Date: 201811
Local time of day: 0001-0600
Location: ZZZ.Airport, US
Flight conditions: Mixed
Aircraft: B737-700
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Descent
Airspace: Class B ZZZ
ATC / advisory: TRACON ZZZ
Second aircraft: Eclipse 500
Reporter organization: Government
Reporter function: Approach
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Time Pressure; Workload
Anomaly: ATC Issue All Types; Conflict Airborne Conflict; Deviation - Speed All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Weather / Turbulence
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Air Traffic Control Separated Traffic
Contributing factors: Airspace Structure; Human Factors; Procedure; Weather
Primary problem: Human Factors

Narrative: I relieved a controller on NR/SR (North Radar/South Radar) with 7 or 8 planes in my airspace being vectored to the [RNAV Approach] final. I received a normal briefing; understood the situation completely; and took responsibility for the position. I was not happy with the traffic situation I sat down to bat clean-up on. I was not in the TRACON to see what actions the previous controller took; but; I was kind of irritated with the situation that I got. We were single arrival runway landing XX. All aircraft on the scope; although different sizes and weights; were high performance turbojets with similar performance capabilities. I was not happy to see two [business jets] hung out 'in space' pulled back to 170 knots with a long way to join the sequence and get to the threshold. I could see what the previous controller was trying to do to set up the sequence as he would have liked it; but; I thought that it was far too conservative and unnecessarily delaying aircraft. It appeared that the two small GA jets were being forced to play 2nd fiddle to the airliners. I began to vector aircraft in an effort to tighten the sequence and get the airplanes in quicker.I guess I would like to preface this by saying that I had spent the entire week diligently studying the weather; both current; and forecasted. There was a very interesting frontal passage moving through the area; and I had spent the week invested in learning everything I could from the unique weather situation that we experienced.On the day of the event; I was able to witness and work traffic in the variances of the back end of the FROPA (Frontal Passage) as the weather finally began to calm and clear. The first half of the shift I worked had high winds; wind shearing at different altitudes; aircraft being pushed very fast from the west with tail winds; bumpy ride reports from pilots; and mixed IFR conditions in the local flying area. There were active SIGMETS and CWAs (Center Weather Advisories) as well as PIREPS reporting bad rides and LIFR. These conditions began to clear and push out of the local area prior to my taking the position relating to the event. On break; I visibly observed clear skies and low wind with rapidly improving conditions. During my preview and pre-brief preps; all of the posted weather and active AWOS/ASOS reports showed all areas as VMC with low winds; 10 mile average reported visibility; and just a random scattering of FEW at 2000 or higher in the local flying area. When I took the position as stated above; Aircraft X was about 15ish miles northwest of ZZZ near the ZZZ2 airport on a vector towards the [RNAV Approach] final. Aircraft Y is a local aircraft with a pilot very familiar with our airspace and procedures. Although; in my opinion; he should have been kept fast and clearly set up to be number one to the runway relative to his position and other traffic; I inherited him and another [business jet] further northeast both pulled back slow showing 180kts or less. Aircraft X was being fed towards the final from the west-northwest. A [Company aircraft] was just passing the ZZZZZ intersection on the ZZZZZ arrival transitioning directly to ZZZZZ1 to join the straight in RNAV ZZZZZ2 approach. My initial plan was to bring Aircraft Y in number one; the [Company aircraft] straight in number two; then Aircraft X number three; and that poor Aircraft Y hung-out 25 miles plus on a delay vector from the previous controller. With the FROPA; although the surface winds were low and negligible; I observed that we still had a strong wind push from the west-southwest at altitude. Airplanes flying south and west were getting punched in the face and slowing quickly in the descent. Aircraft at altitudes of 3000ft. or higher were getting tail shoved a little bit from the west. To work my plan; I told Aircraft Y to hold his present speed or greater (indicated 180 kts on my display) to the final; I asked the [Company Aircraft] straight in to start to slow; I asked Aircraft X to pull back to 170 kts in an effort to match the final join up speed and keep him tight to the airport; and I started working the furthest [business jet] back towards the sequence and airport. Aircraft Y was making descent headway on a modified left base; although I was having to stretch a bit behind him to bring him in first. The [Company Aircraft] surprised me with how quickly he began to slow on the final when directed. I believe it was due to a stout headwind; my instructions to slow and pilot compliance; and the fact that the pilot was trying to naturally slow and stabilize coming in a bit high and fast chasing the straight in approach. Regardless; the fact of the matter is that when [Company Aircraft] began slowing; I inadvertently created a much bigger gap than I expected between him and getting Aircraft Y to the final. Aircraft X was still indicating 220 kts and slowing; on a modified base; and I reckoned that I could get Aircraft Y on final; and squeeze Aircraft X in number two in the unexpected gap in front of the [Company Aircraft]. I reckoned wrong. I had Aircraft X tightening on the right base to final and expecting him to slow further; Aircraft Y dogglegging on the opposite base keeping 180 kts; and the [company aircraft] about 12NM straight in slowing with the gap slowly decreasing. I anticipated Aircraft X to slow to 170; and even reminded him to slow further. He said he had complied; and probably wasn't lying...but he had 200ish still indicated. As I was running Aircraft Y to the turn on; I dropped Aircraft X to 2000 ft.; tweaked him a bit left to widen him out a touch behind Aircraft Y; and figured that as I turned him towards the final he would catch that headwind and slow appropriately. He did not. I ran him too tight; he did not slow as I expected; and what I thought I could easily make work instantly crumbled. I gave Aircraft X a 270 heading to break him out and away from Aircraft Y to gain divergence; called traffic; and gave him my most sincere apologies for terribly poor service. He reported no TCAS RA response. I gave Aircraft Y a traffic call regarding Aircraft X; and a further turn away from Aircraft X to join the final with an approach clearance. I made a poor choice trying to squeeze Aircraft X in tightly. I acted on that choice more poorly. I know that I could have made that sequence work; but I didn't do the prudent things necessary to ensure it would. I believe my recovery was poor. I have beat myself up all week about this one...what I did...what I didn't... This one hurts. Very humbling. This was my first airborne experience of what I thought was reasonable planning; combined with awful execution leading to hazard and poor service. It is an awful pit of the gut hit for me. I've been doing this for a very long time with no history or reputation of ever coming remotely close to banging planes. I wouldn't have tried to set them up if I couldn't confidently trust my abilities to make it work. Reflecting; I could have in at least a dozen different ways. But; I didn't do those things. I did this thing. I was in no way working for the visual approach or expecting or planning for visual separation; however; [Company Aircraft] called Aircraft X in sight; although he clearly stated that he didn't think he could keep him through that FEW layer. I was somewhat expecting that Aircraft Y would call the field and dog straight to the threshold; and that Aircraft X would maybe hand me a gimme by seeing Aircraft Y for the visual follow. When I broke Aircraft X out due west and called traffic to Aircraft Y; and the [business jet] replied; 'Looking;' my heart sank. Follow best practices...be very deliberate when running any opposing base operations. Even opposing doglegs can be foolishness at same altitudes. Try to never vector frustrated at the picture life deals. The planes are where they are. I can't get them on the ground faster than physics. Whatever the scenario; once you see thecards; you just have to play them out as they are. Although the conditions cleared rapidly; there were still some effects tailing the FROPA...strong shifting winds at varying altitudes; a thin but opaque scattering of FEW layers in the LFA. I don't really know what else to say here. Poor judgment; worse execution; betting on aircraft performance/compliance with my overconfidence that I could make it work out.




Synopsis: TRACON Controller reported sequencing with weather frontal passage resulted in airborne conflicts and poor ATC service.