Central Pa. Summer 2024

[paweather]

27 minutes ago, Itstrainingtime said:

1) This is a weather board. He's posting weather models. As much as I'm skeptical, I would never discourage someone from posting a...you know, weather model on a...you know, weather board.

2) There have been multiple times this summer when the models have beaten forecasters. All of them. 

THANK YOU!

[paweather]

7 minutes ago, TheClimateChanger said:

Extreme heat for CPC purposes is defined as a heat index roughly in the mid 90s for this time of the year in the Commonwealth. Those temperatures with unseasonably high dewpoints could easily attain that, and could even approach heat advisory criteria for a day or two.

We can see the threshold for the 6-10 day period for "above normal MHI" is less than 95F for most of the state. This value actually appears to peak a couple weeks before maximum temperatures are achieved, as it's started to come down over the past couple of weeks. We can see in the 6-10 day period, there is an 80-90 percent chance that the heat index will peak above the 95F threshold.

We can see in the 8-14 day max heat index outlook, the threshold is a bit higher. Not because that's a hotter period on average, but because there's two extra days in the period. So the threshold for what's considered an above normal MHI is higher. We have a 70-90 percent chance of reaching this threshold at some point over the period. Of course, there's some overlap in the two periods, so it could very well be on the same date.

Anyways, no reason to suspect we are done with extreme heat for the near future.

No reason to expect for extreme heat either. Let Mother Nature decide. 

[TheClimateChanger]

4 minutes ago, paweather said:

No reason to expect for extreme heat either. Let Mother Nature decide. 

I think there's a reason to expect extreme heat at some point in the 6-14 day timeframe when CPC is saying there's an 80-90% chance heat index readings reach at or above the mid to upper 90s.

[TheClimateChanger]

30 minutes ago, TheClimateChanger said:

Anyways, shaping up to be an HISTORIC summer of epic proportions in the Commonwealth of Pennsylvania. CPC says more heat in the offing over the next 2 weeks and into the month of August, although there appears to be some disagreement there.

Harrisburg - warmest of 137-year POR

Reading - warmest of 129-year POR [by 1.2F]

Bradford - warmest of 66-year POR [by 1.4F]

DuBois - warmest of 59-year POR [by 1.0F]

Altoona - 2nd warmest of 77-year POR

Williamsport - 2nd warmest of 130-year POR

Scranton/Wilkes-Barre - 3rd warmest of 124-year POR

Philadelphia - 3rd warmest of 151+ year POR

Allentown - Tied 4th warmest of 103 year POR

Mount Pocono - 7th warmest of 115-year POR

Pittsburgh - Tied 7th warmest of 150-year POR, by far hottest at the airport site

Erie  - The place to beat the heat in 2024. "Only" 11th warmest of 152-year POR.

 

Also, I've been told in the past that only maximum temperatures count. That is, that people judge summer heat by maximum temperature, and minimum temperatures don't count. The rankings are very similar across the board for mean maximum temperature. Every site is within 2 places of its mean temperature ranking if re-ranked by maximum temperature, with the exception of MPO and IPT. So we are legit cooking, and it's not just some overly inflated minimum temperatures.

[paweather]

3 minutes ago, TheClimateChanger said:

Also, I've been told in the past that only maximum temperatures count. That is, that people judge summer heat by maximum temperature, and minimum temperatures don't count. The rankings are very similar across the board for mean maximum temperature. Every site is within 2 places of its mean temperature ranking if re-ranked by maximum temperature, with the exception of MPO and IPT. So we are legit cooking, and it's not just some overly inflated minimum temperatures.

I'm at 83 today whats your temp? 110? 

[TheClimateChanger]

4 minutes ago, paweather said:

I'm at 83 today whats your temp? 110? 

You're comparing the mean of 53 days with 1 day? But to answer your question, I have a scorching 88F on the trusty weather station.

[TheClimateChanger]

39 minutes ago, TheClimateChanger said:

Anyways, shaping up to be an HISTORIC summer of epic proportions in the Commonwealth of Pennsylvania. CPC says more heat in the offing over the next 2 weeks and into the month of August, although there appears to be some disagreement there.

Harrisburg - warmest of 137-year POR

Reading - warmest of 129-year POR [by 1.2F]

Bradford - warmest of 66-year POR [by 1.4F]

DuBois - warmest of 59-year POR [by 1.0F]

Altoona - 2nd warmest of 77-year POR

Williamsport - 2nd warmest of 130-year POR

Scranton/Wilkes-Barre - 3rd warmest of 124-year POR

Philadelphia - 3rd warmest of 151+ year POR

Allentown - Tied 4th warmest of 103 year POR

Mount Pocono - 7th warmest of 115-year POR

Pittsburgh - Tied 7th warmest of 150-year POR, by far hottest at the airport site

Erie  - The place to beat the heat in 2024. "Only" 11th warmest of 152-year POR.

 

After further review, 1949 is missing the entire month of June at MPO. So toss that year, and make it 6th warmest (of 114 years).

[paweather]

2 minutes ago, TheClimateChanger said:

You're comparing the mean of 53 days with 1 day? But to answer your question, I have a scorching 88F on the trusty weather station.

I don't really care what the mean is. I am comparing today. 

[TheClimateChanger]

Just now, paweather said:

I don't really care what the mean is. I am comparing today. 

But my post was talking about the mean maximum temperature for summer to date, so it sounds like the only thing you really care about is arguing for the hell of it.

[Mount Joy Snowman]

2 minutes ago, TheClimateChanger said:

You're comparing the mean of 53 days with 1 day? But to answer your question, I have a pedestrian 88F on the questionable weather station.

Fixed it for ya. 

[Mount Joy Snowman]

That storm that fired up just south of MU hasn’t budged. 

[Bubbler86]

It has been a while since the CMC elicited this many posts.   Viva Le Montreal. 

[Itstrainingtime]

23 minutes ago, Mount Joy Snowman said:

That storm that fired up just south of MU hasn’t budged. 

What a day to be working remote in Columbia instead of Conestoga. 

You're right - MU has been getting the FU for quite a while. 

[Itstrainingtime]

6 minutes ago, Bubbler86 said:

It has been a while since the CMC elicited this many posts.   Viva Le Montreal. 

Yes indeed. I'm anxiously awaiting "that run" coming in December when a CMC run elicits a string of snow maps from our trusty snowmapaholic. 

[paweather]

11 minutes ago, Bubbler86 said:

It has been a while since the CMC elicited this many posts.   Viva Le Montreal. 

Sorry! I should have stopped. 

[Superstorm]

What a day to be working remote in Columbia instead of Conestoga. 
You're right - MU has been getting the FU for quite a while. 

Pouring rain in Willow Street area


.

[TheClimateChanger]

One thing I haven't seen much discussion of is how the extensive wildfire smoke might affect the upcoming temperatures? We've been fortunate so far that impacts have been minimal, but I do wonder if we won't start to see more smokiness and haze as we head into late summer.

There's some evidence that wildfire smoke could lead to lower temperatures. Last summer saw several episodes of dense smoke, and it was the coldest summer at Harrisburg since 2017. Another good analog is 1950. Read about the Chinchaga fire storms, and Black Sunday here in the Commonwealth. Fascinating stuff.

1950 is tied with 1979 for 13th coldest summer at Harrisburg, and it came on the heels of the scorching summer of 1949. After this summer is complete, 1949 will drop into a 3-way tie for 18th warmest [with 2018 & 1955]. However, at the time, the heat of 1949 was nearly unparalleled among records dating to the 19th century, being exceeded only in the summers of 1900 and 1943. Nobody then foresaw a future where a mean of 75.4F would become rather pedestrian at Harrisburg [having been met or exceeded in 11 of the last 23 summers*]. So the drop-off between 1949 & 1950 must have been quite a shocker to the locals - perhaps a bit of a relief as well in those pre-A/C days.

*Yes, 2024 is not complete. But the mean will most certainly exceed 75.4F.

[TheClimateChanger]

The view from the RAP-SMOKE is probably better since it shows Canada too. Lots of smoke gathering over central Canada. You can kind of imagine this could make a beeline for Pennsylvania if it were to get caught up in some NW to SE oriented jet stream winds. I think we would need the trough to flatten and push east to get into more of a NW flow pattern.

[TheClimateChanger]

4 minutes ago, TheClimateChanger said:

The view from the RAP-SMOKE is probably better since it shows Canada too. Lots of smoke gathering over central Canada. You can kind of imagine this could make a beeline for Pennsylvania if it were to get caught up in some NW to SE oriented jet stream winds. I think we would need the trough to flatten and push east to get into more of a NW flow pattern.

It gets especially intriguing at Hour 51, as it looks like all the smoke gets wrapped up in a giant cyclone. I am not too impressed with modeled concentrations right now. Would want to see more 150 mg/m2 or higher for more significant impacts, IMO.

[Bubbler86]

1 hour ago, paweather said:

Sorry! I should have stopped. 

I am expecting some posts on the CMC late tonight.  Yay on Nay on the heat wave!   I think the fact the Euro is questioning the ridge position is enough to wonder right now. 

[TheClimateChanger]

CPC refusing to back down on the high heat. Significant flash drought risk over the Plains.

 

 

 

[TheClimateChanger]

The moderate risk of extreme heat has been extended for an additional day through August 7, 2024.

US Hazards Outlook
NWS Climate Prediction Center College Park MD
300 PM EDT July 24 2024

Synopsis: Coast-to-coast mid-level high pressure is predicted across the contiguous U.S. (CONUS) during week-2. This is associated with favored warmer-than-normal temperatures for most of the Lower 48 states. Excessive heat is most likely across the west-central, central, and northeastern CONUS during the week-2 outlook period. In Alaska, mid-level low pressure is forecasted across most of the state, with the exception of the Aleutian archipelago where mid-level high pressure is favored.

Hazards

• High risk of excessive heat for the south-central Plains and northern and western Missouri, Thu-Mon, Aug 1-5.
• Moderate risk of excessive heat for the Northeast and Mid-Atlantic region, Thu-Wed, Aug 1-7.
• Moderate risk of excessive heat for portions of the Interior West, all but far southern portions of the Great Plains, and central portions of the Mississippi Valley, Thu-Wed, Aug 1-7.
• Slight risk of excessive heat for the Interior West, most of the Great Plains, most of the Mississippi and Ohio Valleys, the Great Lakes region, Northeast, and Mid-Atlantic, Thu-Wed, Aug 1-7.
• Slight risk of excessive heat for the Central Valley of California, Fri-Wed, Aug 2-7.
• Rapid Onset Drought risk for portions of the Northern and Central Plains.

Detailed Summary

For Saturday July 27 - Wednesday July 31: WPC Days 3-7 U.S. Hazards

For Thursday August 01 - Wednesday August 07: For the week-2 period, ensemble means favor anomalous mid-level ridging and accompanying positive height departures across the CONUS, with maximum 500-hPa heights of at least 594 dm across the southwestern and south-central states.

The week-2 temperature outlook favors above-normal temperatures over almost all of the CONUS. A slight risk of excessive heat is depicted across most of the Lower 48 states outside of the Southeast and southern Texas, and valid for the entire Outlook period. Within this extensive slight risk area, there are two areas where a moderate risk of excessive heat is favored. One area includes the Northeast and much of the Mid-Atlantic region, valid Aug 1-7. The second, larger area includes much of the Interior West, most of the Great Plains, and central sections of the Mississippi Valley, Aug 1-7. Within this second, larger area, there is a high risk of excessive heat for the south-central Plains and adjacent parts of the Mississippi Valley, valid Aug 1-5. A general consensus of temperature and excessive heat guidance indicates actual air temperatures across portions of the Northeast and Mid-Atlantic region may reach well into the 90’s, with heat index values exceeding 100 deg F. For the Plains, maximum air temperatures of 100-105 deg F are expected, with heat index values surpassing 110 deg F over portions of the south-central Plains. A skill weighted, bias-corrected hybrid tool (which considers actual air temperature and heat index), raw temperatures from the ensemble means, and Probabilistic Extremes Tool (PET) temperatures were used in the construction of today’s excessive heat map. Based on these same objective tools, a slight risk of excessive heat is depicted for the Central Valley of California, Aug 2-7, where heat index values may approach or exceed 110 deg F.

The subtropical ridge is predicted to be centered over the Four Corners region during week-2, in its climatological position during the summer monsoon season. The 06z and 12z GEFS runs are predicting a tropical cyclone over the eastern Pacific to pass south of the Gulf of California early in the Outlook period. This scenario may trigger a gulf surge of moisture into the American Southwest, with the PET precipitation tool depicting amounts of about 0.5-inch. However, no precipitation hazard is predicted at this time.

The heaviest precipitation amounts predicted during this outlook period range from 1.0-1.5 inches over a 3-day period, focused along the Southeast and Gulf Coasts. However, normal weekly precipitation amounts for those areas range from 1.0-1.5 inches in most areas to almost 2 inches along the Gulf coast of Florida. Therefore, no precipitation hazards are depicted on today’s hazards map. However, according to the experimental Flood Hazard Outlook, this amount of precipitation is enough to renew flooding chances across the eastern coastal region of North Carolina, which recently experienced heavy precipitation and has elevated soil moisture anomalies.

The combination of continued above-normal temperatures and below-normal precipitation supports the continuation of a Rapid Onset Drought (ROD) risk over many parts of the Northern and Central High Plains. Dry soils, stressed vegetation, and reduced water availability due to low ponds and streams may lead to increased impacts to agriculture and livestock, with some locations already experiencing impacts.

No hazards are posted for Alaska during week-2. However, there is a significant chance of accumulating snow for portions of the central and eastern Brooks Range, which could have an impact on people within that area. This possibility will be reassessed tomorrow after looking at the most recent model solutions. Near Juneau, localized flooding may be a concern associated with the glacial outburst flood for the Mendenhall River.

Forecaster: Anthony Artusa

[TheClimateChanger]

I am on team Artusa. Summer is not over yet!

[Bubbler86]

2 minutes ago, TheClimateChanger said:

I am on team Artusa. Summer is not over yet!

38 days to go.

[paweather]

28 minutes ago, Bubbler86 said:

38 days to go.

540 Line time!

[Bubbler86]

2 minutes ago, paweather said:

540 Line time!

We had the 540 line 2 weeks ago.  I mentio9ned but you may have missed it. 

[Bubbler86]

When I lived in Philly, a lot of people used to use the term "roof it" to mean get rid of something.    CPC is roofing today's 12Z runs as to this forums area. 

[canderson]

I’m buying all the lottery tickets because this is Austin’s forecast  - chilly for late July standards.  

Thursday

A 40 percent chance of showers and thunderstorms. Partly sunny, with a high near 87. Calm wind becoming east northeast around 5 mph in the afternoon. 

Thursday Night

A 20 percent chance of showers and thunderstorms after 1am. Partly cloudy, with a low around 72. East wind around 5 mph becoming calm. 

Friday

A 40 percent chance of showers and thunderstorms. Partly sunny, with a high near 87. Calm wind becoming south around 5 mph in the afternoon. 

Friday Night

Mostly cloudy, with a low around 73. South southeast wind around 5 mph becoming calm in the evening. 

Saturday

A 40 percent chance of showers and thunderstorms. Partly sunny, with a high near 87. Calm wind becoming south southeast around 5 mph in the afternoon. 

Saturday Night

A 20 percent chance of showers and thunderstorms after 1am. Mostly cloudy, with a low around 73. South southeast wind around 5 mph becoming calm in the evening. 

Sunday

A 50 percent chance of showers and thunderstorms. Partly sunny, with a high near 89. Calm wind becoming south southeast around 5 mph in the morning.

[Bubbler86]

Is this the place to post the 18Z GFS has punted the heat wave until 8 more days out?  If not, apologies.    GFS has Rou temp in the mid to upper 60's Monday at 2PM. 

[WmsptWx]

Another bountiful rain is falling currently.