September 2022

[forkyfork]

nervous about a north trend for monday

[binbisso]

The cfs looks even better. I know the skill is low for these long range models but one can hope 

[jm1220]

16 minutes ago, binbisso said:

The new cansips improved significantly for this coming winter with a poleward aleutian ridge and a very cold Canada 

In any Nina that really defines whether it’s a winter success or fail here. With no sharp Aleutian ridge we get flooded with Pacific air, with that ridge we get shots of cold air from the pole. Any help from the NAO is also a plus. But any Nina is strongly driven by the Pacific pattern since the jet is often so strong. 

[winterwx21]

2 hours ago, Brian5671 said:

12Z GFS coming in wet for NYC and north monday....only 3 days away-could it be?!?!?

12z GGEM is showing much less though ... less than a half inch for most of the area. We'll see what Euro shows shortly.

[MANDA]

17 minutes ago, forkyfork said:

nervous about a north trend for monday

Agree.  This is not a done deal where we all do the happy dance in celebration of rainfall just yet.  We'll see what EURO shows shortly but may take until 00Z Sunday runs to hone in on this POTENTIAL event.  I agree though, nervous we miss most of it to the north.

[winterwx21]

Also GGEM is showing almost nothing for monday and holds the rain off until tuesday morning. Last night's Euro also held the rain off until late monday night, so the whole holiday weekend could be ok. We'll see what the new Euro run shows shortly.

[Snowlover11]

29 minutes ago, forkyfork said:

nervous about a north trend for monday

good keep it away from the shore, i wanna go streaking on the beach.

[winterwx21]

12z Euro continue to be mostly dry for the day monday, and holds the rain off until monday night. It does give us a pretty good soaking monday night into tuesday morning though. A half inch to inch for most of the area.

[forkyfork]

17 minutes ago, Snowlover11 said:

good keep it away from the shore, i wanna go streaking on the beach.

i'm on gunnison beach right now <3

[MANDA]

12Z EURO clearly aiming the fire hose of moisture / rainfall north of this forum.  It does have .50 - 1" totals for most of the forum but stand by because if the bulk of the moisture / rainfall does track from south central PA northeastward into central New England the totals over our area could be overdone.  Ways to go and this could sink south some.  Even HPC has cut amounts from 12Z issuance over our area.  Still some time but not overly optimistic for the heavier totals we so badly need.

[Snowlover11]

1 hour ago, forkyfork said:

i'm on gunnison beach right now <3

im heading down to barnegat tonight.

[forkyfork]

1 hour ago, forkyfork said:

i'm on gunnison beach right now <3

nobody's swimming today

[Brian5671]

2 hours ago, forkyfork said:

nervous about a north trend for monday

WAR tends to be stronger than modeled so agree

[nycwinter]

3 hours ago, winterwx21 said:

12z GGEM is showing much less though ... less than a half inch for most of the area. We'll see what Euro shows shortly.

the reservoirs need the rain so this is a good thing..

[donsutherland1]

Tomorrow will be fair with near seasonable temperatures. The weekend will end with warmer readings.

A moderate to significant rainfall is possible from late Monday into Wednesday.

The ongoing intense heatwave will continue into early next week in the West. Today's preliminary high temperatures included:

Bishop, CA: 107° (old record: 106°, 1950)
Boise: 101° (tied record set in 1950)
Burns, OR: 102° (old record: 100°, 1950)
Death Valley, CA: 124° (old record: 123°, 1996)
Lancaster, CA: 113° (old record: 112°, 1950) ***New September record***
Reno: 102° (old record: 101°, 1950) ***Tied September record***
Salt Lake City: 100° (old record: 98°, 1947 and 2019)

In addition, Lytton, BC reached 103° (39.6°C). That set a new September record high for British Columbia.

In the 6 past cases when the June AO averaged +0.750 or above (1950-2021), 67% of the following August and September cases featured above normal temperatures. The August ECMWF forecast shows a warmer than normal September in the Northeast. This warmth would be consistent with the ongoing warming that has been occurring in September.

On August 18, the SOI fell to -32.90. Since 1991, there were 8 cases when the SOI fell to -30 or below during the August 10-25 period. That outcome has often preceded a wetter than normal September in parts of the Northeast. Mean September rainfall figures for those 8 cases: Boston: 4.38" (normal: 3.55"); New York City: 5.08" (normal: 4.31"); and, Philadelphia: 5.12" (normal: 4.40"). Very wet years outnumbered very dry ones by a 2:1 ratio in Boston and 3:1 ratio in both New York City and Philadelphia. 63% of cases saw at least one day with 1" or more rainfall in Boston. 88% saw at least one day with 1" or more in New York City and Philadelphia. 50% of those cases saw at least one day with 2" or more daily rainfall in Philadelphia. In sum, the SOI may be offering a signal that there will be some drought relief for the northern Mid-Atlantic and southern New England regions in September. The recent passage of the MJO through Phase 2 at a very high amplitude (1.500 or above) during late August has introduced greater uncertainty.

The ENSO Region 1+2 anomaly was -0.5°C and the Region 3.4 anomaly was -0.9°C for the week centered around August 24. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.72°C and the ENSO Region 3.4 anomaly has averaged -0.93°C. La Niña conditions will likely persist through the fall.

The SOI was +15.63 today.

The preliminary Arctic Oscillation (AO) was -1.975 today.

On August 31 the MJO was in Phase 2 at an amplitude of 0.938 (RMM). The August 30-adjusted amplitude was 1.066 (RMM).

 

 

[donsutherland1]

Morning thoughts…

It will be mostly sunny and somewhat warmer.  High temperatures will reach the lower and perhaps middle 80s in most of the region. Likely high temperatures around the region include:

New York City (Central Park): 80°

Newark: 82°

Philadelphia: 88°

Generally warmer than normal conditions will persist through the weekend. A moderate to significant rainfall is possible next week.

Normals:

New York City: 30-Year: 80.4°; 15-Year: 80.4°

Newark: 30-Year: 81.8°; 15-Year: 81.9°

Philadelphia: 30-Year: 83.0°; 15-Year: 82.8°

[bluewave]

Some good news for the holiday weekend outdoor activities is that the Euro and RGEM are really slowing the front down due to the stronger WAR. So we could see mostly dry conditions into Labor Day. This means that the warm spots with less clouds could tack on another 90° day. It is going to take a very strong -NAO to bring temps back closer to normal for several days following Labor Day. Then upper 80s to around 90° could return next weekend as the blocking relaxes. As usual, the models haven’t been stellar with the rainfall forecasts recently. So we’ll take whatever we can get.

 

 

[CIK62]

The next 8 days are averaging  76degs.(69/84)  or +4.

Reached  79 here yesterday.

Today:   76-81,  wind s., p. sunny-clouds late.

Again looking  like a bore around here.       Most interesting item might be the EURO keeping Earl closer to the coast than the GFS.      Sept.  12-18 period could have some BN days, but no BN 5- Day period.

69*(75%RH)  here at 7am.       74* at 10am.        75* at Noon.       78* at 3pm.      Reached 79* at 6pm.       73* at 8pm.

 

[Allsnow]

06z euro 1-2 area wide 

[MJO812]

72 here 

[thunderbolt]

1 hour ago, bluewave said:

Some good news for the holiday weekend outdoor activities is that the Euro and RGEM are really slowing the front down due to the stronger WAR. So we could see mostly dry conditions into Labor Day. This means that the warm spots with less clouds could tack on another 90° day. It is going to take a very strong -NAO to bring temps back closer to normal for several days following Labor Day. Then upper 80s to around 90° could return next weekend as the blocking relaxes. As usual, the models haven’t been stellar with the rainfall forecasts recently. So we’ll take whatever we can get.

 

 

Can you please post that NAO graph in the middle of January please

[SACRUS]

73 / 63 up from 58.  A beautiful day on tap for with partly sunny and low / mid 80s.  Depending on clouds tomorrow, the warmer spots could get to 90 and Labor day but clouds and rain timing will determine that.  Best widespread rain chance with 1 or more for most.  By Wed (9/7) we are clearing out and the Western Atlantic ridge builds back along the Northeast coast by Fri (9/9) with next warmup into next weekend and beyond.  Possible to tack on more 90s for the warmer spots.

[psv88]

56 here this morning 

[wdrag]

It's long but if you wish, some supporting information relating summer-fall precip totals to tropical cyclones as appended. Again---to me it appears to be a suppressed Atlantic Basin tropical season (not at all outlooked as it has developed through 9/3/22).  

We need Sun-Tue (4-6) to produce substantial rainfall here...  and late next weekend (11th) as well  - the latter being the lower Ohio Valley-Lower Miss Valley closed low [SHARS FF events nw of vort max in light flow and high PW airmass} hopefully opening up into the mid Atlantic States.  SHARS is Subtle Heavy Rain Signatures - subtle being 'warm top convection'. 

Details for Sun-Tue (4-6) in my mind are still to be determined. Late next weekend not well modeled (in my opinion) yet so nothing seems obvious there and maybe that will prevail but I like the possibility of a shower producer moving into our area.

Below is with a link provided by a former colleague. 

----

Mechanisms of Abrupt Extreme Precipitation Change Over the Northeastern United States
Huanping Huang, Jonathan M. Winter, Erich C. Osterberg
First published: 26 June 2018 https://doi.org/10.1029/2017JD028136Citations: 26
SECTIONSPDFPDFTOOLS SHARE
Abstract

In 1996, the northeastern United States experienced an abrupt increase in extreme precipitation, but the causal mechanisms driving this increase remain poorly understood. We find that 89% of the 1996–2016 increase relative to 1979–1995 is explained by only 273 unique extreme events affecting >5 stations and occurring in the months of February, March, June, July, September, and October. We use daily weather maps to classify the 273 extreme precipitation events by meteorological cause (tropical cyclones, fronts, and extratropical cyclones) and use reanalysis data to determine large-scale changes in the atmosphere and ocean associated with increased extreme precipitation for each classification. Results show that tropical cyclones account for almost half (48%) of the post-1996 extreme precipitation increase, while fronts and extratropical cyclones are responsible for 25% and 15% of the increase, respectively. The remaining 11% is from extreme events in the other 6 months of the year and extreme events that affected <5 stations. The increase in extreme precipitation from tropical cyclones after 1996 is associated with a shift to the Atlantic Multidecadal Oscillation warm phase, higher total column water vapor, and potentially weakened steering winds. September and October tropical cyclones caused significantly more extreme precipitation during the current Atlantic Multidecadal Oscillation warm phase (1996–present) than during the last warm phase (1928–1962), despite the same number of northeast tropical cyclones in both periods. Increased extreme precipitation from fronts is associated with a wavier (higher amplitude) jet stream, which likely facilitates the development of more frequent fronts through the advection of cool northern air into the American Midwest.

Key Points
Eighty-nine percent of the abrupt 1996 extreme precipitation increase is explained by events in early fall, early summer, and late winter
Tropical cyclones account for almost half of that increase (48%), followed by fronts (25%) and extratropical cyclones (15%)
Increased extreme precipitation is associated with warmer Atlantic sea surface temperature, increased water vapor, and a wavier jet stream

 

[wdrag]

Adding a little more info: EC PW generally 1.75+ here Sun-Tue.  A shower tomorrow could be heavy...not necessarily LIGHT.

 

06Z/3 EC as has the 00Z/3 EC trended southward on axis of heavy frontal related (confluence 500MB flow) rainfall basically giving quite bit here. Other can post this if you wish.  Bottom line it going to get pretty wet in part of our subforum soon.

Also PW next weekend SOARS in the Ohio Valley past 2".  So positioning of the upper low will be important for targeting the rain next Sunday.  I think it will make some news, at least in parts of the Ohio Valley. 

[bluewave]

40 minutes ago, thunderbolt said:

Can you please post that NAO graph in the middle of January please

It’s pretty wild how far north the record SSTs in the Atlantic extend. So the -NAO is lining up with that anomalous warm pool. But it’s also far enough south to pump the WAR. Tropical systems winding up in that part of the Atlantic are mostly recurving OTS systems. So they don’t do us much good for drought relief since scattered convection can only do so much.

 

 

[T5403CG]

06z euro 1-2 area wide 

Finally... A real shot of significant rain for the South Shore in Suffolk on the island...

Will be refreshing if it happens...

Sent from my moto g power (2021) using Tapatalk

[binbisso]

12z nam is a drought buster.

[Stormlover74]

8 minutes ago, binbisso said:

12z nam is a drought buster.

3 days on the nam is an eternity 

[SACRUS]