December Discobs Thread 2018

[coolio]

8 hours ago, Eskimo Joe said:

We could have the biggest rainfall of the year Thursday night...some of the guidance is pushing 3"+ regionwide.

I'll wait closer to Thurs. night to check the Euro.  But the NAM had the last system clocked. 

[nj2va]

Based on what I’ve seen so far, seems like 1-2” is the consensus so far.  Won’t be as wet as last weekend (yay!). 

[CAPE]

Yowza. Look at those PWATS. Dews approaching 60 too. Maybe some thunder. Good thing we desperately need the rain.

[smokeybandit]

23 degrees.  I should go check if the still-ponded parts of my back yard are frozen

[CAPE]

24 and frosty.

Bring on the tropical rains. 

[WxUSAF]

4 minutes ago, C.A.P.E. said:

24 and frosty.

Bring on the tropical rains. 

Euro says white Christmas. It’s all good.

[aldie 22]

Was in Tampa yesterday...too dang warm 

[BristowWx]

3 minutes ago, WxUSAF said:

Euro says white Christmas. It’s all good.

I saw that.  oh the irony if is were to snow on Christmas.  The holy grail of snow events. 

[mattie g]

1 hour ago, WxUSAF said:

Euro says white Christmas. It’s all good.

24 hours too late. Pass.

 

 

 

 

[high risk]

5 hours ago, C.A.P.E. said:

Yowza. Look at those PWATS. Dews approaching 60 too. Maybe some thunder. Good thing we desperately need the rain.

 

 

        Thunder definitely seems to be on the table for most of the area Thursday night and for points east on Friday.     Good elevated instability early Friday:

 

[Eskimo Joe]

 

[coolio]

Rainfall totals have been trimmed down a little bit. Eastern shore of MD/VA looking to get more of the precip:

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...

Powerful storm system still on track to impact the region
Thursday night into Saturday bringing with it a variety of
hazards. Strong low-level jet of nearly 60kt at 850 mb will
transport rich air moisture into the area Thursday night with
PWATs climbing over 1.5 inches which is around 400% of normal or
+4 STDs. Rain will arrive after 12Z Thu and become moderate to
heavy after 00Z Fri. Many GFES and EPS members show high
likelihood of forced squall line moving through eastern VA and
likely reaching Spotsylvania Co and southern MD and potentially
reaching as far north as northeast MD around midnight Thu night.
This squall line will bring intense rainfall rates and potential
for winds to gust well over 40 mph and possibly as high as 60
mph depending on the strenght of the convection. Model guidance
has trended somewhat quicker in punching mid-level dry slot into
the area shortly after daybreak Fri potentially cutting down
somewhat on rainfall totals. This is especially true for western
areas where many EPS members do not show significant rainfall.
Model trends also shown significantly higher totals for the
eastern shore of MD/VA. There could be a brief lull in precip
Fri morning before actual cold front crosses the area Fri
evening. Models have also trended a little deeper with sfc and
upper system Fri evening and are now showing deeper convection
moving through Fri afternoon and Fri evening with some risk of
charge separation and increased threat for t-storms. Cold air
will also start filtering in across the west Fri night with rain
showers turning into snow showers over the mtns Fri night. By
Sat, trough axis and sfc low would have shifted northeast of the
area with precip shutting off east of the mtns. Gust NW post-
frontal winds will remain possible through Sat before conditions
begin to improve Sat night.

3:08pm discussion.

[87storms]

i'm actually craving a mild day at this point. looks like east breeze prevails tomorrow, but friday could be the day to at least get some southerly breeze (even if it's damp).  my other hope is that it's not too windy saturday.

[Eskimo Joe]

Rainfall getting trimmed west of 95.  Staring down the barrel of another bust...we suck at weather here.

[yoda]

On 12/18/2018 at 12:43 PM, Eskimo Joe said:

We could have the biggest rainfall of the year Thursday night...some of the guidance is pushing 3"+ regionwide.

 

28 minutes ago, Eskimo Joe said:

Rainfall getting trimmed west of 95.  Staring down the barrel of another bust...we suck at weather here.

You jinxed it

[mappy]

pretty dense freezing fog this morning on my drive into work. 

[donsutherland1]

To date, Baltimore has received 68.82" precipitation this year and Washington, DC has picked up 64.22". The Baltimore figure is nearly 3.7σ above the 1871-2017 mean annual figure and the Washington, DC figure is almost 3.7σ above the 1871-2017 annual mean precipitation. Following this storm, Baltimore will likely have reached or exceeded 70" precipitation for the year ( 3.8σ) and Washington, DC will likely have reached or exceeded 65" ( 3.3σ).

[Fozz]

1 minute ago, donsutherland1 said:

To date, Baltimore has received 68.82" precipitation this year and Washington, DC has picked up 64.22". The Baltimore figure is nearly 3.7σ above the 1871-2017 mean annual figure and the Washington, DC figure is almost 3.7σ above the 1871-2017 annual mean precipitation. Following this storm, Baltimore will likely have reached or exceeded 70" precipitation for the year ( 3.8σ) and Washington, DC will likely have reached or exceeded 65" ( 3.3σ).

That’s an insane anomaly, especially if our precip totals are normally distributed or close to it.

[nw baltimore wx]

Just now, donsutherland1 said:

To date, Baltimore has received 68.82" precipitation this year and Washington, DC has picked up 64.22". The Baltimore figure is nearly 3.7σ above the 1871-2017 mean annual figure and the Washington, DC figure is almost 3.7σ above the 1871-2017 annual mean precipitation. Following this storm, Baltimore will likely have reached or exceeded 70" precipitation for the year ( 3.8σ) and Washington, DC will likely have reached or exceeded 65" ( 3.3σ).

I'm not sure if you posted it before or if I read it somewhere else (maybe RodneyS had posted it?), but do you know the all-time record for most precipitation in any 12 month period?  I don't think we've gotten there yet but we have to be getting close.

 

[donsutherland1]

1 hour ago, nw baltimore wx said:

I'm not sure if you posted it before or if I read it somewhere else (maybe RodneyS had posted it?), but do you know the all-time record for most precipitation in any 12 month period?  I don't think we've gotten there yet but we have to be getting close.

 

Wettest 12 month periods:

Baltimore:  68.82”, January-December 2018

Old record: 66.23”, December 2017-November 2018
Old record prior to any months from 2018: 65.54”, August 1888-July 1889

Washington, DC: 69.76”, August 1885-July 1886

 

 

 

[nj2va]

2 minutes ago, donsutherland1 said:

Wettest 12 month periods:

Baltimore:  68.82”, January-December 2018

Old record: 66.23”, December 2017-November 2018
Old record prior to any months from 2018: 65.54”, August 1888-July 1889

Washington, DC: 69.76”, August 1885-July 1886

 

 

 

You are a treasure trove of information!

[Eskimo Joe]

1 minute ago, nj2va said:

You are a treasure trove of information!

Yup.  Don's the best poster on this board, hands down.

[nw baltimore wx]

15 minutes ago, donsutherland1 said:

Wettest 12 month periods:

Baltimore:  68.82”, January-December 2018

Old record: 66.23”, December 2017-November 2018
Old record prior to any months from 2018: 65.54”, August 1888-July 1889

Washington, DC: 69.76”, August 1885-July 1886

Thanks!

By the way, January 2018 was much below normal precip-wise, so that 12 month record will likely continue to get broken.

[donsutherland1]

9 minutes ago, nw baltimore wx said:

Thanks!

By the way, January 2018 was much below normal precip-wise, so that 12 month record will likely continue to get broken.

Yes. That should happen, especially if the atmosphere begins to behave like a typical El Niño.

[donsutherland1]

25 minutes ago, Eskimo Joe said:

Yup.  Don's the best poster on this board, hands down.

Thanks for the really kind words. There are many outstanding people here. There are also many fantastic meteorologists here, too.

[yoda]

So you say there is a chance Ian...

 

[Fozz]

5 hours ago, donsutherland1 said:

To date, Baltimore has received 68.82" precipitation this year and Washington, DC has picked up 64.22". The Baltimore figure is nearly 3.7σ above the 1871-2017 mean annual figure and the Washington, DC figure is almost 3.7σ above the 1871-2017 annual mean precipitation. Following this storm, Baltimore will likely have reached or exceeded 70" precipitation for the year ( 3.8σ) and Washington, DC will likely have reached or exceeded 65" ( 3.3σ).

5 hours ago, Fozz said:

That’s an insane anomaly, especially if our precip totals are normally distributed or close to it.

I just plugged in that standard deviation, and if it reaches 3.8σ (assuming a normal distribution), then this year's precip total would be a 1 in 13000 year anomaly.

[donsutherland1]

18 minutes ago, Fozz said:

I just plugged in that standard deviation, and if it reaches 3.8σ (assuming a normal distribution), then this year's precip total would be a 1 in 13000 year anomaly.

That's one-tail. Keeping in mind that one can also get 3.8 sigma departures on the dry side, the probability of a 3.8 sigma departure is twice as frequent. If one is just measuring the probability of a 3.8 sigma departure above normal, then that's correct.

[high risk]

52 minutes ago, yoda said:

So you say there is a chance Ian...

 

      There definitely does appear to be a window of opportunity west and northwest of DC Friday afternoon.   Instability is limited, but there is some cape, and lapse rates will steepen as the colder temps aloft arrive.     The shear is outstanding, and there will be forcing along the arriving front.

[peribonca]

Really impressive slug of rain moving up the Eastern US. Don't think I remember such a wide expanse without any frozen even up to Hudson's Bay