strong cold frontal passage.

NWS high-resolution surface weather map for a portion of the eastern United States valid 15Z (10 a.m. EST) 
09 December 2019

Note the coastal front there -- stretching all the way from southern Connecticut to near Charleston, S.C.

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A strong cold front is progged to push across the eastern United States tomorrow, ushering in much colder weather along with the possibility of sleet and snow as the precipitation ends tomorrow night. There could even be some snow here in D.C. proper, although, honestly, that rain-to-snow scenario in the immediate D.C. area is rather rare. Typically, the precipitation shuts off before the sufficiently cold air arrives.

NWS WPC National Digital Forecast Database (NDFD) surface weather map and precipitation type and likelihood looped as shown between 0Z 10 Dec and 0Z 12 Dec 2019

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Here are two relevant CWG entries (links embedded):



And we'll conclude with some radar imagery …

NECONUS base reflectivity radar mosaic looped 1658 - 1808 UTC 09 (11:58 a.m. - 1:08 p.m. EST) Dec 9, 2019

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Sterling (LWX) NWS radar in standard composite mode looped 12:40 p.m. - 1:22 p.m. Dec 9, 2019

The yellows certainly suggest sleet / frozen precipitation in the clouds.

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LWX NWS radar in standard base reflectivity mode looped 12:46 p.m. - 1:28 p.m. Dec 9, 2019

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OK, and with that, I'm going to end this entry. My plan is to post another one later tonight after I get home from the gym.

--Regulus

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